Expose enable_deflate() so the inflater can be opted out of later

With raw lwIP in the main loop the radio is deaf while a sector is written,
so the ESP8266 and RP2040 keep the client quiet until the block is in flash;
with BSD or lwIP sockets the next block can arrive while this one is written.

.github/workflows/ci.yml

@@ -244,11 +244,20 @@ jobs:
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Read prek version from requirements_test.txt
+        id: prek
+        # requirements_test.txt is the only place the version is pinned, so a
+        # Dependabot bump there is picked up here without a second edit.
+        run: |
+          if ! version=$(sed -nE 's/^prek==([^[:space:]#]+).*/\1/p' requirements_test.txt) || [ -z "$version" ]; then
+            echo "::error::No prek== pin found in requirements_test.txt."
+            exit 1
+          fi
+          echo "version=$version" >> "$GITHUB_OUTPUT"
       - name: Run prek
         uses: j178/prek-action@4e14d07f9231acabce116ccfca13b13dd9755ece # v3.0.0
         with:
-          # Keep in sync with requirements_test.txt.
-          prek-version: "0.4.11"
+          prek-version: ${{ steps.prek.outputs.version }}
           # This job only runs on pull requests, so nothing ever populates
           # the cache on dev. Every run would miss and then write a per-pull
           # request copy, which is what the old seed-cache job existed to

.github/workflows/sync-dependency-versions.yml

@@ -0,0 +1,94 @@
+# Keeps pre-commit hook revs in sync with the requirements files.
+#
+# Dependabot only bumps the pins in requirements*.txt. Some of those tools
+# are pinned again as hook revs in .pre-commit-config.yaml. This workflow
+# runs script/sync_dependency_versions.py against the pull request branch
+# and pushes a commit with the revs updated.
+
+name: Sync dependency versions
+
+on:
+  # pull_request_target rather than pull_request so the App secret is
+  # available on Dependabot pull requests (pull_request runs opened by
+  # Dependabot only see Dependabot secrets). The job below only touches
+  # branches in this repository and only ever executes the script from the
+  # base branch checkout, so fork code never runs with the token.
+  pull_request_target:
+    types: [opened, synchronize, reopened]
+    paths:
+      - requirements_dev.txt
+      - requirements_test.txt
+      - .pre-commit-config.yaml
+      - script/sync_dependency_versions.py
+
+# The push to the pull request branch uses the App token minted below, so
+# the workflow's GITHUB_TOKEN does not need any scopes.
+permissions: {}
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  sync:
+    name: Sync pinned versions
+    runs-on: ubuntu-latest
+    # Same-repository branches only: a push to a fork is not possible with
+    # this token, and it keeps untrusted heads out of a privileged job.
+    if: >-
+      github.repository == 'esphome/esphome'
+      && github.event.pull_request.head.repo.full_name == github.repository
+    steps:
+      - name: Generate a token
+        id: generate-token
+        uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3.2.0
+        with:
+          client-id: ${{ vars.ESPHOME_GITHUB_APP_CLIENT_ID }}
+          private-key: ${{ secrets.ESPHOME_GITHUB_APP_PRIVATE_KEY }}
+          # A push made with the workflow's own GITHUB_TOKEN would not start
+          # CI on the new commit; a push with the App token does.
+          permission-contents: write  # git push of the sync commit to the pull request branch
+
+      - name: Check out base branch
+        # Provides the script that runs below. Deliberately the base branch
+        # so the pull request cannot change what executes here.
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          ref: ${{ github.event.pull_request.base.sha }}
+          persist-credentials: false
+
+      - name: Check out pull request branch
+        # No allow-unsafe-pr-checkout here on purpose: checkout v7 only
+        # refuses heads that live in a different repository, and the job
+        # condition above already limits runs to same-repository branches.
+        # Leaving it off keeps that refusal as a backstop for fork heads.
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+          path: pull-request
+          token: ${{ steps.generate-token.outputs.token }}
+
+      - name: Set up Python
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: "3.12"
+
+      - name: Install yamlrocks
+        # The script edits YAML through yamlrocks. Take the pin from the
+        # base branch requirements so this workflow has no copy of its own.
+        run: pip install "$(grep -E '^yamlrocks==' requirements_test.txt | cut -d'#' -f1)"
+
+      - name: Sync pinned versions
+        run: python script/sync_dependency_versions.py --root pull-request
+
+      - name: Push changes
+        working-directory: pull-request
+        run: |
+          if git diff --quiet; then
+            echo "All pinned versions already match the requirements files."
+            exit 0
+          fi
+          git config user.name "esphome[bot]"
+          git config user.email "115708604+esphome[bot]@users.noreply.github.com"
+          git commit -am "Sync pinned tool versions with requirements files"
+          git push

.pre-commit-config.yaml

@@ -1,7 +1,6 @@
 ---
 # See https://pre-commit.com for more information
 # See https://pre-commit.com/hooks.html for more hooks
-
 ci:
   autoupdate_commit_msg: 'pre-commit: autoupdate'
   autoupdate_schedule: off  # Disabled until ruff versions are synced between deps and pre-commit
@@ -11,7 +10,7 @@ ci:
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.16.3
+    rev: v0.16.6
     hooks:
       # Run the linter.
       - id: ruff
@@ -42,7 +41,7 @@ repos:
       - id: pyupgrade
         args: [--py312-plus]
   - repo: https://github.com/adrienverge/yamllint.git
-    rev: v1.37.1
+    rev: v1.38.0
     hooks:
       - id: yamllint
         exclude: ^(\.clang-format|\.clang-tidy)$

AGENTS.md

@@ -553,6 +553,7 @@ file does, and it is the authority when they disagree. The most useful starting
     4.  **Lint:** Run `prek` to ensure code is compliant.
     5.  **Commit:** Commit your changes. There is no strict format for commit messages.
     6.  **Pull Request:** Submit a PR against the `dev` branch. The Pull Request title must start with a `[tag]` prefix. For component work, use the component name (e.g., `[display] Fix bug`, `[abc123] Add new component`); for changes to shared/core code that isn't tied to a single component, use `[core]` (e.g., `[core] Add validator`). Update documentation, examples, and add `CODEOWNERS` entries as needed. Pull requests should always be made using the `.github/PULL_REQUEST_TEMPLATE.md` template - fill out all sections completely without removing any parts of the template.
+    7.  **Comments:** When commenting on GitHub PRs or issues, don't tag contributors, especially bots. Avoid referring to list items (e.g. from reviews) with the form #nn - this will be interpreted by GitHub as a reference to issue or PR nn. Keep comments short and exclude irrelevant details, backstories, restatement of previous comments and anything that is already obvious to the reader.
 
 *   **Documentation Contributions:**
     *   Documentation is hosted in the separate `esphome/esphome.io` repository.
@@ -839,7 +840,7 @@ file does, and it is the authority when they disagree. The most useful starting
         cv.rename_key(
             CONF_OLD_KEY, CONF_NEW_KEY, removed_in="2026.6.0", component="my_component"
         ),
-        cv.Schema({ ... }),
+        cv.Schema({...}),
     )
     ```
     For other deprecations, warn manually during validation:

THREAT_MODEL.md

@@ -125,30 +125,47 @@ design is optimal or that it will not change.
 ## OTA update encryption
 
 The `esphome` OTA platform optionally encrypts updates with the same Noise
-`NNpsk0` pattern the native API uses; one key protects the device. With an
-`encryption:` block configured the guarantees are: the firmware image is
-confidential in transit, the uploader is authenticated by the pre-shared key,
-and the plaintext negotiation preceding the handshake is bound into the
-handshake prologue, so stripping or tampering with it fails the first MAC.
-Both ends fail closed with no override: a device built with a key refuses
+`NNpsk0` pattern the native API uses; one key protects the device. A device
+whose `api:` block has an encryption key, static in the YAML or provisioned at
+runtime, compiles in the transport and offers it on every OTA connection once
+it holds a key, so an uploader presenting that key gets the guarantees below
+even without an `ota: encryption:` block; only that block makes the device
+require encryption. The guarantees are: the firmware image is confidential in
+transit, the uploader is authenticated by the pre-shared key, and the plaintext
+negotiation preceding the handshake is bound into the handshake prologue, so
+stripping or tampering with it fails the first MAC. With `ota: encryption:`
+configured both ends fail closed with no override: the device refuses
 plaintext uploads, and the CLI refuses to send plaintext when a key is
-configured.
+configured. Without that block the CLI tries a static api key when the device
+offers and, until 2027.3.0, falls back to plaintext with a warning when the
+offer is missing or the handshake fails; a runtime provisioned key never
+reaches the CLI, so those uploads stay plaintext.
 
-Defeating any of that without the key is in scope: a keyed device accepting a
-plaintext or downgraded upload, getting past the MAC, or recovering image
-contents from captured traffic.
+Defeating any of that without the key is in scope: a device that requires
+encryption accepting a plaintext or downgraded upload, getting past the MAC,
+or recovering image contents from captured traffic.
 
 The following are **not** vulnerabilities, by design:
 
-- Plaintext OTA on a device with no `encryption:` block. That is the
-  documented default, authenticated (if at all) by the OTA password.
-- The enablement window: turning encryption on takes one last upload of the
-  encryption-enabled firmware over the existing plaintext channel, with the
-  pre-existing plaintext exposure.
-- The web OTA `/update` endpoint alongside encryption. The `web_server`
-  component keeps it always reachable, and `captive_portal:` auto-loads it
-  for the fallback AP window; validation warns about both combinations, and
-  the operator keeps the recovery path.
+- Plaintext OTA on a device with no `ota: encryption:` block, including one
+  that offers encryption because it has an api key. That is the documented
+  default, authenticated (if at all) by the OTA password. An uploader that
+  takes the offer skips the password; the key authenticates it. With a
+  runtime provisioned key and no `provisioning:` window, whoever provisions
+  the key gains that upload path too; validation warns about the pair.
+- The CLI plaintext fallback until 2027.3.0: without `ota: encryption:` an
+  active attacker who strips the offer or breaks the handshake can make a
+  keyed CLI upload plaintext, with the pre-existing plaintext exposure. A
+  device that requires encryption still refuses that upload.
+- The enablement window: firmware built with a static api key already offers
+  encryption, so turning on `ota: encryption:` is itself an encrypted upload.
+  Older firmware needs one last plaintext upload of an offering build, with
+  the pre-existing plaintext exposure.
+- The web OTA `/update` endpoint alongside encryption. With the `web_server`
+  or `prometheus` component the shared listener is always up, so the endpoint
+  stays reachable and validation warns about that combination;
+  `captive_portal:` alone brings the listener up only for the fallback AP
+  window, which is the intended recovery path, so that is not warned about.
 - CLI retry behavior on transport or MAC failures; every attempt renegotiates
   a fresh handshake with fresh ephemerals, so retrying does not weaken
   authentication.

docker/Dockerfile

@@ -22,7 +22,7 @@ RUN \
     -r /requirements.txt
 
 # Install the ESPHome Device Builder dashboard.
-RUN uv pip install --no-cache-dir esphome-device-builder==1.14.0
+RUN uv pip install --no-cache-dir esphome-device-builder==1.14.4
 
 RUN \
     platformio settings set enable_telemetry No \

esphome/__main__.py

@@ -1289,10 +1289,9 @@ def _choose_ota_platform(config: ConfigType, requested: str | None) -> str:
     The native API uses challenge-response auth with MD5/SHA256 hashing of a
     server-issued nonce, so the password is never sent over the wire; the
     ``web_server`` path uses HTTP Basic auth which transmits credentials in
-    cleartext over the LAN. (The native path also supports gzip compression
-    on ESP8266, where flash space is tight; on ESP32/RP2040/LibreTiny the
-    backend reports ``supports_compression() == false`` and the firmware is
-    sent uncompressed regardless of which platform is used.) Falls back to
+    cleartext over the LAN. (The native path also compresses the upload:
+    gzip on ESP8266 and RP2040, which inflate it at reboot, and a deflate
+    stream on ESP32/LibreTiny, which inflate it as it arrives.) Falls back to
     ``web_server`` only when that is the only available platform.
     """
     # Use a dict (insertion-ordered) instead of a list so error messages and
@@ -1335,12 +1334,14 @@ def _upload_via_native_api(
             break
 
     from esphome import espota2
+    from esphome.components.noise import static_encryption_key
 
     remote_port = int(ota_conf[CONF_PORT])
     password = ota_conf.get(CONF_PASSWORD)
     # Fail closed: an encryption block whose key did not resolve must never
     # fall back to a plaintext upload
     noise_psk = None
+    plaintext_fallback = False
     if (encryption_conf := ota_conf.get(CONF_ENCRYPTION)) is not None:
         noise_psk = encryption_conf.get(CONF_KEY)
         if not noise_psk:
@@ -1351,6 +1352,10 @@ def _upload_via_native_api(
         # Ensure the key is a string, as required by the underlying OTA implementation.
         # It arrives here as a SensitiveStr which aioesphomeapi rejects.
         noise_psk = str(noise_psk)
+    elif api_key := static_encryption_key(config.get(CONF_API) or {}):
+        # Remove before 2027.3.0: the api key is tried, falling back to plaintext
+        noise_psk = str(api_key)
+        plaintext_fallback = True
 
     def check_partition_access(option_string: str) -> None:
         if not ota_conf.get("allow_partition_access"):
@@ -1382,7 +1387,13 @@ def _upload_via_native_api(
         _validate_bootloader_binary(binary)
 
     return espota2.run_ota(
-        network_devices, remote_port, password, binary, ota_type, noise_psk
+        network_devices,
+        remote_port,
+        password,
+        binary,
+        ota_type,
+        noise_psk,
+        plaintext_fallback=plaintext_fallback,
     )
 
 

esphome/api_client.py

@@ -23,9 +23,7 @@ from esphome.util import safe_print
 if TYPE_CHECKING:
     from collections.abc import Callable
 
-    from aioesphomeapi.api_pb2 import (
-        SubscribeLogsResponse,  # pylint: disable=no-name-in-module
-    )
+    from aioesphomeapi.api_pb2 import SubscribeLogsResponse  # pylint: disable=no-name-in-module
 
 
 _LOGGER = logging.getLogger(__name__)

esphome/components/anova/anova.cpp

@@ -13,7 +13,7 @@ void Anova::dump_config() { LOG_CLIMATE("", "Anova BLE Cooker", this); }
 
 void Anova::setup() {
   this->codec_ = make_unique<AnovaCodec>();
-  this->current_request_ = 0;
+  this->poll_step_ = PollStep::IDLE;
 }
 
 void Anova::loop() {
@@ -22,6 +22,15 @@ void Anova::loop() {
   this->disable_loop();
 }
 
+void Anova::write_request_(AnovaPacket *pkt) {
+  auto status =
+      esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
+                               pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
+  if (status) {
+    ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
+  }
+}
+
 void Anova::control(const ClimateCall &call) {
   auto mode_val = call.get_mode();
   if (mode_val.has_value()) {
@@ -38,22 +47,11 @@ void Anova::control(const ClimateCall &call) {
         ESP_LOGW(TAG, "Unsupported mode: %d", mode);
         return;
     }
-    auto status =
-        esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
-                                 pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
-    if (status) {
-      ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
-    }
+    this->write_request_(pkt);
   }
   auto target_temp = call.get_target_temperature();
   if (target_temp.has_value()) {
-    auto *pkt = this->codec_->get_set_target_temp_request(*target_temp);
-    auto status =
-        esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
-                                 pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
-    if (status) {
-      ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
-    }
+    this->write_request_(this->codec_->get_set_target_temp_request(*target_temp));
   }
 }
 
@@ -62,6 +60,7 @@ void Anova::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_
     case ESP_GATTC_DISCONNECT_EVT: {
       this->current_temperature = NAN;
       this->target_temperature = NAN;
+      this->poll_step_ = PollStep::IDLE;
       this->publish_state();
       break;
     }
@@ -83,8 +82,8 @@ void Anova::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_
     }
     case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
       this->node_state = espbt::ClientState::ESTABLISHED;
-      this->current_request_ = 0;
-      this->update();
+      this->poll_step_ = PollStep::IDLE;
+      this->update();  // begin the first poll cycle immediately
       break;
     }
     case ESP_GATTC_NOTIFY_EVT: {
@@ -101,33 +100,30 @@ void Anova::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_
         this->mode = this->codec_->running_ ? climate::CLIMATE_MODE_HEAT : climate::CLIMATE_MODE_OFF;
       }
       if (this->codec_->has_unit()) {
-        this->fahrenheit_ = (this->codec_->unit_ == 'f');
-        ESP_LOGD(TAG, "Anova units is %s", this->fahrenheit_ ? "fahrenheit" : "celsius");
-        this->current_request_++;
+        ESP_LOGD(TAG, "Anova units is %s", (this->codec_->unit_ == 'f') ? "fahrenheit" : "celsius");
       }
       this->publish_state();
 
-      if (this->current_request_ > 1) {
-        AnovaPacket *pkt = nullptr;
-        switch (this->current_request_++) {
-          case 2:
-            pkt = this->codec_->get_read_target_temp_request();
-            break;
-          case 3:
-            pkt = this->codec_->get_read_current_temp_request();
-            break;
-          default:
-            this->current_request_ = 1;
-            break;
-        }
-        if (pkt != nullptr) {
-          auto status =
-              esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
-                                       pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
-          if (status) {
-            ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
-          }
-        }
+      // Advance the poll cycle to its next request based on the reply we got.
+      switch (this->poll_step_) {
+        case PollStep::SET_UNIT:
+          this->poll_step_ = PollStep::STATUS;
+          this->write_request_(this->codec_->get_read_device_status_request());
+          break;
+        case PollStep::STATUS:
+          this->poll_step_ = PollStep::TARGET;
+          this->write_request_(this->codec_->get_read_target_temp_request());
+          break;
+        case PollStep::TARGET:
+          this->poll_step_ = PollStep::CURRENT;
+          this->write_request_(this->codec_->get_read_current_temp_request());
+          break;
+        case PollStep::CURRENT:
+          this->poll_step_ = PollStep::IDLE;  // full cycle complete
+          break;
+        default:
+          // A reply to an ad-hoc control() write, outside a managed cycle.
+          break;
       }
       break;
     }
@@ -136,27 +132,26 @@ void Anova::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_
   }
 }
 
-void Anova::set_unit_of_measurement(const char *unit) { this->fahrenheit_ = !strncmp(unit, "f", 1); }
+void Anova::set_unit_of_measurement(const char *unit) { this->want_fahrenheit_ = !strncmp(unit, "f", 1); }
 
 void Anova::update() {
   if (this->node_state != espbt::ClientState::ESTABLISHED)
     return;
-
-  if (this->current_request_ < 2) {
-    AnovaPacket *pkt;
-    if (this->current_request_ == 0) {
-      pkt = this->codec_->get_set_unit_request(this->fahrenheit_ ? 'f' : 'c');
-    } else {
-      pkt = this->codec_->get_read_device_status_request();
-    }
-    auto status =
-        esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
-                                 pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
-    if (status) {
-      ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
-    }
-    this->current_request_++;
+  if (this->poll_step_ != PollStep::IDLE) {
+    // The previous cycle never finished within a full polling interval -- a
+    // reply was missed or a write failed. Restart the cycle rather than stall;
+    // the polling interval itself acts as the timeout. A late reply from the
+    // abandoned cycle is harmless: state decoding happens on every notify
+    // regardless of step, and each notify sends at most one follow-up request.
+    ESP_LOGW(TAG, "[%s] Poll cycle incomplete (step %u); restarting cycle", this->parent_->address_str(),
+             static_cast<uint8_t>(this->poll_step_));
   }
+  // Re-assert the configured unit at the start of every poll cycle, then fall
+  // through the status/temperature reads via the notification handler. Always
+  // command the configured unit (want_fahrenheit_) -- never the last value the
+  // device reported, or a drift to 'c' would lock itself in.
+  this->poll_step_ = PollStep::SET_UNIT;
+  this->write_request_(this->codec_->get_set_unit_request(this->want_fahrenheit_ ? 'f' : 'c'));
 }
 
 }  // namespace esphome::anova

esphome/components/anova/anova.h

@@ -37,11 +37,20 @@ class Anova final : public climate::Climate, public esphome::ble_client::BLEClie
   void set_unit_of_measurement(const char *unit);
 
  protected:
+  // A poll cycle re-asserts the configured unit, then reads device state.
+  // Re-asserting every cycle prevents the cooker from silently reverting to
+  // its default (Celsius); previously the unit was only set once on
+  // connection, so a drift persisted (and corrupted the F/C interpretation of
+  // subsequent readings) until the BLE link was re-established.
+  enum class PollStep : uint8_t { SET_UNIT, STATUS, TARGET, CURRENT, IDLE };
+
+  void write_request_(AnovaPacket *pkt);
+
   std::unique_ptr<AnovaCodec> codec_;
   void control(const climate::ClimateCall &call) override;
   uint16_t char_handle_;
-  uint8_t current_request_;
-  bool fahrenheit_;
+  bool want_fahrenheit_{true};  // configured target unit; never overwritten by device replies
+  PollStep poll_step_{PollStep::IDLE};
 };
 
 }  // namespace esphome::anova

esphome/components/api/__init__.py

@@ -14,6 +14,7 @@ from esphome.components.noise import (  # noqa: F401
     ENCRYPTION_SCHEMA,
     decode_encryption_key,
     encryption_schema,
+    new_psk_progmem,
     validate_encryption_key,
 )
 from esphome.config_helpers import filter_source_files_from_defines, get_logger_level
@@ -589,8 +590,7 @@ async def to_code(config: ConfigType) -> None:
 
     if (encryption_config := config.get(CONF_ENCRYPTION, None)) is not None:
         if key := encryption_config.get(CONF_KEY):
-            decoded = decode_encryption_key(key)
-            cg.add(var.set_noise_psk(list(decoded)))
+            cg.add(var.set_noise_psk(new_psk_progmem(config[CONF_ID], key)))
             cg.add_define("USE_API_NOISE_PSK_FROM_YAML")
         else:
             # No key provided, but encryption desired

esphome/components/api/api_connection.cpp

@@ -2161,7 +2161,10 @@ void APIConnection::on_homeassistant_action_response(const HomeassistantActionRe
 bool APIConnection::send_noise_encryption_set_key_response_(const NoiseEncryptionSetKeyRequest &msg) {
   NoiseEncryptionSetKeyResponse resp;
   resp.success = false;
-
+#ifdef USE_API_NOISE_PSK_FROM_YAML
+  // A yaml key cannot be changed at runtime, so no decode or save path is built
+  ESP_LOGW(TAG, "Key set in YAML");
+#else
 #ifdef USE_PROVISIONING
   // Refuse to set a key once the provisioning window has closed (defense in depth;
   // such connections are already rejected at hello).
@@ -2196,6 +2199,7 @@ bool APIConnection::send_noise_encryption_set_key_response_(const NoiseEncryptio
     }
 #endif
   }
+#endif  // USE_API_NOISE_PSK_FROM_YAML
 
   return this->send_message(resp);
 }

esphome/components/api/api_frame_helper_noise.cpp

@@ -548,7 +548,7 @@ APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, uint16_t len) {
  * @return 0 on success, -1 on error (check errno)
  */
 APIError APINoiseFrameHelper::init_handshake_() {
-  int err = this->handshake_.init(this->ctx_.get_psk(), prologue_.data(), prologue_.size());
+  int err = this->handshake_.init(this->ctx_, prologue_.data(), prologue_.size());
   APIError aerr = handle_noise_error_(err, LOG_STR("noise_handshake_init"), APIError::HANDSHAKESTATE_SETUP_FAILED);
   if (aerr != APIError::OK)
     return aerr;

esphome/components/api/api_server.cpp

@@ -41,13 +41,13 @@ void APIServer::setup() {
   ControllerRegistry::register_controller(this);
 
 #ifdef USE_API_NOISE
+  // Always reserve the slot: flash preferences are positional on esp8266, so
+  // a yaml key build must keep the layout of a runtime key build
   uint32_t hash = 88491486UL;
-
   this->noise_pref_ = global_preferences->make_preference<SavedNoisePsk>(hash, true);
-
 #ifndef USE_API_NOISE_PSK_FROM_YAML
-  // Only load saved PSK if not set from YAML
-  if (this->load_and_apply_noise_psk_()) {
+  // A cleared record loads fine but holds no key
+  if (this->load_and_apply_noise_psk_() && this->noise_ctx_.has_psk()) {
     ESP_LOGD(TAG, "Loaded saved Noise PSK");
   }
 #endif
@@ -550,6 +550,7 @@ const std::vector<APIServer::HomeAssistantStateSubscription> &APIServer::get_sta
 #endif
 
 #ifdef USE_API_NOISE
+#ifndef USE_API_NOISE_PSK_FROM_YAML
 bool APIServer::update_noise_psk_(const SavedNoisePsk &new_psk, const LogString *save_log_msg,
                                   const LogString *fail_log_msg, bool make_active) {
   if (!this->noise_pref_.save(&new_psk)) {
@@ -583,22 +584,19 @@ bool APIServer::update_noise_psk_(const SavedNoisePsk &new_psk, const LogString
 }
 
 bool APIServer::load_and_apply_noise_psk_() {
-  SavedNoisePsk saved{};
-  if (!this->noise_pref_.load(&saved))
+  // Load into a temp so a failed read cannot disturb the key in use
+  SavedNoisePsk loaded{};
+  if (!this->noise_pref_.load(&loaded))
     return false;
-  this->set_noise_psk(saved.psk);
+  this->saved_psk_ = loaded;
+  // An unprovisioned device stores the reserved all-zeros key, which is no key
+  const bool has_key = !noise::NoiseContext::is_all_zeros(this->saved_psk_.psk);
+  this->noise_ctx_.set_psk(has_key ? this->saved_psk_.psk.data() : nullptr);
   return true;
 }
 
 bool APIServer::save_noise_psk(noise::psk_t psk, bool make_active) {
-#ifdef USE_API_NOISE_PSK_FROM_YAML
-  // When PSK is set from YAML, this function should never be called
-  // but if it is, reject the change
-  ESP_LOGW(TAG, "Key set in YAML");
-  return false;
-#else
-  auto &old_psk = this->noise_ctx_.get_psk();
-  if (std::equal(old_psk.begin(), old_psk.end(), psk.begin())) {
+  if (this->saved_psk_.psk == psk) {
     ESP_LOGW(TAG, "New PSK matches old");
     return true;
   }
@@ -614,15 +612,8 @@ bool APIServer::save_noise_psk(noise::psk_t psk, bool make_active) {
   }
 #endif
   return result;
-#endif
 }
 bool APIServer::clear_noise_psk(bool make_active) {
-#ifdef USE_API_NOISE_PSK_FROM_YAML
-  // When PSK is set from YAML, this function should never be called
-  // but if it is, reject the change
-  ESP_LOGW(TAG, "Key set in YAML");
-  return false;
-#else
   SavedNoisePsk empty_psk{};
   bool result = this->update_noise_psk_(empty_psk, LOG_STR("Noise PSK cleared"), LOG_STR("Failed to clear Noise PSK"),
                                         make_active);
@@ -634,8 +625,8 @@ bool APIServer::clear_noise_psk(bool make_active) {
   }
 #endif
   return result;
-#endif
 }
+#endif  // USE_API_NOISE_PSK_FROM_YAML
 #endif
 
 #ifdef USE_HOMEASSISTANT_TIME

esphome/components/api/api_server.h

@@ -76,9 +76,14 @@ class APIServer final : public Component,
   APIBuffer &get_shared_buffer_ref() { return shared_write_buffer_; }
 
 #ifdef USE_API_NOISE
+#ifndef USE_API_NOISE_PSK_FROM_YAML
+  // Runtime key changes exist for the provisioning path only (not lambdas);
+  // with a yaml key they compile out
   bool save_noise_psk(noise::psk_t psk, bool make_active = true);
   bool clear_noise_psk(bool make_active = true);
-  void set_noise_psk(noise::psk_t psk) { this->noise_ctx_.set_psk(psk); }
+#endif
+  /// psk points at 32 bytes that live in flash for the life of the program
+  void set_noise_psk(const uint8_t *psk) { this->noise_ctx_.set_psk(psk); }
   noise::NoiseContext &get_noise_ctx() { return this->noise_ctx_; }
 #endif  // USE_API_NOISE
 
@@ -275,10 +280,12 @@ class APIServer final : public Component,
 #endif
 
 #ifdef USE_API_NOISE
+#ifndef USE_API_NOISE_PSK_FROM_YAML
   bool update_noise_psk_(const SavedNoisePsk &new_psk, const LogString *save_log_msg, const LogString *fail_log_msg,
                          bool make_active);
   // Load saved PSK from preferences and apply it. Returns true on success.
   bool load_and_apply_noise_psk_();
+#endif  // USE_API_NOISE_PSK_FROM_YAML
 #endif  // USE_API_NOISE
 #ifdef USE_API_HOMEASSISTANT_STATES
   // Helper methods to reduce code duplication
@@ -358,6 +365,9 @@ class APIServer final : public Component,
 
 #ifdef USE_API_NOISE
   noise::NoiseContext noise_ctx_;
+#ifndef USE_API_NOISE_PSK_FROM_YAML
+  SavedNoisePsk saved_psk_{};  // backs noise_ctx_ for a runtime provisioned key
+#endif
   ESPPreferenceObject noise_pref_;
 #endif  // USE_API_NOISE
 };

esphome/components/atm90e32/atm90e32.cpp

@@ -9,6 +9,10 @@ namespace esphome::atm90e32 {
 
 static const char *const TAG = "atm90e32";
 
+static const LogString *offset_calibration_name(bool power_offsets) {
+  return power_offsets ? LOG_STR("Power offset") : LOG_STR("Offset");
+}
+
 static uint32_t pref_hash(const char *prefix, const char *name_space) {
   auto hash = fnv1_hash(prefix);
   return fnv1_hash_extend(hash, name_space);
@@ -203,13 +207,12 @@ void ATM90E32Component::setup() {
 
     // Initialize flash storage for power offset calibrations
     uint32_t po_hash = pref_hash("_power_offset_calibration_", cs);
-    this->power_offset_pref_ = global_preferences->make_preference<PowerOffsetCalibration[3]>(po_hash, true);
+    this->power_offset_pref_ = global_preferences->make_preference<OffsetCalibration[3]>(po_hash, true);
     bool migrated_power_offset = false;
     if (has_distinct_legacy_namespace) {
       uint32_t legacy_po_hash = pref_hash("_power_offset_calibration_", legacy_cs);
-      auto legacy_power_offset_pref =
-          global_preferences->make_preference<PowerOffsetCalibration[3]>(legacy_po_hash, true);
-      PowerOffsetCalibration power_offset_data[3]{};
+      auto legacy_power_offset_pref = global_preferences->make_preference<OffsetCalibration[3]>(legacy_po_hash, true);
+      OffsetCalibration power_offset_data[3]{};
       int migration_status =
           migrate_legacy_pref_if_needed(this->power_offset_pref_, legacy_power_offset_pref, &power_offset_data);
       migrated_power_offset = migration_status > 0;
@@ -224,20 +227,20 @@ void ATM90E32Component::setup() {
       global_preferences->sync();
     }
 
-    this->restore_offset_calibrations_();
-    this->restore_power_offset_calibrations_();
+    this->restore_offset_calibrations_(OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_VOLTAGE_CURRENT);
+    this->restore_offset_calibrations_(OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER);
   } else {
     ESP_LOGI(TAG, "[CALIBRATION][%s] Power & Voltage/Current offset calibration is disabled. Using config file values.",
              cs);
     for (uint8_t phase = 0; phase < 3; ++phase) {
       this->write16_(this->voltage_offset_registers[phase],
-                     static_cast<uint16_t>(this->offset_phase_[phase].voltage_offset_));
+                     static_cast<uint16_t>(this->offset_phase_[phase].first_offset));
       this->write16_(this->current_offset_registers[phase],
-                     static_cast<uint16_t>(this->offset_phase_[phase].current_offset_));
+                     static_cast<uint16_t>(this->offset_phase_[phase].second_offset));
       this->write16_(this->power_offset_registers[phase],
-                     static_cast<uint16_t>(this->power_offset_phase_[phase].active_power_offset));
+                     static_cast<uint16_t>(this->power_offset_phase_[phase].first_offset));
       this->write16_(this->reactive_power_offset_registers[phase],
-                     static_cast<uint16_t>(this->power_offset_phase_[phase].reactive_power_offset));
+                     static_cast<uint16_t>(this->power_offset_phase_[phase].second_offset));
     }
   }
 
@@ -317,8 +320,8 @@ void ATM90E32Component::log_calibration_status_() {
              cs);
     for (uint8_t phase = 0; phase < 3; ++phase) {
       ESP_LOGW(TAG, "[CALIBRATION][%s] |   %c   |  %6d  | %6d  |  %6d  | %6d  |", cs, 'A' + phase,
-               this->config_offset_phase_[phase].voltage_offset_, this->offset_phase_[phase].voltage_offset_,
-               this->config_offset_phase_[phase].current_offset_, this->offset_phase_[phase].current_offset_);
+               this->config_offset_phase_[phase].first_offset, this->offset_phase_[phase].first_offset,
+               this->config_offset_phase_[phase].second_offset, this->offset_phase_[phase].second_offset);
     }
     ESP_LOGW(TAG,
              "[CALIBRATION][%s] ===============================================================================", cs);
@@ -335,10 +338,8 @@ void ATM90E32Component::log_calibration_status_() {
              cs);
     for (uint8_t phase = 0; phase < 3; ++phase) {
       ESP_LOGW(TAG, "[CALIBRATION][%s] |   %c   |  %6d  | %6d  |  %6d  | %6d  |", cs, 'A' + phase,
-               this->config_power_offset_phase_[phase].active_power_offset,
-               this->power_offset_phase_[phase].active_power_offset,
-               this->config_power_offset_phase_[phase].reactive_power_offset,
-               this->power_offset_phase_[phase].reactive_power_offset);
+               this->config_power_offset_phase_[phase].first_offset, this->power_offset_phase_[phase].first_offset,
+               this->config_power_offset_phase_[phase].second_offset, this->power_offset_phase_[phase].second_offset);
     }
     ESP_LOGW(TAG,
              "[CALIBRATION][%s] ===============================================================================", cs);
@@ -372,7 +373,7 @@ void ATM90E32Component::log_calibration_status_() {
     ESP_LOGI(TAG, "[CALIBRATION][%s] --------------------------------------------------------------", cs);
     for (uint8_t phase = 0; phase < 3; phase++) {
       ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |     %6d      |     %6d      |", cs, 'A' + phase,
-               this->offset_phase_[phase].voltage_offset_, this->offset_phase_[phase].current_offset_);
+               this->offset_phase_[phase].first_offset, this->offset_phase_[phase].second_offset);
     }
     ESP_LOGI(TAG, "[CALIBRATION][%s] ==============================================================\\n", cs);
   }
@@ -385,8 +386,7 @@ void ATM90E32Component::log_calibration_status_() {
     ESP_LOGI(TAG, "[CALIBRATION][%s] ---------------------------------------------------------------------", cs);
     for (uint8_t phase = 0; phase < 3; phase++) {
       ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |       %6d        |        %6d        |", cs, 'A' + phase,
-               this->power_offset_phase_[phase].active_power_offset,
-               this->power_offset_phase_[phase].reactive_power_offset);
+               this->power_offset_phase_[phase].first_offset, this->power_offset_phase_[phase].second_offset);
     }
     ESP_LOGI(TAG, "[CALIBRATION][%s] =====================================================================\n", cs);
   }
@@ -756,36 +756,68 @@ void ATM90E32Component::save_gain_calibration_to_memory_() {
   }
 }
 
-void ATM90E32Component::save_offset_calibration_to_memory_() {
+void ATM90E32Component::finish_offset_calibration_(const OffsetCalibration (&previous)[3], bool previous_restored,
+                                                   bool previous_using_saved, OffsetCalibrationType type) {
+  const bool power_offsets = type == OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER;
   const char *cs = this->get_calibration_id_();
-  bool success = this->offset_pref_.save(&this->offset_phase_);
-  global_preferences->sync();
-  if (success) {
-    this->using_saved_calibrations_ = true;
-    this->restored_offset_calibration_ = true;
-    for (bool &phase : this->offset_calibration_mismatch_)
-      phase = false;
-    ESP_LOGI(TAG, "[CALIBRATION][%s] Offset calibration saved to memory.", cs);
-  } else {
-    this->using_saved_calibrations_ = false;
-    ESP_LOGE(TAG, "[CALIBRATION][%s] Failed to save offset calibration to memory!", cs);
-  }
-}
+  const LogString *name = offset_calibration_name(power_offsets);
+  OffsetCalibration(*offsets)[3] = power_offsets ? &this->power_offset_phase_ : &this->offset_phase_;
+  ESPPreferenceObject *preference = power_offsets ? &this->power_offset_pref_ : &this->offset_pref_;
+  bool *has_stored =
+      power_offsets ? &this->has_stored_power_offset_calibration_ : &this->has_stored_offset_calibration_;
+  bool *restored = power_offsets ? &this->restored_power_offset_calibration_ : &this->restored_offset_calibration_;
+  bool *mismatches = power_offsets ? this->power_offset_calibration_mismatch_ : this->offset_calibration_mismatch_;
 
-void ATM90E32Component::save_power_offset_calibration_to_memory_() {
-  const char *cs = this->get_calibration_id_();
-  bool success = this->power_offset_pref_.save(&this->power_offset_phase_);
-  global_preferences->sync();
-  if (success) {
-    this->using_saved_calibrations_ = true;
-    this->restored_power_offset_calibration_ = true;
-    for (bool &phase : this->power_offset_calibration_mismatch_)
-      phase = false;
-    ESP_LOGI(TAG, "[CALIBRATION][%s] Power offset calibration saved to memory.", cs);
-  } else {
-    this->using_saved_calibrations_ = false;
-    ESP_LOGE(TAG, "[CALIBRATION][%s] Failed to save power offset calibration to memory!", cs);
+  const bool writes_verified = this->verify_offset_writes_(type);
+  bool saved = false;
+  bool synced = false;
+  if (writes_verified) {
+    saved = preference->save(offsets);
+    synced = global_preferences->sync();
   }
+
+  if (writes_verified && saved && synced) {
+    this->using_saved_calibrations_ = true;
+    *has_stored = true;
+    *restored = true;
+    for (uint8_t phase = 0; phase < 3; phase++)
+      mismatches[phase] = false;
+    ESP_LOGI(TAG, "[CALIBRATION][%s] %s calibration saved to memory. %s calibration completed and verified.", cs,
+             LOG_STR_ARG(name), LOG_STR_ARG(name));
+    return;
+  }
+
+  if (writes_verified) {
+    ESP_LOGE(TAG, "[CALIBRATION][%s] Failed to save %s calibration to memory!", cs, LOG_STR_ARG(name));
+  }
+
+  for (uint8_t phase = 0; phase < 3; phase++) {
+    this->write_offsets_to_registers_(phase, previous[phase].first_offset, previous[phase].second_offset, type);
+  }
+  const bool rollback_verified = this->verify_offset_writes_(type);
+
+  bool rollback_persisted = false;
+  if (writes_verified) {
+    OffsetCalibration rollback[3]{};
+    prepare_offset_rollback(previous, previous_restored, rollback);
+    const bool rollback_saved = preference->save(&rollback);
+    const bool rollback_synced = global_preferences->sync();
+    rollback_persisted = rollback_saved && rollback_synced;
+    if (!rollback_saved || !rollback_synced) {
+      ESP_LOGE(TAG, "[CALIBRATION][%s] Failed to persist restored %s calibration values!", cs, LOG_STR_ARG(name));
+    }
+  }
+
+  *restored = previous_restored;
+  if (rollback_persisted)
+    *has_stored = previous_restored;
+  this->using_saved_calibrations_ = previous_using_saved;
+  if (!rollback_verified) {
+    ESP_LOGE(TAG, "[CALIBRATION][%s] %s calibration failed; rollback readback verification failed.", cs,
+             LOG_STR_ARG(name));
+    return;
+  }
+  ESP_LOGE(TAG, "[CALIBRATION][%s] %s calibration failed; previous values restored.", cs, LOG_STR_ARG(name));
 }
 
 void ATM90E32Component::run_offset_calibrations() {
@@ -803,11 +835,16 @@ void ATM90E32Component::run_offset_calibrations() {
   ESP_LOGI(TAG, "[CALIBRATION][%s] | Phase | offset_voltage | offset_current |", cs);
   ESP_LOGI(TAG, "[CALIBRATION][%s] ------------------------------------------------------------------", cs);
 
+  OffsetCalibration previous_offsets[3] = {this->offset_phase_[0], this->offset_phase_[1], this->offset_phase_[2]};
+  const bool previous_restored = this->restored_offset_calibration_;
+  const bool previous_using_saved = this->using_saved_calibrations_;
+
   for (uint8_t phase = 0; phase < 3; phase++) {
     int16_t voltage_offset = calibrate_offset(phase, true);
     int16_t current_offset = calibrate_offset(phase, false);
 
-    this->write_offsets_to_registers_(phase, voltage_offset, current_offset);
+    this->write_offsets_to_registers_(phase, voltage_offset, current_offset,
+                                      OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_VOLTAGE_CURRENT);
 
     ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |     %6d      |     %6d      |", cs, 'A' + phase, voltage_offset,
              current_offset);
@@ -815,7 +852,8 @@ void ATM90E32Component::run_offset_calibrations() {
 
   ESP_LOGI(TAG, "[CALIBRATION][%s] ==================================================================\n", cs);
 
-  this->save_offset_calibration_to_memory_();
+  this->finish_offset_calibration_(previous_offsets, previous_restored, previous_using_saved,
+                                   OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_VOLTAGE_CURRENT);
 }
 
 void ATM90E32Component::run_power_offset_calibrations() {
@@ -834,18 +872,25 @@ void ATM90E32Component::run_power_offset_calibrations() {
   ESP_LOGI(TAG, "[CALIBRATION][%s] | Phase | offset_active_power | offset_reactive_power |", cs);
   ESP_LOGI(TAG, "[CALIBRATION][%s] ---------------------------------------------------------------------", cs);
 
+  OffsetCalibration previous_offsets[3] = {this->power_offset_phase_[0], this->power_offset_phase_[1],
+                                           this->power_offset_phase_[2]};
+  const bool previous_restored = this->restored_power_offset_calibration_;
+  const bool previous_using_saved = this->using_saved_calibrations_;
+
   for (uint8_t phase = 0; phase < 3; ++phase) {
     int16_t active_offset = calibrate_power_offset(phase, false);
     int16_t reactive_offset = calibrate_power_offset(phase, true);
 
-    this->write_power_offsets_to_registers_(phase, active_offset, reactive_offset);
+    this->write_offsets_to_registers_(phase, active_offset, reactive_offset,
+                                      OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER);
 
     ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |       %6d        |        %6d        |", cs, 'A' + phase, active_offset,
              reactive_offset);
   }
   ESP_LOGI(TAG, "[CALIBRATION][%s] =====================================================================\n", cs);
 
-  this->save_power_offset_calibration_to_memory_();
+  this->finish_offset_calibration_(previous_offsets, previous_restored, previous_using_saved,
+                                   OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER);
 }
 
 void ATM90E32Component::write_gains_to_registers_() {
@@ -859,35 +904,26 @@ void ATM90E32Component::write_gains_to_registers_() {
   this->write16_(ATM90E32_REGISTER_CFGREGACCEN, 0x0000);
 }
 
-void ATM90E32Component::write_offsets_to_registers_(uint8_t phase, int16_t voltage_offset, int16_t current_offset) {
-  // Save to runtime
-  this->offset_phase_[phase].voltage_offset_ = voltage_offset;
-  this->phase_[phase].voltage_offset_ = voltage_offset;
+void ATM90E32Component::write_offsets_to_registers_(uint8_t phase, int16_t first_offset, int16_t second_offset,
+                                                    OffsetCalibrationType type) {
+  const bool power_offsets = type == OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER;
+  OffsetCalibration &offsets = power_offsets ? this->power_offset_phase_[phase] : this->offset_phase_[phase];
+  offsets.first_offset = first_offset;
+  offsets.second_offset = second_offset;
+  if (power_offsets) {
+    this->phase_[phase].active_power_offset_ = first_offset;
+    this->phase_[phase].reactive_power_offset_ = second_offset;
+  } else {
+    this->phase_[phase].voltage_offset_ = first_offset;
+    this->phase_[phase].current_offset_ = second_offset;
+  }
 
-  // Save to flash-storable struct
-  this->offset_phase_[phase].current_offset_ = current_offset;
-  this->phase_[phase].current_offset_ = current_offset;
-
-  // Write to registers
+  const uint16_t *first_registers = power_offsets ? this->power_offset_registers : this->voltage_offset_registers;
+  const uint16_t *second_registers =
+      power_offsets ? this->reactive_power_offset_registers : this->current_offset_registers;
   this->write16_(ATM90E32_REGISTER_CFGREGACCEN, 0x55AA);
-  this->write16_(voltage_offset_registers[phase], static_cast<uint16_t>(voltage_offset));
-  this->write16_(current_offset_registers[phase], static_cast<uint16_t>(current_offset));
-  this->write16_(ATM90E32_REGISTER_CFGREGACCEN, 0x0000);
-}
-
-void ATM90E32Component::write_power_offsets_to_registers_(uint8_t phase, int16_t p_offset, int16_t q_offset) {
-  // Save to runtime
-  this->phase_[phase].active_power_offset_ = p_offset;
-  this->phase_[phase].reactive_power_offset_ = q_offset;
-
-  // Save to flash-storable struct
-  this->power_offset_phase_[phase].active_power_offset = p_offset;
-  this->power_offset_phase_[phase].reactive_power_offset = q_offset;
-
-  // Write to registers
-  this->write16_(ATM90E32_REGISTER_CFGREGACCEN, 0x55AA);
-  this->write16_(this->power_offset_registers[phase], static_cast<uint16_t>(p_offset));
-  this->write16_(this->reactive_power_offset_registers[phase], static_cast<uint16_t>(q_offset));
+  this->write16_(first_registers[phase], static_cast<uint16_t>(first_offset));
+  this->write16_(second_registers[phase], static_cast<uint16_t>(second_offset));
   this->write16_(ATM90E32_REGISTER_CFGREGACCEN, 0x0000);
 }
 
@@ -947,89 +983,78 @@ void ATM90E32Component::restore_gain_calibrations_() {
   ESP_LOGW(TAG, "[CALIBRATION][%s] No stored gain calibrations found. Using config file values.", cs);
 }
 
-void ATM90E32Component::restore_offset_calibrations_() {
+void ATM90E32Component::restore_offset_calibrations_(OffsetCalibrationType type) {
+  const bool power_offsets = type == OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER;
   const char *cs = this->get_calibration_id_();
+  const LogString *name = power_offsets ? LOG_STR("power offset") : LOG_STR("offset");
+  OffsetCalibration(*offsets)[3] = power_offsets ? &this->power_offset_phase_ : &this->offset_phase_;
+  OffsetCalibration(*config_offsets)[3] =
+      power_offsets ? &this->config_power_offset_phase_ : &this->config_offset_phase_;
+  ESPPreferenceObject *preference = power_offsets ? &this->power_offset_pref_ : &this->offset_pref_;
+  bool *has_stored =
+      power_offsets ? &this->has_stored_power_offset_calibration_ : &this->has_stored_offset_calibration_;
+  bool *restored = power_offsets ? &this->restored_power_offset_calibration_ : &this->restored_offset_calibration_;
+  bool *mismatches = power_offsets ? this->power_offset_calibration_mismatch_ : this->offset_calibration_mismatch_;
+  const bool *has_first = power_offsets ? this->has_config_active_power_offset_ : this->has_config_voltage_offset_;
+  const bool *has_second = power_offsets ? this->has_config_reactive_power_offset_ : this->has_config_current_offset_;
+
   for (uint8_t i = 0; i < 3; ++i)
-    this->config_offset_phase_[i] = this->offset_phase_[i];
-
-  bool have_data = this->offset_pref_.load(&this->offset_phase_);
+    (*config_offsets)[i] = (*offsets)[i];
 
+  const bool have_data = preference->load(offsets);
   bool all_zero = true;
   if (have_data) {
-    for (auto &phase : this->offset_phase_) {
-      if (phase.voltage_offset_ != 0 || phase.current_offset_ != 0) {
+    for (const auto &phase : *offsets) {
+      if (phase.first_offset != 0 || phase.second_offset != 0) {
         all_zero = false;
         break;
       }
     }
   }
 
-  if (have_data && !all_zero) {
-    this->restored_offset_calibration_ = true;
-    for (uint8_t phase = 0; phase < 3; phase++) {
-      auto &offset = this->offset_phase_[phase];
-      bool mismatch = false;
-      if (this->has_config_voltage_offset_[phase] &&
-          offset.voltage_offset_ != this->config_offset_phase_[phase].voltage_offset_)
-        mismatch = true;
-      if (this->has_config_current_offset_[phase] &&
-          offset.current_offset_ != this->config_offset_phase_[phase].current_offset_)
-        mismatch = true;
-      if (mismatch)
-        this->offset_calibration_mismatch_[phase] = true;
+  *has_stored = have_data && !all_zero;
+  *restored = false;
+  for (uint8_t phase = 0; phase < 3; phase++) {
+    mismatches[phase] = false;
+    if (*has_stored) {
+      mismatches[phase] =
+          (has_first[phase] && (*offsets)[phase].first_offset != (*config_offsets)[phase].first_offset) ||
+          (has_second[phase] && (*offsets)[phase].second_offset != (*config_offsets)[phase].second_offset);
     }
-  } else {
+  }
+
+  if (!*has_stored) {
     for (uint8_t phase = 0; phase < 3; phase++)
-      this->offset_phase_[phase] = this->config_offset_phase_[phase];
-    ESP_LOGW(TAG, "[CALIBRATION][%s] No stored offset calibrations found. Using default values.", cs);
+      (*offsets)[phase] = (*config_offsets)[phase];
+    ESP_LOGW(TAG, "[CALIBRATION][%s] No stored %s calibrations found. Using default values.", cs, LOG_STR_ARG(name));
   }
 
   for (uint8_t phase = 0; phase < 3; phase++) {
-    write_offsets_to_registers_(phase, this->offset_phase_[phase].voltage_offset_,
-                                this->offset_phase_[phase].current_offset_);
+    this->write_offsets_to_registers_(phase, (*offsets)[phase].first_offset, (*offsets)[phase].second_offset, type);
   }
-}
-
-void ATM90E32Component::restore_power_offset_calibrations_() {
-  const char *cs = this->get_calibration_id_();
-  for (uint8_t i = 0; i < 3; ++i)
-    this->config_power_offset_phase_[i] = this->power_offset_phase_[i];
-
-  bool have_data = this->power_offset_pref_.load(&this->power_offset_phase_);
-
-  bool all_zero = true;
-  if (have_data) {
-    for (auto &phase : this->power_offset_phase_) {
-      if (phase.active_power_offset != 0 || phase.reactive_power_offset != 0) {
-        all_zero = false;
-        break;
-      }
-    }
+  const bool initial_values_verified = this->verify_offset_writes_(type);
+  if (initial_values_verified) {
+    const auto state = resolve_offset_restore_state(*has_stored, true, false);
+    *restored = state.restored;
+    ESP_LOGI(TAG, "[CALIBRATION][%s] %s calibration values verified.", cs, LOG_STR_ARG(name));
+    return;
   }
 
-  if (have_data && !all_zero) {
-    this->restored_power_offset_calibration_ = true;
-    for (uint8_t phase = 0; phase < 3; ++phase) {
-      auto &offset = this->power_offset_phase_[phase];
-      bool mismatch = false;
-      if (this->has_config_active_power_offset_[phase] &&
-          offset.active_power_offset != this->config_power_offset_phase_[phase].active_power_offset)
-        mismatch = true;
-      if (this->has_config_reactive_power_offset_[phase] &&
-          offset.reactive_power_offset != this->config_power_offset_phase_[phase].reactive_power_offset)
-        mismatch = true;
-      if (mismatch)
-        this->power_offset_calibration_mismatch_[phase] = true;
-    }
+  this->using_saved_calibrations_ = false;
+  for (uint8_t phase = 0; phase < 3; phase++)
+    mismatches[phase] = false;
+  for (uint8_t phase = 0; phase < 3; phase++) {
+    (*offsets)[phase] = (*config_offsets)[phase];
+    this->write_offsets_to_registers_(phase, (*offsets)[phase].first_offset, (*offsets)[phase].second_offset, type);
+  }
+  const auto state = resolve_offset_restore_state(*has_stored, false, this->verify_offset_writes_(type));
+  *restored = state.restored;
+  if (state.values_verified) {
+    ESP_LOGE(TAG, "[CALIBRATION][%s] %s calibration restore failed verification; config values verified.", cs,
+             LOG_STR_ARG(name));
   } else {
-    for (uint8_t phase = 0; phase < 3; ++phase)
-      this->power_offset_phase_[phase] = this->config_power_offset_phase_[phase];
-    ESP_LOGW(TAG, "[CALIBRATION][%s] No stored power offsets found. Using default values.", cs);
-  }
-
-  for (uint8_t phase = 0; phase < 3; ++phase) {
-    write_power_offsets_to_registers_(phase, this->power_offset_phase_[phase].active_power_offset,
-                                      this->power_offset_phase_[phase].reactive_power_offset);
+    ESP_LOGE(TAG, "[CALIBRATION][%s] %s calibration restore and config fallback both failed verification.", cs,
+             LOG_STR_ARG(name));
   }
 }
 
@@ -1084,14 +1109,14 @@ void ATM90E32Component::clear_gain_calibrations() {
 
 void ATM90E32Component::clear_offset_calibrations() {
   const char *cs = this->get_calibration_id_();
-  if (!this->restored_offset_calibration_) {
+  if (!this->has_stored_offset_calibration_) {
     ESP_LOGI(TAG, "[CALIBRATION][%s] No stored offset calibrations to clear. Current values:", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] --------------------------------------------------------------", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] | Phase | offset_voltage | offset_current |", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] --------------------------------------------------------------", cs);
     for (uint8_t phase = 0; phase < 3; phase++) {
       ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |     %6d      |     %6d      |", cs, 'A' + phase,
-               this->offset_phase_[phase].voltage_offset_, this->offset_phase_[phase].current_offset_);
+               this->offset_phase_[phase].first_offset, this->offset_phase_[phase].second_offset);
     }
     ESP_LOGI(TAG, "[CALIBRATION][%s] ==============================================================\n", cs);
     return;
@@ -1104,10 +1129,11 @@ void ATM90E32Component::clear_offset_calibrations() {
 
   for (uint8_t phase = 0; phase < 3; phase++) {
     int16_t voltage_offset =
-        this->has_config_voltage_offset_[phase] ? this->config_offset_phase_[phase].voltage_offset_ : 0;
+        this->has_config_voltage_offset_[phase] ? this->config_offset_phase_[phase].first_offset : 0;
     int16_t current_offset =
-        this->has_config_current_offset_[phase] ? this->config_offset_phase_[phase].current_offset_ : 0;
-    this->write_offsets_to_registers_(phase, voltage_offset, current_offset);
+        this->has_config_current_offset_[phase] ? this->config_offset_phase_[phase].second_offset : 0;
+    this->write_offsets_to_registers_(phase, voltage_offset, current_offset,
+                                      OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_VOLTAGE_CURRENT);
     ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |     %6d      |     %6d      |", cs, 'A' + phase, voltage_offset,
              current_offset);
   }
@@ -1117,6 +1143,7 @@ void ATM90E32Component::clear_offset_calibrations() {
   this->offset_pref_.save(&zero_offsets);  // Clear stored values in flash
   global_preferences->sync();
 
+  this->has_stored_offset_calibration_ = false;
   this->restored_offset_calibration_ = false;
   for (bool &phase : this->offset_calibration_mismatch_)
     phase = false;
@@ -1126,15 +1153,14 @@ void ATM90E32Component::clear_offset_calibrations() {
 
 void ATM90E32Component::clear_power_offset_calibrations() {
   const char *cs = this->get_calibration_id_();
-  if (!this->restored_power_offset_calibration_) {
+  if (!this->has_stored_power_offset_calibration_) {
     ESP_LOGI(TAG, "[CALIBRATION][%s] No stored power offsets to clear. Current values:", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] ---------------------------------------------------------------------", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] | Phase | offset_active_power | offset_reactive_power |", cs);
     ESP_LOGI(TAG, "[CALIBRATION][%s] ---------------------------------------------------------------------", cs);
     for (uint8_t phase = 0; phase < 3; phase++) {
       ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |       %6d        |        %6d        |", cs, 'A' + phase,
-               this->power_offset_phase_[phase].active_power_offset,
-               this->power_offset_phase_[phase].reactive_power_offset);
+               this->power_offset_phase_[phase].first_offset, this->power_offset_phase_[phase].second_offset);
     }
     ESP_LOGI(TAG, "[CALIBRATION][%s] =====================================================================\n", cs);
     return;
@@ -1147,20 +1173,21 @@ void ATM90E32Component::clear_power_offset_calibrations() {
 
   for (uint8_t phase = 0; phase < 3; phase++) {
     int16_t active_offset =
-        this->has_config_active_power_offset_[phase] ? this->config_power_offset_phase_[phase].active_power_offset : 0;
-    int16_t reactive_offset = this->has_config_reactive_power_offset_[phase]
-                                  ? this->config_power_offset_phase_[phase].reactive_power_offset
-                                  : 0;
-    this->write_power_offsets_to_registers_(phase, active_offset, reactive_offset);
+        this->has_config_active_power_offset_[phase] ? this->config_power_offset_phase_[phase].first_offset : 0;
+    int16_t reactive_offset =
+        this->has_config_reactive_power_offset_[phase] ? this->config_power_offset_phase_[phase].second_offset : 0;
+    this->write_offsets_to_registers_(phase, active_offset, reactive_offset,
+                                      OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER);
     ESP_LOGI(TAG, "[CALIBRATION][%s] |   %c   |       %6d        |        %6d        |", cs, 'A' + phase, active_offset,
              reactive_offset);
   }
   ESP_LOGI(TAG, "[CALIBRATION][%s] =====================================================================\n", cs);
 
-  PowerOffsetCalibration zero_power_offsets[3]{{0, 0}, {0, 0}, {0, 0}};
+  OffsetCalibration zero_power_offsets[3]{{0, 0}, {0, 0}, {0, 0}};
   this->power_offset_pref_.save(&zero_power_offsets);
   global_preferences->sync();
 
+  this->has_stored_power_offset_calibration_ = false;
   this->restored_power_offset_calibration_ = false;
   for (bool &phase : this->power_offset_calibration_mismatch_)
     phase = false;
@@ -1215,6 +1242,31 @@ bool ATM90E32Component::verify_gain_writes_() {
   return success;  // Return true if all writes were successful, false otherwise
 }
 
+bool ATM90E32Component::verify_offset_writes_(OffsetCalibrationType type) {
+  const bool power_offsets = type == OffsetCalibrationType::OFFSET_CALIBRATION_TYPE_POWER;
+  const char *cs = this->get_calibration_id_();
+  const LogString *name = offset_calibration_name(power_offsets);
+  const LogString *first_name = power_offsets ? LOG_STR("active") : LOG_STR("voltage");
+  const LogString *second_name = power_offsets ? LOG_STR("reactive") : LOG_STR("current");
+  const OffsetCalibration *offsets = power_offsets ? this->power_offset_phase_ : this->offset_phase_;
+  const uint16_t *first_registers = power_offsets ? this->power_offset_registers : this->voltage_offset_registers;
+  const uint16_t *second_registers =
+      power_offsets ? this->reactive_power_offset_registers : this->current_offset_registers;
+  bool success = true;
+  for (uint8_t phase = 0; phase < 3; phase++) {
+    const uint16_t first = this->read16_(first_registers[phase]);
+    const uint16_t second = this->read16_(second_registers[phase]);
+    if (!offset_register_value_matches(first, offsets[phase].first_offset) ||
+        !offset_register_value_matches(second, offsets[phase].second_offset)) {
+      ESP_LOGE(TAG, "[CALIBRATION][%s] %s readback failed for Phase %s: %s %d/%d, %s %d/%d.", cs, LOG_STR_ARG(name),
+               phase_labels[phase], LOG_STR_ARG(first_name), static_cast<int16_t>(first), offsets[phase].first_offset,
+               LOG_STR_ARG(second_name), static_cast<int16_t>(second), offsets[phase].second_offset);
+      success = false;
+    }
+  }
+  return success;
+}
+
 #ifdef USE_TEXT_SENSOR
 void ATM90E32Component::check_phase_status() {
   uint16_t state0 = this->read16_(ATM90E32_REGISTER_EMMSTATE0);

esphome/components/atm90e32/atm90e32.h

@@ -13,6 +13,40 @@
 
 namespace esphome::atm90e32 {
 
+inline bool offset_register_value_matches(uint16_t actual, int16_t expected) {
+  return actual == static_cast<uint16_t>(expected);
+}
+
+struct OffsetCalibration {
+  int16_t first_offset{0};
+  int16_t second_offset{0};
+};
+
+static_assert(sizeof(OffsetCalibration[3]) == 12, "Offset calibration preference layout must remain compatible");
+
+enum class OffsetCalibrationType : uint8_t {
+  OFFSET_CALIBRATION_TYPE_VOLTAGE_CURRENT,
+  OFFSET_CALIBRATION_TYPE_POWER,
+};
+
+struct OffsetRestoreState {
+  bool restored;
+  bool values_verified;
+};
+
+inline OffsetRestoreState resolve_offset_restore_state(bool has_stored_values, bool initial_values_verified,
+                                                       bool fallback_values_verified) {
+  if (initial_values_verified)
+    return {has_stored_values, true};
+  return {false, fallback_values_verified};
+}
+
+inline void prepare_offset_rollback(const OffsetCalibration (&previous)[3], bool had_stored_values,
+                                    OffsetCalibration (&rollback)[3]) {
+  for (uint8_t phase = 0; phase < 3; phase++)
+    rollback[phase] = had_stored_values ? previous[phase] : OffsetCalibration{};
+}
+
 class ATM90E32Component final : public PollingComponent,
                                 public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_HIGH,
                                                       spi::CLOCK_PHASE_TRAILING, spi::DATA_RATE_1MHZ> {
@@ -71,19 +105,19 @@ class ATM90E32Component final : public PollingComponent,
     this->has_config_current_gain_[phase] = true;
   }
   void set_voltage_offset(uint8_t phase, int16_t offset) {
-    this->offset_phase_[phase].voltage_offset_ = offset;
+    this->offset_phase_[phase].first_offset = offset;
     this->has_config_voltage_offset_[phase] = true;
   }
   void set_current_offset(uint8_t phase, int16_t offset) {
-    this->offset_phase_[phase].current_offset_ = offset;
+    this->offset_phase_[phase].second_offset = offset;
     this->has_config_current_offset_[phase] = true;
   }
   void set_active_power_offset(uint8_t phase, int16_t offset) {
-    this->power_offset_phase_[phase].active_power_offset = offset;
+    this->power_offset_phase_[phase].first_offset = offset;
     this->has_config_active_power_offset_[phase] = true;
   }
   void set_reactive_power_offset(uint8_t phase, int16_t offset) {
-    this->power_offset_phase_[phase].reactive_power_offset = offset;
+    this->power_offset_phase_[phase].second_offset = offset;
     this->has_config_reactive_power_offset_[phase] = true;
   }
   void set_freq_sensor(sensor::Sensor *freq_sensor) { freq_sensor_ = freq_sensor; }
@@ -171,16 +205,16 @@ class ATM90E32Component final : public PollingComponent,
   float get_chip_temperature_();
   bool get_publish_interval_flag_() { return publish_interval_flag_; };
   void set_publish_interval_flag_(bool flag) { publish_interval_flag_ = flag; };
-  void restore_offset_calibrations_();
-  void restore_power_offset_calibrations_();
+  void restore_offset_calibrations_(OffsetCalibrationType type);
   void restore_gain_calibrations_();
-  void save_offset_calibration_to_memory_();
   void save_gain_calibration_to_memory_();
-  void save_power_offset_calibration_to_memory_();
-  void write_offsets_to_registers_(uint8_t phase, int16_t voltage_offset, int16_t current_offset);
-  void write_power_offsets_to_registers_(uint8_t phase, int16_t p_offset, int16_t q_offset);
+  void finish_offset_calibration_(const OffsetCalibration (&previous)[3], bool previous_restored,
+                                  bool previous_using_saved, OffsetCalibrationType type);
+  void write_offsets_to_registers_(uint8_t phase, int16_t first_offset, int16_t second_offset,
+                                   OffsetCalibrationType type);
   void write_gains_to_registers_();
   bool verify_gain_writes_();
+  bool verify_offset_writes_(OffsetCalibrationType type);
   bool validate_spi_read_(uint16_t expected, const char *context = nullptr);
   void log_calibration_status_();
   const char *get_calibration_id_();
@@ -219,19 +253,10 @@ class ATM90E32Component final : public PollingComponent,
     uint32_t cumulative_reverse_active_energy_{0};
   } phase_[3];
 
-  struct OffsetCalibration {
-    int16_t voltage_offset_{0};
-    int16_t current_offset_{0};
-  } offset_phase_[3];
-
+  OffsetCalibration offset_phase_[3];
   OffsetCalibration config_offset_phase_[3];
-
-  struct PowerOffsetCalibration {
-    int16_t active_power_offset{0};
-    int16_t reactive_power_offset{0};
-  } power_offset_phase_[3];
-
-  PowerOffsetCalibration config_power_offset_phase_[3];
+  OffsetCalibration power_offset_phase_[3];
+  OffsetCalibration config_power_offset_phase_[3];
 
   struct GainCalibration {
     uint16_t voltage_gain{1};
@@ -265,6 +290,8 @@ class ATM90E32Component final : public PollingComponent,
   bool enable_offset_calibration_{false};
   bool enable_gain_calibration_{false};
   const char *instance_id_{nullptr};
+  bool has_stored_offset_calibration_{false};
+  bool has_stored_power_offset_calibration_{false};
   bool restored_offset_calibration_{false};
   bool restored_power_offset_calibration_{false};
   bool restored_gain_calibration_{false};

esphome/components/audio/audio_decoder.cpp

@@ -313,9 +313,10 @@ FileDecoderState AudioDecoder::decode_mp3_() {
       this->output_transfer_buffer_->increase_buffer_length(
           this->audio_stream_info_.value().frames_to_bytes(samples_decoded));
     }
-  } else if (result == micro_mp3::MP3_STREAM_INFO_READY) {
-    // First successful header parse: capture stream info and resize the output buffer to fit one full frame.
-    // microMP3 always outputs 16-bit PCM.
+  } else if (result == micro_mp3::MP3_STREAM_INFO_READY || result == micro_mp3::MP3_STREAM_INFO_CHANGED) {
+    // Header parsed: capture stream info and resize the output buffer to fit one full frame.
+    // microMP3 always outputs 16-bit PCM. MP3_STREAM_INFO_CHANGED is handled identically: despite its
+    // negative value it is documented as recoverable, so it must not reach the catch-all below.
     this->audio_stream_info_ =
         audio::AudioStreamInfo(16, this->mp3_decoder_->get_channels(), this->mp3_decoder_->get_sample_rate());
     this->free_buffer_required_ =

esphome/components/ble_client/automation.h

@@ -22,6 +22,23 @@ class Automation {
   static const char *const TAG;
 };
 
+// Base for nodes that never read the parent's services.
+// The parent releases its services only once every node reports Established, so a node that never
+// reports it keeps that memory allocated for the life of the connection.
+class BLEClientServicelessNode : public BLEClientNode {
+ public:
+  // Final so that Established is always reported on SEARCH_CMPL, before the derived node sees the event.
+  void gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param) final {
+    if (event == ESP_GATTC_SEARCH_CMPL_EVT)
+      this->node_state = espbt::ClientState::ESTABLISHED;
+    this->on_gattc_event(event, gattc_if, param);
+  }
+
+ protected:
+  // Derived nodes handle GATT events here rather than by overriding the handler above.
+  virtual void on_gattc_event(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param) {}
+};
+
 // implement on_connect automation.
 class BLEClientConnectTrigger final : public Trigger<>, public BLEClientNode {
  public:
@@ -61,7 +78,7 @@ class BLEClientDisconnectTrigger final : public Trigger<>, public BLEClientNode
   }
 };
 
-class BLEClientPasskeyRequestTrigger final : public Trigger<>, public BLEClientNode {
+class BLEClientPasskeyRequestTrigger final : public Trigger<>, public BLEClientServicelessNode {
  public:
   explicit BLEClientPasskeyRequestTrigger(BLEClient *parent) { parent->register_ble_node(this); }
   void loop() override {}
@@ -71,7 +88,7 @@ class BLEClientPasskeyRequestTrigger final : public Trigger<>, public BLEClientN
   }
 };
 
-class BLEClientPasskeyNotificationTrigger final : public Trigger<uint32_t>, public BLEClientNode {
+class BLEClientPasskeyNotificationTrigger final : public Trigger<uint32_t>, public BLEClientServicelessNode {
  public:
   explicit BLEClientPasskeyNotificationTrigger(BLEClient *parent) { parent->register_ble_node(this); }
   void loop() override {}
@@ -82,7 +99,7 @@ class BLEClientPasskeyNotificationTrigger final : public Trigger<uint32_t>, publ
   }
 };
 
-class BLEClientNumericComparisonRequestTrigger final : public Trigger<uint32_t>, public BLEClientNode {
+class BLEClientNumericComparisonRequestTrigger final : public Trigger<uint32_t>, public BLEClientServicelessNode {
  public:
   explicit BLEClientNumericComparisonRequestTrigger(BLEClient *parent) { parent->register_ble_node(this); }
   void loop() override {}
@@ -315,19 +332,17 @@ template<typename... Ts> class BLEClientRemoveBondAction final : public Action<T
   BLEClient *parent_{nullptr};
 };
 
-template<typename... Ts> class BLEClientConnectAction final : public Action<Ts...>, public BLEClientNode {
+template<typename... Ts> class BLEClientConnectAction final : public Action<Ts...>, public BLEClientServicelessNode {
  public:
   BLEClientConnectAction(BLEClient *ble_client) {
     ble_client->register_ble_node(this);
     ble_client_ = ble_client;
   }
-  void gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
-                           esp_ble_gattc_cb_param_t *param) override {
+  void on_gattc_event(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param) override {
     if (this->num_running_ == 0)
       return;
     switch (event) {
       case ESP_GATTC_SEARCH_CMPL_EVT:
-        this->node_state = espbt::ClientState::ESTABLISHED;
         this->parent()->run_later([this]() { this->play_next_tuple_(this->var_); });
         break;
       // if the connection is closed, terminate the automation chain.
@@ -364,14 +379,13 @@ template<typename... Ts> class BLEClientConnectAction final : public Action<Ts..
   std::tuple<Ts...> var_{};
 };
 
-template<typename... Ts> class BLEClientDisconnectAction final : public Action<Ts...>, public BLEClientNode {
+template<typename... Ts> class BLEClientDisconnectAction final : public Action<Ts...>, public BLEClientServicelessNode {
  public:
   BLEClientDisconnectAction(BLEClient *ble_client) {
     ble_client->register_ble_node(this);
     ble_client_ = ble_client;
   }
-  void gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
-                           esp_ble_gattc_cb_param_t *param) override {
+  void on_gattc_event(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param) override {
     if (this->num_running_ == 0)
       return;
     switch (event) {

esphome/components/climate/__init__.py

@@ -125,6 +125,19 @@ CLIMATE_SWING_MODES = {
 
 validate_climate_swing_mode = cv.enum(CLIMATE_SWING_MODES, upper=True)
 
+ClimateAction = climate_ns.enum("ClimateAction")
+CLIMATE_ACTIONS = {
+    "OFF": ClimateAction.CLIMATE_ACTION_OFF,
+    "COOLING": ClimateAction.CLIMATE_ACTION_COOLING,
+    "HEATING": ClimateAction.CLIMATE_ACTION_HEATING,
+    "IDLE": ClimateAction.CLIMATE_ACTION_IDLE,
+    "DRYING": ClimateAction.CLIMATE_ACTION_DRYING,
+    "FAN": ClimateAction.CLIMATE_ACTION_FAN,
+    "DEFROSTING": ClimateAction.CLIMATE_ACTION_DEFROSTING,
+}
+
+validate_climate_action = cv.enum(CLIMATE_ACTIONS, upper=True)
+
 CONF_MIN_HUMIDITY = "min_humidity"
 CONF_MAX_HUMIDITY = "max_humidity"
 CONF_TARGET_HUMIDITY = "target_humidity"

esphome/components/dallas_temp/dallas_temp.cpp

@@ -6,6 +6,7 @@ namespace esphome::dallas_temp {
 static const char *const TAG = "dallas.temp.sensor";
 
 static const uint8_t DALLAS_MODEL_DS18S20 = 0x10;
+static const uint8_t DALLAS_MODEL_DS18B20 = 0x28;
 static const uint8_t DALLAS_COMMAND_START_CONVERSION = 0x44;
 static const uint8_t DALLAS_COMMAND_READ_SCRATCH_PAD = 0xBE;
 static const uint8_t DALLAS_COMMAND_WRITE_SCRATCH_PAD = 0x4E;
@@ -154,7 +155,14 @@ float DallasTemperatureSensor::get_temp_c_() {
     default:
       break;
   }
-
+  // undocumented test for powerup measurement of 85
+  // https://github.com/cpetrich/counterfeit_DS18B20#solution-to-the-85-c-problem
+  if ((this->address_ & 0xff) == DALLAS_MODEL_DS18B20) {
+    if ((temp == 85 * 16) && (this->scratch_pad_[6] == 0xc)) {
+      ESP_LOGD(TAG, "dropping reading caused by sensor reset");
+      return NAN;
+    }
+  }
   return temp / 16.0f;
 }
 

esphome/components/debug/debug_esp32.cpp

@@ -66,11 +66,15 @@ const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFE
 
   unsigned reason = esp_reset_reason();
   if (reason < sizeof(RESET_REASONS) / sizeof(RESET_REASONS[0])) {
-    if (reason == ESP_RST_SW) {
+    if (reason == ESP_RST_SW || reason == ESP_RST_WDT) {
+      // On some ESP32-S3 configurations (e.g. SPIRAM with fetch-instructions/rodata),
+      // esp_restart() intermittently produces RTCWDT_RTC_RST (ESP_RST_WDT) instead of
+      // ESP_RST_SW. Check the stored reboot source for both reset reasons so a software
+      // reboot that ends up as WDT still reports the correct source.
       auto pref = global_preferences->make_preference(REBOOT_MAX_LEN,
                                                       fnv1_hash_extend(fnv1_hash(REBOOT_KEY), App.get_name().c_str()));
       char reboot_source[REBOOT_MAX_LEN]{};
-      if (pref.load(&reboot_source)) {
+      if (pref.load(&reboot_source) && reboot_source[0] != '\0') {
         reboot_source[REBOOT_MAX_LEN - 1] = '\0';
         snprintf(buf, size, "Reboot request from %s", reboot_source);
       } else {

esphome/components/debug/sensor.py

@@ -23,11 +23,7 @@ from esphome.const import (
 )
 from esphome.types import ConfigType
 
-from . import (  # noqa: F401  pylint: disable=unused-import
-    CONF_DEBUG_ID,
-    FILTER_SOURCE_FILES,
-    DebugComponent,
-)
+from . import CONF_DEBUG_ID, FILTER_SOURCE_FILES, DebugComponent  # noqa: F401  pylint: disable=unused-import
 
 DEPENDENCIES = ["debug"]
 

esphome/components/debug/text_sensor.py

@@ -9,11 +9,7 @@ from esphome.const import (
 )
 from esphome.types import ConfigType
 
-from . import (  # noqa: F401  pylint: disable=unused-import
-    CONF_DEBUG_ID,
-    FILTER_SOURCE_FILES,
-    DebugComponent,
-)
+from . import CONF_DEBUG_ID, FILTER_SOURCE_FILES, DebugComponent  # noqa: F401  pylint: disable=unused-import
 
 DEPENDENCIES = ["debug"]
 

esphome/components/esp32/const.py

@@ -3,18 +3,11 @@ import esphome.codegen as cg
 # Re-exported for the many esp32-side users; defined in esphome.const
 # and esphome.espidf so the upload/logs fast path can use them without
 # importing this package.
-from esphome.const import (  # noqa: F401  # pylint: disable=unused-import
-    KEY_ESP32,
-    KEY_FLASH_SIZE,
-    KEY_IDF_VERSION,
-    KEY_VARIANT,
-)
+from esphome.const import KEY_ESP32, KEY_FLASH_SIZE, KEY_IDF_VERSION, KEY_VARIANT  # noqa: F401  # pylint: disable=unused-import
 
 # Back compat for external components only; in-tree callers import it
 # from esphome.espidf directly.
-from esphome.espidf import (  # noqa: F401  # pylint: disable=unused-import
-    variant_to_idf_target,
-)
+from esphome.espidf import variant_to_idf_target  # noqa: F401  # pylint: disable=unused-import
 
 KEY_BOARD = "board"
 KEY_SDKCONFIG_OPTIONS = "sdkconfig_options"

esphome/components/esp32_ble/ble.cpp

@@ -100,21 +100,38 @@ void ESP32BLE::disable() {
 #ifdef USE_ESP32_BLE_ADVERTISING
 void ESP32BLE::advertising_start() {
   this->advertising_init_();
-  if (!this->is_active())
+  this->advertising_ref_count_++;
+  this->advertising_refresh();
+}
+
+void ESP32BLE::advertising_stop() {
+  if (this->advertising_ref_count_ == 0)
     return;
-  this->advertising_->start();
+  this->advertising_ref_count_--;
+  this->advertising_refresh();
+}
+
+void ESP32BLE::advertising_refresh() {
+  if (this->advertising_ == nullptr || !this->is_active())
+    return;
+  // Advertise while any component still needs it, otherwise stop
+  if (this->advertising_ref_count_ == 0) {
+    this->advertising_->stop();
+  } else {
+    this->advertising_->start();
+  }
 }
 
 void ESP32BLE::advertising_set_service_data(const std::vector<uint8_t> &data) {
   this->advertising_init_();
   this->advertising_->set_service_data(data);
-  this->advertising_start();
+  this->advertising_refresh();
 }
 
 void ESP32BLE::advertising_set_manufacturer_data(const std::vector<uint8_t> &data) {
   this->advertising_init_();
   this->advertising_->set_manufacturer_data(data);
-  this->advertising_start();
+  this->advertising_refresh();
 }
 
 void ESP32BLE::advertising_set_service_data_and_name(std::span<const uint8_t> data, bool include_name) {
@@ -136,7 +153,7 @@ void ESP32BLE::advertising_set_service_data_and_name(std::span<const uint8_t> da
     this->advertising_->set_service_data(data);
   }
 
-  this->advertising_start();
+  this->advertising_refresh();
 }
 
 void ESP32BLE::advertising_register_raw_advertisement_callback(std::function<void(bool)> &&callback) {
@@ -147,13 +164,13 @@ void ESP32BLE::advertising_register_raw_advertisement_callback(std::function<voi
 void ESP32BLE::advertising_add_service_uuid(ESPBTUUID uuid) {
   this->advertising_init_();
   this->advertising_->add_service_uuid(uuid);
-  this->advertising_start();
+  this->advertising_refresh();
 }
 
 void ESP32BLE::advertising_remove_service_uuid(ESPBTUUID uuid) {
   this->advertising_init_();
   this->advertising_->remove_service_uuid(uuid);
-  this->advertising_start();
+  this->advertising_refresh();
 }
 #endif
 
@@ -575,6 +592,10 @@ void ESP32BLE::loop_handle_state_transition_not_active_() {
     }
 
     this->state_ = BLE_COMPONENT_STATE_ACTIVE;
+#ifdef USE_ESP32_BLE_ADVERTISING
+    // Requests made before the stack was up (or before it was re-enabled) take effect now
+    this->advertising_refresh();
+#endif
   }
 }
 

esphome/components/esp32_ble/ble.h

@@ -114,7 +114,17 @@ class ESP32BLE final : public Component {
   void set_name(const char *name) { this->name_ = name; }
 
 #ifdef USE_ESP32_BLE_ADVERTISING
+  /** Request advertising on behalf of a component.
+   *
+   * Requests are reference counted: advertising runs until every component that called
+   * advertising_start() has released it again with advertising_stop(). Each component must
+   * pair its calls, so nothing advertises until something actually asks for it.
+   */
   void advertising_start();
+  /// Release a request made with advertising_start(); advertising stops at the last release.
+  void advertising_stop();
+  /// Apply the current payload and request count: advertise while requested, otherwise stop.
+  void advertising_refresh();
   void advertising_set_service_data(const std::vector<uint8_t> &data);
   void advertising_set_manufacturer_data(const std::vector<uint8_t> &data);
   void advertising_set_appearance(uint16_t appearance) { this->appearance_ = appearance; }
@@ -226,6 +236,9 @@ class ESP32BLE final : public Component {
   // 1-byte aligned members (grouped together to minimize padding)
   BLEComponentState state_{BLE_COMPONENT_STATE_OFF};  // 1 byte (uint8_t enum)
   bool enable_on_boot_{};                             // 1 byte
+#ifdef USE_ESP32_BLE_ADVERTISING
+  uint8_t advertising_ref_count_{0};  // 1 byte, number of components requesting advertising
+#endif
 
 #ifdef ESPHOME_ESP32_BLE_EXTENDED_AUTH_PARAMS
   optional<esp_ble_auth_req_t> auth_req_mode_;

esphome/components/esp32_ble_beacon/esp32_ble_beacon.cpp

@@ -67,6 +67,8 @@ void ESP32BLEBeacon::setup() {
       this->on_advertise_();
     }
   });
+  // A beacon always needs the device to advertise, and never releases the request
+  global_ble->advertising_start();
 }
 
 void ESP32BLEBeacon::on_advertise_() {

esphome/components/esp32_ble_server/__init__.py

@@ -596,6 +596,18 @@ async def to_code(config):
     cg.add(var.set_parent(parent))
     cg.add(parent.advertising_set_appearance(config[CONF_APPEARANCE]))
     cg.add(var.set_max_clients(config[CONF_MAX_CLIENTS]))
+    # Only advertise for the server itself when the configuration gives clients something to
+    # find. A server that is auto-loaded purely to host a runtime service (esp32_improv) stays
+    # silent until that service asks for advertising.
+    cg.add(
+        var.set_advertising_required(
+            CONF_MANUFACTURER_DATA in config
+            or any(
+                not uuid_is(service_config[CONF_UUID], DEVICE_INFORMATION_SERVICE_UUID)
+                for service_config in config[CONF_SERVICES]
+            )
+        )
+    )
     if CONF_MANUFACTURER_DATA in config:
         cg.add(var.set_manufacturer_data(config[CONF_MANUFACTURER_DATA]))
     for service_config in config[CONF_SERVICES]:

esphome/components/esp32_ble_server/ble_server.cpp

@@ -81,6 +81,7 @@ void BLEServer::loop() {
       if (this->device_information_service_->is_running()) {
         this->state_ = RUNNING;
         this->restart_advertising_();
+        this->request_advertising_();
         ESP_LOGD(TAG, "BLE server setup successfully");
       } else if (this->device_information_service_->is_created()) {
         this->device_information_service_->start();
@@ -98,6 +99,20 @@ void BLEServer::restart_advertising_() {
   }
 }
 
+void BLEServer::request_advertising_() {
+  if (!this->advertising_required_ || this->advertising_requested_)
+    return;
+  this->advertising_requested_ = true;
+  this->parent_->advertising_start();
+}
+
+void BLEServer::release_advertising_() {
+  if (!this->advertising_requested_)
+    return;
+  this->advertising_requested_ = false;
+  this->parent_->advertising_stop();
+}
+
 BLEService *BLEServer::create_service(ESPBTUUID uuid, bool advertise, uint16_t num_handles) {
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
   char uuid_buf[esp32_ble::UUID_STR_LEN];
@@ -170,7 +185,7 @@ void BLEServer::gatts_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_t ga
       this->add_client_(param->connect.conn_id);
       // Resume advertising so additional clients can discover and connect
       if (this->client_count_ < this->max_clients_) {
-        this->parent_->advertising_start();
+        this->parent_->advertising_refresh();
       }
       this->dispatch_callbacks_(CallbackType::ON_CONNECT, param->connect.conn_id);
       break;
@@ -178,7 +193,7 @@ void BLEServer::gatts_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_t ga
     case ESP_GATTS_DISCONNECT_EVT: {
       ESP_LOGD(TAG, "BLE Client disconnected");
       this->remove_client_(param->disconnect.conn_id);
-      this->parent_->advertising_start();
+      this->parent_->advertising_refresh();
       this->dispatch_callbacks_(CallbackType::ON_DISCONNECT, param->disconnect.conn_id);
       break;
     }
@@ -226,6 +241,8 @@ void BLEServer::remove_client_(uint16_t conn_id) {
 }
 
 void BLEServer::ble_before_disabled_event_handler() {
+  // Advertising is re-requested once the server is running again after BLE is re-enabled
+  this->release_advertising_();
   // Delete all clients
   this->client_count_ = 0;
   // Delete all services

esphome/components/esp32_ble_server/ble_server.h

@@ -38,6 +38,13 @@ class BLEServer final : public Component, public Parented<ESP32BLE> {
     this->restart_advertising_();
   }
 
+  /** Whether this server needs the device to advertise so clients can find and connect to it.
+   *
+   * False for a server that only hosts services created at runtime (e.g. esp32_improv), which
+   * request advertising themselves for as long as they need it.
+   */
+  void set_advertising_required(bool required) { this->advertising_required_ = required; }
+
   void set_max_clients(uint8_t max_clients) { this->max_clients_ = max_clients; }
   uint8_t get_max_clients() const { return this->max_clients_; }
 
@@ -82,6 +89,8 @@ class BLEServer final : public Component, public Parented<ESP32BLE> {
   };
 
   void restart_advertising_();
+  void request_advertising_();
+  void release_advertising_();
 
   int8_t find_client_index_(uint16_t conn_id) const;
   void add_client_(uint16_t conn_id);
@@ -93,6 +102,8 @@ class BLEServer final : public Component, public Parented<ESP32BLE> {
   std::vector<uint8_t> manufacturer_data_{};
   esp_gatt_if_t gatts_if_{0};
   bool registered_{false};
+  bool advertising_required_{true};
+  bool advertising_requested_{false};
 
   uint16_t clients_[USE_ESP32_BLE_MAX_CONNECTIONS]{};
   uint8_t client_count_{0};

esphome/components/esp32_hosted/__init__.py

@@ -37,6 +37,25 @@ CONF_HANDSHAKE_PIN = "handshake_pin"
 CONF_SDIO_FREQUENCY = "sdio_frequency"
 CONF_SPI_MODE = "spi_mode"
 
+# ESP-NOW-over-hosted shim (esp_now_hosted.cpp). esp-hosted proxies esp_wifi.h
+# but not esp_now.h (espressif/esp-hosted-mcu#19), and esp_wifi_remote injects
+# the esp_now.h header on the ESP32-P4 host with no implementation, leaving the
+# esp_now_* symbols undefined at link. On a P4 host, esp_now_hosted.cpp DEFINES
+# those symbols and forwards each call to the co-processor over esp-hosted's
+# CustomRpc "peer data transfer" channel, so ESPHome's `espnow` component links
+# and runs unchanged (proven on a Tab5, 2026-07-20). The .cpp is guarded to
+# CONFIG_IDF_TARGET_ESP32P4 so it compiles to nothing on hosts with a native
+# ESP-NOW stack. CustomRpc needs these two host-side Kconfig options. Host
+# registers 3 handlers (RESP, RECV, SEND); the coprocessor registers 1 (REQ);
+# we ask for 8 to leave room for other CustomRpc extensions alongside.
+#
+# The coprocessor must run the matching custom firmware (a parallel effort in
+# esphome/esp-hosted-firmware). esp_now_hosted_rpc.h here is the canonical copy
+# of the wire contract and MUST stay byte-identical to the copy that coprocessor
+# firmware uses — the packed structs are the on-wire layout, so any divergence
+# silently corrupts every ESP-NOW frame.
+_MAX_CUSTOM_MSG_HANDLERS = 8
+
 # Shared fields for both transport modes
 BASE_SCHEMA = cv.Schema(
     {
@@ -262,6 +281,23 @@ async def to_code(config: ConfigType) -> None:
     else:
         _configure_spi(config)
 
+    # ESP-NOW-over-hosted shim: only the radio-less ESP32-P4 host needs it (see
+    # the note by _MAX_CUSTOM_MSG_HANDLERS). Enabled for every P4 host, not
+    # gated on the `espnow` component being present: the shim is tiny and the
+    # esp_now_* symbols/CustomRpc calls it defines require these Kconfig options
+    # to link whenever esp_now_hosted.cpp compiles (which is on any P4 host), so
+    # coupling the two keeps the build consistent. When `espnow` is absent the
+    # symbols are simply unused and never register a callback at runtime.
+    if esp32.get_esp32_variant() == esp32.VARIANT_ESP32P4:
+        add_define("USE_ESP_NOW_HOSTED")
+        # esp-hosted's CustomRpc ("peer data transfer") path — off by default.
+        esp32.add_idf_sdkconfig_option(
+            "CONFIG_ESP_HOSTED_ENABLE_PEER_DATA_TRANSFER", True
+        )
+        esp32.add_idf_sdkconfig_option(
+            "CONFIG_ESP_HOSTED_MAX_CUSTOM_MSG_HANDLERS", _MAX_CUSTOM_MSG_HANDLERS
+        )
+
     # Place the transport mempool in PSRAM. Required on memory-tight host
     # configurations (e.g. P4 with a large LVGL UI) where the internal-RAM
     # mempool allocation fails at boot with `sdio_mempool_create` assert.

esphome/components/esp32_hosted/esp_now_hosted.cpp

@@ -0,0 +1,467 @@
+/*
+ * esp_now_hosted — host-side shim implementing <esp_now.h> over esp-hosted
+ * CustomRpc, so ESPHome's `espnow` component can run on a radio-less host
+ * (e.g. the ESP32-P4) whose radio lives on an esp-hosted co-processor.
+ *
+ * A radio-less host has no native ESP-NOW. esp_wifi_remote INJECTS the full
+ * esp_now.h header (types + declarations) but ships NO implementation, so every
+ * esp_now_* symbol is an undefined reference at link time. This translation
+ * unit provides those definitions; each forwards to the co-processor over
+ * CustomRpc (see esphome/esp-hosted-firmware for the matching coprocessor
+ * handlers). No esp-hosted or esp_wifi_remote source is patched, and there is no
+ * duplicate-symbol clash because nothing else defines these symbols here.
+ *
+ * See esp_now_hosted_rpc.h for the wire protocol.
+ */
+
+#include "sdkconfig.h"
+
+// Only build the shim on the radio-less host. On chips with a native ESP-NOW
+// stack (S3, C6, …) the real symbols exist and this file must stay empty to
+// avoid duplicate definitions.
+#if defined(CONFIG_IDF_TARGET_ESP32P4)
+
+#include <cstring>
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/semphr.h"
+
+#include "esp_idf_version.h"
+#include "esp_log.h"
+#include "esp_timer.h"
+
+#include <esp_now.h>         // injected declarations we are now DEFINING
+#include <esp_wifi_types.h>  // wifi_pkt_rx_ctrl_t, wifi_tx_info_t
+
+// esp_hosted_misc.h (host) ships WITHOUT an extern "C" guard, so including it
+// from C++ would give its declarations C++ linkage and the real C symbols in
+// libesp_hosted would go unresolved at link. Wrap it. (Verified vs
+// esp_hosted 2.12.9.)
+extern "C" {
+#include "esp_hosted_misc.h"  // esp_hosted_{send_custom_data,register_custom_callback}
+}
+
+#include "esp_now_hosted_rpc.h"
+
+namespace {
+
+const char *const TAG = "esp_now_hosted";
+
+// One outstanding request at a time. ESPHome drives esp_now_* from the main
+// loop; the matching response and the async RECV/SEND events all arrive on the
+// single esp-hosted RPC RX thread. Serializing requests keeps the shared
+// response slot race-free; a sequence number stops a late/stale response from
+// being mistaken for ours.
+SemaphoreHandle_t g_req_mutex = nullptr;
+SemaphoreHandle_t g_resp_sem = nullptr;  // given when the matching RESP lands
+bool g_setup_done = false;               // set only after setup fully succeeds
+uint8_t g_seq = 0;
+volatile uint8_t g_expect_seq = 0;
+volatile int32_t g_resp_status = 0;
+uint8_t g_resp_ret[16];
+volatile uint16_t g_resp_ret_len = 0;
+
+// Written from the main loop (register/unregister/deinit), read from the
+// esp-hosted RX thread (on_recv/on_send). volatile for the same reason the
+// g_resp_* globals are: force the RX thread to observe an updated pointer
+// (e.g. a nulling by esp_now_deinit) rather than a cached one.
+volatile esp_now_recv_cb_t g_recv_cb = nullptr;
+volatile esp_now_send_cb_t g_send_cb = nullptr;
+
+// Local mirror of the co-processor's peer table. ESPHome's espnow component
+// calls esp_now_is_peer_exist() on the main loop for every received frame
+// (twice) and every send; forwarding each as a blocking RPC round-trip stalls
+// the loop. The shim is the only path that mutates the co-processor peer table
+// (add/del/deinit all go through here), so this mirror is authoritative and
+// esp_now_is_peer_exist() can answer from it with no round-trip.
+//
+// esp_now_* are public C symbols: any component or user lambda may call them,
+// and although ESPHome's espnow touches peers only from the main loop today
+// (its RX/TX callbacks merely enqueue), the shim cannot rely on that. A short
+// spinlock keeps the mirror consistent from any task/core, matching native
+// esp_now_*'s own internal thread-safety. The critical sections are a bounded
+// (<=20-entry) scan, so they stay tiny. ESP_NOW_MAX_TOTAL_PEER_NUM is 20.
+constexpr size_t ESP_NOW_HOSTED_MAX_PEERS = 20;
+uint8_t g_peer_cache[ESP_NOW_HOSTED_MAX_PEERS][6];
+size_t g_peer_count = 0;
+portMUX_TYPE g_peer_lock = portMUX_INITIALIZER_UNLOCKED;
+
+// Caller must hold g_peer_lock.
+int peer_cache_find_locked(const uint8_t *mac) {
+  for (size_t i = 0; i < g_peer_count; i++) {
+    if (memcmp(g_peer_cache[i], mac, 6) == 0)
+      return static_cast<int>(i);
+  }
+  return -1;
+}
+
+bool peer_cache_contains(const uint8_t *mac) {
+  portENTER_CRITICAL(&g_peer_lock);
+  const bool found = peer_cache_find_locked(mac) >= 0;
+  portEXIT_CRITICAL(&g_peer_lock);
+  return found;
+}
+
+void peer_cache_add(const uint8_t *mac) {
+  portENTER_CRITICAL(&g_peer_lock);
+  if (peer_cache_find_locked(mac) < 0 && g_peer_count < ESP_NOW_HOSTED_MAX_PEERS)
+    memcpy(g_peer_cache[g_peer_count++], mac, 6);
+  portEXIT_CRITICAL(&g_peer_lock);
+}
+
+void peer_cache_remove(const uint8_t *mac) {
+  portENTER_CRITICAL(&g_peer_lock);
+  const int idx = peer_cache_find_locked(mac);
+  if (idx >= 0) {
+    g_peer_count--;
+    if (static_cast<size_t>(idx) != g_peer_count)  // move the last entry into the gap
+      memcpy(g_peer_cache[idx], g_peer_cache[g_peer_count], 6);
+  }
+  portEXIT_CRITICAL(&g_peer_lock);
+}
+
+void peer_cache_clear() {
+  portENTER_CRITICAL(&g_peer_lock);
+  g_peer_count = 0;
+  portEXIT_CRITICAL(&g_peer_lock);
+}
+
+// ── CustomRpc event handlers (run on the esp-hosted RPC RX thread) ──────────
+// Keep them short and non-blocking. In particular they MUST NOT call back into
+// any esp_now_* shim function: that would try to take g_req_mutex / wait on the
+// RX thread that delivers the response, and deadlock.
+
+void on_resp(uint32_t /*msg_id*/, const uint8_t *data, size_t len, void * /*ctx*/) {
+  if (len < sizeof(esp_now_hosted_resp_t)) {
+    ESP_LOGW(TAG, "RESP too short: %u bytes", static_cast<unsigned>(len));
+    return;
+  }
+  const auto *r = reinterpret_cast<const esp_now_hosted_resp_t *>(data);
+  if (r->seq != g_expect_seq) {  // late response from a timed-out request (expected)
+    ESP_LOGV(TAG, "dropping stale RESP seq %u (want %u)", r->seq, g_expect_seq);
+    return;
+  }
+  g_resp_status = r->status;
+  uint16_t rl = r->ret_len;
+  if (rl > sizeof(g_resp_ret)) {
+    // Larger than any real opcode return — a likely wire-format drift signal.
+    ESP_LOGW(TAG, "RESP ret_len %u exceeds buffer, clamping (wire drift?)", rl);
+    rl = sizeof(g_resp_ret);
+  }
+  if (len >= sizeof(esp_now_hosted_resp_t) + rl) {
+    memcpy(g_resp_ret, r->ret, rl);
+  } else {
+    // Truncated frame: fail closed. Never hand the caller stale bytes left in
+    // g_resp_ret by a previous response, and don't let request() report a
+    // zeroed payload as success — override the status to an error.
+    ESP_LOGW(TAG, "RESP truncated: claims %u ret bytes, frame too short", rl);
+    rl = 0;
+    g_resp_status = ESP_ERR_INVALID_RESPONSE;
+  }
+  g_resp_ret_len = rl;
+  xSemaphoreGive(g_resp_sem);
+}
+
+void on_recv(uint32_t /*msg_id*/, const uint8_t *data, size_t len, void * /*ctx*/) {
+  // Read the volatile pointer once: esp_now_unregister_recv_cb()/deinit() (via
+  // the espnow component's disable()) can null it on the main loop between the
+  // guard and the call, which would otherwise turn the call into a null-deref.
+  const esp_now_recv_cb_t cb = g_recv_cb;
+  if (cb == nullptr)
+    return;
+  if (len < sizeof(esp_now_hosted_recv_evt_t)) {
+    ESP_LOGW(TAG, "RECV too short: %u bytes", static_cast<unsigned>(len));
+    return;
+  }
+  const auto *e = reinterpret_cast<const esp_now_hosted_recv_evt_t *>(data);
+  if (len < sizeof(esp_now_hosted_recv_evt_t) + e->data_len) {
+    ESP_LOGW(TAG, "RECV data_len %u exceeds frame", e->data_len);
+    return;
+  }
+
+  // ESPHome dereferences info->rx_ctrl->{rssi,timestamp}; give it a real one.
+  wifi_pkt_rx_ctrl_t rx_ctrl;
+  memset(&rx_ctrl, 0, sizeof(rx_ctrl));
+  rx_ctrl.rssi = e->rssi;
+  rx_ctrl.channel = e->channel;
+  rx_ctrl.timestamp = static_cast<uint32_t>(esp_timer_get_time());
+
+  esp_now_recv_info_t info;
+  info.src_addr = const_cast<uint8_t *>(e->src_addr);
+  info.des_addr = const_cast<uint8_t *>(e->des_addr);
+  info.rx_ctrl = &rx_ctrl;
+  cb(&info, e->data, static_cast<int>(e->data_len));
+}
+
+void on_send(uint32_t /*msg_id*/, const uint8_t *data, size_t len, void * /*ctx*/) {
+  // Read the volatile pointer once (see on_recv): disable()/deinit() can null it
+  // on the main loop concurrently with this RX-thread callback.
+  const esp_now_send_cb_t cb = g_send_cb;
+  if (cb == nullptr)
+    return;
+  if (len < sizeof(esp_now_hosted_send_evt_t)) {
+    ESP_LOGW(TAG, "SEND evt too short: %u bytes", static_cast<unsigned>(len));
+    return;
+  }
+  const auto *e = reinterpret_cast<const esp_now_hosted_send_evt_t *>(data);
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 5, 0)
+  // IDF >= 5.5: esp_now_send_cb_t takes esp_now_send_info_t (== wifi_tx_info_t),
+  // whose des_addr is a POINTER (not an inline array). Point it at the event's
+  // MAC (valid for this callback) — do NOT memcpy into it (that writes NULL and
+  // faults). ESPHome reads only info->des_addr.
+  esp_now_send_info_t si;
+  memset(&si, 0, sizeof(si));
+  si.des_addr = const_cast<uint8_t *>(e->des_addr);
+  cb(&si, static_cast<esp_now_send_status_t>(e->status));
+#else
+  cb(e->des_addr, static_cast<esp_now_send_status_t>(e->status));
+#endif
+}
+
+esp_err_t ensure_setup() {
+  // Gate on g_setup_done, not on g_req_mutex: a failure part-way through (a
+  // semaphore that did not allocate, a callback that did not register) must not
+  // leave a later call thinking setup completed. Semaphore creation is guarded
+  // so a retry after a partial failure does not leak the earlier handles.
+  if (g_setup_done)
+    return ESP_OK;
+  if (g_req_mutex == nullptr)
+    g_req_mutex = xSemaphoreCreateMutex();
+  if (g_resp_sem == nullptr)
+    g_resp_sem = xSemaphoreCreateBinary();
+  if (g_req_mutex == nullptr || g_resp_sem == nullptr)
+    return ESP_ERR_NO_MEM;
+  esp_err_t err;
+  if ((err = esp_hosted_register_custom_callback(ESP_NOW_HOSTED_MSG_RESP, on_resp, nullptr)) != ESP_OK)
+    return err;
+  if ((err = esp_hosted_register_custom_callback(ESP_NOW_HOSTED_MSG_RECV, on_recv, nullptr)) != ESP_OK)
+    return err;
+  if ((err = esp_hosted_register_custom_callback(ESP_NOW_HOSTED_MSG_SEND, on_send, nullptr)) != ESP_OK)
+    return err;
+  g_setup_done = true;
+  return ESP_OK;
+}
+
+// Send one request envelope. With wait=true (default) block until the matching
+// response (or timeout); with wait=false return as soon as the frame is handed
+// to the transport (fire-and-forget, used by esp_now_send).
+//
+// `tail` is an optional second chunk written straight after `payload`. Callers
+// with a fixed header plus a bulk body (esp_now_send) pass the two separately
+// so they never need a build buffer of their own: both chunks are laid into the
+// request buffer here, under g_req_mutex, which keeps concurrent callers from
+// racing and saves a full copy of the body on every transmit.
+esp_err_t request(uint8_t opcode, const void *payload, uint16_t plen, void *ret, uint16_t ret_cap, uint16_t *ret_len,
+                  bool wait = true, const void *tail = nullptr, uint16_t tail_len = 0) {
+  esp_err_t err = ensure_setup();
+  if (err != ESP_OK)
+    return err;
+  if (plen > ESP_NOW_HOSTED_MAX_PAYLOAD || tail_len > ESP_NOW_HOSTED_MAX_PAYLOAD - plen)
+    return ESP_ERR_INVALID_SIZE;
+  const uint16_t total_len = static_cast<uint16_t>(plen + tail_len);
+
+  if (xSemaphoreTake(g_req_mutex, portMAX_DELAY) != pdTRUE)
+    return ESP_FAIL;
+
+  static uint8_t buf[sizeof(esp_now_hosted_req_t) + ESP_NOW_HOSTED_MAX_PAYLOAD];  // guarded by g_req_mutex
+  auto *req = reinterpret_cast<esp_now_hosted_req_t *>(buf);
+  req->opcode = opcode;
+  req->seq = ++g_seq;
+  req->payload_len = total_len;
+  if (plen != 0)
+    memcpy(req->payload, payload, plen);
+  if (tail_len != 0)
+    memcpy(req->payload + plen, tail, tail_len);
+  g_expect_seq = req->seq;
+
+  xSemaphoreTake(g_resp_sem, 0);  // drain any stale signal before sending
+  err = esp_hosted_send_custom_data(ESP_NOW_HOSTED_MSG_REQ, buf, sizeof(esp_now_hosted_req_t) + total_len);
+  if (err != ESP_OK) {
+    xSemaphoreGive(g_req_mutex);
+    return err;
+  }
+  if (!wait) {
+    // Fire-and-forget (esp_now_send): the co-processor enqueues the frame and
+    // reports the real TX result later via the async SEND event, exactly like
+    // native esp_now_send. Returning here keeps the main loop off the ~100 ms+
+    // RPC round-trip. The matching RESP is ignored (seq won't match the next
+    // waited request, so on_resp drops it).
+    xSemaphoreGive(g_req_mutex);
+    return ESP_OK;
+  }
+  if (xSemaphoreTake(g_resp_sem, pdMS_TO_TICKS(ESP_NOW_HOSTED_TIMEOUT_MS)) != pdTRUE) {
+    ESP_LOGW(TAG, "opcode %u timed out", opcode);
+    xSemaphoreGive(g_req_mutex);
+    return ESP_ERR_TIMEOUT;
+  }
+
+  const int32_t status = g_resp_status;
+  if (ret != nullptr && ret_cap != 0) {
+    uint16_t n = g_resp_ret_len < ret_cap ? g_resp_ret_len : ret_cap;
+    memcpy(ret, const_cast<const uint8_t *>(g_resp_ret), n);
+    if (ret_len != nullptr)
+      *ret_len = n;
+  }
+  xSemaphoreGive(g_req_mutex);
+  return static_cast<esp_err_t>(status);
+}
+
+}  // namespace
+
+// ── The <esp_now.h> surface, defined for the radio-less host ────────────────
+extern "C" {
+
+esp_err_t esp_now_init(void) { return request(ESP_NOW_HOSTED_OP_INIT, nullptr, 0, nullptr, 0, nullptr); }
+
+esp_err_t esp_now_deinit(void) {
+  g_recv_cb = nullptr;
+  g_send_cb = nullptr;
+  peer_cache_clear();  // the co-processor drops all peers on deinit
+  return request(ESP_NOW_HOSTED_OP_DEINIT, nullptr, 0, nullptr, 0, nullptr);
+}
+
+esp_err_t esp_now_get_version(uint32_t *version) {
+  uint32_t v = 0;
+  uint16_t rl = 0;
+  esp_err_t err = request(ESP_NOW_HOSTED_OP_GET_VERSION, nullptr, 0, &v, sizeof(v), &rl);
+  if (version != nullptr)
+    *version = v;
+  return err;
+}
+
+esp_err_t esp_now_register_recv_cb(esp_now_recv_cb_t cb) {
+  // Only arm the callback once the CustomRpc handlers are actually registered,
+  // so a failed setup leaves g_recv_cb null rather than falsely "registered".
+  esp_err_t err = ensure_setup();
+  if (err != ESP_OK)
+    return err;
+  g_recv_cb = cb;
+  return ESP_OK;
+}
+esp_err_t esp_now_unregister_recv_cb(void) {
+  g_recv_cb = nullptr;
+  return ESP_OK;
+}
+esp_err_t esp_now_register_send_cb(esp_now_send_cb_t cb) {
+  esp_err_t err = ensure_setup();
+  if (err != ESP_OK)
+    return err;
+  g_send_cb = cb;
+  return ESP_OK;
+}
+esp_err_t esp_now_unregister_send_cb(void) {
+  g_send_cb = nullptr;
+  return ESP_OK;
+}
+
+static esp_err_t add_or_mod_peer(uint8_t opcode, const esp_now_peer_info_t *peer, bool wait) {
+  if (peer == nullptr)
+    return ESP_ERR_ESPNOW_ARG;
+  esp_now_hosted_peer_t p;
+  memset(&p, 0, sizeof(p));
+  memcpy(p.peer_addr, peer->peer_addr, 6);
+  memcpy(p.lmk, peer->lmk, 16);
+  p.channel = peer->channel;
+  p.ifidx = static_cast<uint8_t>(peer->ifidx);
+  p.encrypt = peer->encrypt ? 1 : 0;
+  return request(opcode, &p, sizeof(p), nullptr, 0, nullptr, wait);
+}
+esp_err_t esp_now_add_peer(const esp_now_peer_info_t *peer) {
+  // Fire-and-forget (wait=false): adding a peer is a blocking RPC round-trip,
+  // and ESPHome's espnow calls it on the main loop when a device joins the mesh
+  // — under co-processor load that stalls the UI (peer-churn stutter). Issue it
+  // without waiting and mirror it locally. Safe against a following
+  // esp_now_send to the same peer: both ride the same in-order CustomRpc
+  // channel (mutex-serialized on the host) and the co-processor processes REQs
+  // FIFO, so ADD_PEER is applied before the SEND. Trade-off: a co-processor-side
+  // failure (e.g. peer table full) is no longer reported synchronously — the
+  // same limitation as esp_now_send — but ESPHome only adds peers it validated.
+  esp_err_t err = add_or_mod_peer(ESP_NOW_HOSTED_OP_ADD_PEER, peer, /*wait=*/false);
+  if (err == ESP_OK)
+    peer_cache_add(peer->peer_addr);  // keep the local mirror in sync
+  return err;
+}
+esp_err_t esp_now_mod_peer(const esp_now_peer_info_t *peer) {
+  // mod_peer changes a peer's parameters, not its existence, so the cache is
+  // unaffected. Kept synchronous — it is not on any hot path (espnow never
+  // calls it), so the extra round-trip does not matter and the status is useful.
+  return add_or_mod_peer(ESP_NOW_HOSTED_OP_MOD_PEER, peer, /*wait=*/true);
+}
+
+esp_err_t esp_now_del_peer(const uint8_t *peer_addr) {
+  if (peer_addr == nullptr)
+    return ESP_ERR_ESPNOW_ARG;
+  // Fire-and-forget for the same reason as add_peer (peer churn on the main
+  // loop). Removal is order-independent, so this is strictly safe.
+  esp_err_t err = request(ESP_NOW_HOSTED_OP_DEL_PEER, peer_addr, 6, nullptr, 0, nullptr, /*wait=*/false);
+  if (err == ESP_OK)
+    peer_cache_remove(peer_addr);  // keep the local mirror in sync
+  return err;
+}
+
+bool esp_now_is_peer_exist(const uint8_t *peer_addr) {
+  if (peer_addr == nullptr)
+    return false;
+  // Answered from the local mirror — no RPC round-trip. ESPHome's espnow calls
+  // this on the main loop for every received frame and every send, so a
+  // blocking round-trip here would stall rendering under mesh traffic.
+  return peer_cache_contains(peer_addr);
+}
+
+esp_err_t esp_now_send(const uint8_t *peer_addr, const uint8_t *data, size_t len) {
+  if (len > ESP_NOW_HOSTED_MAX_FRAME)
+    return ESP_ERR_ESPNOW_ARG;
+  if (data == nullptr && len != 0)  // native esp_now_send treats this as an arg error
+    return ESP_ERR_ESPNOW_ARG;
+  // Only the small fixed header is built here; the caller's frame goes over as
+  // the request tail, so request() lays both into its own buffer under
+  // g_req_mutex. esp_now_send is a public C symbol and may be called from any
+  // task, and a shared build buffer here would let two callers corrupt each
+  // other's frame. Passing the body through also drops a full-frame copy per
+  // transmit, on the path this shim exists to keep quick.
+  uint8_t hdr[sizeof(esp_now_hosted_send_req_t)];
+  auto *s = reinterpret_cast<esp_now_hosted_send_req_t *>(hdr);
+  s->has_addr = peer_addr != nullptr ? 1 : 0;
+  if (peer_addr != nullptr)
+    memcpy(s->peer_addr, peer_addr, 6);
+  else
+    memset(s->peer_addr, 0, 6);
+  s->data_len = static_cast<uint16_t>(len);
+  // Fire-and-forget (wait=false): native esp_now_send returns once the frame is
+  // queued, with the real TX result delivered later through the send callback.
+  // The co-processor mirrors that — it acks enqueue immediately and reports the
+  // outcome via the async SEND event (on_send -> on_send_report). Waiting for
+  // the RPC RESP here would block the main loop for the full round-trip on
+  // every transmit.
+  return request(ESP_NOW_HOSTED_OP_SEND, hdr, sizeof(hdr), nullptr, 0, nullptr, /*wait=*/false, data,
+                 static_cast<uint16_t>(len));
+}
+
+esp_err_t esp_now_set_pmk(const uint8_t *pmk) {
+  if (pmk == nullptr)
+    return ESP_ERR_ESPNOW_ARG;
+  return request(ESP_NOW_HOSTED_OP_SET_PMK, pmk, 16, nullptr, 0, nullptr);
+}
+
+// Remainder of the <esp_now.h> surface. Not used by ESPHome's espnow component
+// today; provided so the whole header links and future callers get a defined
+// (if unimplemented) symbol rather than a link error. Wire them through
+// CustomRpc if a use case appears.
+esp_err_t esp_now_get_peer(const uint8_t * /*peer_addr*/, esp_now_peer_info_t * /*peer*/) {
+  return ESP_ERR_NOT_SUPPORTED;
+}
+esp_err_t esp_now_fetch_peer(bool /*from_head*/, esp_now_peer_info_t * /*peer*/) { return ESP_ERR_NOT_SUPPORTED; }
+esp_err_t esp_now_get_peer_num(esp_now_peer_num_t * /*num*/) { return ESP_ERR_NOT_SUPPORTED; }
+esp_err_t esp_now_set_wake_window(uint16_t /*window*/) {
+  return ESP_ERR_NOT_SUPPORTED;  // power-save wake window is not forwarded; don't claim success
+}
+esp_err_t esp_now_set_peer_rate_config(const uint8_t * /*peer_addr*/, esp_now_rate_config_t * /*cfg*/) {
+  return ESP_ERR_NOT_SUPPORTED;
+}
+esp_err_t esp_wifi_config_espnow_rate(wifi_interface_t /*ifx*/, wifi_phy_rate_t /*rate*/) {
+  return ESP_ERR_NOT_SUPPORTED;
+}
+
+}  // extern "C"
+
+#endif  // CONFIG_IDF_TARGET_ESP32P4

esphome/components/esp32_hosted/esp_now_hosted_rpc.h

@@ -0,0 +1,128 @@
+/*
+ * esp_now_hosted — ESP-NOW-over-CustomRpc wire protocol.
+ *
+ * Shared, byte-for-byte-identical contract between:
+ *   - the host shim         (esphome/components/esp32_hosted/esp_now_hosted.cpp)
+ *   - the coprocessor firmware (esphome/esp-hosted-firmware)
+ *
+ * It rides esp-hosted's CustomRpc channel (RPC ID 388, "peer data transfer",
+ * available since esp-hosted v2.8.1), teaching the radio-less host <-> radio
+ * co-processor link to carry esp_now.h, which esp-hosted itself does not proxy
+ * (Espressif issue espressif/esp-hosted-mcu#19).
+ *
+ * KEEP THE TWO COPIES IN SYNC. The canonical copy lives here; the coprocessor
+ * firmware uses a verbatim copy. Both sides are little-endian, so these packed
+ * structs are wire-compatible with no byte-swapping.
+ */
+
+#ifndef ESP_NOW_HOSTED_RPC_H
+#define ESP_NOW_HOSTED_RPC_H
+
+#ifdef __cplusplus
+#include <cstdint>
+#else
+#include <stdint.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ── CustomRpc message IDs (any uint32_t except 0xFFFFFFFF) ──────────────────
+ * One REQ handler slot on the device; three event handler slots on the host.
+ * The bytes spell "now" + index, a private range unlikely to clash with other
+ * CustomRpc users (e.g. the stock peer_data_transfer example's 1..6).         */
+#define ESP_NOW_HOSTED_MSG_REQ 0x6E6F7701u  /* host   -> device : request envelope */
+#define ESP_NOW_HOSTED_MSG_RESP 0x6E6F7702u /* device -> host   : reply to a REQ   */
+#define ESP_NOW_HOSTED_MSG_RECV 0x6E6F7703u /* device -> host   : async RX frame   */
+#define ESP_NOW_HOSTED_MSG_SEND 0x6E6F7704u /* device -> host   : async TX status  */
+
+/* ── Request opcodes ────────────────────────────────────────────────────── */
+enum {
+  ESP_NOW_HOSTED_OP_INIT = 1,          /* esp_now_init + register device recv/send cbs */
+  ESP_NOW_HOSTED_OP_DEINIT = 2,        /* unregister cbs + esp_now_deinit             */
+  ESP_NOW_HOSTED_OP_ADD_PEER = 3,      /* payload: esp_now_hosted_peer_t              */
+  ESP_NOW_HOSTED_OP_DEL_PEER = 4,      /* payload: 6-byte peer MAC                    */
+  ESP_NOW_HOSTED_OP_IS_PEER_EXIST = 5, /* payload: 6-byte MAC; ret: 1 byte bool       */
+  ESP_NOW_HOSTED_OP_SEND = 6,          /* payload: esp_now_hosted_send_req_t          */
+  ESP_NOW_HOSTED_OP_GET_VERSION = 7,   /* ret: uint32 version                        */
+  ESP_NOW_HOSTED_OP_SET_PMK = 8,       /* payload: 16-byte PMK                        */
+  ESP_NOW_HOSTED_OP_MOD_PEER = 9,      /* payload: esp_now_hosted_peer_t              */
+};
+
+/* Largest ESP-NOW payload we forward. ESP-NOW v2 (IDF >= 5.4) is 1470 B; well
+ * under esp-hosted's 8166 B CustomRpc cap, so the shim never truncates.        */
+#define ESP_NOW_HOSTED_MAX_FRAME 1470u
+/* Envelope slack for the largest opcode payload (a SEND req wrapping a frame). */
+#define ESP_NOW_HOSTED_MAX_PAYLOAD (ESP_NOW_HOSTED_MAX_FRAME + 16u)
+/* Host request/response round-trip timeout over the transport. Generous:
+ * normal RTT is sub-millisecond, but Wi-Fi/BLE contention on the co-processor
+ * can stall the RX thread.                                                     */
+#define ESP_NOW_HOSTED_TIMEOUT_MS 2000
+
+/* ── Envelopes ──────────────────────────────────────────────────────────── */
+
+/* These payloads are shared verbatim with the C co-processor firmware, so they
+ * use C's `typedef struct {...} name;` idiom rather than C++ `using` aliases,
+ * which would not compile there. Silence clang-tidy's modernize-use-using for
+ * the shared struct block. */
+// NOLINTBEGIN(modernize-use-using)
+typedef struct {
+  uint8_t opcode;       /* one of ESP_NOW_HOSTED_OP_*                        */
+  uint8_t seq;          /* wraps 0..255; echoed in the response for matching */
+  uint16_t payload_len; /* bytes of opcode-specific payload that follow      */
+  uint8_t payload[];    /* flexible                                          */
+} __attribute__((packed)) esp_now_hosted_req_t;
+
+typedef struct {
+  uint8_t opcode;   /* echoes the request opcode                         */
+  uint8_t seq;      /* echoes the request seq                            */
+  int32_t status;   /* esp_err_t from the native call on the co-processor */
+  uint16_t ret_len; /* bytes of return payload that follow               */
+  uint8_t ret[];    /* flexible (e.g. version u32, is_peer_exist bool)   */
+} __attribute__((packed)) esp_now_hosted_resp_t;
+
+/* ── Opcode payloads ────────────────────────────────────────────────────── */
+
+/* esp_now_peer_info_t minus the host-only `priv` pointer, which is meaningless
+ * across the transport and never set by ESPHome's espnow component.           */
+typedef struct {
+  uint8_t peer_addr[6];
+  uint8_t lmk[16];
+  uint8_t channel; /* 0 = current channel                              */
+  uint8_t ifidx;   /* wifi_interface_t (0=STA, 1=AP)                    */
+  uint8_t encrypt; /* bool                                             */
+} __attribute__((packed)) esp_now_hosted_peer_t;
+
+typedef struct {
+  uint8_t has_addr; /* 0 => peer_addr is NULL (broadcast to all peers)   */
+  uint8_t peer_addr[6];
+  uint16_t data_len;
+  uint8_t data[]; /* flexible, up to ESP_NOW_HOSTED_MAX_FRAME          */
+} __attribute__((packed)) esp_now_hosted_send_req_t;
+
+/* ── Async events (device -> host) ──────────────────────────────────────── */
+
+/* Reconstructed on the host into an esp_now_recv_info_t + a minimal
+ * wifi_pkt_rx_ctrl_t. ESPHome's espnow reads info->src_addr, info->des_addr,
+ * info->rx_ctrl->rssi and info->rx_ctrl->timestamp.                           */
+typedef struct {
+  uint8_t src_addr[6];
+  uint8_t des_addr[6];
+  int8_t rssi;
+  uint8_t channel;
+  uint16_t data_len;
+  uint8_t data[]; /* flexible                                          */
+} __attribute__((packed)) esp_now_hosted_recv_evt_t;
+
+typedef struct {
+  uint8_t des_addr[6];
+  uint8_t status; /* esp_now_send_status_t (0 = success)               */
+} __attribute__((packed)) esp_now_hosted_send_evt_t;
+// NOLINTEND(modernize-use-using)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ESP_NOW_HOSTED_RPC_H */

esphome/components/esp32_improv/esp32_improv_component.cpp

@@ -112,6 +112,7 @@ void ESP32ImprovComponent::loop() {
       this->state_callback_.call(this->state_, this->error_state_);
 #endif
     }
+    this->release_advertising_();
     this->incoming_data_.clear();
     return;
   }
@@ -143,8 +144,9 @@ void ESP32ImprovComponent::loop() {
           ESP_LOGV(TAG, "Starting with device name advertising");
           this->advertising_device_name_ = true;
           this->last_name_adv_time_ = App.get_loop_component_start_time();
+          // Set the payload before requesting, so advertising starts exactly once
           esp32_ble::global_ble->advertising_set_service_data_and_name(std::span<const uint8_t>{}, true);
-          esp32_ble::global_ble->advertising_start();
+          this->request_advertising_();
 
           // Set initial state based on whether we have an authorizer
           this->set_state_(this->get_initial_state_(), false);
@@ -326,6 +328,8 @@ void ESP32ImprovComponent::stop() {
   this->set_timeout("end-service", STOP_ADVERTISING_DELAY, [this] {
     if (this->state_ == improv::STATE_STOPPED || this->service_ == nullptr)
       return;
+    // Release first so removing the service UUID does not restart advertising on the way out
+    this->release_advertising_();
     this->service_->stop();
     this->set_state_(improv::STATE_STOPPED);
   });
@@ -520,6 +524,20 @@ void ESP32ImprovComponent::update_advertising_type_() {
   }
 }
 
+void ESP32ImprovComponent::request_advertising_() {
+  if (this->advertising_requested_)
+    return;
+  this->advertising_requested_ = true;
+  esp32_ble::global_ble->advertising_start();
+}
+
+void ESP32ImprovComponent::release_advertising_() {
+  if (!this->advertising_requested_)
+    return;
+  this->advertising_requested_ = false;
+  esp32_ble::global_ble->advertising_stop();
+}
+
 improv::State ESP32ImprovComponent::get_initial_state_() const {
 #ifdef USE_BINARY_SENSOR
   // If we have an authorizer, start in awaiting authorization state

esphome/components/esp32_improv/esp32_improv_component.h

@@ -104,8 +104,11 @@ class ESP32ImprovComponent final : public Component, public improv_base::ImprovB
   bool status_indicator_state_{false};
   uint32_t last_name_adv_time_{0};
   bool advertising_device_name_{false};
+  bool advertising_requested_{false};
   void set_status_indicator_state_(bool state);
   void update_advertising_type_();
+  void request_advertising_();
+  void release_advertising_();
 
   void set_state_(improv::State state, bool update_advertising = true);
   void set_error_(improv::Error error);

esphome/components/esphome/ota/__init__.py

@@ -2,12 +2,12 @@ import logging
 
 import esphome.codegen as cg
 from esphome.components.noise import (
-    decode_encryption_key,
     encryption_schema,
-    is_reserved_key,
+    new_psk_progmem,
+    static_encryption_key,
 )
 from esphome.components.ota import BASE_OTA_SCHEMA, OTAComponent, ota_to_code
-from esphome.config_helpers import merge_config
+from esphome.config_helpers import filter_source_files_from_defines, merge_config
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_API,
@@ -31,7 +31,6 @@ import esphome.final_validate as fv
 from esphome.types import ConfigType
 
 CONF_ALLOW_PARTITION_ACCESS = "allow_partition_access"
-CONF_CAPTIVE_PORTAL = "captive_portal"
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -41,11 +40,10 @@ DEPENDENCIES = ["network"]
 
 
 def AUTO_LOAD(config: ConfigType) -> list[str]:
-    """Auto-load noise only when encryption is configured."""
+    """Auto-load noise only when encryption is configured; the api key offer
+    inherits it from the api component."""
     base = ["sha256", "socket"]
-    # A falsy config is a tooling probe for the maximal set (None from
-    # dependency resolution, {} from the components-graph platform probe);
-    # a validated config always carries defaults, never empty
+    # A falsy config is a tooling probe for the maximal set
     if not config or CONF_ENCRYPTION in config:
         return base + ["noise"]
     return base
@@ -132,12 +130,56 @@ def ota_esphome_final_validate(config: ConfigType) -> None:
         _validate_no_password_with_encryption(ota_conf)
         if (encryption_conf := ota_conf.get(CONF_ENCRYPTION)) is not None:
             _resolve_encryption_key(encryption_conf, api_conf)
-    if any(
-        conf.get(CONF_PLATFORM) == CONF_WEB_SERVER for conf in full_ota_conf
-    ) and any(
-        CONF_ENCRYPTION in conf for conf in merged_ota_esphome_configs_by_port.values()
+        elif CONF_PASSWORD in ota_conf and static_encryption_key(api_conf) is not None:
+            _LOGGER.warning(
+                "'%s' %s wastes significant flash and RAM (about 3.5 KB and 60 "
+                "bytes plus the password on the heap): the device already offers "
+                "encryption with the '%s' %s %s, which authenticates any uploader "
+                "that takes it, and a password only matters for uploaders without "
+                "encryption support; remove '%s' and add '%s' under '%s' so "
+                "uploads use the key and encryption is required",
+                CONF_OTA,
+                CONF_PASSWORD,
+                CONF_API,
+                CONF_ENCRYPTION,
+                CONF_KEY,
+                CONF_PASSWORD,
+                CONF_ENCRYPTION,
+                CONF_OTA,
+            )
+        elif (
+            CONF_PASSWORD in ota_conf
+            and CONF_ENCRYPTION in api_conf
+            and not api_conf[CONF_ENCRYPTION].get(CONF_KEY)
+        ):
+            # The CLI still needs the password; whoever provisions the key skips it
+            _LOGGER.warning(
+                "The '%s' %s %s provisioned at runtime also authenticates OTA "
+                "uploads once provisioned; '%s' %s then only guards plaintext "
+                "uploads. Whoever provisions the key can upload firmware "
+                "without the password, so add a 'provisioning:' block to limit "
+                "when that is possible",
+                CONF_API,
+                CONF_ENCRYPTION,
+                CONF_KEY,
+                CONF_OTA,
+                CONF_PASSWORD,
+            )
+    # web_server and prometheus keep the shared listener up; the captive
+    # portal's copy only exists on the fallback AP and is the recovery path
+    if (
+        (CONF_WEB_SERVER in full_conf or "prometheus" in full_conf)
+        and any(conf.get(CONF_PLATFORM) == CONF_WEB_SERVER for conf in full_ota_conf)
+        and any(
+            CONF_ENCRYPTION in conf
+            for conf in merged_ota_esphome_configs_by_port.values()
+        )
     ):
-        _warn_web_server_ota(full_conf)
+        _LOGGER.warning(
+            "OTA encryption does not cover the %s OTA platform; its "
+            "plaintext /update endpoint accepts the same image",
+            CONF_WEB_SERVER,
+        )
 
     full_conf[CONF_OTA] = new_ota_conf
     fv.full_config.set(full_conf)
@@ -152,33 +194,11 @@ def ota_esphome_final_validate(config: ConfigType) -> None:
         )
 
 
-def _warn_web_server_ota(full_conf: ConfigType) -> None:
-    """The web_server ota platform accepts the same image over plaintext HTTP
-    with basic auth, bypassing the encryption; warn rather than fail so the
-    operator keeps the recovery path."""
-    if CONF_CAPTIVE_PORTAL in full_conf and CONF_WEB_SERVER not in full_conf:
-        # The captive_portal auto-load: the endpoint only exists while the
-        # fallback AP is active
-        _LOGGER.warning(
-            "OTA encryption does not cover the %s OTA platform (auto-loaded "
-            "by captive_portal); the plaintext /update endpoint stays "
-            "reachable while the fallback AP is active",
-            CONF_WEB_SERVER,
-        )
-    else:
-        _LOGGER.warning(
-            "OTA encryption does not cover the %s OTA platform; its "
-            "plaintext /update endpoint accepts the same image",
-            CONF_WEB_SERVER,
-        )
-
-
 def _resolve_encryption_key(encryption_conf: ConfigType, api_conf: ConfigType) -> None:
     """Resolve the one encryption key per device into the ota block.
 
     An explicit ota key must match the api key, a bare block inherits it,
-    a runtime provisioned api key cannot be inherited, and the all-zeros
-    provisioning sentinel is rejected (the device treats it as no key).
+    a runtime provisioned api key cannot be inherited.
     """
     api_key = api_conf.get(CONF_ENCRYPTION, {}).get(CONF_KEY)
     if ota_key := encryption_conf.get(CONF_KEY):
@@ -201,11 +221,6 @@ def _resolve_encryption_key(encryption_conf: ConfigType, api_conf: ConfigType) -
         )
     else:
         encryption_conf[CONF_KEY] = api_key
-    if is_reserved_key(encryption_conf[CONF_KEY]):
-        raise cv.Invalid(
-            f"The all-zeros {CONF_KEY} is reserved and provides no protection; "
-            f"generate a real key with: openssl rand -base64 32"
-        )
 
 
 # Also called on merged same-port configs in final validate, where schemas
@@ -267,15 +282,17 @@ CONFIG_SCHEMA = cv.All(
 FINAL_VALIDATE_SCHEMA = ota_esphome_final_validate
 
 
-def FILTER_SOURCE_FILES() -> list[str]:
-    """Filter out the noise transport when no ota entry configures encryption."""
-    for ota_conf in CORE.config.get(CONF_OTA, []):
-        if (
-            ota_conf.get(CONF_PLATFORM) == CONF_ESPHOME
-            and ota_conf.get(CONF_ENCRYPTION) is not None
-        ):
-            return []
-    return ["ota_esphome_noise.cpp"]
+FILTER_SOURCE_FILES = filter_source_files_from_defines(
+    {
+        "ota_esphome_noise.cpp": "USE_OTA_ENCRYPTION",
+        "ota_esphome_inflate.c": "USE_OTA_DEFLATE",
+    }
+)
+
+
+def enable_deflate() -> None:
+    """Compile the on-the-fly inflater for compressed uploads."""
+    cg.add_define("USE_OTA_DEFLATE")
 
 
 @coroutine_with_priority(CoroPriority.OTA_UPDATES)
@@ -296,11 +313,28 @@ async def to_code(config: ConfigType) -> None:
     if config.get(CONF_ALLOW_PARTITION_ACCESS):
         cg.add_define("USE_OTA_PARTITIONS")
 
-    if (encryption_conf := config.get(CONF_ENCRYPTION)) is not None:
-        # A missing key was resolved from the api component in final validate.
-        key = encryption_conf[CONF_KEY]
+    # ESP8266 and RP2040 inflate gzip at reboot; the rest inflate on the fly
+    if not (CORE.is_esp8266 or CORE.is_rp2):
+        enable_deflate()
+
+    # One key per device: an api encryption block supplies it (static or
+    # runtime) and offers; the ota block only adds the requirement
+    api_conf = CORE.config.get(CONF_API) or {}
+    encryption_conf = config.get(CONF_ENCRYPTION)
+    own_key = None
+    if encryption_conf is not None and static_encryption_key(api_conf) is None:
+        own_key = encryption_conf[CONF_KEY]
+    if own_key is not None:
         cg.add_define("USE_OTA_ENCRYPTION")
-        cg.add(var.set_noise_psk(list(decode_encryption_key(key))))
+        cg.add(var.set_noise_psk(new_psk_progmem(config[CONF_ID], own_key)))
+    elif CONF_ENCRYPTION in api_conf:
+        cg.add_define("USE_OTA_ENCRYPTION")
+        cg.add_define("USE_OTA_ENCRYPTION_FROM_API")
+        if static_encryption_key(api_conf) is None:
+            # The key arrives at runtime, so the offer has to look for it
+            cg.add_define("USE_OTA_ENCRYPTION_PROVISIONED")
+    if encryption_conf is not None:
+        cg.add_define("USE_OTA_ENCRYPTION_REQUIRED")
 
     # Build flag so lwip_fast_select.c (a .c file that can't include defines.h) sees it.
     cg.add_build_flag("-DUSE_OTA_PLATFORM_ESPHOME")

esphome/components/esphome/ota/ota_esphome.cpp

@@ -1,4 +1,7 @@
 #include "ota_esphome.h"
+#ifdef USE_OTA_ENCRYPTION_FROM_API
+#include "esphome/components/api/api_server.h"
+#endif
 #ifdef USE_OTA
 #ifdef USE_OTA_PASSWORD
 #include "esphome/components/sha256/sha256.h"
@@ -21,14 +24,27 @@
 
 #include <cerrno>
 #include <cstdio>
+#include <new>
 #include <sys/time.h>
 
 namespace esphome {
 
 static const char *const TAG = "esphome.ota";
+
+#ifdef USE_OTA_ENCRYPTION
+const noise::NoiseContext &ESPHomeOTAComponent::noise_context_() const {
+#ifdef USE_OTA_ENCRYPTION_FROM_API
+  return api::global_api_server->get_noise_ctx();
+#else
+  return this->noise_ctx_;
+#endif
+}
+#endif
 static constexpr uint16_t OTA_BLOCK_SIZE = 8192;
 static constexpr uint32_t OTA_SOCKET_TIMEOUT_HANDSHAKE = 20000;  // milliseconds for initial handshake
 static constexpr uint32_t OTA_SOCKET_TIMEOUT_DATA = 90000;       // milliseconds for data transfer
+static constexpr uint32_t OTA_PROGRESS_INTERVAL_MS = 1000;
+static constexpr size_t OTA_SIZE_FIELD_BYTES = 4;  // sizes on the wire are 4 bytes MSB first
 
 // Single-instance pointer — multi-port configs are rejected in final_validate.
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
@@ -97,18 +113,30 @@ void ESPHomeOTAComponent::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "Over-The-Air updates:\n"
                 "  Address: %s:%u\n"
-                "  Version: %d",
-                network::get_use_address_to(addr_buf), this->port_, USE_OTA_VERSION);
+                "  Version: %d"
+#ifdef USE_OTA_ENCRYPTION
+                "\n  Encryption: %s"
+#endif
+                ,
+                network::get_use_address_to(addr_buf), this->port_, USE_OTA_VERSION
+#ifdef USE_OTA_ENCRYPTION_REQUIRED
+                ,
+                LOG_STR_LITERAL("required")
+#elif defined(USE_OTA_ENCRYPTION_PROVISIONED)
+                // A runtime provisioned key may not exist yet
+                ,
+                this->noise_context_().has_psk() ? LOG_STR_LITERAL("offered, plaintext accepted")
+                                                 : LOG_STR_LITERAL("offered once the api key is provisioned")
+#elif defined(USE_OTA_ENCRYPTION)
+                ,
+                LOG_STR_LITERAL("offered, plaintext accepted")
+#endif
+  );
 #ifdef USE_OTA_PASSWORD
   if (!this->password_.empty()) {
     ESP_LOGCONFIG(TAG, "  Password configured");
   }
 #endif
-#ifdef USE_OTA_ENCRYPTION
-  if (this->noise_ctx_.has_psk()) {
-    ESP_LOGCONFIG(TAG, "  Encryption configured");
-  }
-#endif
 #ifdef USE_OTA_PARTITIONS
   ESP_LOGCONFIG(TAG,
                 "  Partition access allowed\n"
@@ -154,9 +182,25 @@ static constexpr uint8_t CLIENT_FEATURE_SUPPORTS_COMPRESSION = 0x01;
 static constexpr uint8_t CLIENT_FEATURE_SUPPORTS_SHA256_AUTH = 0x02;
 static constexpr uint8_t CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL = 0x04;
 static constexpr uint8_t CLIENT_FEATURE_SUPPORTS_NOISE = 0x08;
+static constexpr uint8_t CLIENT_FEATURE_SUPPORTS_DEFLATE = 0x10;
+// Noise needs the extended protocol: the prologue binds the 2-byte feature ack
+static constexpr uint8_t CLIENT_NOISE_FEATURES =
+    CLIENT_FEATURE_SUPPORTS_NOISE | CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL;
 static constexpr uint8_t SERVER_FEATURE_SUPPORTS_COMPRESSION = 0x01;
 static constexpr uint8_t SERVER_FEATURE_SUPPORTS_PARTITION_ACCESS = 0x02;
 static constexpr uint8_t SERVER_FEATURE_SUPPORTS_NOISE = 0x04;
+// Raw deflate, window <= OTA_INFLATE_WINDOW_SIZE. Binding once offered: the
+// client must then send the image size frame and a deflate stream.
+static constexpr uint8_t SERVER_FEATURE_SUPPORTS_DEFLATE = 0x08;
+
+inline bool ESPHomeOTAComponent::extended_proto_() const {
+#ifdef USE_OTA_ENCRYPTION_REQUIRED
+  // FEATURE_READ already refused every client without the extended protocol
+  return true;
+#else
+  return (this->ota_features_ & CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL) != 0;
+#endif
+}
 
 void ESPHomeOTAComponent::handle_handshake_() {
   /// Handle the OTA handshake and authentication.
@@ -241,12 +285,9 @@ void ESPHomeOTAComponent::handle_handshake_() {
       this->ota_features_ = this->handshake_buf_[0];
       ESP_LOGV(TAG, "Features: 0x%02X", this->ota_features_);
 
-#ifdef USE_OTA_ENCRYPTION
-      // Fail closed: with a PSK configured the client must negotiate encryption
-      // (which requires the extended protocol); refuse plaintext uploads.
-      static constexpr uint8_t NOISE_REQUIRED_FEATURES =
-          CLIENT_FEATURE_SUPPORTS_NOISE | CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL;
-      if (this->noise_ctx_.has_psk() && (this->ota_features_ & NOISE_REQUIRED_FEATURES) != NOISE_REQUIRED_FEATURES) {
+#ifdef USE_OTA_ENCRYPTION_REQUIRED
+      // `ota: encryption:` requires the client to negotiate encryption
+      if ((this->ota_features_ & CLIENT_NOISE_FEATURES) != CLIENT_NOISE_FEATURES) {
         ESP_LOGW(TAG, "Client does not support encryption");
         this->send_error_and_cleanup_(ota::OTA_RESPONSE_ERROR_ENCRYPTION_REQUIRED);
         return;
@@ -256,23 +297,37 @@ void ESPHomeOTAComponent::handle_handshake_() {
       this->transition_ota_state_(OTAState::FEATURE_ACK);
 
       const bool supports_compression =
-          (this->ota_features_ & CLIENT_FEATURE_SUPPORTS_COMPRESSION) != 0 && this->backend_->supports_compression();
+          (this->ota_features_ & CLIENT_FEATURE_SUPPORTS_COMPRESSION) != 0 && ota::OTABackend::supports_compression();
 
       // Compose the feature-ack response. When the client negotiates the extended protocol we emit
       // a 2-byte response (marker + server feature flags); otherwise we emit the single-byte
       // legacy response.
-      this->extended_proto_ = (this->ota_features_ & CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL) != 0;
-      if (this->extended_proto_) {
+      if (this->extended_proto_()) {
         static_assert(HANDSHAKE_BUF_SIZE >= 2, "handshake_buf_ must hold the 2-byte extended-protocol feature ack");
         this->handshake_buf_[0] = ota::OTA_RESPONSE_FEATURE_FLAGS;
         this->handshake_buf_[1] = (supports_compression ? SERVER_FEATURE_SUPPORTS_COMPRESSION : 0);
 #ifdef USE_OTA_PARTITIONS
         this->handshake_buf_[1] |= SERVER_FEATURE_SUPPORTS_PARTITION_ACCESS;
 #endif
-#ifdef USE_OTA_ENCRYPTION
-        if (this->noise_ctx_.has_psk()) {
+#ifdef USE_OTA_ENCRYPTION_PROVISIONED
+        // A runtime provisioned key may not exist yet
+        if (this->noise_context_().has_psk()) {
           this->handshake_buf_[1] |= SERVER_FEATURE_SUPPORTS_NOISE;
         }
+#elif defined(USE_OTA_ENCRYPTION)
+        // A yaml key always exists: validation rejects the all-zeros key
+        this->handshake_buf_[1] |= SERVER_FEATURE_SUPPORTS_NOISE;
+#endif
+#ifdef USE_OTA_DEFLATE
+        // Offered only once the session memory is in hand; else uncompressed
+        if ((this->ota_features_ & CLIENT_FEATURE_SUPPORTS_DEFLATE) != 0) {
+          this->inflate_.reset(new (std::nothrow) InflateSession());
+          if (this->inflate_ != nullptr) {
+            this->handshake_buf_[1] |= SERVER_FEATURE_SUPPORTS_DEFLATE;
+          } else {
+            ESP_LOGW(TAG, "No memory to inflate");
+          }
+        }
 #endif
       } else {
         this->handshake_buf_[0] =
@@ -284,15 +339,15 @@ void ESPHomeOTAComponent::handle_handshake_() {
     case OTAState::FEATURE_ACK: {
       static constexpr size_t STANDARD_PROTO_ACK_SIZE = 1;
       static constexpr size_t EXTENDED_PROTO_ACK_SIZE = 2;
-      const size_t ack_size = this->extended_proto_ ? EXTENDED_PROTO_ACK_SIZE : STANDARD_PROTO_ACK_SIZE;
+      const size_t ack_size = this->extended_proto_() ? EXTENDED_PROTO_ACK_SIZE : STANDARD_PROTO_ACK_SIZE;
       if (!this->try_write_(ack_size, LOG_STR("ack feature"))) {
         return;
       }
 #ifdef USE_OTA_ENCRYPTION
-      // With a PSK configured the rest of the session runs inside the noise
-      // transport; the client sends the first handshake frame next, so there
-      // is nothing to do until data arrives.
-      if (this->noise_ctx_.has_psk()) {
+      // Latch the offer actually sent: a key activating between the two
+      // states must not start a session the client never expects
+      if ((this->handshake_buf_[1] & SERVER_FEATURE_SUPPORTS_NOISE) != 0 &&
+          (this->ota_features_ & CLIENT_NOISE_FEATURES) == CLIENT_NOISE_FEATURES) {
         // handshake_buf_ still holds the feature ack composed above; a
         // would-block re-entry lands here without rebuilding it
         if (!this->noise_start_session_(this->handshake_buf_[1])) {
@@ -390,16 +445,11 @@ void ESPHomeOTAComponent::handle_data_() {
   // Backend calls overwrite this with OK; reset to UNKNOWN before any
   // goto error that follows a successful begin()/write()
   ota::OTAResponseTypes error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
-  size_t total = 0;
-  uint32_t last_progress = 0;
-  uint32_t last_data_ms = 0;
+  DataTransfer xfer;
   uint8_t buf[OTA_BUFFER_SIZE];
   char *sbuf = reinterpret_cast<char *>(buf);
-  size_t ota_size;
+  size_t image_size;
   ota::OTAType ota_type = ota::OTA_TYPE_UPDATE_APP;
-#if USE_OTA_VERSION == 2
-  size_t size_acknowledged = 0;
-#endif
 
   // Set socket timeouts and blocking mode (see strategy table above)
   struct timeval tv;
@@ -412,7 +462,7 @@ void ESPHomeOTAComponent::handle_data_() {
   // Acknowledge auth OK - 1 byte
   this->data_write_byte_(ota::OTA_RESPONSE_AUTH_OK);
 
-  if (this->extended_proto_) {
+  if (this->extended_proto_()) {
     // Read ota type, 1 byte
     if (!this->data_readall_(buf, 1)) {
       this->log_read_error_(LOG_STR("OTA type"));
@@ -422,14 +472,13 @@ void ESPHomeOTAComponent::handle_data_() {
   }
   ESP_LOGV(TAG, "OTA type is 0x%02x", ota_type);
 
-  // Read size, 4 bytes MSB first
-  if (!this->data_readall_(buf, 4)) {
-    this->log_read_error_(LOG_STR("size"));
+  if (!this->read_size_(buf, xfer.ota_size, LOG_STR("size")))
     goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
-  }
-  ota_size = (static_cast<size_t>(buf[0]) << 24) | (static_cast<size_t>(buf[1]) << 16) |
-             (static_cast<size_t>(buf[2]) << 8) | buf[3];
-  ESP_LOGV(TAG, "Size is %zu bytes", ota_size);
+  image_size = xfer.ota_size;
+#ifdef USE_OTA_DEFLATE
+  if (this->inflate_ != nullptr && !this->read_size_(buf, image_size, LOG_STR("image size")))
+    goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
+#endif
 
 #ifndef USE_OTA_PARTITIONS
   if (ota_type != ota::OTA_TYPE_UPDATE_APP) {
@@ -449,7 +498,7 @@ void ESPHomeOTAComponent::handle_data_() {
 #endif
 
   // begin() returns quickly; flash sectors are erased incrementally during write().
-  error_code = this->backend_->begin(ota_size, ota_type);
+  error_code = this->backend_->begin(image_size, ota_type);
   if (error_code != ota::OTA_RESPONSE_OK)
     goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
 
@@ -469,75 +518,25 @@ void ESPHomeOTAComponent::handle_data_() {
   // Acknowledge MD5 OK - 1 byte
   this->data_write_byte_(ota::OTA_RESPONSE_BIN_MD5_OK);
 
-  // Track when we last received data so a silently-vanished peer (no FIN/RST
-  // delivered, e.g. uploader killed mid-transfer or NAT/router dropped state)
-  // can't wedge the device indefinitely. Without this, the loop only exits
-  // on actual data, EOF, or a non-EWOULDBLOCK error from read(), and lwIP
-  // TCP keepalive isn't enabled here.
-  last_data_ms = millis();
-  while (total < ota_size) {
-    if (millis() - last_data_ms > OTA_SOCKET_TIMEOUT_DATA) {
-      ESP_LOGW(TAG, "No data received for %u ms", (unsigned) OTA_SOCKET_TIMEOUT_DATA);
-      error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
+  xfer.last_data_ms = millis();
+#ifdef USE_OTA_DEFLATE
+  if (this->inflate_ != nullptr) {
+    error_code = this->inflate_data_(buf, image_size, xfer);
+    if (error_code != ota::OTA_RESPONSE_OK)
       goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
-    }
-    size_t remaining = ota_size - total;
-    size_t requested = remaining < OTA_BUFFER_SIZE ? remaining : OTA_BUFFER_SIZE;
-    ssize_t read;
-#ifdef USE_OTA_ENCRYPTION
-    if (this->noise_ != nullptr) {
-      // One frame per call; noise_read_data_ waits internally (readall_), so
-      // there is no would-block retry here and failures are already logged.
-      read = this->noise_read_data_(buf, requested);
-      if (read <= 0) {
+  } else
+#endif
+  {
+    while (xfer.total < xfer.ota_size) {
+      ssize_t read = this->receive_data_(buf, xfer);
+      if (read < 0) {
         error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
         goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
       }
-    } else
-#endif
-    {
-      read = this->client_->read(buf, requested);
-      if (read == -1) {
-        const int err = errno;
-        if (this->would_block_(err)) {
-          // read() already waited up to SO_RCVTIMEO for data, just feed WDT
-          App.feed_wdt();
-          continue;
-        }
-        ESP_LOGW(TAG, "Read err %d", err);
-        error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
+      error_code = this->write_flash_(buf, read);
+      if (error_code != ota::OTA_RESPONSE_OK)
         goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
-      } else if (read == 0) {
-        ESP_LOGW(TAG, "Remote closed");
-        error_code = ota::OTA_RESPONSE_ERROR_UNKNOWN;
-        goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
-      }
-    }
-
-    last_data_ms = millis();
-    error_code = this->backend_->write(buf, read);
-    if (error_code != ota::OTA_RESPONSE_OK) {
-      ESP_LOGW(TAG, "Flash write err %d", error_code);
-      goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
-    }
-    total += read;
-#if USE_OTA_VERSION == 2
-    while (size_acknowledged + OTA_BLOCK_SIZE <= total || (total == ota_size && size_acknowledged < ota_size)) {
-      this->data_write_byte_(ota::OTA_RESPONSE_CHUNK_OK);
-      size_acknowledged += OTA_BLOCK_SIZE;
-    }
-#endif
-
-    uint32_t now = millis();
-    if (now - last_progress > 1000) {
-      last_progress = now;
-      float percentage = (total * 100.0f) / ota_size;
-      ESP_LOGD(TAG, "Progress: %0.1f%%", percentage);
-#ifdef USE_OTA_STATE_LISTENER
-      this->notify_state_(ota::OTA_IN_PROGRESS, percentage, 0);
-#endif
-      // feed watchdog and give other tasks a chance to run
-      this->yield_and_feed_watchdog_();
+      this->ack_written_(xfer);
     }
   }
 
@@ -734,6 +733,169 @@ bool ESPHomeOTAComponent::try_write_(size_t to_write, const LogString *desc) {
   return this->handshake_buf_pos_ >= to_write;
 }
 
+bool ESPHomeOTAComponent::read_size_(uint8_t *buf, size_t &size, const LogString *desc) {
+  if (!this->data_readall_(buf, OTA_SIZE_FIELD_BYTES)) {
+    this->log_read_error_(desc);
+    return false;
+  }
+  size = encode_uint32(buf[0], buf[1], buf[2], buf[3]);
+  ESP_LOGV(TAG, "%s is %zu bytes", LOG_STR_ARG(desc), size);
+  return true;
+}
+
+ota::OTAResponseTypes ESPHomeOTAComponent::write_flash_(uint8_t *data, size_t len) {
+  ota::OTAResponseTypes result = this->backend_->write(data, len);
+  if (result != ota::OTA_RESPONSE_OK) {
+    ESP_LOGW(TAG, "Flash write err %d", result);
+  }
+  return result;
+}
+
+ssize_t ESPHomeOTAComponent::receive_data_(uint8_t *buf, DataTransfer &xfer) {
+  const size_t remaining = xfer.ota_size - xfer.total;
+  const size_t requested = std::min(remaining, OTA_BUFFER_SIZE);
+  ssize_t read;
+  for (;;) {
+    // A silently-vanished peer (no FIN/RST delivered, e.g. uploader killed
+    // mid-transfer or NAT/router dropped state) must not wedge the device:
+    // read() only fails on EOF or a real error, and lwIP TCP keepalive isn't
+    // enabled here.
+    if (millis() - xfer.last_data_ms > OTA_SOCKET_TIMEOUT_DATA) {
+      ESP_LOGW(TAG, "No data received for %u ms", (unsigned) OTA_SOCKET_TIMEOUT_DATA);
+      return -1;
+    }
+#ifdef USE_OTA_ENCRYPTION
+    if (this->noise_ != nullptr) {
+      // One frame per call; noise_read_data_ waits internally (readall_), so
+      // there is no would-block retry here and failures are already logged.
+      read = this->noise_read_data_(buf, requested);
+      if (read <= 0)
+        return -1;
+      break;
+    }
+#endif
+    read = this->client_->read(buf, requested);
+    if (read > 0)
+      break;
+    if (read == 0) {
+      this->log_remote_closed_(LOG_STR("data"));
+      return -1;
+    }
+    if (!this->would_block_(errno)) {
+      this->log_socket_error_(LOG_STR("data"));
+      return -1;
+    }
+    // read() already waited up to SO_RCVTIMEO for data, just feed WDT
+    App.feed_wdt();
+  }
+
+  const uint32_t now = millis();
+  xfer.last_data_ms = now;
+  xfer.total += read;
+  this->ack_received_(xfer);
+  if (now - xfer.last_progress > OTA_PROGRESS_INTERVAL_MS) {
+    xfer.last_progress = now;
+    float percentage = (xfer.total * 100.0f) / xfer.ota_size;
+    ESP_LOGD(TAG, "Progress: %0.1f%%", percentage);
+#ifdef USE_OTA_STATE_LISTENER
+    this->notify_state_(ota::OTA_IN_PROGRESS, percentage, 0);
+#endif
+    // feed watchdog and give other tasks a chance to run
+    this->yield_and_feed_watchdog_();
+  }
+  return read;
+}
+
+void ESPHomeOTAComponent::send_chunk_acks_(DataTransfer &xfer) {
+#if USE_OTA_VERSION == 2
+  while (xfer.acknowledged + OTA_BLOCK_SIZE <= xfer.total ||
+         (xfer.total == xfer.ota_size && xfer.acknowledged < xfer.ota_size)) {
+    this->data_write_byte_(ota::OTA_RESPONSE_CHUNK_OK);
+    xfer.acknowledged += OTA_BLOCK_SIZE;
+  }
+#endif
+}
+
+#ifdef USE_OTA_DEFLATE
+// The window doubles as the output buffer; flushed bytes stay as back
+// reference history for the next windowful.
+ota::OTAResponseTypes ESPHomeOTAComponent::inflate_flush_(InflateSession &session) {
+  const size_t produced = session.dest - session.window;
+  const size_t pending = produced - session.flushed;
+  if (pending == 0)
+    return ota::OTA_RESPONSE_OK;
+  if (pending > session.image_size - session.written) {
+    ESP_LOGW(TAG, "Inflate overrun");
+    return ota::OTA_RESPONSE_ERROR_UNKNOWN;
+  }
+  ota::OTAResponseTypes result = this->write_flash_(session.window + session.flushed, pending);
+  if (result != ota::OTA_RESPONSE_OK)
+    return result;
+  session.flushed = produced;
+  session.written += pending;
+  // A compressible region yields many windows per socket read
+  App.feed_wdt();
+  this->ack_written_(*session.xfer);
+  return ota::OTA_RESPONSE_OK;
+}
+
+ota::OTAResponseTypes ESPHomeOTAComponent::inflate_data_(uint8_t *in, size_t image_size, DataTransfer &xfer) {
+  InflateSession &session = *this->inflate_;
+  session.self = this;
+  session.xfer = &xfer;
+  session.in = in;
+  session.image_size = image_size;
+  session.written = 0;
+  session.error = ota::OTA_RESPONSE_OK;
+  ota_inflate_init(&session, session.window, OTA_INFLATE_WINDOW_SIZE);
+  // Where the ack must follow the write, flush and ack before waiting for
+  // input, or the client waits for an ack while the decoder waits for data
+  session.source_read_cb = [](OtaInflateState *d) -> int {
+    auto *s = static_cast<InflateSession *>(d);
+    if (ACK_AFTER_WRITE) {
+      s->error = s->self->inflate_flush_(*s);
+      if (s->error != ota::OTA_RESPONSE_OK)
+        return -1;
+    }
+    // More input than announced; reported by the size check below
+    if (s->xfer->total >= s->xfer->ota_size)
+      return -1;
+    ssize_t read = s->self->receive_data_(s->in, *s->xfer);
+    if (read <= 0) {
+      // Already logged by receive_data_
+      s->error = ota::OTA_RESPONSE_ERROR_UNKNOWN;
+      return -1;
+    }
+    d->source = s->in + 1;
+    d->source_limit = s->in + read;
+    return s->in[0];
+  };
+
+  int res;
+  do {
+    // The ring index wrapped to 0 exactly when the window filled
+    session.dest = session.window;
+    session.dest_limit = session.window + OTA_INFLATE_WINDOW_SIZE;
+    session.flushed = 0;
+    res = ota_inflate(&session);
+    // A stored block keeps emitting zeros after a failed read, hence eof
+    if (res < 0 || session.eof)
+      break;
+    session.error = this->inflate_flush_(session);
+  } while (res != OTA_INFLATE_DONE && session.error == ota::OTA_RESPONSE_OK);
+
+  // Transport and flash failures are logged where they happen
+  if (session.error != ota::OTA_RESPONSE_OK)
+    return session.error;
+  if (res != OTA_INFLATE_DONE || session.written != image_size || xfer.total != xfer.ota_size) {
+    ESP_LOGW(TAG, "Inflate err %d", res);
+    return ota::OTA_RESPONSE_ERROR_UNKNOWN;
+  }
+  ESP_LOGD(TAG, "Inflated %zu bytes from %zu", session.written, xfer.total);
+  return ota::OTA_RESPONSE_OK;
+}
+#endif  // USE_OTA_DEFLATE
+
 void ESPHomeOTAComponent::cleanup_connection_() {
   this->client_->close();
   this->client_ = nullptr;
@@ -747,6 +909,9 @@ void ESPHomeOTAComponent::cleanup_connection_() {
 #endif
 #ifdef USE_OTA_ENCRYPTION
   this->noise_ = nullptr;
+#endif
+#ifdef USE_OTA_DEFLATE
+  this->inflate_ = nullptr;
 #endif
   // Intentionally no disable_loop() — letting loop() run one more iteration catches
   // any connection that queued on the listener mid-session (otherwise the wake flag,

esphome/components/esphome/ota/ota_esphome.h

@@ -7,6 +7,9 @@
 #ifdef USE_OTA_ENCRYPTION
 #include "esphome/components/noise/noise_handshake.h"
 #endif
+#ifdef USE_OTA_DEFLATE
+#include "ota_esphome_inflate.h"
+#endif
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/preferences.h"
@@ -44,8 +47,9 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
   }
 #endif  // USE_OTA_PASSWORD
 
-#ifdef USE_OTA_ENCRYPTION
-  void set_noise_psk(noise::psk_t psk) { this->noise_ctx_.set_psk(psk); }
+#if defined(USE_OTA_ENCRYPTION) && !defined(USE_OTA_ENCRYPTION_FROM_API)
+  /// psk points at 32 bytes that live in flash for the life of the program
+  void set_noise_psk(const uint8_t *psk) { this->noise_ctx_.set_psk(psk); }
 #endif
 
   /// Manually set the port OTA should listen on
@@ -85,9 +89,12 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
     bool writing{false};    // a produced handshake frame is still being flushed
     uint8_t frame_buf[noise::FRAME_HEADER_SIZE + 1 + noise::MAX_HANDSHAKE_SIZE];
   };
+  // The api server's live context when the api has encryption, else our own
+  const noise::NoiseContext &noise_context_() const;
   bool noise_start_session_(uint8_t server_feature_flags);
   bool handle_noise_handshake_();
   bool noise_try_read_frame_();
+  size_t noise_frame_payload_len_(const uint8_t *header, size_t min_len, size_t max_len);
   bool noise_try_write_frame_();
   void noise_send_reject_(const LogString *reason);
   ssize_t noise_decrypt_(uint8_t *buf, size_t len);
@@ -115,6 +122,38 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
     return this->readall_(buf, len);
   }
 
+  // Upload accounting shared by the data loop and the inflate read callback
+  struct DataTransfer {
+    size_t ota_size{0};  // bytes the client sends
+    size_t total{0};     // bytes received so far
+#if USE_OTA_VERSION == 2
+    size_t acknowledged{0};
+#endif
+    uint32_t last_data_ms{0};
+    uint32_t last_progress{0};
+  };
+  // Up to OTA_BUFFER_SIZE bytes into buf; returns bytes read, -1 on failure (logged)
+  inline ssize_t receive_data_(uint8_t *buf, DataTransfer &xfer);
+  // Raw lwIP cannot service the radio during a sector write, so the ack waits
+  // for the write there; a socket task lets the next block arrive meanwhile
+#ifdef USE_SOCKET_IMPL_LWIP_TCP
+  static constexpr bool ACK_AFTER_WRITE = true;
+#else
+  static constexpr bool ACK_AFTER_WRITE = false;
+#endif
+  void send_chunk_acks_(DataTransfer &xfer);
+  inline void ack_received_(DataTransfer &xfer) {
+    if (!ACK_AFTER_WRITE)
+      this->send_chunk_acks_(xfer);
+  }
+  inline void ack_written_(DataTransfer &xfer) {
+    if (ACK_AFTER_WRITE)
+      this->send_chunk_acks_(xfer);
+  }
+  inline bool read_size_(uint8_t *buf, size_t &size, const LogString *desc);
+  // Writes to the backend and logs a failure
+  inline ota::OTAResponseTypes write_flash_(uint8_t *data, size_t len);
+
   bool try_read_(size_t to_read, const LogString *desc);
   bool try_write_(size_t to_write, const LogString *desc);
 
@@ -144,7 +183,9 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
   std::unique_ptr<uint8_t[]> auth_buf_;
 #endif  // USE_OTA_PASSWORD
 #ifdef USE_OTA_ENCRYPTION
+#ifndef USE_OTA_ENCRYPTION_FROM_API
   noise::NoiseContext noise_ctx_;
+#endif
   std::unique_ptr<NoiseSession> noise_;
 #endif  // USE_OTA_ENCRYPTION
 
@@ -165,7 +206,34 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
   static_assert(OTA_BUFFER_SIZE >= NOISE_CLIENT_MAX_PLAINTEXT + noise::MAC_SIZE,
                 "OTA_BUFFER_SIZE must fit a full encrypted data frame");
 #endif
+#ifdef USE_OTA_DEFLATE
+  // At least 1 << espota2.DEFLATE_WINDOW_BITS; also the inflate output buffer
+  static constexpr size_t OTA_INFLATE_WINDOW_SIZE = 4096;
+  // Heap-allocated only while a deflate upload is negotiated; the decoder
+  // state is the base so the read callback can recover the session
+  struct InflateSession : OtaInflateState {
+    ESPHomeOTAComponent *self;
+    DataTransfer *xfer;
+    uint8_t *in;  // caller's buffer for the compressed input, valid during inflate_data_
+    size_t image_size;
+    size_t written;               // inflated bytes in flash
+    size_t flushed;               // bytes of the current window already in flash
+    ota::OTAResponseTypes error;  // first failure inside the read callback
+    uint8_t window[OTA_INFLATE_WINDOW_SIZE];
+  };
+#ifndef CLANG_TIDY  // static analysis sets every define at once
+  static_assert(!ota::OTABackend::supports_compression(),
+                "USE_OTA_DEFLATE is for backends that cannot store a gzip image");
+#endif
+  // Writes the decoded bytes not yet in flash without moving dest
+  ota::OTAResponseTypes inflate_flush_(InflateSession &session);
+  ota::OTAResponseTypes inflate_data_(uint8_t *in, size_t image_size, DataTransfer &xfer);
+  std::unique_ptr<InflateSession> inflate_;
+#endif
+
   static constexpr uint8_t MAGIC_BYTES[5] = {0x6C, 0x26, 0xF7, 0x5C, 0x45};
+  // Derived from the feature byte; storing it would pad the trailing bytes
+  bool extended_proto_() const;
 #ifdef USE_OTA_PARTITIONS
   uint32_t running_app_offset_{0};
   size_t running_app_size_{0};
@@ -179,7 +247,6 @@ class ESPHomeOTAComponent final : public ota::OTAComponent {
   uint8_t auth_buf_pos_{0};
   uint8_t auth_type_{0};  // Store auth type to know which hasher to use
 #endif                    // USE_OTA_PASSWORD
-  bool extended_proto_{false};
 };
 
 }  // namespace esphome

esphome/components/esphome/ota/ota_esphome_inflate.c

@@ -0,0 +1,498 @@
+/*
+ * uzlib  -  tiny deflate/inflate library (deflate, gzip, zlib)
+ *
+ * Copyright (c) 2003 by Joergen Ibsen / Jibz
+ * All Rights Reserved
+ * http://www.ibsensoftware.com/
+ *
+ * Copyright (c) 2014-2018 by Paul Sokolovsky
+ *
+ * This software is provided 'as-is', without any express
+ * or implied warranty.  In no event will the authors be
+ * held liable for any damages arising from the use of
+ * this software.
+ *
+ * Permission is granted to anyone to use this software
+ * for any purpose, including commercial applications,
+ * and to alter it and redistribute it freely, subject to
+ * the following restrictions:
+ *
+ * 1. The origin of this software must not be
+ *    misrepresented; you must not claim that you
+ *    wrote the original software. If you use this
+ *    software in a product, an acknowledgment in
+ *    the product documentation would be appreciated
+ *    but is not required.
+ *
+ * 2. Altered source versions must be plainly marked
+ *    as such, and must not be misrepresented as
+ *    being the original software.
+ *
+ * 3. This notice may not be removed or altered from
+ *    any source distribution.
+ */
+
+/*
+ * Altered for ESPHome: this is the raw deflate decoder from uzlib's
+ * tinflate.c (v2.9.5) with the gzip/zlib header parsers, checksums,
+ * runtime table builder and in-memory (non ring window) output path
+ * removed, and the public names prefixed with ota_inflate.
+ */
+
+#include "ota_esphome_inflate.h"
+
+#include <stddef.h>
+
+#define TINF_OK OTA_INFLATE_OK
+#define TINF_DONE OTA_INFLATE_DONE
+#define TINF_DATA_ERROR OTA_INFLATE_DATA_ERROR
+#define TINF_DICT_ERROR OTA_INFLATE_DICT_ERROR
+#define TINF_DATA struct OtaInflateState
+#define TINF_TREE struct OtaInflateTree
+#define TINF_ARRAY_SIZE(arr) (sizeof(arr) / sizeof(*(arr)))
+
+/* every output byte also goes into the ring window */
+#define TINF_PUT(d, c) \
+  { \
+    *d->dest++ = c; \
+    d->dict_ring[d->dict_idx++] = c; \
+    if (d->dict_idx == d->dict_size) \
+      d->dict_idx = 0; \
+  }
+
+/* --------------------------------------------------- *
+ * -- constant tables (upstream builds them at runtime) -- *
+ * --------------------------------------------------- */
+
+static const unsigned char LENGTH_BITS[30] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2,
+                                              2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5};
+static const unsigned short LENGTH_BASE[30] = {3,  4,  5,  6,  7,  8,  9,  10, 11,  13,  15,  17,  19,  23, 27,
+                                               31, 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258};
+
+static const unsigned char DIST_BITS[30] = {0, 0, 0, 0, 1, 1, 2, 2,  3,  3,  4,  4,  5,  5,  6,
+                                            6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
+static const unsigned short DIST_BASE[30] = {1,    2,    3,    4,    5,    7,    9,    13,    17,    25,
+                                             33,   49,   65,   97,   129,  193,  257,  385,   513,   769,
+                                             1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
+
+/* special ordering of code length codes */
+static const unsigned char CLCIDX[] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/* ----------------------- *
+ * -- utility functions -- *
+ * ----------------------- */
+
+/* given an array of code lengths, build a tree */
+static void tinf_build_tree(TINF_TREE *t, const unsigned char *lengths, unsigned int num) {
+  unsigned short offs[16];
+  unsigned int i, sum;
+
+  /* clear code length count table */
+  for (i = 0; i < 16; ++i)
+    t->table[i] = 0;
+
+  /* scan symbol lengths, and sum code length counts */
+  for (i = 0; i < num; ++i)
+    t->table[lengths[i]]++;
+
+  /* In the lengths array, 0 means unused code. So, t->table[0] now contains
+     number of unused codes. But table's purpose is to contain # of codes of
+     particular length, and there're 0 codes of length 0. */
+  t->table[0] = 0;
+
+  /* compute offset table for distribution sort */
+  for (sum = 0, i = 0; i < 16; ++i) {
+    offs[i] = sum;
+    sum += t->table[i];
+  }
+
+  /* create code->symbol translation table (symbols sorted by code) */
+  for (i = 0; i < num; ++i) {
+    if (lengths[i])
+      t->trans[offs[lengths[i]]++] = i;
+  }
+}
+
+/* ---------------------- *
+ * -- decode functions -- *
+ * ---------------------- */
+
+static unsigned char uzlib_get_byte(TINF_DATA *d) {
+  /* If end of source buffer is not reached, return next byte from source
+     buffer. */
+  if (d->source < d->source_limit) {
+    return *d->source++;
+  }
+
+  /* Otherwise if there's callback and we haven't seen EOF yet, try to
+     read next byte using it. (Note: the callback can also update ->source
+     and ->source_limit). */
+  if (!d->eof) {
+    int val = d->source_read_cb(d);
+    if (val >= 0) {
+      return (unsigned char) val;
+    }
+  }
+
+  /* Otherwise, we hit EOF (either from ->source_read_cb() or from exhaustion
+     of the buffer), and it will be "sticky", i.e. further calls to this
+     function will end up here too. */
+  d->eof = true;
+
+  return 0;
+}
+
+/* get one bit from source stream */
+static int tinf_getbit(TINF_DATA *d) {
+  unsigned int bit;
+
+  /* check if tag is empty */
+  if (!d->bitcount--) {
+    /* load next tag */
+    d->tag = uzlib_get_byte(d);
+    d->bitcount = 7;
+  }
+
+  /* shift bit out of tag */
+  bit = d->tag & 0x01;
+  d->tag >>= 1;
+
+  return bit;
+}
+
+/* read a num bit value from a stream and add base */
+static unsigned int tinf_read_bits(TINF_DATA *d, int num, int base) {
+  unsigned int val = 0;
+
+  /* read num bits */
+  if (num) {
+    unsigned int limit = 1 << (num);
+    unsigned int mask;
+
+    for (mask = 1; mask < limit; mask *= 2)
+      if (tinf_getbit(d))
+        val += mask;
+  }
+
+  return val + base;
+}
+
+/* given a data stream and a tree, decode a symbol */
+static int tinf_decode_symbol(TINF_DATA *d, TINF_TREE *t) {
+  int sum = 0, cur = 0, len = 0;
+
+  /* get more bits while code value is above sum */
+  do {
+    cur = 2 * cur + tinf_getbit(d);
+
+    if (++len == TINF_ARRAY_SIZE(t->table)) {
+      return TINF_DATA_ERROR;
+    }
+
+    sum += t->table[len];
+    cur -= t->table[len];
+
+  } while (cur >= 0);
+
+  sum += cur;
+  if (sum < 0 || sum >= t->size) {
+    return TINF_DATA_ERROR;
+  }
+
+  return t->trans[sum];
+}
+
+/* given a data stream, decode dynamic trees from it */
+static int tinf_decode_trees(TINF_DATA *d, TINF_TREE *lt, TINF_TREE *dt) {
+  /* code lengths for 288 literal/len symbols and 32 dist symbols */
+  unsigned char lengths[288 + 32];
+  unsigned int hlit, hdist, hclen, hlimit;
+  unsigned int i, num, length;
+
+  /* get 5 bits HLIT (257-286) */
+  hlit = tinf_read_bits(d, 5, 257);
+
+  /* get 5 bits HDIST (1-32) */
+  hdist = tinf_read_bits(d, 5, 1);
+
+  /* get 4 bits HCLEN (4-19) */
+  hclen = tinf_read_bits(d, 4, 4);
+
+  for (i = 0; i < 19; ++i)
+    lengths[i] = 0;
+
+  /* read code lengths for code length alphabet */
+  for (i = 0; i < hclen; ++i) {
+    /* get 3 bits code length (0-7) */
+    unsigned int clen = tinf_read_bits(d, 3, 0);
+
+    lengths[CLCIDX[i]] = clen;
+  }
+
+  /* build code length tree, temporarily use length tree */
+  tinf_build_tree(lt, lengths, 19);
+
+  /* decode code lengths for the dynamic trees */
+  hlimit = hlit + hdist;
+  for (num = 0; num < hlimit;) {
+    int sym = tinf_decode_symbol(d, lt);
+    unsigned char fill_value = 0;
+    int lbits, lbase = 3;
+
+    /* error decoding */
+    if (sym < 0)
+      return sym;
+
+    switch (sym) {
+      case 16:
+        /* copy previous code length 3-6 times (read 2 bits) */
+        if (num == 0)
+          return TINF_DATA_ERROR;
+        fill_value = lengths[num - 1];
+        lbits = 2;
+        break;
+      case 17:
+        /* repeat code length 0 for 3-10 times (read 3 bits) */
+        lbits = 3;
+        break;
+      case 18:
+        /* repeat code length 0 for 11-138 times (read 7 bits) */
+        lbits = 7;
+        lbase = 11;
+        break;
+      default:
+        /* values 0-15 represent the actual code lengths */
+        lengths[num++] = sym;
+        /* continue the for loop */
+        continue;
+    }
+
+    /* special code length 16-18 are handled here */
+    length = tinf_read_bits(d, lbits, lbase);
+    if (num + length > hlimit)
+      return TINF_DATA_ERROR;
+    for (; length; --length) {
+      lengths[num++] = fill_value;
+    }
+  }
+
+  /* Check that there's "end of block" symbol */
+  if (lengths[256] == 0) {
+    return TINF_DATA_ERROR;
+  }
+
+  /* build dynamic trees */
+  tinf_build_tree(lt, lengths, hlit);
+  tinf_build_tree(dt, lengths + hlit, hdist);
+
+  return TINF_OK;
+}
+
+/* build the fixed huffman trees (RFC 1951 3.2.6) through the generic tree
+   builder; altered from upstream, which unrolls them by hand */
+static void tinf_build_fixed_trees(TINF_TREE *lt, TINF_TREE *dt) {
+  unsigned char lengths[288];
+  unsigned int i;
+
+  for (i = 0; i < 144; ++i)
+    lengths[i] = 8;
+  for (; i < 256; ++i)
+    lengths[i] = 9;
+  for (; i < 280; ++i)
+    lengths[i] = 7;
+  for (; i < 288; ++i)
+    lengths[i] = 8;
+  tinf_build_tree(lt, lengths, 288);
+
+  for (i = 0; i < 32; ++i)
+    lengths[i] = 5;
+  tinf_build_tree(dt, lengths, 32);
+}
+
+/* ----------------------------- *
+ * -- block inflate functions -- *
+ * ----------------------------- */
+
+/* given a stream and two trees, inflate next chunk of output (a byte or more) */
+static int tinf_inflate_block_data(TINF_DATA *d, TINF_TREE *lt, TINF_TREE *dt) {
+  if (d->curlen == 0) {
+    unsigned int offs;
+    int dist;
+    int sym = tinf_decode_symbol(d, lt);
+
+    if (d->eof) {
+      return TINF_DATA_ERROR;
+    }
+
+    if (sym < 0) {
+      return sym;
+    }
+
+    /* literal byte */
+    if (sym < 256) {
+      TINF_PUT(d, sym);
+      return TINF_OK;
+    }
+
+    /* end of block */
+    if (sym == 256) {
+      return TINF_DONE;
+    }
+
+    /* substring from sliding dictionary */
+    sym -= 257;
+    if (sym >= 29) {
+      return TINF_DATA_ERROR;
+    }
+
+    /* possibly get more bits from length code */
+    d->curlen = tinf_read_bits(d, LENGTH_BITS[sym], LENGTH_BASE[sym]);
+
+    dist = tinf_decode_symbol(d, dt);
+    if (dist < 0 || dist >= 30) {
+      return TINF_DATA_ERROR;
+    }
+
+    /* possibly get more bits from distance code */
+    offs = tinf_read_bits(d, DIST_BITS[dist], DIST_BASE[dist]);
+
+    /* calculate and validate actual LZ offset to use */
+    if (offs > d->dict_size) {
+      return TINF_DICT_ERROR;
+    }
+    /* Note: we don't try to catch offset which points to not yet filled
+       part of the dictionary here. Doing so would require keeping another
+       variable to track "filled in" size of the dictionary. Appearance of
+       such an offset cannot lead to accessing memory outside of the
+       dictionary buffer, and clients which don't want to leak unrelated
+       information, should explicitly initialize dictionary buffer passed
+       to uzlib. */
+
+    d->lz_off = d->dict_idx - offs;
+    if (d->lz_off < 0) {
+      d->lz_off += d->dict_size;
+    }
+  }
+
+  /* copy next byte from dict substring */
+  TINF_PUT(d, d->dict_ring[d->lz_off]);
+  if ((unsigned) ++d->lz_off == d->dict_size) {
+    d->lz_off = 0;
+  }
+  d->curlen--;
+  return TINF_OK;
+}
+
+/* inflate next byte from uncompressed block of data */
+static int tinf_inflate_uncompressed_block(TINF_DATA *d) {
+  if (d->curlen == 0) {
+    unsigned int length, invlength;
+
+    /* get length */
+    length = uzlib_get_byte(d);
+    length += 256 * uzlib_get_byte(d);
+    /* get one's complement of length */
+    invlength = uzlib_get_byte(d);
+    invlength += 256 * uzlib_get_byte(d);
+    /* check length */
+    if (length != (~invlength & 0x0000ffff))
+      return TINF_DATA_ERROR;
+
+    /* increment length to properly return TINF_DONE below, without
+       producing data at the same time */
+    d->curlen = length + 1;
+
+    /* make sure we start next block on a byte boundary */
+    d->bitcount = 0;
+  }
+
+  if (--d->curlen == 0) {
+    return TINF_DONE;
+  }
+
+  unsigned char c = uzlib_get_byte(d);
+  TINF_PUT(d, c);
+  return TINF_OK;
+}
+
+/* ---------------------- *
+ * -- public functions -- *
+ * ---------------------- */
+
+/* initialize decompression structure */
+void ota_inflate_init(TINF_DATA *d, unsigned char *dict, unsigned int dict_len) {
+  d->source = NULL;
+  d->source_limit = NULL;
+  d->tag = 0;
+  d->eof = 0;
+  d->bitcount = 0;
+  d->lz_off = 0;
+  d->bfinal = 0;
+  d->btype = -1;
+  d->dict_size = dict_len;
+  d->dict_ring = dict;
+  d->dict_idx = 0;
+  d->curlen = 0;
+  d->ltree.trans = d->ltrans;
+  d->ltree.size = TINF_ARRAY_SIZE(d->ltrans);
+  d->dtree.trans = d->dtrans;
+  d->dtree.size = TINF_ARRAY_SIZE(d->dtrans);
+}
+
+/* inflate next output bytes from compressed stream */
+int ota_inflate(TINF_DATA *d) {
+  do {
+    int res;
+
+    /* start a new block */
+    if (d->btype == -1) {
+      int old_btype;
+    next_blk:
+      old_btype = d->btype;
+      /* read final block flag */
+      d->bfinal = tinf_getbit(d);
+      /* read block type (2 bits) */
+      d->btype = tinf_read_bits(d, 2, 0);
+
+      if (d->btype == 1 && old_btype != 1) {
+        /* build fixed huffman trees */
+        tinf_build_fixed_trees(&d->ltree, &d->dtree);
+      } else if (d->btype == 2) {
+        /* decode trees from stream */
+        res = tinf_decode_trees(d, &d->ltree, &d->dtree);
+        if (res != TINF_OK) {
+          return res;
+        }
+      }
+    }
+
+    /* process current block */
+    switch (d->btype) {
+      case 0:
+        /* decompress uncompressed block */
+        res = tinf_inflate_uncompressed_block(d);
+        break;
+      case 1:
+      case 2:
+        /* decompress block with fixed/dynamic huffman trees */
+        /* trees were decoded previously, so it's the same routine for both */
+        res = tinf_inflate_block_data(d, &d->ltree, &d->dtree);
+        break;
+      default:
+        return TINF_DATA_ERROR;
+    }
+
+    if (res == TINF_DONE && !d->bfinal) {
+      /* the block has ended (without producing more data), but we
+         can't return without data, so start procesing next block */
+      goto next_blk;
+    }
+
+    if (res != TINF_OK) {
+      return res;
+    }
+
+  } while (d->dest < d->dest_limit);
+
+  return TINF_OK;
+}

esphome/components/esphome/ota/ota_esphome_inflate.h

@@ -0,0 +1,66 @@
+#pragma once
+// Raw deflate decoder cut down from uzlib (https://github.com/pfalcon/uzlib,
+// zlib licence, see the .c file); output goes through a ring window.
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum OtaInflateResult {
+  OTA_INFLATE_OK = 0,   /* more data produced, call again */
+  OTA_INFLATE_DONE = 1, /* end of compressed stream reached */
+  OTA_INFLATE_DATA_ERROR = -3,
+  OTA_INFLATE_DICT_ERROR = -5,
+};
+
+struct OtaInflateTree {
+  uint16_t table[16]; /* table of code length counts */
+  uint16_t *trans;    /* code -> symbol translation table, size entries */
+  uint16_t size;
+};
+
+struct OtaInflateState {
+  /* Next byte in the input buffer and one past its end */
+  const unsigned char *source;
+  const unsigned char *source_limit;
+  /* Called when source is exhausted; returns the next byte or -1 at EOF.
+     It may refill source/source_limit for buffered operation. */
+  int (*source_read_cb)(struct OtaInflateState *d);
+
+  unsigned int tag;
+  unsigned int bitcount;
+
+  /* Output cursor and one past the end of the output buffer */
+  unsigned char *dest;
+  unsigned char *dest_limit;
+
+  bool eof;
+
+  int btype;
+  int bfinal;
+  unsigned int curlen;
+  int lz_off;
+  /* Ring window holding the last dict_size output bytes for back references */
+  unsigned char *dict_ring;
+  unsigned int dict_size;
+  unsigned int dict_idx;
+
+  struct OtaInflateTree ltree; /* dynamic length/symbol tree */
+  struct OtaInflateTree dtree; /* dynamic distance tree */
+  uint16_t ltrans[288];
+  uint16_t dtrans[32]; /* the distance alphabet has 30 symbols, so the tree is kept small */
+};
+
+/* dict must cover the encoder's window (its largest back reference) */
+void ota_inflate_init(struct OtaInflateState *d, unsigned char *dict, unsigned int dict_len);
+/* Fills dest up to dest_limit (OK) or to the end of the stream (DONE). dest may
+   alias dict only if dest_limit - dest == dict_len and dest is reset to dict
+   exactly when a call returns OK, so the ring index and dest stay in lockstep */
+int ota_inflate(struct OtaInflateState *d);
+
+#ifdef __cplusplus
+}
+#endif

esphome/components/esphome/ota/ota_esphome_noise.cpp

@@ -3,6 +3,7 @@
 #ifdef USE_OTA_ENCRYPTION
 #include "esphome/components/noise/noise.h"
 #include "esphome/components/ota/ota_backend.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
 #include <cstring>
@@ -40,24 +41,17 @@ ESPHomeOTAComponent::NoiseSession::~NoiseSession() {
  *   "NoiseOTAInit" | magic(5) | OK,version | client_features | FEATURE_FLAGS,server_flags
  */
 bool ESPHomeOTAComponent::noise_start_session_(uint8_t server_feature_flags) {
+  // A provisioned key cleared between the offer and here is not guarded: the
+  // session runs on the zero key load_psk fills in and fails the client's MAC.
+  // Default-init: the frame buffer is written before it is read
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks)
-  this->noise_ = std::unique_ptr<NoiseSession>(new (std::nothrow) NoiseSession());
-  if (this->noise_ == nullptr) {
-    ESP_LOGW(TAG, "Session allocation failed");
-    this->cleanup_connection_();
-    return false;
-  }
-
+  this->noise_ = std::unique_ptr<NoiseSession>(new (std::nothrow) NoiseSession);
   static constexpr size_t PROLOGUE_ACK_LEN = 2;  // OTA_RESPONSE_OK + version
   static constexpr size_t PROLOGUE_CLIENT_FEATURES_LEN = 1;
   static constexpr size_t PROLOGUE_FEATURE_ACK_LEN = 2;  // OTA_RESPONSE_FEATURE_FLAGS + server flags
   uint8_t prologue[OTA_NOISE_PROLOGUE_INIT_LEN + sizeof(MAGIC_BYTES) + PROLOGUE_ACK_LEN + PROLOGUE_CLIENT_FEATURES_LEN +
                    PROLOGUE_FEATURE_ACK_LEN];
-#ifdef USE_ESP8266
-  memcpy_P(prologue, OTA_NOISE_PROLOGUE_INIT, OTA_NOISE_PROLOGUE_INIT_LEN);
-#else
-  std::memcpy(prologue, OTA_NOISE_PROLOGUE_INIT, OTA_NOISE_PROLOGUE_INIT_LEN);
-#endif
+  progmem_memcpy(prologue, OTA_NOISE_PROLOGUE_INIT, OTA_NOISE_PROLOGUE_INIT_LEN);
   uint8_t *p = prologue + OTA_NOISE_PROLOGUE_INIT_LEN;
   // Magic bytes, already validated in MAGIC_READ
   std::memcpy(p, MAGIC_BYTES, sizeof(MAGIC_BYTES));
@@ -71,9 +65,13 @@ bool ESPHomeOTAComponent::noise_start_session_(uint8_t server_feature_flags) {
   *p++ = ota::OTA_RESPONSE_FEATURE_FLAGS;
   *p++ = server_feature_flags;
 
-  int err = this->noise_->handshake.init(this->noise_ctx_.get_psk(), prologue, sizeof(prologue));
+  // The caller only starts a session when the context holds a key
+  int err = this->noise_ == nullptr ? NOISE_ERROR_NO_MEMORY
+                                    : this->noise_->handshake.init(this->noise_context_(), prologue, sizeof(prologue));
   if (err != 0) {
-    ESP_LOGW(TAG, "Handshake init: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
+    // Raw noise codes throughout: the name table would cost flash in builds
+    // where only the OTA uses noise
+    ESP_LOGW(TAG, "Session init: %d", err);
     this->cleanup_connection_();
     return false;
   }
@@ -105,14 +103,16 @@ bool ESPHomeOTAComponent::handle_noise_handshake_() {
         s.frame_pos = 0;
         s.frame_len = 0;
         if (s.frame_buf[noise::FRAME_HEADER_SIZE] != noise::HANDSHAKE_STATUS_OK) {
-          ESP_LOGW(TAG, "Bad handshake error byte: %u", s.frame_buf[noise::FRAME_HEADER_SIZE]);
+          ESP_LOGW(TAG, "Client rejected the handshake: %u", s.frame_buf[noise::FRAME_HEADER_SIZE]);
           this->cleanup_connection_();
           return false;
         }
         int err = s.handshake.read_message(s.frame_buf + noise::FRAME_HEADER_SIZE + 1, payload_len - 1);
         if (err != 0) {
-          ESP_LOGW(TAG, "Handshake read: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
-          this->noise_send_reject_(noise::reject_reason_for(err));
+          // A MAC failure here almost always means the uploader has a different key
+          const LogString *reason = noise::reject_reason_for(err);
+          ESP_LOGW(TAG, "Handshake read: %s (%d)", LOG_STR_ARG(reason), err);
+          this->noise_send_reject_(reason);
           this->cleanup_connection_();
           return false;
         }
@@ -123,7 +123,7 @@ bool ESPHomeOTAComponent::handle_noise_handshake_() {
         int err =
             s.handshake.write_message(s.frame_buf + noise::FRAME_HEADER_SIZE + 1, noise::MAX_HANDSHAKE_SIZE, msg_len);
         if (err != 0) {
-          ESP_LOGW(TAG, "Handshake write: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
+          ESP_LOGW(TAG, "Handshake write: %d", err);
           this->cleanup_connection_();
           return false;
         }
@@ -138,7 +138,7 @@ bool ESPHomeOTAComponent::handle_noise_handshake_() {
       case noise::NoiseResponderHandshake::Action::ACTION_SPLIT: {
         int err = s.handshake.split(s.send_cipher, s.recv_cipher);
         if (err != 0) {
-          ESP_LOGW(TAG, "Handshake split: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
+          ESP_LOGW(TAG, "Handshake split: %d", err);
           this->cleanup_connection_();
           return false;
         }
@@ -154,33 +154,41 @@ bool ESPHomeOTAComponent::handle_noise_handshake_() {
   }
 }
 
+/// Payload length from a frame header, or 0 (logged) when the indicator or
+/// the length is out of range. Callers pass min_len >= 1 so 0 is never valid.
+size_t ESPHomeOTAComponent::noise_frame_payload_len_(const uint8_t *header, size_t min_len, size_t max_len) {
+  const size_t payload_len = encode_uint16(header[1], header[2]);
+  if (header[0] != noise::FRAME_INDICATOR || payload_len < min_len || payload_len > max_len) {
+    ESP_LOGW(TAG, "Bad frame: 0x%02X, %zu bytes", header[0], payload_len);
+    return 0;
+  }
+  return payload_len;
+}
+
 /// Non-blocking read of one handshake frame into the session buffer.
 bool ESPHomeOTAComponent::noise_try_read_frame_() {
   NoiseSession &s = *this->noise_;
-  while (s.frame_pos < noise::FRAME_HEADER_SIZE) {
-    ssize_t read = this->client_->read(s.frame_buf + s.frame_pos, noise::FRAME_HEADER_SIZE - s.frame_pos);
-    if (!this->handle_read_error_(read, LOG_STR("read noise header"))) {
-      return false;
+  while (true) {
+    // The header first, then the body once the header says how long it is
+    const uint16_t want = s.frame_len == 0 ? noise::FRAME_HEADER_SIZE : s.frame_len;
+    if (s.frame_pos < want) {
+      ssize_t read = this->client_->read(s.frame_buf + s.frame_pos, want - s.frame_pos);
+      if (!this->handle_read_error_(read, LOG_STR("read noise"))) {
+        return false;
+      }
+      s.frame_pos += read;
+      continue;
     }
-    s.frame_pos += read;
-  }
-  if (s.frame_len == 0) {
-    const uint16_t payload_len = encode_uint16(s.frame_buf[1], s.frame_buf[2]);
-    if (s.frame_buf[0] != noise::FRAME_INDICATOR || payload_len < 1 || payload_len > 1 + noise::MAX_HANDSHAKE_SIZE) {
-      ESP_LOGW(TAG, "Bad handshake frame: 0x%02X, %u bytes", s.frame_buf[0], payload_len);
+    if (s.frame_len != 0) {
+      return true;
+    }
+    const size_t payload_len = this->noise_frame_payload_len_(s.frame_buf, 1, 1 + noise::MAX_HANDSHAKE_SIZE);
+    if (payload_len == 0) {
       this->cleanup_connection_();
       return false;
     }
     s.frame_len = noise::FRAME_HEADER_SIZE + payload_len;
   }
-  while (s.frame_pos < s.frame_len) {
-    ssize_t read = this->client_->read(s.frame_buf + s.frame_pos, s.frame_len - s.frame_pos);
-    if (!this->handle_read_error_(read, LOG_STR("read noise frame"))) {
-      return false;
-    }
-    s.frame_pos += read;
-  }
-  return true;
 }
 
 /// Non-blocking write of the pending session-buffer frame.
@@ -214,7 +222,7 @@ ssize_t ESPHomeOTAComponent::noise_decrypt_(uint8_t *buf, size_t len) {
   noise_buffer_set_inout(mbuf, buf, len, len);
   int err = noise_cipherstate_decrypt(this->noise_->recv_cipher, &mbuf);
   if (err != 0) {
-    ESP_LOGW(TAG, "Decrypt: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
+    ESP_LOGW(TAG, "Decrypt: %d", err);
     return -1;
   }
   return mbuf.size;
@@ -229,9 +237,8 @@ ssize_t ESPHomeOTAComponent::noise_read_frame_blocking_(uint8_t *buf, size_t min
   if (!this->readall_(header, sizeof(header))) {
     return -1;
   }
-  const size_t ciphertext_len = encode_uint16(header[1], header[2]);
-  if (header[0] != noise::FRAME_INDICATOR || ciphertext_len < min_ciphertext || ciphertext_len > max_ciphertext) {
-    ESP_LOGW(TAG, "Bad frame: 0x%02X, %zu bytes", header[0], ciphertext_len);
+  const size_t ciphertext_len = this->noise_frame_payload_len_(header, min_ciphertext, max_ciphertext);
+  if (ciphertext_len == 0) {
     return -1;
   }
   if (!this->readall_(buf, ciphertext_len)) {
@@ -267,7 +274,7 @@ bool ESPHomeOTAComponent::noise_write_byte_(uint8_t byte) {
   noise_buffer_set_inout(mbuf, frame + noise::FRAME_HEADER_SIZE, 1, 1 + noise::MAC_SIZE);
   int err = noise_cipherstate_encrypt(this->noise_->send_cipher, &mbuf);
   if (err != 0) {
-    ESP_LOGW(TAG, "Encrypt: %s", LOG_STR_ARG(noise::noise_err_to_logstr(err)));
+    ESP_LOGW(TAG, "Encrypt: %d", err);
     return false;
   }
   noise::write_frame_header(frame, mbuf.size);

esphome/components/espnow/__init__.py

@@ -3,6 +3,7 @@ from typing import Any
 from esphome import automation, core
 import esphome.codegen as cg
 from esphome.components import wifi
+from esphome.components.esp32 import VARIANT_ESP32P4, get_esp32_variant
 from esphome.components.udp import CONF_ON_RECEIVE
 import esphome.config_validation as cv
 from esphome.const import (
@@ -17,6 +18,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, HexInt
 from esphome.cpp_generator import MockObj, TemplateArgsType
+import esphome.final_validate as fv
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@jesserockz"]
@@ -132,6 +134,24 @@ CONFIG_SCHEMA = cv.All(
 )
 
 
+def _validate_variant(config: ConfigType) -> ConfigType:
+    # ESP-NOW rides the Wi-Fi PHY. Radio-less esp32 variants have no native
+    # ESP-NOW; only the ESP32-P4 has a path, via the esp32_hosted shim that
+    # supplies the esp_now_* symbols. Fail here with a clear message instead of
+    # letting the build reach an "undefined reference to esp_now_*" link error.
+    variant = get_esp32_variant()
+    if wifi.variant_has_wifi(variant):
+        return config
+    if variant != VARIANT_ESP32P4:
+        raise cv.Invalid(f"ESP-NOW is not supported on {variant} (no Wi-Fi radio)")
+    if "esp32_hosted" not in fv.full_config.get():
+        raise cv.Invalid(f"ESP-NOW on {variant} requires the esp32_hosted component")
+    return config
+
+
+FINAL_VALIDATE_SCHEMA = _validate_variant
+
+
 async def _trigger_to_code(config: ConfigType) -> MockObj:
     if address := config.get(CONF_ADDRESS):
         address = address.parts

esphome/components/i2s_audio/speaker/i2s_audio_speaker.cpp

@@ -91,7 +91,14 @@ void I2SAudioSpeakerBase::loop() {
     this->speaker_task_handle_ = nullptr;
 
     this->stop_i2s_driver_();
-    xEventGroupClearBits(this->event_group_, SpeakerEventGroupBits::ALL_BITS);
+    // ALL_BITS includes COMMAND_START. Take the bits from the clear itself, not from the snapshot at
+    // the top of loop(): the audio source's task can raise a start at any point above, including
+    // during stop_i2s_driver_(), and nothing would ever re-issue it.
+    const EventBits_t bits_before_clear = xEventGroupClearBits(this->event_group_, SpeakerEventGroupBits::ALL_BITS);
+    if (bits_before_clear & SpeakerEventGroupBits::COMMAND_START) {
+      ESP_LOGD(TAG, "Start requested while stopping; keeping the request");
+      xEventGroupSetBits(this->event_group_, SpeakerEventGroupBits::COMMAND_START);
+    }
     this->status_clear_error();
 
     this->on_task_stopped();

esphome/components/logger/logger_esp32.cpp

@@ -5,6 +5,7 @@
 #include <esp_log.h>
 
 #include <driver/uart.h>
+#include <soc/soc_caps.h>
 
 #ifdef USE_LOGGER_UART_SELECTION_USB_SERIAL_JTAG
 #include <driver/usb_serial_jtag.h>
@@ -76,7 +77,11 @@ void init_uart(uart_port_t uart_num, uint32_t baud_rate, int tx_buffer_size) {
   uart_config.parity = UART_PARITY_DISABLE;
   uart_config.stop_bits = UART_STOP_BITS_1;
   uart_config.flow_ctrl = UART_HW_FLOWCTRL_DISABLE;
+#if SOC_UART_SUPPORT_XTAL_CLK
+  uart_config.source_clk = UART_SCLK_XTAL;
+#else
   uart_config.source_clk = UART_SCLK_DEFAULT;
+#endif
   uart_param_config(uart_num, &uart_config);
   // The logger only writes to UART, never reads, so use the minimum RX buffer.
   // ESP-IDF requires rx_buffer_size > UART_HW_FIFO_LEN (128 bytes).

esphome/components/lvgl/widgets/keyboard.py

@@ -15,6 +15,7 @@ from ..defines import (
 from ..types import LvCompound, LvType
 from . import Widget, WidgetType, get_widgets
 from .buttonmatrix import CONF_BUTTONMATRIX
+from .label import CONF_LABEL
 from .textarea import CONF_TEXTAREA, lv_textarea_t
 
 CONF_KEYBOARD = "keyboard"
@@ -49,7 +50,7 @@ class KeyboardType(WidgetType):
         )
 
     def get_uses(self):
-        return CONF_KEYBOARD, CONF_TEXTAREA, CONF_BUTTONMATRIX
+        return CONF_KEYBOARD, CONF_TEXTAREA, CONF_BUTTONMATRIX, CONF_LABEL
 
     async def to_code(self, w: Widget, config: dict):
         add_lv_use("KEY_LISTENER")

esphome/components/lvgl/widgets/qrcode.py

@@ -10,6 +10,7 @@ from ..types import lv_obj_t
 from . import Widget, WidgetType
 from .canvas import CONF_CANVAS
 from .img import CONF_IMAGE
+from .label import CONF_LABEL
 
 CONF_QRCODE = "qrcode"
 CONF_DARK_COLOR = "dark_color"
@@ -41,7 +42,7 @@ class QrCodeType(WidgetType):
         )
 
     def get_uses(self):
-        return CONF_CANVAS, CONF_IMAGE
+        return CONF_CANVAS, CONF_IMAGE, CONF_LABEL
 
     async def to_code(self, w: Widget, config):
         await w.set_property(

esphome/components/lvgl/widgets/tabview.py

@@ -28,6 +28,7 @@ from ..types import LV_EVENT, LvType, ObjUpdateAction, lv_obj_t, lv_obj_t_ptr
 from . import Widget, WidgetType, add_widgets, get_widgets, set_obj_properties
 from .button import button_spec
 from .buttonmatrix import CONF_BUTTONMATRIX, buttonmatrix_spec
+from .label import CONF_LABEL
 from .obj import obj_spec
 
 CONF_TABVIEW = "tabview"
@@ -74,7 +75,7 @@ class TabviewType(WidgetType):
         )
 
     def get_uses(self):
-        return CONF_BUTTONMATRIX, TYPE_FLEX, CONF_BUTTON
+        return CONF_BUTTONMATRIX, TYPE_FLEX, CONF_BUTTON, CONF_LABEL
 
     async def to_code(self, w: Widget, config: dict):
         await w.set_property(

esphome/components/mdns/__init__.py

@@ -192,6 +192,8 @@ async def to_code(config: ConfigType) -> None:
     if CORE.using_arduino:
         if CORE.is_esp8266:
             cg.add_library("ESP8266mDNS", None)
+            # No MDNS global in the build; mdns_esp8266.cpp owns a guarded MDNSResponder
+            cg.add_build_flag("-DNO_GLOBAL_MDNS")
         elif CORE.is_rp2:
             cg.add_library("LEAmDNS", None)
 

esphome/components/mdns/mdns_esp8266.cpp

@@ -13,8 +13,47 @@
 
 namespace esphome::mdns {
 
+// Main-loop calls into LEAmDNS that send (update() and close(); begin(), addService() and
+// the scheduled restart never reach a send) can yield inside UdpContext::sendTimeout(); a
+// packet arriving then re-enters LEAmDNS from lwIP on the same UdpContext and both sides
+// free the same tx pbufs (#18760). Received packets stay queued during such a call and are
+// processed from the main loop afterwards.
+class GuardedMDNSResponder : public ::esp8266::MDNSImplementation::MDNSResponder {
+ public:
+  void update_guarded() { this->run_guarded_(&GuardedMDNSResponder::update); }
+  void close_guarded() { this->run_guarded_(&GuardedMDNSResponder::close); }
+
+ private:
+  void run_guarded_(bool (GuardedMDNSResponder::*fn)()) {
+    UdpContext *ctx = this->m_pUDPContext;
+    if (ctx == nullptr) {
+      (this->*fn)();
+      return;
+    }
+    // Set every time: a restart replaces the context together with its stock handler. Only
+    // begin() and the scheduled netif callback restart, never update() or close(), so the
+    // context cannot change underneath this call.
+    ctx->onRx([this]() {
+      if (!this->in_loop_call_) {
+        this->_callProcess();
+      }
+    });
+    this->in_loop_call_ = true;
+    (this->*fn)();
+    // close() releases the context; a yield in here queues further packets for this loop too
+    while (this->m_pUDPContext != nullptr && this->m_pUDPContext->next()) {
+      this->_parseMessage();
+    }
+    this->in_loop_call_ = false;
+  }
+
+  volatile bool in_loop_call_{false};
+};
+
+static GuardedMDNSResponder mdns_responder;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
 static void register_esp8266(MDNSComponent *, StaticVector<MDNSService, MDNS_SERVICE_COUNT> &services) {
-  MDNS.begin(App.get_name().c_str());
+  mdns_responder.begin(App.get_name().c_str());
 
   for (const auto &service : services) {
     // Strip the leading underscore from the proto and service_type. While it is
@@ -30,10 +69,10 @@ static void register_esp8266(MDNSComponent *, StaticVector<MDNSService, MDNS_SER
       service_type++;
     }
     uint16_t port = service.port.value();
-    MDNS.addService(FPSTR(service_type), FPSTR(proto), port);
+    mdns_responder.addService(FPSTR(service_type), FPSTR(proto), port);
     for (const auto &record : service.txt_records) {
-      MDNS.addServiceTxt(FPSTR(service_type), FPSTR(proto), FPSTR(MDNS_STR_ARG(record.key)),
-                         FPSTR(MDNS_STR_ARG(record.value)));
+      mdns_responder.addServiceTxt(FPSTR(service_type), FPSTR(proto), FPSTR(MDNS_STR_ARG(record.key)),
+                                   FPSTR(MDNS_STR_ARG(record.value)));
     }
   }
 }
@@ -52,7 +91,7 @@ void MDNSComponent::start_polling_window_() {
     if (wifi->is_roaming() || (!wifi->is_connected() && !wifi->is_ap_active()))
       return;
 #endif
-    MDNS.update();
+    mdns_responder.update_guarded();
   });
   this->set_timeout(MDNS_POLL_STOP_ID, MDNS_POLL_WINDOW_MS, [this]() { this->cancel_interval(MDNS_POLL_ID); });
 }
@@ -81,7 +120,7 @@ void MDNSComponent::on_ip_state(const network::IPAddresses &ips, const network::
 #endif
 
 void MDNSComponent::on_shutdown() {
-  MDNS.close();
+  mdns_responder.close_guarded();
   delay(10);
 }
 

esphome/components/mipi_dsi/mipi_dsi.cpp

@@ -35,8 +35,8 @@ void MipiDsi::setup() {
       .bus_id = 0,  // index from 0, specify the DSI host to use
       .num_data_lanes =
           this->lanes_,  // Number of data lanes to use, can't set a value that exceeds the chip's capability
-      .phy_clk_src = MIPI_DSI_PHY_CLK_SRC_DEFAULT,  // Clock source for the DPHY
-      .lane_bit_rate_mbps = this->lane_bit_rate_,   // Bit rate of the data lanes, in Mbps
+      // phy_clk_src left at 0 to enable runtime auto-select.
+      .lane_bit_rate_mbps = this->lane_bit_rate_,  // Bit rate of the data lanes, in Mbps
   };
   auto err = esp_lcd_new_dsi_bus(&bus_config, &this->bus_handle_);
   if (err != ESP_OK) {

esphome/components/mqtt/mqtt_light.cpp

@@ -67,6 +67,9 @@ void MQTTJSONLightComponent::send_discovery(JsonObject root, mqtt::SendDiscovery
   if (traits.supports_color_mode(ColorMode::RGB_COLD_WARM_WHITE))
     color_modes.add(ESPHOME_F("rgbww"));
 
+  if (traits.supports_color_capability(ColorCapability::BRIGHTNESS))
+    root[ESPHOME_F("brightness")] = true;
+
   if (traits.supports_color_mode(ColorMode::COLOR_TEMPERATURE) ||
       traits.supports_color_mode(ColorMode::COLD_WARM_WHITE)) {
     root[MQTT_MIN_MIREDS] = traits.get_min_mireds();

esphome/components/nextion/display.py

@@ -14,12 +14,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, TimePeriod
 
-from . import (  # noqa: F401  pylint: disable=unused-import
-    FILTER_SOURCE_FILES,
-    Nextion,
-    nextion_ns,
-    nextion_ref,
-)
+from . import FILTER_SOURCE_FILES, Nextion, nextion_ns, nextion_ref  # noqa: F401  pylint: disable=unused-import
 from .base_component import (
     CONF_AUTO_WAKE_ON_TOUCH,
     CONF_COMMAND_SPACING,

esphome/components/noise/__init__.py

@@ -4,7 +4,9 @@ from typing import Any
 
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.const import CONF_KEY
+from esphome.const import CONF_ENCRYPTION, CONF_KEY
+from esphome.core import ID
+from esphome.cpp_generator import MockObj
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@esphome/core"]
@@ -23,6 +25,14 @@ def validate_encryption_key(value: Any) -> str:
 
     if len(decoded) != 32:
         raise cv.Invalid("Encryption key must be base64 and 32 bytes long")
+    if not any(decoded):
+        # The device treats the all-zeros key as no key at all (it is the
+        # provisioning sentinel), so it must never reach a build
+        raise cv.Invalid(
+            f"The all-zeros {CONF_KEY} is reserved and provides no protection; "
+            f"omit the {CONF_KEY} to provision it at runtime, or generate a real "
+            "key with: openssl rand -base64 32"
+        )
 
     # Return original data for roundtrip conversion
     return value
@@ -45,15 +55,6 @@ def decode_encryption_key(value: str) -> bytes:
     return decoded
 
 
-def is_reserved_key(value: str) -> bool:
-    """Whether the key is the reserved all-zeros provisioning sentinel.
-
-    The device treats it as no key configured, so consumers that require a
-    real key must reject it.
-    """
-    return not any(decode_encryption_key(value))
-
-
 ENCRYPTION_SCHEMA = cv.Schema(
     {
         cv.Optional(CONF_KEY): cv.sensitive(validate_encryption_key),
@@ -61,6 +62,21 @@ ENCRYPTION_SCHEMA = cv.Schema(
 )
 
 
+def static_encryption_key(conf: ConfigType) -> str | None:
+    """The build time key of a component config; None without one or when
+    the key is provisioned at runtime."""
+    return (conf.get(CONF_ENCRYPTION) or {}).get(CONF_KEY) or None
+
+
+def new_psk_progmem(parent_id: ID, key: str) -> MockObj:
+    """Emit the decoded key as a PROGMEM array; the component keeps a pointer
+    so the key never occupies RAM."""
+    return cg.progmem_array(
+        ID(f"{parent_id.id}_psk", is_declaration=True, type=cg.uint8),
+        list(decode_encryption_key(key)),
+    )
+
+
 def encryption_schema(config: ConfigType | None) -> ConfigType:
     # A bare `encryption:` block is valid; a missing key means the consumer
     # falls back to its keyless behavior (api provisioning, ota inheriting
@@ -72,12 +88,12 @@ def encryption_schema(config: ConfigType | None) -> ConfigType:
 
 async def to_code(config: ConfigType) -> None:
     cg.add_define("USE_NOISE")
-    cg.add_library("esphome/noise-c", "0.1.21")
+    cg.add_library("esphome/noise-c", "0.1.24")
     # noise-c depends on libsodium, but declaring it here too lets the
     # library manager see the full set up front instead of discovering
     # libsodium only after noise-c has downloaded, so the two can download
     # in parallel. The version must match noise-c's library.json.
-    cg.add_library("esphome/libsodium", "1.10021.4")
+    cg.add_library("esphome/libsodium", "1.10021.6")
     # Enable optimized memzero/memcmp in libsodium instead of volatile byte loops
     cg.add_build_flag("-DHAVE_WEAK_SYMBOLS=1")
     cg.add_build_flag("-DHAVE_INLINE_ASM=1")

esphome/components/noise/noise.cpp

@@ -1,5 +1,6 @@
 #include "noise.h"
 #ifdef USE_NOISE
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
 #include <algorithm>
@@ -15,6 +16,14 @@ namespace esphome::noise {
 
 static const char *const TAG = "noise";
 
+void NoiseContext::load_psk(psk_t &out) const {
+  if (this->psk_ == nullptr) {
+    out.fill(0);
+    return;
+  }
+  progmem_memcpy(out.data(), this->psk_, out.size());
+}
+
 const LogString *noise_err_to_logstr(int err) {
   if (err == NOISE_ERROR_NO_MEMORY)
     return LOG_STR("NO_MEMORY");

esphome/components/noise/noise.h

@@ -23,16 +23,16 @@ class NoiseContext {
     }
     return acc == 0;
   }
-  void set_psk(psk_t psk) {
-    this->psk_ = psk;
-    this->has_psk_ = !is_all_zeros(psk);
-  }
-  const psk_t &get_psk() const { return this->psk_; }
-  bool has_psk() const { return this->has_psk_; }
+  /// psk points at 32 bytes that outlive the context (PROGMEM or caller owned
+  /// RAM); nullptr means no key. Runtime callers map the all-zeros key to
+  /// nullptr themselves; validation keeps it out of yaml.
+  void set_psk(const uint8_t *psk) { this->psk_ = psk; }
+  /// Copy the key out (flash-aware on ESP8266); all zeros when none is set.
+  void load_psk(psk_t &out) const;
+  bool has_psk() const { return this->psk_ != nullptr; }
 
  protected:
-  psk_t psk_{};
-  bool has_psk_{false};
+  const uint8_t *psk_{nullptr};
 };
 
 /// Convert a noise error code to a readable error

esphome/components/noise/noise_handshake.cpp

@@ -20,7 +20,7 @@ NoiseResponderHandshake::~NoiseResponderHandshake() {
   }
 }
 
-int NoiseResponderHandshake::init(const psk_t &psk, const uint8_t *prologue, size_t prologue_len) {
+int NoiseResponderHandshake::init(const NoiseContext &ctx, const uint8_t *prologue, size_t prologue_len) {
   if (this->handshake_ != nullptr) {
     noise_handshakestate_free(this->handshake_);
     this->handshake_ = nullptr;
@@ -44,6 +44,9 @@ int NoiseResponderHandshake::init(const psk_t &psk, const uint8_t *prologue, siz
     HANDSHAKE_STEP_LOG("noise_handshakestate_new_by_id", err);
     return err;
   }
+  // noise-c keeps its own copy, so the key only passes through the stack here
+  psk_t psk;
+  ctx.load_psk(psk);
   err = noise_handshakestate_set_pre_shared_key(this->handshake_, psk.data(), psk.size());
   if (err != 0) {
     HANDSHAKE_STEP_LOG("noise_handshakestate_set_pre_shared_key", err);

esphome/components/noise/noise_handshake.h

@@ -36,9 +36,9 @@ class NoiseResponderHandshake {
   NoiseResponderHandshake(const NoiseResponderHandshake &) = delete;
   NoiseResponderHandshake &operator=(const NoiseResponderHandshake &) = delete;
 
-  /// Create and start the handshake with the given PSK and prologue. A
-  /// repeated call frees the previous handshake state and starts over.
-  [[nodiscard]] int init(const psk_t &psk, const uint8_t *prologue, size_t prologue_len);
+  /// Create and start the handshake with the context's PSK and the prologue.
+  /// A repeated call frees the previous handshake state and starts over.
+  [[nodiscard]] int init(const NoiseContext &ctx, const uint8_t *prologue, size_t prologue_len);
   /// ACTION_FAILED is the catch-all: returned before init(), after split()
   /// has released the state, and when noise-c reports a failed handshake.
   [[nodiscard]] Action action() const;

esphome/components/ota/ota_backend.h

@@ -7,6 +7,7 @@
 #include <concepts>
 #include <cstddef>
 #include <cstdint>
+#include <type_traits>
 
 #ifdef USE_OTA_STATE_LISTENER
 #include <vector>
@@ -102,6 +103,8 @@ enum OTAType : uint8_t {
 // - set_update_md5: expected digest of the incoming image, hex string.
 // - write: consume the next chunk; end: finalize and mark bootable.
 // - abort: safe to call in any state, including after end().
+// - supports_compression: constexpr, whether a gzip image is stored as is and
+//   inflated at reboot.
 template<typename T>
 concept OTABackendContract = requires(T backend, size_t image_size, uint8_t *data, size_t len, const char *md5) {
   { backend.begin(image_size, OTA_TYPE_UPDATE_APP) } -> std::same_as<OTAResponseTypes>;
@@ -110,7 +113,9 @@ concept OTABackendContract = requires(T backend, size_t image_size, uint8_t *dat
   { backend.write(data, len) } -> std::same_as<OTAResponseTypes>;
   { backend.end() } -> std::same_as<OTAResponseTypes>;
   backend.abort();
-  { backend.supports_compression() } -> std::same_as<bool>;
+  { T::supports_compression() } -> std::same_as<bool>;
+  // The value must be a constant expression
+  typename std::bool_constant<T::supports_compression()>;
 };
 
 /** Listener interface for OTA state changes.

esphome/components/ota/ota_backend_arduino_libretiny.h

@@ -13,7 +13,7 @@ class ArduinoLibreTinyOTABackend final {
   OTAResponseTypes write(uint8_t *data, size_t len);
   OTAResponseTypes end();
   void abort();
-  bool supports_compression() { return false; }
+  static constexpr bool supports_compression() { return false; }
 
  private:
   bool md5_set_{false};

esphome/components/ota/ota_backend_arduino_rp2.h

@@ -6,6 +6,8 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/macros.h"
 
+#include <RP2040Version.h>
+
 namespace esphome::ota {
 
 class ArduinoRP2OTABackend final {
@@ -15,7 +17,12 @@ class ArduinoRP2OTABackend final {
   OTAResponseTypes write(uint8_t *data, size_t len);
   OTAResponseTypes end();
   void abort();
-  bool supports_compression() { return false; }
+  // The core's OTA stub inflates a staged gzip image at reboot, on every chip
+  // from 4.0.3 (ESPHome pins 6.0.0). begin() only sees the gzip size; the
+  // inflated size is known when the stub reads the trailer.
+  static constexpr bool supports_compression() {
+    return VERSION_CODE(ARDUINO_PICO_MAJOR, ARDUINO_PICO_MINOR, ARDUINO_PICO_REVISION) >= VERSION_CODE(4, 0, 3);
+  }
 
  private:
   bool md5_set_{false};

esphome/components/ota/ota_backend_esp8266.h

@@ -20,7 +20,7 @@ class ESP8266OTABackend final {
   OTAResponseTypes end();
   void abort();
   // Compression supported in all ESP8266 Arduino versions ESPHome supports (>= 2.7.0)
-  bool supports_compression() { return true; }
+  static constexpr bool supports_compression() { return true; }
 
  protected:
   /// Erase flash sector if current address is at sector boundary

esphome/components/ota/ota_backend_esp_idf.h

@@ -33,7 +33,7 @@ class IDFOTABackend final {
   OTAResponseTypes write(uint8_t *data, size_t len);
   OTAResponseTypes end();
   void abort();
-  bool supports_compression() { return false; }
+  static constexpr bool supports_compression() { return false; }
 
  protected:
 #ifdef USE_OTA_PARTITIONS

esphome/components/ota/ota_backend_factory.h

@@ -25,7 +25,7 @@ struct StubOTABackend {
   OTAResponseTypes write(uint8_t *data, size_t len) { return OTA_RESPONSE_ERROR_UNKNOWN; }
   OTAResponseTypes end() { return OTA_RESPONSE_ERROR_UNKNOWN; }
   void abort() {}
-  bool supports_compression() { return false; }
+  static constexpr bool supports_compression() { return false; }
 };
 std::unique_ptr<StubOTABackend> make_ota_backend();
 }  // namespace esphome::ota
@@ -33,6 +33,7 @@ std::unique_ptr<StubOTABackend> make_ota_backend();
 
 namespace esphome::ota {
 using OTABackendPtr = decltype(make_ota_backend());
-static_assert(OTABackendContract<OTABackendPtr::element_type>,
+using OTABackend = OTABackendPtr::element_type;
+static_assert(OTABackendContract<OTABackend>,
               "The platform's OTA backend is missing part of the backend surface (ota_backend.h)");
 }  // namespace esphome::ota

esphome/components/ota/ota_backend_host.h

@@ -19,7 +19,7 @@ class HostOTABackend final {
   OTAResponseTypes write(uint8_t *data, size_t len);
   OTAResponseTypes end();
   void abort();
-  bool supports_compression() { return false; }
+  static constexpr bool supports_compression() { return false; }
 
  protected:
   md5::MD5Digest md5_{};

esphome/components/rf_bridge/rf_bridge.cpp

@@ -18,6 +18,16 @@ void RFBridgeComponent::ack_() {
 }
 
 bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
+  if (this->bucket_frame_candidate_ && byte == RF_CODE_START) {
+    // A queued next frame proves the trailing 0x55 really was the bucket
+    // frame's terminator: Portisch builds pulse entries from alternating
+    // signal edges, so the two level bits inside one pulse byte are always
+    // opposite — 0xAA (two high-level nibbles) cannot occur in pulse data.
+    // Finalize before this byte starts the new frame, so back-to-back
+    // deliveries are split even when loop() never observed a quiet gap
+    // between them.
+    this->finish_bucket_frame_();
+  }
   size_t at = this->rx_buffer_.size();
   this->rx_buffer_.push_back(byte);
   const uint8_t *raw = &this->rx_buffer_[0];
@@ -84,26 +94,21 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
       break;
     }
     case RF_CODE_RFIN_BUCKET: {
-      if (byte != RF_CODE_STOP) {
-        return true;
+      if (at == 2) {
+        // The count byte: Portisch sends at most 7 buckets + sync, so 0 or
+        // >8 cannot be a genuine capture — reject before it can occupy the
+        // buffer for a full frame timeout.
+        return byte != 0 && byte <= B1_MAX_BUCKET_COUNT;
       }
-
-      uint8_t buckets = raw[2] << 1;
-      std::string str;
-      char next_byte[3];  // 2 hex chars + null
-
-      for (uint32_t i = 0; i <= at; i++) {
-        buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[i]);
-        str += next_byte;
-        if ((i > 3) && buckets) {
-          buckets--;
-        }
-        if ((i < 3) || (buckets % 2) || (i == at - 1)) {
-          str += " ";
-        }
-      }
-      ESP_LOGI(TAG, "Received RFBridge Bucket: %s", str.c_str());
-      break;
+      // 0x55 is legal DATA inside a B1 frame: bucket durations are sent
+      // with only their HIGH byte masked to 7 bits, so a duration such as
+      // 0x0155 puts a raw 0x55 low byte inside the table — the first 0x55
+      // must therefore not end the capture. The header declares the table
+      // length (raw[2] pairs), so a 0x55 there is always data; one at or
+      // past the first pulse index is a terminator CANDIDATE, confirmed
+      // once the UART goes quiet (finish_bucket_frame_ in loop()).
+      this->bucket_frame_candidate_ = byte == RF_CODE_STOP && at >= 3 + static_cast<size_t>(raw[2]) * 2;
+      return true;
     }
     default:
       ESP_LOGW(TAG, "Unknown action: 0x%02X", action);
@@ -119,6 +124,47 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
   return false;
 }
 
+void RFBridgeComponent::finish_bucket_frame_() {
+  if (this->rx_buffer_.size() < 4) {
+    // The candidate flag requires a header + non-empty bucket table, so
+    // this cannot happen while flag and buffer stay consistent; guard the
+    // raw[2] / size-1 reads against any future divergence anyway.
+    this->rx_buffer_.clear();
+    this->bucket_frame_candidate_ = false;
+    return;
+  }
+  const uint8_t *raw = this->rx_buffer_.data();
+  const size_t at = this->rx_buffer_.size() - 1;
+
+  uint8_t buckets = raw[2] << 1;
+  std::string str;
+  char next_byte[3];  // 2 hex chars + null
+
+  for (uint32_t i = 0; i <= at; i++) {
+    buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[i]);
+    str += next_byte;
+    if ((i > 3) && buckets) {
+      buckets--;
+    }
+    if ((i < 3) || (buckets % 2) || (i == at - 1)) {
+      str += " ";
+    }
+  }
+  ESP_LOGI(TAG, "Received RFBridge Bucket: %s", str.c_str());
+
+  // Deliberately NOT ACKed: Portisch's B1 command handler leaves its
+  // last_sniffing_command at the previous mode (RF_CODE_RFIN), and its
+  // host-ACK handler re-arms sniffing from that stale value — so ACKing a
+  // bucket delivery silently reverts the radio to standard sniffing and
+  // ends bucket capture. Its delivery path is fire-and-forget and never
+  // waits for a host ACK. Stock Itead firmware never sends B1 frames, so
+  // suppressing this ACK cannot change stock-firmware behavior.
+  // https://github.com/esphome/esphome/issues/17682
+
+  this->rx_buffer_.clear();
+  this->bucket_frame_candidate_ = false;
+}
+
 void RFBridgeComponent::write_byte_str_(const std::string &codes) {
   uint8_t code;
   int size = codes.length();
@@ -130,12 +176,31 @@ void RFBridgeComponent::write_byte_str_(const std::string &codes) {
 
 void RFBridgeComponent::loop() {
   const uint32_t now = App.get_loop_component_start_time();
-  if (now - this->last_bridge_byte_ > 50) {
+  size_t avail = this->available();
+  if (avail == 0 && this->bucket_frame_candidate_ && now - this->last_bridge_byte_ > BUCKET_CANDIDATE_QUIET_MS) {
+    // The trailing 0x55 was followed by UART quiet, so it really was the
+    // frame terminator and not an interior data byte.
+    this->finish_bucket_frame_();
+    this->last_bridge_byte_ = now;
+  }
+  const bool receiving_bucket = this->rx_buffer_.size() >= 2 && this->rx_buffer_[1] == RF_CODE_RFIN_BUCKET;
+  if (receiving_bucket) {
+    // Never declare an in-progress bucket frame dead while its continuation
+    // bytes are already queued: a stalled loop() otherwise discards a live
+    // frame that the UART buffer proves is still arriving.
+    if (avail == 0 && now - this->last_bridge_byte_ > BUCKET_FRAME_TIMEOUT_MS) {
+      ESP_LOGD(TAG, "Discarding incomplete RFBridge Bucket frame (%u bytes)",
+               static_cast<unsigned>(this->rx_buffer_.size()));
+      this->rx_buffer_.clear();
+      this->bucket_frame_candidate_ = false;
+      this->last_bridge_byte_ = now;
+    }
+  } else if (now - this->last_bridge_byte_ > 50) {
     this->rx_buffer_.clear();
+    this->bucket_frame_candidate_ = false;
     this->last_bridge_byte_ = now;
   }
 
-  size_t avail = this->available();
   while (avail > 0) {
     uint8_t buf[64];
     size_t to_read = std::min(avail, sizeof(buf));
@@ -146,12 +211,14 @@ void RFBridgeComponent::loop() {
     for (size_t i = 0; i < to_read; i++) {
       if (this->rx_buffer_.size() > MAX_RX_BUFFER_SIZE) {
         this->rx_buffer_.clear();
+        this->bucket_frame_candidate_ = false;
       }
       if (this->parse_bridge_byte_(buf[i])) {
         ESP_LOGVV(TAG, "Parsed: 0x%02X", buf[i]);
         this->last_bridge_byte_ = now;
       } else {
         this->rx_buffer_.clear();
+        this->bucket_frame_candidate_ = false;
       }
     }
   }

esphome/components/rf_bridge/rf_bridge.h

@@ -30,6 +30,17 @@ static const uint8_t RF_CODE_BEEP = 0xC0;
 static const uint8_t RF_CODE_STOP = 0x55;
 static const uint8_t RF_DEBOUNCE = 200;
 static const size_t MAX_RX_BUFFER_SIZE = 512;
+// ~10 byte times at 19200 baud: long enough to prove the UART went quiet
+// after a possible bucket-frame terminator, short enough to finish well
+// before the next radio capture can be delivered.
+static const uint32_t BUCKET_CANDIDATE_QUIET_MS = 5;
+// Portisch drains a B1 frame's header, bucket table, and pulse data as
+// separate UART writes, so an in-progress bucket frame tolerates a longer
+// inter-region gap than the generic 50 ms inter-byte timeout.
+static const uint32_t BUCKET_FRAME_TIMEOUT_MS = 250;
+// Portisch's uart_put_RF_buckets sends at most 7 buckets plus the sync
+// bucket, so a B1 count byte above 8 (or 0) is malformed for any protocol.
+static const uint8_t B1_MAX_BUCKET_COUNT = 8;
 
 struct RFBridgeData {
   uint16_t sync;
@@ -67,10 +78,12 @@ class RFBridgeComponent final : public uart::UARTDevice, public Component {
   void ack_();
   void decode_();
   bool parse_bridge_byte_(uint8_t byte);
+  void finish_bucket_frame_();
   void write_byte_str_(const std::string &codes);
 
   std::vector<uint8_t> rx_buffer_;
   uint32_t last_bridge_byte_{0};
+  bool bucket_frame_candidate_{false};
 
   CallbackManager<void(RFBridgeData)> data_callback_;
   CallbackManager<void(RFBridgeAdvancedData)> advanced_data_callback_;

esphome/components/template/climate/__init__.py

@@ -0,0 +1,465 @@
+from esphome import automation
+import esphome.codegen as cg
+from esphome.components import climate, sensor
+from esphome.components.climate import climate_ns
+import esphome.config_validation as cv
+from esphome.const import (
+    CONF_ACTION,
+    CONF_CURRENT_TEMPERATURE,
+    CONF_CUSTOM_FAN_MODE,
+    CONF_CUSTOM_FAN_MODES,
+    CONF_CUSTOM_PRESET,
+    CONF_CUSTOM_PRESETS,
+    CONF_FAN_MODE,
+    CONF_HUMIDITY_SENSOR,
+    CONF_ID,
+    CONF_INITIAL_STATE,
+    CONF_MODE,
+    CONF_OPTIMISTIC,
+    CONF_PRESET,
+    CONF_RESTORE_MODE,
+    CONF_SENSOR,
+    CONF_SUPPORTED_FAN_MODES,
+    CONF_SUPPORTED_MODES,
+    CONF_SUPPORTED_PRESETS,
+    CONF_SUPPORTED_SWING_MODES,
+    CONF_SWING_MODE,
+    CONF_TARGET_TEMPERATURE,
+    CONF_TARGET_TEMPERATURE_HIGH,
+    CONF_TARGET_TEMPERATURE_LOW,
+)
+from esphome.core import ID
+from esphome.cpp_generator import MockObj, TemplateArgsType
+from esphome.types import ConfigType
+
+from .. import template_ns
+
+CONF_CURRENT_HUMIDITY = "current_humidity"
+CONF_TARGET_HUMIDITY = "target_humidity"
+CONF_SUPPORTS_ACTION = "supports_action"
+CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE = "supports_two_point_target_temperature"
+CONF_SUPPORTS_TARGET_HUMIDITY = "supports_target_humidity"
+CONF_SUPPORTS_CURRENT_TEMPERATURE = "supports_current_temperature"
+CONF_SUPPORTS_CURRENT_HUMIDITY = "supports_current_humidity"
+CONF_SET_MODE_ACTION = "set_mode_action"
+CONF_SET_TARGET_TEMPERATURE_ACTION = "set_target_temperature_action"
+CONF_SET_TARGET_TEMPERATURE_LOW_ACTION = "set_target_temperature_low_action"
+CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION = "set_target_temperature_high_action"
+CONF_SET_TARGET_HUMIDITY_ACTION = "set_target_humidity_action"
+CONF_SET_FAN_MODE_ACTION = "set_fan_mode_action"
+CONF_SET_CUSTOM_FAN_MODE_ACTION = "set_custom_fan_mode_action"
+CONF_SET_SWING_MODE_ACTION = "set_swing_mode_action"
+CONF_SET_PRESET_ACTION = "set_preset_action"
+CONF_SET_CUSTOM_PRESET_ACTION = "set_custom_preset_action"
+
+TemplateClimate = template_ns.class_("TemplateClimate", climate.Climate, cg.Component)
+TemplateClimatePublishAction = template_ns.class_(
+    "TemplateClimatePublishAction",
+    automation.Action,
+    cg.Parented.template(TemplateClimate),
+)
+
+TemplateClimateRestoreMode = template_ns.enum(
+    "TemplateClimateRestoreMode", is_class=True
+)
+CLIMATE_RESTORE_MODES = {
+    "NO_RESTORE": TemplateClimateRestoreMode.TEMPLATE_CLIMATE_RESTORE_MODE_NO_RESTORE,
+    "RESTORE": TemplateClimateRestoreMode.TEMPLATE_CLIMATE_RESTORE_MODE_RESTORE,
+}
+
+# Per-field actions that forward a requested value on. The third item is the type of `x`.
+SET_ACTIONS = (
+    (CONF_SET_MODE_ACTION, "get_set_mode_trigger", climate.ClimateMode),
+    (
+        CONF_SET_TARGET_TEMPERATURE_ACTION,
+        "get_set_target_temperature_trigger",
+        cg.float_,
+    ),
+    (
+        CONF_SET_TARGET_TEMPERATURE_LOW_ACTION,
+        "get_set_target_temperature_low_trigger",
+        cg.float_,
+    ),
+    (
+        CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION,
+        "get_set_target_temperature_high_trigger",
+        cg.float_,
+    ),
+    (CONF_SET_TARGET_HUMIDITY_ACTION, "get_set_target_humidity_trigger", cg.float_),
+    (CONF_SET_FAN_MODE_ACTION, "get_set_fan_mode_trigger", climate.ClimateFanMode),
+    (
+        CONF_SET_CUSTOM_FAN_MODE_ACTION,
+        "get_set_custom_fan_mode_trigger",
+        cg.StringRef,
+    ),
+    (
+        CONF_SET_SWING_MODE_ACTION,
+        "get_set_swing_mode_trigger",
+        climate.ClimateSwingMode,
+    ),
+    (CONF_SET_PRESET_ACTION, "get_set_preset_trigger", climate.ClimatePreset),
+    (CONF_SET_CUSTOM_PRESET_ACTION, "get_set_custom_preset_trigger", cg.StringRef),
+)
+
+# supports_* keys have no default so that an omitted key can mean "derive it from the sensor or
+# set action that makes the trait useful", which is not expressible once a default fills it in.
+DERIVED_SUPPORTS = (
+    (CONF_SUPPORTS_CURRENT_TEMPERATURE, (CONF_SENSOR,)),
+    (CONF_SUPPORTS_CURRENT_HUMIDITY, (CONF_HUMIDITY_SENSOR,)),
+    (
+        CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE,
+        (
+            CONF_SET_TARGET_TEMPERATURE_LOW_ACTION,
+            CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION,
+        ),
+    ),
+    (CONF_SUPPORTS_TARGET_HUMIDITY, (CONF_SET_TARGET_HUMIDITY_ACTION,)),
+)
+
+
+# Custom fan modes/presets are opaque user-defined strings with no build-time correctness check
+# elsewhere (Climate::set_supported_custom_fan_modes()/set_supported_custom_presets() don't block
+# empty entries), so reject empty ones here -- they could never be selected at runtime anyway.
+validate_custom_climate_string = cv.All(cv.string_strict, cv.Length(min=1))
+
+
+def _validate_two_point(config: ConfigType) -> ConfigType:
+    has_low = CONF_TARGET_TEMPERATURE_LOW in config
+    has_high = CONF_TARGET_TEMPERATURE_HIGH in config
+    if has_low != has_high:
+        raise cv.Invalid(
+            f"'{CONF_TARGET_TEMPERATURE_LOW}' and '{CONF_TARGET_TEMPERATURE_HIGH}' must be used together"
+        )
+    if (has_low or has_high) and CONF_TARGET_TEMPERATURE in config:
+        raise cv.Invalid(
+            f"'{CONF_TARGET_TEMPERATURE}' cannot be used together with "
+            f"'{CONF_TARGET_TEMPERATURE_LOW}'/'{CONF_TARGET_TEMPERATURE_HIGH}'"
+        )
+    return config
+
+
+def _validate_set_actions(config: ConfigType) -> ConfigType:
+    has_low = CONF_SET_TARGET_TEMPERATURE_LOW_ACTION in config
+    has_high = CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION in config
+    if has_low != has_high:
+        raise cv.Invalid(
+            f"'{CONF_SET_TARGET_TEMPERATURE_LOW_ACTION}' and "
+            f"'{CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION}' must be used together"
+        )
+    if (has_low or has_high) and CONF_SET_TARGET_TEMPERATURE_ACTION in config:
+        raise cv.Invalid(
+            f"'{CONF_SET_TARGET_TEMPERATURE_ACTION}' cannot be used together with "
+            f"'{CONF_SET_TARGET_TEMPERATURE_LOW_ACTION}'/'{CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION}'"
+        )
+    return config
+
+
+def _resolve_supports(config: ConfigType) -> ConfigType:
+    # An explicit true stays valid without either, since climate.template.publish can report the
+    # value; an explicit false that contradicts the configuration is an error, not a silent override.
+    for key, sources in DERIVED_SUPPORTS:
+        configured = [source for source in sources if source in config]
+        if key not in config:
+            config[key] = bool(configured)
+        elif not config[key] and configured:
+            raise cv.Invalid(
+                f"'{key}' cannot be false while '{configured[0]}' is configured",
+                path=[key],
+            )
+    return config
+
+
+def _validate_initial_state(config: ConfigType) -> ConfigType:
+    # Climate keeps target_temperature and target_temperature_low in a union, so writing the wrong
+    # one of the pair corrupts the setpoint with no runtime complaint.
+    if (initial_state := config.get(CONF_INITIAL_STATE)) is None:
+        return config
+
+    two_point = config[CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE]
+    if two_point and CONF_TARGET_TEMPERATURE in initial_state:
+        raise cv.Invalid(
+            f"'{CONF_TARGET_TEMPERATURE}' is not available while "
+            f"'{CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE}' is enabled; use "
+            f"'{CONF_TARGET_TEMPERATURE_LOW}'/'{CONF_TARGET_TEMPERATURE_HIGH}' instead",
+            path=[CONF_INITIAL_STATE, CONF_TARGET_TEMPERATURE],
+        )
+    if not two_point:
+        for key in (CONF_TARGET_TEMPERATURE_LOW, CONF_TARGET_TEMPERATURE_HIGH):
+            if key in initial_state:
+                raise cv.Invalid(
+                    f"'{key}' requires '{CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE}' to be enabled",
+                    path=[CONF_INITIAL_STATE, key],
+                )
+    if (
+        CONF_TARGET_HUMIDITY in initial_state
+        and not config[CONF_SUPPORTS_TARGET_HUMIDITY]
+    ):
+        raise cv.Invalid(
+            f"'{CONF_TARGET_HUMIDITY}' requires '{CONF_SUPPORTS_TARGET_HUMIDITY}' to be enabled",
+            path=[CONF_INITIAL_STATE, CONF_TARGET_HUMIDITY],
+        )
+    return config
+
+
+# Same settable fields as climate.template.publish, minus current_temperature/current_humidity/
+# action: those are reported values (from a sensor or the device), not meaningful static defaults.
+INITIAL_STATE_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.Optional(CONF_MODE): climate.validate_climate_mode,
+            cv.Optional(CONF_TARGET_TEMPERATURE): cv.temperature,
+            cv.Optional(CONF_TARGET_TEMPERATURE_LOW): cv.temperature,
+            cv.Optional(CONF_TARGET_TEMPERATURE_HIGH): cv.temperature,
+            cv.Optional(CONF_TARGET_HUMIDITY): cv.percentage_int,
+            cv.Exclusive(CONF_FAN_MODE, "fan_mode"): climate.validate_climate_fan_mode,
+            cv.Exclusive(
+                CONF_CUSTOM_FAN_MODE, "fan_mode"
+            ): validate_custom_climate_string,
+            cv.Optional(CONF_SWING_MODE): climate.validate_climate_swing_mode,
+            cv.Exclusive(CONF_PRESET, "preset"): climate.validate_climate_preset,
+            cv.Exclusive(CONF_CUSTOM_PRESET, "preset"): validate_custom_climate_string,
+        }
+    ),
+    _validate_two_point,
+)
+
+CONFIG_SCHEMA = cv.All(
+    climate.climate_schema(TemplateClimate)
+    .extend(
+        {
+            cv.Optional(CONF_SENSOR): cv.use_id(sensor.Sensor),
+            cv.Optional(CONF_HUMIDITY_SENSOR): cv.use_id(sensor.Sensor),
+            # action only ever arrives through climate.template.publish, so unlike the other
+            # supports_* keys there is no set action to derive it from.
+            cv.Optional(CONF_SUPPORTS_ACTION, default=False): cv.boolean,
+            cv.Optional(CONF_SUPPORTS_CURRENT_TEMPERATURE): cv.boolean,
+            cv.Optional(CONF_SUPPORTS_CURRENT_HUMIDITY): cv.boolean,
+            cv.Optional(CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE): cv.boolean,
+            cv.Optional(CONF_SUPPORTS_TARGET_HUMIDITY): cv.boolean,
+            cv.Required(CONF_SUPPORTED_MODES): cv.All(
+                cv.ensure_list(climate.validate_climate_mode), cv.Unique()
+            ),
+            cv.Optional(CONF_SUPPORTED_FAN_MODES): cv.All(
+                cv.ensure_list(climate.validate_climate_fan_mode), cv.Unique()
+            ),
+            cv.Optional(CONF_CUSTOM_FAN_MODES): cv.All(
+                cv.ensure_list(validate_custom_climate_string), cv.Unique()
+            ),
+            cv.Optional(CONF_SUPPORTED_SWING_MODES): cv.All(
+                cv.ensure_list(climate.validate_climate_swing_mode), cv.Unique()
+            ),
+            cv.Optional(CONF_SUPPORTED_PRESETS): cv.All(
+                cv.ensure_list(climate.validate_climate_preset), cv.Unique()
+            ),
+            cv.Optional(CONF_CUSTOM_PRESETS): cv.All(
+                cv.ensure_list(validate_custom_climate_string), cv.Unique()
+            ),
+            cv.Optional(CONF_OPTIMISTIC, default=True): cv.boolean,
+            cv.Optional(CONF_RESTORE_MODE, default="RESTORE"): cv.enum(
+                CLIMATE_RESTORE_MODES, upper=True
+            ),
+            cv.Optional(CONF_INITIAL_STATE): INITIAL_STATE_SCHEMA,
+            cv.Optional(CONF_SET_MODE_ACTION): automation.validate_automation(
+                single=True
+            ),
+            cv.Optional(
+                CONF_SET_TARGET_TEMPERATURE_ACTION
+            ): automation.validate_automation(single=True),
+            cv.Optional(
+                CONF_SET_TARGET_TEMPERATURE_LOW_ACTION
+            ): automation.validate_automation(single=True),
+            cv.Optional(
+                CONF_SET_TARGET_TEMPERATURE_HIGH_ACTION
+            ): automation.validate_automation(single=True),
+            cv.Optional(
+                CONF_SET_TARGET_HUMIDITY_ACTION
+            ): automation.validate_automation(single=True),
+            cv.Optional(CONF_SET_FAN_MODE_ACTION): automation.validate_automation(
+                single=True
+            ),
+            cv.Optional(
+                CONF_SET_CUSTOM_FAN_MODE_ACTION
+            ): automation.validate_automation(single=True),
+            cv.Optional(CONF_SET_SWING_MODE_ACTION): automation.validate_automation(
+                single=True
+            ),
+            cv.Optional(CONF_SET_PRESET_ACTION): automation.validate_automation(
+                single=True
+            ),
+            cv.Optional(CONF_SET_CUSTOM_PRESET_ACTION): automation.validate_automation(
+                single=True
+            ),
+        }
+    )
+    .extend(cv.COMPONENT_SCHEMA),
+    _validate_set_actions,
+    _resolve_supports,
+    _validate_initial_state,
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await climate.register_climate(var, config)
+
+    if (sens := config.get(CONF_SENSOR)) is not None:
+        cg.add(var.set_sensor(await cg.get_variable(sens)))
+
+    if (sens := config.get(CONF_HUMIDITY_SENSOR)) is not None:
+        cg.add(var.set_humidity_sensor(await cg.get_variable(sens)))
+
+    for key, flag in (
+        (CONF_SUPPORTS_ACTION, climate_ns.CLIMATE_SUPPORTS_ACTION),
+        (
+            CONF_SUPPORTS_CURRENT_TEMPERATURE,
+            climate_ns.CLIMATE_SUPPORTS_CURRENT_TEMPERATURE,
+        ),
+        (CONF_SUPPORTS_CURRENT_HUMIDITY, climate_ns.CLIMATE_SUPPORTS_CURRENT_HUMIDITY),
+        (
+            CONF_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE,
+            climate_ns.CLIMATE_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE,
+        ),
+        (CONF_SUPPORTS_TARGET_HUMIDITY, climate_ns.CLIMATE_SUPPORTS_TARGET_HUMIDITY),
+    ):
+        if config[key]:
+            cg.add(var.add_feature_flags(flag))
+
+    for mode in config[CONF_SUPPORTED_MODES]:
+        cg.add(var.add_supported_mode(mode))
+
+    for mode in config.get(CONF_SUPPORTED_FAN_MODES, []):
+        cg.add(var.add_supported_fan_mode(mode))
+
+    if CONF_CUSTOM_FAN_MODES in config:
+        cg.add(
+            var.set_supported_custom_fan_modes(
+                cg.ArrayInitializer(*config[CONF_CUSTOM_FAN_MODES])
+            )
+        )
+
+    for mode in config.get(CONF_SUPPORTED_SWING_MODES, []):
+        cg.add(var.add_supported_swing_mode(mode))
+
+    for preset in config.get(CONF_SUPPORTED_PRESETS, []):
+        cg.add(var.add_supported_preset(preset))
+
+    if CONF_CUSTOM_PRESETS in config:
+        cg.add(
+            var.set_supported_custom_presets(
+                cg.ArrayInitializer(*config[CONF_CUSTOM_PRESETS])
+            )
+        )
+
+    for key, trigger_getter, arg_type in SET_ACTIONS:
+        if (conf := config.get(key)) is not None:
+            await automation.build_automation(
+                getattr(var, trigger_getter)(), [(arg_type, "x")], conf
+            )
+
+    cg.add(var.set_optimistic(config[CONF_OPTIMISTIC]))
+    cg.add(var.set_restore_mode(config[CONF_RESTORE_MODE]))
+
+    if (initial_state := config.get(CONF_INITIAL_STATE)) is not None:
+        if (v := initial_state.get(CONF_MODE)) is not None:
+            cg.add(var.set_mode(v))
+        if (v := initial_state.get(CONF_TARGET_TEMPERATURE)) is not None:
+            cg.add(var.set_target_temperature(v))
+        if (v := initial_state.get(CONF_TARGET_TEMPERATURE_LOW)) is not None:
+            cg.add(var.set_target_temperature_low(v))
+        if (v := initial_state.get(CONF_TARGET_TEMPERATURE_HIGH)) is not None:
+            cg.add(var.set_target_temperature_high(v))
+        if (v := initial_state.get(CONF_TARGET_HUMIDITY)) is not None:
+            cg.add(var.set_target_humidity(v))
+        if (v := initial_state.get(CONF_FAN_MODE)) is not None:
+            cg.add(var.set_fan_mode(v))
+        if (v := initial_state.get(CONF_CUSTOM_FAN_MODE)) is not None:
+            cg.add(var.set_custom_fan_mode(v))
+        if (v := initial_state.get(CONF_SWING_MODE)) is not None:
+            cg.add(var.set_swing_mode(v))
+        if (v := initial_state.get(CONF_PRESET)) is not None:
+            cg.add(var.set_preset(v))
+        if (v := initial_state.get(CONF_CUSTOM_PRESET)) is not None:
+            cg.add(var.set_custom_preset(v))
+
+
+CLIMATE_TEMPLATE_PUBLISH_ACTION_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.use_id(TemplateClimate),
+            cv.Optional(CONF_CURRENT_TEMPERATURE): cv.templatable(cv.temperature),
+            cv.Optional(CONF_CURRENT_HUMIDITY): cv.templatable(cv.percentage_int),
+            cv.Optional(CONF_TARGET_TEMPERATURE): cv.templatable(cv.temperature),
+            cv.Optional(CONF_TARGET_TEMPERATURE_LOW): cv.templatable(cv.temperature),
+            cv.Optional(CONF_TARGET_TEMPERATURE_HIGH): cv.templatable(cv.temperature),
+            cv.Optional(CONF_TARGET_HUMIDITY): cv.templatable(cv.percentage_int),
+            cv.Optional(CONF_MODE): cv.templatable(climate.validate_climate_mode),
+            cv.Optional(CONF_ACTION): cv.templatable(climate.validate_climate_action),
+            cv.Exclusive(CONF_FAN_MODE, "fan_mode"): cv.templatable(
+                climate.validate_climate_fan_mode
+            ),
+            cv.Exclusive(CONF_CUSTOM_FAN_MODE, "fan_mode"): cv.templatable(
+                validate_custom_climate_string
+            ),
+            cv.Optional(CONF_SWING_MODE): cv.templatable(
+                climate.validate_climate_swing_mode
+            ),
+            cv.Exclusive(CONF_PRESET, "preset"): cv.templatable(
+                climate.validate_climate_preset
+            ),
+            cv.Exclusive(CONF_CUSTOM_PRESET, "preset"): cv.templatable(
+                validate_custom_climate_string
+            ),
+        }
+    ),
+    _validate_two_point,
+)
+
+
+@automation.register_action(
+    "climate.template.publish",
+    TemplateClimatePublishAction,
+    CLIMATE_TEMPLATE_PUBLISH_ACTION_SCHEMA,
+    synchronous=True,
+)
+async def climate_template_publish_to_code(
+    config: ConfigType,
+    action_id: ID,
+    template_arg: cg.TemplateArguments,
+    args: TemplateArgsType,
+) -> MockObj:
+    var = cg.new_Pvariable(action_id, template_arg)
+    await cg.register_parented(var, config[CONF_ID])
+
+    if (v := config.get(CONF_CURRENT_TEMPERATURE)) is not None:
+        cg.add(var.set_current_temperature(await cg.templatable(v, args, cg.float_)))
+    if (v := config.get(CONF_CURRENT_HUMIDITY)) is not None:
+        cg.add(var.set_current_humidity(await cg.templatable(v, args, cg.float_)))
+    if (v := config.get(CONF_TARGET_TEMPERATURE)) is not None:
+        cg.add(var.set_target_temperature(await cg.templatable(v, args, cg.float_)))
+    if (v := config.get(CONF_TARGET_TEMPERATURE_LOW)) is not None:
+        cg.add(var.set_target_temperature_low(await cg.templatable(v, args, cg.float_)))
+    if (v := config.get(CONF_TARGET_TEMPERATURE_HIGH)) is not None:
+        cg.add(
+            var.set_target_temperature_high(await cg.templatable(v, args, cg.float_))
+        )
+    if (v := config.get(CONF_TARGET_HUMIDITY)) is not None:
+        cg.add(var.set_target_humidity(await cg.templatable(v, args, cg.float_)))
+    if (v := config.get(CONF_MODE)) is not None:
+        cg.add(var.set_mode(await cg.templatable(v, args, climate.ClimateMode)))
+    if (v := config.get(CONF_ACTION)) is not None:
+        cg.add(var.set_action(await cg.templatable(v, args, climate.ClimateAction)))
+    if (v := config.get(CONF_FAN_MODE)) is not None:
+        cg.add(var.set_fan_mode(await cg.templatable(v, args, climate.ClimateFanMode)))
+    if (v := config.get(CONF_CUSTOM_FAN_MODE)) is not None:
+        cg.add(var.set_custom_fan_mode(await cg.templatable(v, args, cg.std_string)))
+    if (v := config.get(CONF_SWING_MODE)) is not None:
+        cg.add(
+            var.set_swing_mode(await cg.templatable(v, args, climate.ClimateSwingMode))
+        )
+    if (v := config.get(CONF_PRESET)) is not None:
+        cg.add(var.set_preset(await cg.templatable(v, args, climate.ClimatePreset)))
+    if (v := config.get(CONF_CUSTOM_PRESET)) is not None:
+        cg.add(var.set_custom_preset(await cg.templatable(v, args, cg.std_string)))
+
+    return var

esphome/components/template/climate/automation.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include "template_climate.h"
+#include "esphome/core/automation.h"
+
+namespace esphome::template_ {
+
+template<typename... Ts>
+class TemplateClimatePublishAction final : public Action<Ts...>, public Parented<TemplateClimate> {
+ public:
+  TEMPLATABLE_VALUE(float, current_temperature)
+  TEMPLATABLE_VALUE(float, current_humidity)
+  TEMPLATABLE_VALUE(float, target_temperature)
+  TEMPLATABLE_VALUE(float, target_temperature_low)
+  TEMPLATABLE_VALUE(float, target_temperature_high)
+  TEMPLATABLE_VALUE(float, target_humidity)
+  TEMPLATABLE_VALUE(climate::ClimateMode, mode)
+  TEMPLATABLE_VALUE(climate::ClimateAction, action)
+  TEMPLATABLE_VALUE(climate::ClimateFanMode, fan_mode)
+  TEMPLATABLE_VALUE(std::string, custom_fan_mode)
+  TEMPLATABLE_VALUE(climate::ClimateSwingMode, swing_mode)
+  TEMPLATABLE_VALUE(climate::ClimatePreset, preset)
+  TEMPLATABLE_VALUE(std::string, custom_preset)
+
+  void play(const Ts &...x) override {
+    if (this->current_temperature_.has_value())
+      this->parent_->current_temperature = this->current_temperature_.value(x...);
+    if (this->current_humidity_.has_value())
+      this->parent_->current_humidity = this->current_humidity_.value(x...);
+    if (this->target_temperature_.has_value())
+      this->parent_->set_target_temperature(this->target_temperature_.value(x...));
+    if (this->target_temperature_low_.has_value())
+      this->parent_->set_target_temperature_low(this->target_temperature_low_.value(x...));
+    if (this->target_temperature_high_.has_value())
+      this->parent_->set_target_temperature_high(this->target_temperature_high_.value(x...));
+    if (this->target_humidity_.has_value())
+      this->parent_->set_target_humidity(this->target_humidity_.value(x...));
+    if (this->mode_.has_value())
+      this->parent_->set_mode(this->mode_.value(x...));
+    if (this->action_.has_value())
+      this->parent_->action = this->action_.value(x...);
+    if (this->fan_mode_.has_value())
+      this->parent_->set_fan_mode(this->fan_mode_.value(x...));
+    if (this->custom_fan_mode_.has_value())
+      this->parent_->set_custom_fan_mode(StringRef(this->custom_fan_mode_.value(x...)));
+    if (this->swing_mode_.has_value())
+      this->parent_->set_swing_mode(this->swing_mode_.value(x...));
+    if (this->preset_.has_value())
+      this->parent_->set_preset(this->preset_.value(x...));
+    if (this->custom_preset_.has_value())
+      this->parent_->set_custom_preset(StringRef(this->custom_preset_.value(x...)));
+
+    this->parent_->publish_state();
+  }
+};
+
+}  // namespace esphome::template_

esphome/components/template/climate/template_climate.cpp

@@ -0,0 +1,164 @@
+#include "template_climate.h"
+#include "esphome/core/log.h"
+
+namespace esphome::template_ {
+
+static const char *const TAG = "template.climate";
+
+void TemplateClimate::setup() {
+  if (this->restore_mode_ == TemplateClimateRestoreMode::TEMPLATE_CLIMATE_RESTORE_MODE_RESTORE) {
+    auto restore = this->restore_state_();
+    if (restore.has_value()) {
+      restore->apply(this);
+    }
+  }
+
+  // Sensors publish every reading, not just changes, so only re-publish when the value moved.
+  // NAN means the sensor went unavailable and is passed through rather than dropped; the second
+  // check stops an unavailable sensor re-publishing forever, since NAN never equals NAN.
+#ifdef USE_SENSOR
+  if (this->sensor_ != nullptr) {
+    this->current_temperature = this->sensor_->state;
+    this->sensor_->add_on_state_callback([this](float state) {
+      if (state != this->current_temperature && !(std::isnan(state) && std::isnan(this->current_temperature))) {
+        this->current_temperature = state;
+        this->publish_state();
+      }
+    });
+  }
+
+  if (this->humidity_sensor_ != nullptr) {
+    this->current_humidity = this->humidity_sensor_->state;
+    this->humidity_sensor_->add_on_state_callback([this](float state) {
+      if (state != this->current_humidity && !(std::isnan(state) && std::isnan(this->current_humidity))) {
+        this->current_humidity = state;
+        this->publish_state();
+      }
+    });
+  }
+#endif
+}
+
+void TemplateClimate::dump_config() {
+  LOG_CLIMATE("", "Template Climate", this);
+  ESP_LOGCONFIG(TAG, "  Optimistic: %s", YESNO(this->optimistic_));
+}
+
+void TemplateClimate::control(const climate::ClimateCall &call) {
+  // Each field present fires its set_*_action; on_control sees the whole call. optimistic: true
+  // also applies the values right away, false waits for a climate.template.publish report.
+  if (auto mode = call.get_mode()) {
+    if (this->optimistic_)
+      this->mode = *mode;
+    this->set_mode_trigger_.trigger(*mode);
+  }
+
+  if (auto target_temp = call.get_target_temperature()) {
+    if (this->optimistic_)
+      this->target_temperature = *target_temp;
+    this->set_target_temperature_trigger_.trigger(*target_temp);
+  }
+
+  if (auto target_temp_low = call.get_target_temperature_low()) {
+    if (this->optimistic_)
+      this->target_temperature_low = *target_temp_low;
+    this->set_target_temperature_low_trigger_.trigger(*target_temp_low);
+  }
+
+  if (auto target_temp_high = call.get_target_temperature_high()) {
+    if (this->optimistic_)
+      this->target_temperature_high = *target_temp_high;
+    this->set_target_temperature_high_trigger_.trigger(*target_temp_high);
+  }
+
+  if (auto target_humidity = call.get_target_humidity()) {
+    if (this->optimistic_)
+      this->target_humidity = *target_humidity;
+    this->set_target_humidity_trigger_.trigger(*target_humidity);
+  }
+
+  if (auto fan_mode = call.get_fan_mode()) {
+    if (this->optimistic_)
+      this->set_fan_mode_(*fan_mode);
+    this->set_fan_mode_trigger_.trigger(*fan_mode);
+  }
+
+  if (call.has_custom_fan_mode()) {
+    if (this->optimistic_)
+      this->set_custom_fan_mode_(call.get_custom_fan_mode());
+    this->set_custom_fan_mode_trigger_.trigger(call.get_custom_fan_mode());
+  }
+
+  if (auto swing_mode = call.get_swing_mode()) {
+    if (this->optimistic_)
+      this->swing_mode = *swing_mode;
+    this->set_swing_mode_trigger_.trigger(*swing_mode);
+  }
+
+  if (auto preset = call.get_preset()) {
+    if (this->optimistic_)
+      this->set_preset_(*preset);
+    this->set_preset_trigger_.trigger(*preset);
+  }
+
+  if (call.has_custom_preset()) {
+    if (this->optimistic_)
+      this->set_custom_preset_(call.get_custom_preset());
+    this->set_custom_preset_trigger_.trigger(call.get_custom_preset());
+  }
+
+  if (this->optimistic_)
+    this->publish_state();
+}
+
+// A climate.template.publish report (and initial_state:) never goes through ClimateCall::validate_(),
+// so check here instead -- otherwise a typo is published as state the receiving end will reject.
+void TemplateClimate::set_mode(climate::ClimateMode mode) {
+  if (!this->traits_.supports_mode(mode)) {
+    ESP_LOGW(TAG, "'%s' - Unsupported mode %u", this->get_name().c_str(), static_cast<unsigned>(mode));
+    return;
+  }
+  this->mode = mode;
+}
+
+void TemplateClimate::set_swing_mode(climate::ClimateSwingMode swing_mode) {
+  if (!this->traits_.supports_swing_mode(swing_mode)) {
+    ESP_LOGW(TAG, "'%s' - Unsupported swing mode %u", this->get_name().c_str(), static_cast<unsigned>(swing_mode));
+    return;
+  }
+  this->swing_mode = swing_mode;
+}
+
+void TemplateClimate::set_fan_mode(climate::ClimateFanMode fan_mode) {
+  if (!this->traits_.supports_fan_mode(fan_mode)) {
+    ESP_LOGW(TAG, "'%s' - Unsupported fan mode %u", this->get_name().c_str(), static_cast<unsigned>(fan_mode));
+    return;
+  }
+  this->set_fan_mode_(fan_mode);
+}
+
+void TemplateClimate::set_preset(climate::ClimatePreset preset) {
+  if (!this->traits_.supports_preset(preset)) {
+    ESP_LOGW(TAG, "'%s' - Unsupported preset %u", this->get_name().c_str(), static_cast<unsigned>(preset));
+    return;
+  }
+  this->set_preset_(preset);
+}
+
+void TemplateClimate::set_custom_fan_mode(StringRef mode) {
+  if (this->find_custom_fan_mode_(mode.c_str(), mode.size()) == nullptr) {
+    ESP_LOGW(TAG, "'%s' - Unsupported custom fan mode '%s'", this->get_name().c_str(), mode.c_str());
+    return;
+  }
+  this->set_custom_fan_mode_(mode);
+}
+
+void TemplateClimate::set_custom_preset(StringRef preset) {
+  if (this->find_custom_preset_(preset.c_str(), preset.size()) == nullptr) {
+    ESP_LOGW(TAG, "'%s' - Unsupported custom preset '%s'", this->get_name().c_str(), preset.c_str());
+    return;
+  }
+  this->set_custom_preset_(preset);
+}
+
+}  // namespace esphome::template_

esphome/components/template/climate/template_climate.h

@@ -0,0 +1,92 @@
+#pragma once
+
+#include "esphome/core/automation.h"
+#include "esphome/core/component.h"
+#include "esphome/components/climate/climate.h"
+#ifdef USE_SENSOR
+#include "esphome/components/sensor/sensor.h"
+#endif
+
+namespace esphome::template_ {
+
+enum class TemplateClimateRestoreMode {
+  TEMPLATE_CLIMATE_RESTORE_MODE_NO_RESTORE,
+  TEMPLATE_CLIMATE_RESTORE_MODE_RESTORE,
+};
+
+class TemplateClimate final : public climate::Climate, public Component {
+ public:
+  void setup() override;
+  void dump_config() override;
+
+  climate::ClimateTraits traits() override { return this->traits_; }
+
+  void add_feature_flags(uint32_t flags) { this->traits_.add_feature_flags(flags); }
+
+#ifdef USE_SENSOR
+  // The matching feature flag is added from codegen, so the configuration alone decides it.
+  void set_sensor(sensor::Sensor *sensor) { this->sensor_ = sensor; }
+  void set_humidity_sensor(sensor::Sensor *sensor) { this->humidity_sensor_ = sensor; }
+#endif
+
+  void add_supported_mode(climate::ClimateMode mode) { this->traits_.add_supported_mode(mode); }
+  void add_supported_fan_mode(climate::ClimateFanMode mode) { this->traits_.add_supported_fan_mode(mode); }
+  void add_supported_swing_mode(climate::ClimateSwingMode mode) { this->traits_.add_supported_swing_mode(mode); }
+  void add_supported_preset(climate::ClimatePreset preset) { this->traits_.add_supported_preset(preset); }
+
+  void set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
+  void set_restore_mode(TemplateClimateRestoreMode restore_mode) { this->restore_mode_ = restore_mode; }
+
+  // Fired from control() for each field the call carries, so a device-backed config can forward
+  // it on. Which of these are configured also decides the two-point/target-humidity traits.
+  Trigger<climate::ClimateMode> *get_set_mode_trigger() { return &this->set_mode_trigger_; }
+  Trigger<float> *get_set_target_temperature_trigger() { return &this->set_target_temperature_trigger_; }
+  Trigger<float> *get_set_target_temperature_low_trigger() { return &this->set_target_temperature_low_trigger_; }
+  Trigger<float> *get_set_target_temperature_high_trigger() { return &this->set_target_temperature_high_trigger_; }
+  Trigger<float> *get_set_target_humidity_trigger() { return &this->set_target_humidity_trigger_; }
+  Trigger<climate::ClimateFanMode> *get_set_fan_mode_trigger() { return &this->set_fan_mode_trigger_; }
+  Trigger<StringRef> *get_set_custom_fan_mode_trigger() { return &this->set_custom_fan_mode_trigger_; }
+  Trigger<climate::ClimateSwingMode> *get_set_swing_mode_trigger() { return &this->set_swing_mode_trigger_; }
+  Trigger<climate::ClimatePreset> *get_set_preset_trigger() { return &this->set_preset_trigger_; }
+  Trigger<StringRef> *get_set_custom_preset_trigger() { return &this->set_custom_preset_trigger_; }
+
+  // Used by TemplateClimatePublishAction, which is not a Climate subclass and so cannot reach the
+  // protected setters, and by codegen to apply `initial_state:` before setup() runs.
+  void set_target_temperature(float value) { this->target_temperature = value; }
+  void set_target_temperature_low(float value) { this->target_temperature_low = value; }
+  void set_target_temperature_high(float value) { this->target_temperature_high = value; }
+  void set_target_humidity(float value) { this->target_humidity = value; }
+  void set_mode(climate::ClimateMode mode);
+  void set_swing_mode(climate::ClimateSwingMode mode);
+  void set_fan_mode(climate::ClimateFanMode mode);
+  void set_custom_fan_mode(const char *mode) { this->set_custom_fan_mode(StringRef(mode)); }
+  void set_custom_fan_mode(StringRef mode);
+  void set_preset(climate::ClimatePreset preset);
+  void set_custom_preset(const char *preset) { this->set_custom_preset(StringRef(preset)); }
+  void set_custom_preset(StringRef preset);
+
+ protected:
+  void control(const climate::ClimateCall &call) override;
+
+  climate::ClimateTraits traits_;
+  bool optimistic_{false};
+  TemplateClimateRestoreMode restore_mode_{TemplateClimateRestoreMode::TEMPLATE_CLIMATE_RESTORE_MODE_NO_RESTORE};
+
+#ifdef USE_SENSOR
+  sensor::Sensor *sensor_{nullptr};
+  sensor::Sensor *humidity_sensor_{nullptr};
+#endif
+
+  Trigger<climate::ClimateMode> set_mode_trigger_;
+  Trigger<float> set_target_temperature_trigger_;
+  Trigger<float> set_target_temperature_low_trigger_;
+  Trigger<float> set_target_temperature_high_trigger_;
+  Trigger<float> set_target_humidity_trigger_;
+  Trigger<climate::ClimateFanMode> set_fan_mode_trigger_;
+  Trigger<StringRef> set_custom_fan_mode_trigger_;
+  Trigger<climate::ClimateSwingMode> set_swing_mode_trigger_;
+  Trigger<climate::ClimatePreset> set_preset_trigger_;
+  Trigger<StringRef> set_custom_preset_trigger_;
+};
+
+}  // namespace esphome::template_

esphome/components/tuya/tuya.cpp

@@ -1,10 +1,13 @@
 #include "tuya.h"
-#include "esphome/components/network/util.h"
 #include "esphome/core/gpio.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/util.h"
 
+#ifdef USE_NETWORK
+#include "esphome/components/network/util.h"
+#endif
+
 #ifdef USE_WIFI
 #include "esphome/components/wifi/wifi_component.h"
 #endif
@@ -22,6 +25,14 @@ static const int MAX_RETRIES = 5;
 // Max bytes to log for datapoint values (larger values are truncated)
 static constexpr size_t MAX_DATAPOINT_LOG_BYTES = 16;
 
+static bool network_is_connected() {
+#ifdef USE_NETWORK
+  return network::is_connected();
+#else
+  return false;
+#endif
+}
+
 void Tuya::setup() {
   this->set_interval("heartbeat", 15000, [this] { this->send_empty_command_(TuyaCommandType::HEARTBEAT); });
   if (this->status_pin_ != nullptr) {
@@ -554,14 +565,14 @@ void Tuya::send_empty_command_(TuyaCommandType command) {
 }
 
 void Tuya::set_status_pin_() {
-  bool is_network_ready = network::is_connected() && remote_is_connected();
+  bool is_network_ready = network_is_connected() && remote_is_connected();
   this->status_pin_->digital_write(is_network_ready);
 }
 
 uint8_t Tuya::get_wifi_status_code_() {
   uint8_t status = 0x02;
 
-  if (network::is_connected()) {
+  if (network_is_connected()) {
     status = 0x03;
 
     // Protocol version 3 also supports specifying when connected to "the cloud"

esphome/components/udp/__init__.py

@@ -1,5 +1,4 @@
-from collections.abc import Callable
-from typing import Any, NoReturn
+from typing import Any
 
 from esphome import automation
 from esphome.automation import Trigger
@@ -48,17 +47,10 @@ UDP_SCHEMA = cv.Schema(
 )
 
 
-def is_relocated(option: str) -> Callable[[Any], NoReturn]:
-    def validator(value: Any) -> NoReturn:
-        raise cv.Invalid(
-            f"The '{option}' option should now be configured in the 'packet_transport' component"
-        )
-
-    return validator
-
-
 RELOCATED = {
-    cv.Optional(x): is_relocated(x)
+    cv.Optional(x): cv.invalid(
+        f"The '{x}' option should now be configured in the 'packet_transport' component"
+    )
     for x in (
         CONF_PROVIDERS,
         CONF_ENCRYPTION,

esphome/components/usb_uart/usb_uart.cpp

@@ -434,11 +434,12 @@ void USBUartTypeCdcAcm::on_connected() {
       auto err_comm = usb_host_interface_claim(this->handle_, this->device_handle_,
                                                channel->cdc_dev_.interrupt_interface_number, 0);
       if (err_comm != ESP_OK) {
+        // Continue anyway: the interface number stays valid for CDC request addressing
         ESP_LOGW(TAG, "Could not claim comm interface %d: %s", channel->cdc_dev_.interrupt_interface_number,
                  esp_err_to_name(err_comm));
-        channel->cdc_dev_.interrupt_interface_number = 0xFF;  // Mark as unavailable, but continue anyway
       } else {
         ESP_LOGD(TAG, "Claimed comm interface %d", channel->cdc_dev_.interrupt_interface_number);
+        channel->cdc_dev_.interrupt_interface_claimed = true;
       }
     }
     auto err =
@@ -465,14 +466,15 @@ void USBUartTypeCdcAcm::on_disconnected() {
       usb_host_endpoint_halt(this->device_handle_, channel->cdc_dev_.out_ep->bEndpointAddress);
       usb_host_endpoint_flush(this->device_handle_, channel->cdc_dev_.out_ep->bEndpointAddress);
     }
-    if (channel->cdc_dev_.notify_ep != nullptr) {
+    // Only tear down the notify pipe when we claimed its interface ourselves;
+    // no transfer is ever submitted on it, so there is nothing else to cancel.
+    if (channel->cdc_dev_.notify_ep != nullptr && channel->cdc_dev_.interrupt_interface_claimed) {
       usb_host_endpoint_halt(this->device_handle_, channel->cdc_dev_.notify_ep->bEndpointAddress);
       usb_host_endpoint_flush(this->device_handle_, channel->cdc_dev_.notify_ep->bEndpointAddress);
     }
-    if (channel->cdc_dev_.interrupt_interface_number != 0xFF &&
-        channel->cdc_dev_.interrupt_interface_number != channel->cdc_dev_.bulk_interface_number) {
+    if (channel->cdc_dev_.interrupt_interface_claimed) {
       usb_host_interface_release(this->handle_, this->device_handle_, channel->cdc_dev_.interrupt_interface_number);
-      channel->cdc_dev_.interrupt_interface_number = 0xFF;
+      channel->cdc_dev_.interrupt_interface_claimed = false;
     }
     usb_host_interface_release(this->handle_, this->device_handle_, channel->cdc_dev_.bulk_interface_number);
     // Reset the input and output started flags to their initial state to avoid the possibility of spurious restarts

esphome/components/usb_uart/usb_uart.h

@@ -34,7 +34,10 @@ struct CdcEps {
   const usb_ep_desc_t *in_ep;
   const usb_ep_desc_t *out_ep;
   uint8_t bulk_interface_number;
+  // Also the wIndex target for CDC class requests (SET_LINE_CODING etc.), so it
+  // must remain valid even when the interface itself is not claimed.
   uint8_t interrupt_interface_number;
+  bool interrupt_interface_claimed{false};
 };
 
 enum CH34xChipType : uint8_t {

esphome/components/wifi/__init__.py

@@ -66,13 +66,14 @@ from esphome.const import (
 )
 from esphome.core import (
     CORE,
+    ID,
     CoroPriority,
     EsphomeError,
     HexInt,
     coroutine_with_priority,
 )
 import esphome.final_validate as fv
-from esphome.types import ConfigType
+from esphome.types import ConfigType, TemplateArgsType
 
 from . import wpa2_eap
 
@@ -208,6 +209,7 @@ WiFiEnabledCondition = wifi_ns.class_("WiFiEnabledCondition", Condition)
 WiFiAPActiveCondition = wifi_ns.class_("WiFiAPActiveCondition", Condition)
 WiFiEnableAction = wifi_ns.class_("WiFiEnableAction", automation.Action)
 WiFiDisableAction = wifi_ns.class_("WiFiDisableAction", automation.Action)
+WiFiRoamAction = wifi_ns.class_("WiFiRoamAction", automation.Action)
 WiFiConfigureAction = wifi_ns.class_(
     "WiFiConfigureAction", automation.Action, cg.Component
 )
@@ -820,6 +822,18 @@ async def wifi_disable_to_code(config, action_id, template_arg, args):
     return cg.new_Pvariable(action_id, template_arg)
 
 
+@automation.register_action(
+    "wifi.roam", WiFiRoamAction, cv.Schema({}), synchronous=True
+)
+async def wifi_roam_to_code(
+    config: ConfigType,
+    action_id: ID,
+    template_arg: cg.TemplateArguments,
+    args: TemplateArgsType,
+) -> cg.MockObj:
+    return cg.new_Pvariable(action_id, template_arg)
+
+
 KEEP_SCAN_RESULTS_KEY = "wifi_keep_scan_results"
 RUNTIME_POWER_SAVE_KEY = "wifi_runtime_power_save"
 RUNTIME_ROAMING_SUPPRESSION_KEY = "wifi_runtime_roaming_suppression"

esphome/components/wifi/automation.h

@@ -31,6 +31,11 @@ template<typename... Ts> class WiFiDisableAction final : public Action<Ts...> {
   void play(const Ts &...x) override { global_wifi_component->disable(); }
 };
 
+template<typename... Ts> class WiFiRoamAction final : public Action<Ts...> {
+ public:
+  void play(const Ts &...x) override { global_wifi_component->force_roam_check(); }
+};
+
 template<typename... Ts> class WiFiConfigureAction final : public Action<Ts...>, public Component {
  public:
   TEMPLATABLE_VALUE(std::string, ssid)

esphome/components/wifi/wifi_component.cpp

@@ -846,17 +846,18 @@ void WiFiComponent::loop() {
           this->notify_connect_state_listeners_();
 #endif
 
-          // Post-connect roaming: check for better AP
-          if (this->post_connect_roaming_) {
-            if (this->is_roaming_scan_active()) {
-              if (this->scan_done_) {
-                this->process_roaming_scan_();
-              }
-              // else: scan in progress, wait
-            } else if (this->roaming_state_ == RoamingState::IDLE && this->roaming_attempts_ < ROAMING_MAX_ATTEMPTS &&
-                       now - this->roaming_last_check_ >= ROAMING_CHECK_INTERVAL && !this->roaming_suppressed_()) {
-              this->check_roaming_(now);
+          // Post-connect roaming: check for better AP. A scan may have been started by an
+          // explicit force_roam_check() even when post_connect_roaming_ is disabled, so the
+          // scan must always be consumed here to avoid leaving roaming_state_ stuck.
+          if (this->is_roaming_scan_active()) {
+            if (this->scan_done_) {
+              this->process_roaming_scan_();
             }
+            // else: scan in progress, wait
+          } else if (this->post_connect_roaming_ && this->roaming_state_ == RoamingState::IDLE &&
+                     this->roaming_attempts_ < ROAMING_MAX_ATTEMPTS &&
+                     now - this->roaming_last_check_ >= ROAMING_CHECK_INTERVAL && !this->roaming_suppressed_()) {
+            this->check_roaming_(now);
           }
         }
         break;
@@ -2463,6 +2464,17 @@ void WiFiComponent::notify_scan_results_listeners_() {
 }
 #endif  // USE_WIFI_SCAN_RESULTS_LISTENERS
 
+void WiFiComponent::force_roam_check() {
+  if (!this->is_connected() || this->roaming_state_ != RoamingState::IDLE || this->roaming_suppressed_()) {
+    ESP_LOGD(TAG, "Roam check requested, but not able to check now");
+    return;
+  }
+  // Reset the attempt counter so a prior run of failed roams doesn't block this explicit request
+  // Note that this re-arms automatic roaming if enabled.
+  this->roaming_attempts_ = 0;
+  this->check_roaming_(millis());
+}
+
 void WiFiComponent::check_roaming_(uint32_t now) {
   // Guard: not for hidden networks (may not appear in scan)
   const WiFiAP *selected = this->get_selected_sta_();
@@ -2484,7 +2496,11 @@ void WiFiComponent::check_roaming_(uint32_t now) {
 
   ESP_LOGD(TAG, "Roam scan (%d dBm, attempt %u/%u)", rssi, this->roaming_attempts_, ROAMING_MAX_ATTEMPTS);
   this->roaming_state_ = RoamingState::SCANNING;
-  this->wifi_scan_start_(this->passive_scan_);
+  if (!this->wifi_scan_start_(this->passive_scan_)) {
+    // Scan failed to start (e.g. busy) - don't get stuck in SCANNING forever
+    ESP_LOGD(TAG, "Roam scan failed to start");
+    this->roaming_state_ = RoamingState::IDLE;
+  }
 }
 
 void WiFiComponent::process_roaming_scan_() {

esphome/components/wifi/wifi_component.h

@@ -565,6 +565,12 @@ class WiFiComponent final : public Component {
   void set_keep_scan_results(bool keep_scan_results) { this->keep_scan_results_ = keep_scan_results; }
   void set_post_connect_roaming(bool enabled) { this->post_connect_roaming_ = enabled; }
 
+  /** Force an immediate post-connect roaming check, bypassing the periodic interval and the
+   * per-connection attempt limit. Does nothing (besides a debug log) if not connected, if a
+   * roam scan or connect is already in progress, or if roaming is currently suppressed.
+   */
+  void force_roam_check();
+
 #ifdef USE_WIFI_CONNECT_TRIGGER
   Trigger<> *get_connect_trigger() { return &this->connect_trigger_; }
 #endif

esphome/config_validation.py

@@ -133,6 +133,7 @@ Upper = vol.Upper
 Length = vol.Length
 Exclusive = vol.Exclusive
 Inclusive = vol.Inclusive
+Unique = vol.Unique
 ALLOW_EXTRA = vol.ALLOW_EXTRA
 UNDEFINED = vol.UNDEFINED
 RequiredFieldInvalid = vol.RequiredFieldInvalid

esphome/core/defines.h

@@ -71,6 +71,7 @@
 #define USE_ESP32_HOSTED
 #define USE_ESP32_HOSTED_HTTP_UPDATE
 #define USE_ESP32_IMPROV_STATE_CALLBACK
+#define USE_ESP_NOW_HOSTED
 #define USE_EVENT
 #define USE_FAN
 #define USE_GPIO_BINARY_SENSOR_INTERRUPT
@@ -243,7 +244,11 @@
 #define USE_RUNTIME_IMAGE_QOI
 #define USE_RUNTIME_STATS
 #define USE_OTA
+#define USE_OTA_DEFLATE
 #define USE_OTA_ENCRYPTION
+#define USE_OTA_ENCRYPTION_FROM_API
+#define USE_OTA_ENCRYPTION_PROVISIONED
+#define USE_OTA_ENCRYPTION_REQUIRED
 #define USE_OTA_PASSWORD
 #define USE_OTA_VERSION 2
 #define USE_TIME_TIMEZONE

esphome/espota2.py

@@ -11,6 +11,7 @@ import secrets
 import socket
 import time
 from typing import Any
+import zlib
 
 from esphome.core import EsphomeError
 from esphome.helpers import ProgressBar, resolve_ip_address
@@ -65,9 +66,15 @@ CLIENT_FEATURE_SUPPORTS_COMPRESSION = 0x01
 CLIENT_FEATURE_SUPPORTS_SHA256_AUTH = 0x02
 CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL = 0x04
 CLIENT_FEATURE_SUPPORTS_NOISE = 0x08
+CLIENT_FEATURE_SUPPORTS_DEFLATE = 0x10
 SERVER_FEATURE_SUPPORTS_COMPRESSION = 0x01
 SERVER_FEATURE_SUPPORTS_PARTITION_ACCESS = 0x02
 SERVER_FEATURE_SUPPORTS_NOISE = 0x04
+# Binding once offered: the device then expects the image size and a deflate stream
+SERVER_FEATURE_SUPPORTS_DEFLATE = 0x08
+
+# Wire constant: the deflate bit promises a 4 KB window (OTA_INFLATE_WINDOW_SIZE)
+DEFLATE_WINDOW_BITS = 12
 
 NOISE_FRAME_INDICATOR = 0x01
 NOISE_HANDSHAKE_OK = 0x00
@@ -87,6 +94,9 @@ _SUPPORTED_OTA_TYPES: frozenset[int] = frozenset(
 )
 
 UPLOAD_BLOCK_SIZE = 8192
+# Sizes on the wire are 4 bytes MSB first
+SIZE_FIELD_BYTES = 4
+COMPRESS_LEVEL = 9
 UPLOAD_BUFFER_SIZE = UPLOAD_BLOCK_SIZE * 8
 
 # Flaky Wi-Fi links often drop the first OTA attempt, and the device may need time
@@ -202,6 +212,49 @@ class OTANetworkError(OTAError):
     """Network-level OTA failure (timeout, reset, closed connection); retrying may succeed."""
 
 
+# Remove before 2027.3.0
+class OTAEncryptionFallback(OTAError):
+    """The encrypted attempt failed and the caller may retry in plaintext."""
+
+
+# Remove before 2027.3.0
+PLAINTEXT_FALLBACK_NOTICE = (
+    "A device with an api encryption key offers encryption after this "
+    "install; add 'encryption:' under 'ota: platform: esphome' to require it. "
+    "This plaintext fallback is removed in 2027.3.0."
+)
+
+
+# Remove before 2027.3.0
+class _EncryptionAttempt:
+    """The key an upload tries and whether it may fall back to plaintext;
+    a rejected handshake falls back at once, a transport fault only on repeat."""
+
+    def __init__(self, noise_psk: str | None, plaintext_fallback: bool) -> None:
+        self.noise_psk = noise_psk
+        self.plaintext_fallback = plaintext_fallback
+        self.handshake_faults = 0
+
+    def handshake_fault_falls_back(self) -> bool:
+        self.handshake_faults += 1
+        return self.plaintext_fallback and self.handshake_faults >= 2
+
+    def downgrade(self, reason: str) -> None:
+        _LOGGER.warning(
+            "%s. Retrying in plaintext; a device that requires encryption "
+            "refuses it. %s",
+            reason,
+            PLAINTEXT_FALLBACK_NOTICE,
+        )
+        self.noise_psk = None
+        self.plaintext_fallback = False
+
+
+# Remove before 2027.3.0: only the fallback decision needs this distinction
+class OTAHandshakeNetworkError(OTANetworkError):
+    """A transport failure inside the noise handshake; retrying encrypted may succeed."""
+
+
 def _committed_error(err: OTANetworkError) -> OTAError:
     """Wrap a network failure that happened once the device had the full image.
 
@@ -464,6 +517,7 @@ def perform_ota(
     filename: Path,
     ota_type: int = OTA_TYPE_UPDATE_APP,
     noise_psk: str | None = None,
+    plaintext_fallback: bool = False,
 ) -> None:
     # Validate up front; an out-of-range value would only surface as a
     # ValueError deep inside send_check, bypassing OTAError handling
@@ -503,6 +557,7 @@ def perform_ota(
         CLIENT_FEATURE_SUPPORTS_COMPRESSION
         | CLIENT_FEATURE_SUPPORTS_SHA256_AUTH
         | CLIENT_FEATURE_SUPPORTS_EXTENDED_PROTOCOL
+        | CLIENT_FEATURE_SUPPORTS_DEFLATE
     )
     if noise_psk:
         features_to_send |= CLIENT_FEATURE_SUPPORTS_NOISE
@@ -528,19 +583,28 @@ def perform_ota(
     else:
         features = 0
 
-    if noise_psk:
-        # Fail closed: never fall back to a plaintext upload when an
-        # encryption key is configured, an active attacker could otherwise
-        # strip the feature flag and capture the image (it contains the wifi
-        # credentials and the api encryption key).
-        if not (extended_proto and features & SERVER_FEATURE_SUPPORTS_NOISE):
+    if noise_psk and not (extended_proto and features & SERVER_FEATURE_SUPPORTS_NOISE):
+        if plaintext_fallback:
+            # Remove before 2027.3.0: older firmware that cannot encrypt still
+            # gets its update on this connection
+            _LOGGER.warning(
+                "The device did not offer OTA encryption; continuing in plaintext. %s",
+                PLAINTEXT_FALLBACK_NOTICE,
+            )
+            noise_psk = None
+        else:
+            # Fail closed: an attacker could otherwise strip the offer and
+            # capture the image (wifi credentials, api key)
             raise OTAError(
                 "An OTA encryption key is configured but the device did not "
                 "offer encryption; refusing to send the image in plaintext. "
-                "If the running firmware predates OTA encryption, first update "
-                "it without the 'ota: encryption:' block (over a trusted "
-                "network or via USB), then restore the block and upload again."
+                "The running firmware predates ESPHome 2026.9.0 or has no "
+                "'api: encryption: key'. With an api key, install once "
+                "without the 'ota: encryption:' block (that build offers "
+                "encryption), then restore it; otherwise flash by serial or "
+                "the web_server OTA platform."
             )
+    if noise_psk:
         # The prologue binds every negotiation byte both sides saw, so any
         # tampering with the plaintext preamble breaks the handshake.
         prologue = (
@@ -549,8 +613,18 @@ def perform_ota(
             + bytes([RESPONSE_OK, version, features_to_send])
             + bytes([RESPONSE_FEATURE_FLAGS, features])
         )
+        # Built outside the try: a local failure must never downgrade the upload
         sock = NoiseSocketWrapper(sock, noise_psk, prologue)
-        sock.do_handshake()
+        try:
+            sock.do_handshake()
+        except OTANetworkError as err:
+            # A transport fault: retry encrypted before considering plaintext
+            raise OTAHandshakeNetworkError(str(err)) from err
+        except OTAError as err:
+            # Remove before 2027.3.0
+            if plaintext_fallback:
+                raise OTAEncryptionFallback(str(err)) from err
+            raise
         _LOGGER.info("Encrypted connection established")
 
     if ota_type != OTA_TYPE_UPDATE_APP:
@@ -577,8 +651,16 @@ def perform_ota(
                 f"retry {flag_name}."
             )
 
-    if features & SERVER_FEATURE_SUPPORTS_COMPRESSION:
-        upload_contents = gzip.compress(file_contents, compresslevel=9)
+    deflate = bool(extended_proto and features & SERVER_FEATURE_SUPPORTS_DEFLATE)
+    if deflate:
+        # The device inflates while receiving through a small ring window
+        upload_contents = zlib.compress(
+            file_contents, COMPRESS_LEVEL, wbits=-DEFLATE_WINDOW_BITS
+        )
+        _LOGGER.info("Compressed to %s bytes (deflate)", len(upload_contents))
+    elif features & SERVER_FEATURE_SUPPORTS_COMPRESSION:
+        # The device stores the gzip file and inflates it when it reboots
+        upload_contents = gzip.compress(file_contents, compresslevel=COMPRESS_LEVEL)
         _LOGGER.info("Compressed to %s bytes", len(upload_contents))
     else:
         upload_contents = file_contents
@@ -638,22 +720,20 @@ def perform_ota(
         send_check(sock, ota_type, "ota type")
 
     upload_size = len(upload_contents)
-    upload_size_encoded = [
-        (upload_size >> 24) & 0xFF,
-        (upload_size >> 16) & 0xFF,
-        (upload_size >> 8) & 0xFF,
-        (upload_size >> 0) & 0xFF,
-    ]
     # The device erases flash between receiving the size and acking the
     # prepare, so this window shows the erase cost (near zero when the
     # device erases lazily during the upload)
     prepare_start = time.perf_counter()
-    send_check(sock, upload_size_encoded, "binary size")
+    send_check(sock, upload_size.to_bytes(SIZE_FIELD_BYTES, "big"), "binary size")
+    if deflate:
+        # Own frame: an encrypted session carries one field per frame
+        send_check(sock, file_size.to_bytes(SIZE_FIELD_BYTES, "big"), "image size")
     receive_exactly(sock, 1, "update prepare result", RESPONSE_UPDATE_PREPARE_OK)
     prepare_duration = time.perf_counter() - prepare_start
     _LOGGER.info("Preparing for upload took %.2f seconds", prepare_duration)
 
-    upload_md5 = hashlib.md5(upload_contents).hexdigest()
+    # The device hashes what it writes: the inflated image, else the received bytes
+    upload_md5 = hashlib.md5(file_contents if deflate else upload_contents).hexdigest()
     _LOGGER.debug("MD5 of upload is %s", upload_md5)
 
     send_check(sock, upload_md5, "file checksum")
@@ -757,6 +837,7 @@ def run_ota_impl_(
     filename: Path,
     ota_type: int = OTA_TYPE_UPDATE_APP,
     noise_psk: str | None = None,
+    plaintext_fallback: bool = False,
 ) -> tuple[int, str | None]:
     from esphome.core import CORE
 
@@ -795,7 +876,9 @@ def run_ota_impl_(
     total_attempts = len(res) + EXTRA_UPLOAD_ATTEMPTS
     last_error = ""
     reached_device = False
-    for attempt in range(total_attempts):
+    attempt = 0
+    encryption = _EncryptionAttempt(noise_psk, plaintext_fallback)
+    while attempt < total_attempts:
         af, socktype, _, _, sa = res[attempt % len(res)]
         if reached_device or attempt >= len(res):
             _LOGGER.info(
@@ -815,17 +898,40 @@ def run_ota_impl_(
             sock.close()
             _LOGGER.warning("Connecting to %s port %s failed: %s", sa[0], sa[1], err)
             last_error = f"connecting to {sa[0]} failed: {err}"
+            attempt += 1
             continue
 
         _LOGGER.info("Connected to %s", sa[0])
         reached_device = True
         with contextlib.closing(sock), Path(filename).open("rb") as file_handle:
             try:
-                perform_ota(sock, password, file_handle, filename, ota_type, noise_psk)
+                perform_ota(
+                    sock,
+                    password,
+                    file_handle,
+                    filename,
+                    ota_type,
+                    encryption.noise_psk,
+                    encryption.plaintext_fallback,
+                )
+            except OTAEncryptionFallback as err:
+                # Same address and attempt budget: not a network retry
+                last_error = str(err)
+                encryption.downgrade(last_error)
+                continue
+            except OTAHandshakeNetworkError as err:
+                last_error = str(err)
+                if encryption.handshake_fault_falls_back():
+                    encryption.downgrade(last_error)
+                    continue
+                _LOGGER.warning("%s", last_error)
+                attempt += 1
+                continue
             except OTANetworkError as err:
                 # Transient network failure; retry
                 last_error = str(err)
                 _LOGGER.warning("%s", last_error)
+                attempt += 1
                 continue
             except OTAError as err:
                 # Device-reported error (wrong password, wrong flash size, ...);
@@ -847,10 +953,17 @@ def run_ota(
     filename: Path,
     ota_type: int = OTA_TYPE_UPDATE_APP,
     noise_psk: str | None = None,
+    plaintext_fallback: bool = False,
 ) -> tuple[int, str | None]:
     try:
         return run_ota_impl_(
-            remote_host, remote_port, password, filename, ota_type, noise_psk
+            remote_host,
+            remote_port,
+            password,
+            filename,
+            ota_type,
+            noise_psk,
+            plaintext_fallback,
         )
     except OTAError as err:
         _LOGGER.error(err)

esphome/framework_helpers.py

@@ -23,6 +23,7 @@ from esphome.net_retry import (
 )
 
 if TYPE_CHECKING:
+    from filelock import FileLock
     import requests
 
 PathType = str | os.PathLike
@@ -909,6 +910,61 @@ def _part_path(dest: Path) -> Path:
     return dest.with_name(dest.name + ".part")
 
 
+def downloaded_bytes(dest: Path, size: int | None = None) -> int:
+    """Bytes of ``dest`` on disk (its ``.part`` while streaming), capped at ``size``."""
+    done = 0
+    for candidate in (_part_path(dest), dest):
+        try:
+            done = candidate.stat().st_size
+            break
+        except FileNotFoundError:
+            continue
+    return done if size is None else min(done, size)
+
+
+# Short lock-acquire slices so a waiting worker still observes Ctrl-C
+_DOWNLOAD_LOCK_POLL = 1
+
+# Waiting on another process's download; past this the caller leaves the
+# file to its holder (the later sequential install waits on the same lock)
+DOWNLOAD_LOCK_TIMEOUT = 60
+
+
+class DownloadLockUnavailable(OSError):
+    """The lock file cannot be used at all (a lock-less filesystem)."""
+
+
+def wait_for_download_lock(
+    lock: "FileLock",
+    tracker: Callable[[int], None],
+    on_disk: Callable[[], int],
+    name: str,
+) -> None:
+    """Acquire ``lock``, reporting ``on_disk()`` to ``tracker`` each poll so the
+    bar follows the holder's download. Raises filelock's ``Timeout`` once
+    ``DOWNLOAD_LOCK_TIMEOUT`` seconds pass."""
+    from filelock import Timeout
+
+    deadline = time.monotonic() + DOWNLOAD_LOCK_TIMEOUT
+    waiting = False
+    while True:
+        try:
+            lock.acquire(timeout=_DOWNLOAD_LOCK_POLL)
+            return
+        except Timeout:
+            pass
+        except OSError as err:
+            # Distinct from an OSError out of on_disk(), which must not
+            # read as "locks unsupported"
+            raise DownloadLockUnavailable(*err.args) from err
+        if not waiting:
+            waiting = True
+            _LOGGER.info("Waiting for another process downloading %s", name)
+        tracker(on_disk())  # raises when the batch is cancelled
+        if time.monotonic() >= deadline:
+            raise Timeout(lock.lock_file)
+
+
 def discard_partial_download(dest: Path) -> None:
     """Remove ``dest`` and the resume sidecars of an abandoned download."""
     part = _part_path(dest)
@@ -1319,10 +1375,7 @@ def download_from_mirrors(
             )
             # Tick with the bytes already on disk so a combined bar holds
             # steady during the backoff instead of rewinding to zero
-            done = 0
-            if progress is not None:
-                part = _part_path(path_target)
-                done = part.stat().st_size if part.is_file() else 0
+            done = downloaded_bytes(path_target) if progress is not None else 0
             _cancellable_sleep(delay, progress, done)
 
     # 3. Report every attempted URL if all mirrors failed. failures spans

esphome/happy_eyeballs.py

@@ -69,10 +69,7 @@ def _make_create_connection() -> Callable[..., socket.socket]:
 
     from aiohappyeyeballs import start_connection
     from urllib3.exceptions import LocationParseError
-    from urllib3.util.connection import (  # noqa: PLC2701
-        _set_socket_options,
-        allowed_gai_family,
-    )
+    from urllib3.util.connection import _set_socket_options, allowed_gai_family  # noqa: PLC2701
     from urllib3.util.timeout import _DEFAULT_TIMEOUT  # noqa: PLC2701
 
     from esphome import async_thread

esphome/platformio/library.py

@@ -616,11 +616,15 @@ def _make_registry_client() -> Any:
     elsewhere, not by the PlatformIO registry.
     """
     from platformio.package.manager._registry import PackageManagerRegistryMixin
+    from platformio.registry.client import RegistryClient
 
     class _Registry(PackageManagerRegistryMixin):
         def __init__(self) -> None:
-            self._registry_client = None
             self.pkg_type = "library"
+            self._registry_client = RegistryClient()
+            # The probe sleeps ~500 ms per lookup (see runner.patch_registry_private_packages);
+            # instance-level so the ESPHome process never patches PlatformIO's class
+            self._registry_client.allowed_private_packages = lambda: False
 
         @staticmethod
         def is_system_compatible(value: Any, custom_system: Any = None) -> bool:

esphome/platformio/prefetch.py

@@ -33,11 +33,14 @@ import time
 from typing import Any, NamedTuple
 
 from esphome.framework_helpers import (
+    DownloadLockUnavailable,
     content_length,
     discard_partial_download,
+    downloaded_bytes,
     failure_reason,
     resume_fetch_job,
     run_batch_downloads,
+    wait_for_download_lock,
     warn_prefetch_failures,
 )
 from esphome.helpers import get_bool_env, get_usable_cpu_count, rmtree
@@ -61,16 +64,10 @@ _RESOLVE_WORKERS = 8
 # A hung child must not block the build; downloads resume on the next run
 _PREFETCH_TIMEOUT = 20 * 60
 
-# Waiting on another process's URL download; past this, leave it to pio
-_DOWNLOAD_LOCK_TIMEOUT = 60
-
 # Child exit for a handled, already-warned failure; 1 would collide with
 # the interpreter's own import-failure exit
 _EXIT_HANDLED = 3
 
-# Short lock-acquire slices so a waiting worker still observes Ctrl-C
-_URI_LOCK_POLL = 1
-
 # Resolution errored (vs a clean skip); suppresses the warm sentinel
 _RESOLVE_FAILED = object()
 
@@ -462,51 +459,54 @@ def _uri_jobs(
 
 
 def _serialized_fetch_job(
-    dl_path: Path, lock_path: str, body: Any, unlocked_ok: bool = True
+    dl_path: Path,
+    lock_path: str,
+    body: Any,
+    size: int,
+    stream_dest: Path | None = None,
+    unlocked_ok: bool = True,
 ) -> Any:
-    """Wrap ``body`` so the shared destination is single-writer.
-
-    Interleaved writers truncate each other's ``.part`` bytes (see
-    registry.py). The bounded poll observes Ctrl-C via the tracker; a
-    blown deadline is a clean skip (the holder's copy is what the build
-    needs). On a lock-less filesystem a sha256-verified body runs
-    unlocked with one warning; a checksum-less one
-    (``unlocked_ok=False``) is a counted failure instead.
+    """Wrap ``body`` so the shared destination is single-writer (interleaved
+    writers truncate each other's ``.part``, see registry.py). A blown deadline
+    is a clean skip. On a lock-less filesystem a sha256-verified body runs
+    unlocked with one warning; a checksum-less one (``unlocked_ok=False``) fails.
     """
 
+    def on_disk() -> int:
+        # A URL job's holder streams beside the staging path until it
+        # promotes; after that only dl_path is left
+        done = downloaded_bytes(dl_path, size)
+        if not done and stream_dest is not None:
+            done = downloaded_bytes(stream_dest, size)
+        return done
+
     def run(tracker: Any) -> None:
         from filelock import FileLock, Timeout
 
         # fallback_to_soft would leave a stale marker on lock-less
         # filesystems that blocks every later build (see git.py)
         lock = FileLock(lock_path, fallback_to_soft=False)
-        deadline = time.monotonic() + _DOWNLOAD_LOCK_TIMEOUT
-        while True:
-            try:
-                lock.acquire(timeout=_URI_LOCK_POLL)
-                break
-            except Timeout:
-                tracker(0)  # raises when the batch is cancelled
-                if time.monotonic() >= deadline:
-                    # Another process is fetching this same file; its copy
-                    # is what the build needs (a large framework archive
-                    # can hold the lock far longer than this deadline)
-                    _LOGGER.debug("Leaving %s to its current downloader", dl_path.name)
-                    return
-            except OSError as err:
-                if not unlocked_ok:
-                    # A body with no checksum to catch interleaved corruption
-                    raise
-                lock = None
-                _LOGGER.warning(
-                    "Could not lock %s (%s); downloading unlocked",
-                    dl_path.name,
-                    err,
-                )
-                break
+        try:
+            wait_for_download_lock(lock, tracker, on_disk, dl_path.name)
+        except Timeout:
+            # The holder's copy is what the build needs (a large
+            # framework archive can outlast this deadline)
+            _LOGGER.debug("Leaving %s to its current downloader", dl_path.name)
+            return
+        except DownloadLockUnavailable as err:
+            if not unlocked_ok:
+                # A body with no checksum to catch interleaved corruption
+                raise
+            lock = None
+            _LOGGER.warning(
+                "Could not lock %s (%s); downloading unlocked",
+                dl_path.name,
+                err,
+            )
         try:
             if dl_path.is_file():
-                return  # another process finished it while we waited
+                tracker(size)  # another process finished it while we waited
+                return
             body(tracker)
         finally:
             if lock is not None:
@@ -540,6 +540,7 @@ def _registry_fetch_job(
         dl_path,
         f"{dl_path}.esphome.lock",
         resume_fetch_job(url, dl_path, sha256=checksum, size=size),
+        size,
     )
 
     def run(tracker: Any) -> None:
@@ -571,9 +572,9 @@ def _uri_fetch_job(manager: Any, url: str, dl_path: Path, size: int) -> Any:
         tmp.replace(dl_path)
 
     def run(tracker: Any) -> None:
-        _serialized_fetch_job(dl_path, f"{tmp}.lock", promote, unlocked_ok=False)(
-            tracker
-        )
+        _serialized_fetch_job(
+            dl_path, f"{tmp}.lock", promote, size, tmp, unlocked_ok=False
+        )(tracker)
         if dl_path.is_file():
             # Won or lost, the race is over; staging files left behind
             # are dead weight PlatformIO's cache never prunes
@@ -950,8 +951,10 @@ def main(argv: list[str]) -> int:
     """Subprocess entry point: ``prefetch <build_dir> <env_name>``."""
     from esphome.core import CORE
     from esphome.log import setup_log
+    from esphome.platformio.runner import patch_registry_private_packages
 
     signal.signal(signal.SIGTERM, _sigterm)
+    patch_registry_private_packages()
     raw_level = os.environ.get("ESPHOME_PREFETCH_LOG_LEVEL")
     try:
         level = int(raw_level) if raw_level is not None else logging.INFO

esphome/platformio/registry.py

@@ -17,8 +17,10 @@ from esphome.framework_helpers import (
     archive_extract_all,
     download_from_mirrors,
     download_with_resume,
+    downloaded_bytes,
     rmdir,
     run_batch_downloads,
+    wait_for_download_lock,
 )
 from esphome.net_retry import fetch_with_retry, http_request
 
@@ -164,11 +166,17 @@ class _PendingArchive(NamedTuple):
     name: str
     version: str
     dest: Path
+    archive: Path
     url: str
     sha256: str
     size: int
 
 
+def _archive_path(downloads_dir: Path, name: str, version: str) -> Path:
+    """The one archive path the prefetch and the sequential install share."""
+    return downloads_dir / f"{name}-{version}"
+
+
 def _already_installed(dest: Path) -> bool:
     """Whether ``dest`` holds a completed install (extraction marker)."""
     return (dest / ".esphome_extracted").is_file()
@@ -187,18 +195,18 @@ def prefetch_packages(
     lock as ``install_package``: the archive's ``.part`` file is shared, and
     two concurrent writers would truncate each other's bytes.
     """
-    from filelock import FileLock
+    from filelock import FileLock, Timeout
 
     pending: list[_PendingArchive] = []
-    seen: set[str] = set()
+    seen: set[Path] = set()
     for name, version, dest, mirrors in packages:
         if mirrors or (dest / ".esphome_extracted").is_file():
             continue
-        archive_name = f"{name}-{version}"
-        if archive_name in seen:
+        archive = _archive_path(downloads_dir, name, version)
+        if archive in seen:
             # A duplicate entry would race itself between two workers
             continue
-        seen.add(archive_name)
+        seen.add(archive)
         try:
             url, sha256, size = registry_download(name, version)
         except EsphomeError as err:
@@ -207,10 +215,9 @@ def prefetch_packages(
             continue
         if not size:
             continue
-        archive = downloads_dir / archive_name
         if archive.is_file() and archive.stat().st_size == size:
             continue
-        pending.append(_PendingArchive(name, version, dest, url, sha256, size))
+        pending.append(_PendingArchive(name, version, dest, archive, url, sha256, size))
     if len(pending) < 2:
         return
     downloads_dir.mkdir(parents=True, exist_ok=True)
@@ -222,20 +229,36 @@ def prefetch_packages(
 
     def _fetch(entry: _PendingArchive, tracker: Callable[[int], None]) -> None:
         entry.dest.parent.mkdir(parents=True, exist_ok=True)
-        with FileLock(f"{entry.dest}.lock", fallback_to_soft=False):
-            # Marker re-check: a concurrent build may have installed (and
-            # deleted the archive of) this package while we waited;
-            # re-downloading would orphan a fresh copy in downloads_dir
-            # no branch: the thread tracer misses the skip edge; both
-            # arms of _already_installed are pinned directly
-            if not _already_installed(entry.dest):  # pragma: no branch
-                download_with_resume(
-                    entry.url,
-                    downloads_dir / f"{entry.name}-{entry.version}",
-                    sha256=entry.sha256,
-                    size=entry.size,
-                    progress=tracker,
-                )
+
+        def on_disk() -> int:
+            if done := downloaded_bytes(entry.archive, entry.size):
+                return done
+            # The holder deletes the archive once it has installed it
+            return entry.size if _already_installed(entry.dest) else 0
+
+        lock = FileLock(f"{entry.dest}.lock", fallback_to_soft=False)
+        try:
+            wait_for_download_lock(lock, tracker, on_disk, entry.name)
+        except Timeout:
+            # install_package waits on this same lock and verifies the
+            # holder's copy
+            _LOGGER.debug("Leaving %s to its current downloader", entry.name)
+            return
+        try:
+            if _already_installed(entry.dest):
+                # A concurrent build installed it while we waited; a
+                # re-download would orphan a fresh copy in downloads_dir
+                tracker(entry.size)
+                return
+            download_with_resume(
+                entry.url,
+                entry.archive,
+                sha256=entry.sha256,
+                size=entry.size,
+                progress=tracker,
+            )
+        finally:
+            lock.release()
 
     failures = run_batch_downloads(
         "Downloading packages",
@@ -288,7 +311,7 @@ def install_package(
         rmdir(dest, msg=f"Clean up incomplete {name} install")
         # Persistent location so an interrupted download resumes across runs.
         downloads_dir.mkdir(parents=True, exist_ok=True)
-        archive = downloads_dir / f"{name}-{version}"
+        archive = _archive_path(downloads_dir, name, version)
         _LOGGER.info("Downloading %s %s ...", name, version)
         if mirrors:
             _LOGGER.warning(

esphome/platformio/runner.py

@@ -2,7 +2,8 @@
 
 Invoked via ``python -m esphome.platformio.runner`` instead of
 ``python -m platformio`` so that the patches (incremental rebuild
-preservation, download retries) apply inside the subprocess. Running
+preservation, download retries, skipping the private-package probe) apply
+inside the subprocess. Running
 PlatformIO in a subprocess keeps its ``sys.path`` mutations and other
 global state from leaking into the ESPHome process.
 """
@@ -105,6 +106,16 @@ def patch_file_downloader() -> None:
     FileDownloader.__init__ = patched_init
 
 
+def patch_registry_private_packages() -> None:
+    """Skip PlatformIO's private-package probe; it sleeps ~500 ms per lookup.
+
+    ESPHome never uses private packages, so the answer is always False.
+    """
+    from platformio.registry.client import RegistryClient
+
+    RegistryClient.allowed_private_packages = staticmethod(lambda: False)  # type: ignore[method-assign]
+
+
 _IGNORE_LIB_WARNINGS = "(?:Hash|Update)"
 # Regex patterns matched against each line of PlatformIO output. Lines that
 # match are dropped by RedirectText before they reach the parent process.
@@ -152,6 +163,7 @@ FILTER_PLATFORMIO_LINES = [
 def main() -> int:
     patch_structhash()
     patch_file_downloader()
+    patch_registry_private_packages()
 
     # Wrap stdout/stderr with RedirectText before PlatformIO runs:
     #

esphome/wizard.py

@@ -148,11 +148,13 @@ def wizard_file(**kwargs: Unpack[WizardFileKwargs]) -> str:
     if "api_encryption_key" in kwargs:
         config += f'  encryption:\n    key: "{kwargs["api_encryption_key"]}"\n'
 
-    # Configure OTA
+    # The api key also secures OTA; a password only serves older uploaders
     config += "\nota:\n"
     config += "  - platform: esphome\n"
     if "ota_password" in kwargs:
         config += f'    password: "{kwargs["ota_password"]}"'
+    elif "api_encryption_key" in kwargs:
+        config += "    encryption:"
 
     # Configuring wifi
     config += "\n\nwifi:\n"
@@ -529,20 +531,9 @@ def wizard(path: Path) -> int:
         safe_print()
         safe_print("You'll need this key when adding the device to Home Assistant.")
         sleep(1)
-
-        safe_print()
-        safe_print(
-            f"Do you want to set a {color(AnsiFore.GREEN, 'password')} for OTA updates? "
-            "This can be insecure if you do not trust the WiFi network."
-        )
-        safe_print()
-        sleep(0.25)
-        safe_print("Press ENTER for no password")
-        ota_password = safe_input(color(AnsiFore.BOLD_WHITE, "(password): "))
     else:
         ssid, psk = "", ""
         api_encryption_key = None
-        ota_password = ""
 
     kwargs = {
         "path": path,
@@ -553,10 +544,9 @@ def wizard(path: Path) -> int:
         "psk": psk,
         "type": "basic",
     }
+    # The api key also secures OTA updates, so the wizard sets no OTA password
     if api_encryption_key:
         kwargs["api_encryption_key"] = api_encryption_key
-    if ota_password:
-        kwargs["ota_password"] = ota_password
 
     if not wizard_write(**kwargs):
         return 1

platformio.ini

@@ -45,7 +45,7 @@ lib_deps_base =
 lib_deps =
     ${common.lib_deps_base}
     https://github.com/dudanov/MideaUART.git#eeea6c3e9b4474f067054592b435be1c4e466815 ; midea
-    esphome/noise-c@0.1.21                 ; noise (api, ota)
+    esphome/noise-c@0.1.24                 ; noise (api, ota)
     improv/Improv@1.2.7                    ; improv_serial / esp32_improv
     kikuchan98/pngle@1.1.0                 ; online_image
     ; Using the repository directly, otherwise ESP-IDF can't use the library
@@ -244,7 +244,7 @@ lib_deps =
     ${common:idf-component-libs.lib_deps}
     ESP32Async/ESPAsyncWebServer@3.9.6    ; web_server_base
     droscy/esp_wireguard@0.4.5            ; wireguard
-    esphome/noise-c@0.1.21                ; noise (api, ota)
+    esphome/noise-c@0.1.24                ; noise (api, ota)
     ESP32Async/AsyncTCP@3.4.5             ; async_tcp
     DNSServer                             ; captive_portal
     heman/AsyncMqttClient-esphome@2.0.0   ; mqtt
@@ -641,7 +641,7 @@ build_unflags =
 extends = common
 platform = platformio/native
 lib_deps =
-    esphome/noise-c@0.1.21  ; used by noise (api, ota)
+    esphome/noise-c@0.1.24  ; used by noise (api, ota)
     lvgl/lvgl@9.5.0         ; lvgl
 build_flags =
     ${common.build_flags}

requirements.txt

@@ -27,7 +27,7 @@ bleak==3.0.2
 smpclient==7.2.0
 requests==2.34.2
 py7zr==1.1.3
-platformdirs==4.11.5  # native esp-idf toolchain global cache dir
+platformdirs==4.11.7  # native esp-idf toolchain global cache dir
 ninja==1.13.2  # native esp8266 arduino toolchain build driver
 filelock==3.32.5  # inter-process locks (PlatformIO cache heal, git clone cache); >=3.32 for FileLock(fallback_to_soft=...), older versions silently drop the kwarg
 

requirements_dev.txt

@@ -1,4 +1,4 @@
 # Useful stuff when working in a development environment
-clang-format==13.0.1  # also change in .pre-commit-config.yaml and Dockerfile when updating
+clang-format==13.0.1  # .pre-commit-config.yaml rev synced by script/sync_dependency_versions.py
 clang-tidy==22.1.8
-yamllint==1.38.0  # also change in .pre-commit-config.yaml when updating
+yamllint==1.38.0  # .pre-commit-config.yaml rev synced by script/sync_dependency_versions.py

requirements_test.txt

@@ -1,8 +1,9 @@
 pylint==4.0.8
-flake8==7.3.0  # also change in .pre-commit-config.yaml when updating
-ruff==0.16.5  # also change in .pre-commit-config.yaml when updating
-pyupgrade==3.21.2  # also change in .pre-commit-config.yaml when updating
-prek==0.5.0  # also change in .github/workflows/ci.yml when updating
+flake8==7.3.0  # .pre-commit-config.yaml rev synced by script/sync_dependency_versions.py
+ruff==0.16.6  # .pre-commit-config.yaml rev synced by script/sync_dependency_versions.py
+pyupgrade==3.21.2  # .pre-commit-config.yaml rev synced by script/sync_dependency_versions.py
+prek==0.5.2  # .github/workflows/ci.yml reads this pin
+yamlrocks==0.6.1  # used by script/sync_dependency_versions.py
 
 # Unit tests
 pytest==9.1.1

script/ci-custom.py

@@ -294,6 +294,9 @@ def highlight(s):
         "esphome/components/socket/headers.h",
         "esphome/core/defines.h",
         "esphome/components/http_request/httplib.h",
+        # Shared C wire header (byte-identical with the co-processor firmware);
+        # these are protocol constants and constexpr is C++-only.
+        "esphome/components/esp32_hosted/esp_now_hosted_rpc.h",
     ],
 )
 def lint_no_defines(fname, match):
@@ -816,6 +819,12 @@ def lint_relative_py_import(fname: Path, line, col, content):
         "esphome/components/host/helpers.cpp",
         "esphome/components/zephyr/helpers.cpp",
         "esphome/components/http_request/httplib.h",
+        # Global extern "C" esp_now_* linker symbols + shared C wire header;
+        # neither can live in a C++ namespace.
+        "esphome/components/esp32_hosted/esp_now_hosted.cpp",
+        "esphome/components/esp32_hosted/esp_now_hosted_rpc.h",
+        # C header shared with the vendored decoder
+        "esphome/components/esphome/ota/ota_esphome_inflate.h",
     ],
 )
 def lint_namespace(fname: Path, content: str) -> str | None:
@@ -841,7 +850,15 @@ def lint_esphome_h(fname, line, col, content):
     )
 
 
-@lint_content_check(include=["*.h"], exclude=["esphome/core/entity_types.h"])
+@lint_content_check(
+    include=["*.h"],
+    exclude=[
+        "esphome/core/entity_types.h",
+        # Shared C wire header; uses a classic #ifndef guard for portability
+        # across the co-processor firmware repo it stays byte-identical with.
+        "esphome/components/esp32_hosted/esp_now_hosted_rpc.h",
+    ],
+)
 def lint_pragma_once(fname, content):
     if "#pragma once" not in content:
         return (

script/git-hooks/post-checkout

@@ -14,7 +14,31 @@ top=$(git rev-parse --show-toplevel 2>/dev/null) || exit 0
 [ -x "$top/venv/bin/python" ] && exit 0
 [ -x "$top/script/setup" ] || exit 0
 
+# Every worktree shares the hooks directory of the checkout it was created
+# from, and the script/setup run below is the one from whichever branch was just
+# checked out. Older branches install their own pre-commit hook without checking
+# for a worktree: that moves the shared hook aside as pre-commit.legacy and
+# replaces it with one tied to this worktree's virtual environment, so commits
+# break in every checkout. To rule that out, the hooks directory is copied
+# before script/setup runs and put back exactly as it was afterwards, including
+# removing any file script/setup added.
+hooks=$(git rev-parse --path-format=absolute --git-path hooks 2>/dev/null) || exit 0
+snap=$(mktemp -d "$hooks/.post-checkout.XXXXXX") || exit 0
+cp -p "$hooks"/* "$snap"/ 2>/dev/null
+
 # Clear VIRTUAL_ENV so a checkout made from a shell with an environment already
 # activated still gets its own, rather than having the active one repointed at
 # this working tree.
-exec env -u VIRTUAL_ENV "$top/script/setup"
+env -u VIRTUAL_ENV "$top/script/setup"
+status=$?
+
+for f in "$hooks"/*; do
+  [ -e "$snap/${f##*/}" ] || rm -f "$f"
+done
+# Files are moved rather than copied so a hook that is still running, such as
+# this one, is swapped out atomically instead of being rewritten in place.
+for f in "$snap"/*; do
+  cmp -s "$f" "$hooks/${f##*/}" 2>/dev/null || mv -f "$f" "$hooks/${f##*/}"
+done
+rm -rf "$snap"
+exit $status

script/sync_dependency_versions.py

@@ -0,0 +1,164 @@
+#!/usr/bin/env python3
+"""Keep pre-commit hook revs in sync with the requirements files.
+
+Dependabot only bumps the ``package==version`` pins in ``requirements*.txt``.
+Some of those tools are pinned a second time as hook ``rev`` values in
+``.pre-commit-config.yaml``. This script treats the requirements files as
+the source of truth and rewrites the revs to match, editing the config
+through yamlrocks so comments and layout survive.
+
+Run without arguments to apply the changes in place, or with ``--check`` to
+only report drift (exit status 1 when anything is out of sync).
+"""
+
+from __future__ import annotations
+
+import argparse
+from dataclasses import dataclass
+from pathlib import Path
+import re
+import sys
+from typing import Any
+
+import yamlrocks
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+PRECOMMIT_CONFIG = ".pre-commit-config.yaml"
+
+
+class SyncError(Exception):
+    """A pin could not be located in a requirements file or the config."""
+
+
+@dataclass(frozen=True)
+class SyncTarget:
+    """A requirements pin and the pre-commit repo whose rev mirrors it."""
+
+    package: str
+    requirements_file: str
+    repo: str
+
+
+SYNC_TARGETS: tuple[SyncTarget, ...] = (
+    SyncTarget(
+        "ruff", "requirements_test.txt", "https://github.com/astral-sh/ruff-pre-commit"
+    ),
+    SyncTarget("flake8", "requirements_test.txt", "https://github.com/PyCQA/flake8"),
+    SyncTarget(
+        "pyupgrade", "requirements_test.txt", "https://github.com/asottile/pyupgrade"
+    ),
+    SyncTarget(
+        "clang-format",
+        "requirements_dev.txt",
+        "https://github.com/pre-commit/mirrors-clang-format",
+    ),
+    SyncTarget(
+        "yamllint",
+        "requirements_dev.txt",
+        "https://github.com/adrienverge/yamllint.git",
+    ),
+)
+
+
+def read_requirement_version(requirements: str, package: str) -> str | None:
+    """Return the ``==`` pin for ``package`` or None when it is not pinned."""
+    pattern = re.compile(
+        rf"^{re.escape(package)}==(?P<version>[^\s#]+)",
+        re.MULTILINE | re.IGNORECASE,
+    )
+    match = pattern.search(requirements)
+    return match.group("version") if match else None
+
+
+def find_repo_entry(doc: Any, repo: str) -> Any:
+    """Return the single ``- repo:`` block for ``repo`` in a pre-commit doc."""
+    try:
+        entries = [entry for entry in doc["repos"] if entry["repo"] == repo]
+    except KeyError as err:
+        raise SyncError(f"malformed pre-commit config, missing key {err}") from None
+    if len(entries) != 1:
+        raise SyncError(
+            f"expected exactly one block for repo {repo}, found {len(entries)}"
+        )
+    return entries[0]
+
+
+def current_rev(entry: Any, repo: str) -> tuple[str, str]:
+    """Split the block's rev into its tag prefix (``v`` or empty) and version."""
+    if "rev" not in entry:
+        raise SyncError(f"repo {repo} has no rev")
+    rev = entry["rev"]
+    if not isinstance(rev, str):
+        # A rev such as ``1.0`` parses as a number and cannot be compared or
+        # rewritten safely; quote it in the config instead.
+        raise SyncError(f"rev of repo {repo} is not a string: {rev!r}")
+    prefix = "v" if rev.startswith("v") else ""
+    return prefix, rev.removeprefix("v")
+
+
+def sync(root: Path, *, write: bool) -> list[str]:
+    """Bring every hook rev in line with its requirements pin.
+
+    Returns one description per rev that was (or, when ``write`` is False,
+    would be) changed. Raises SyncError when a pin cannot be found, which
+    means SYNC_TARGETS has gone stale and needs updating by hand.
+    """
+    config_path = root / PRECOMMIT_CONFIG
+    doc = yamlrocks.loads(config_path.read_bytes(), option=yamlrocks.OPT_ROUND_TRIP)
+    requirements: dict[str, str] = {}
+    changes: list[str] = []
+    for target in SYNC_TARGETS:
+        if target.requirements_file not in requirements:
+            requirements[target.requirements_file] = (
+                root / target.requirements_file
+            ).read_text()
+        version = read_requirement_version(
+            requirements[target.requirements_file], target.package
+        )
+        if version is None:
+            raise SyncError(
+                f"{target.requirements_file}: no '{target.package}==' pin found"
+            )
+
+        entry = find_repo_entry(doc, target.repo)
+        prefix, current = current_rev(entry, target.repo)
+        if current == version:
+            continue
+        changes.append(f"{target.package}: {current} -> {version}")
+        entry["rev"] = f"{prefix}{version}"
+
+    if changes and write:
+        config_path.write_bytes(doc.to_yaml())
+    return changes
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument(
+        "--check",
+        action="store_true",
+        help="report drift without modifying any file; exit 1 if out of sync",
+    )
+    parser.add_argument(
+        "--root",
+        type=Path,
+        default=REPO_ROOT,
+        help="repository checkout to operate on (default: this checkout)",
+    )
+    args = parser.parse_args(argv)
+
+    try:
+        changes = sync(args.root, write=not args.check)
+    except SyncError as err:
+        print(f"error: {err}", file=sys.stderr)
+        return 1
+
+    for change in changes:
+        print(change)
+    if args.check and changes:
+        return 1
+    return 0
+
+
+if __name__ == "__main__":  # pragma: no cover
+    sys.exit(main())

tests/component_tests/esp32_ble_server/config/improv_only.yaml

@@ -0,0 +1,13 @@
+esphome:
+  name: test
+
+esp32:
+  variant: esp32
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+# esp32_ble_server is only auto-loaded here, so it has no services of its own.
+esp32_improv:
+  authorizer: none

tests/component_tests/esp32_ble_server/config/manufacturer_data_only.yaml

@@ -0,0 +1,9 @@
+esphome:
+  name: test
+
+esp32:
+  variant: esp32
+
+esp32_ble_server:
+  id: ble_server
+  manufacturer_data: [0x72, 0x04, 0x00, 0x23]

tests/component_tests/esp32_ble_server/config/own_service.yaml

@@ -0,0 +1,14 @@
+esphome:
+  name: test
+
+esp32:
+  variant: esp32
+
+esp32_ble_server:
+  id: ble_server
+  services:
+    - uuid: 2a24b789-7aab-4535-af3e-ee76a35cc12d
+      characteristics:
+        - uuid: cad48e28-7fbe-41cf-bae9-d77a6c233423
+          read: true
+          value: [1, 2, 3, 4]

tests/component_tests/esp32_ble_server/test_esp32_ble_server.py

@@ -1,5 +1,10 @@
 """Tests for esp32_ble_server configuration helpers."""
 
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+
 import pytest
 
 from esphome.components.esp32_ble_server import (
@@ -45,3 +50,26 @@ def test_uuid_is_matches_descriptor_short_strings(uuid16) -> None:
     assert uuid_is(uuid16, uuid16)
     assert uuid_is(f"{uuid16:04X}", uuid16)
     assert uuid_is(f"{uuid16:08X}", uuid16)
+
+
+@pytest.mark.parametrize(
+    ("config_file", "required"),
+    [
+        # Auto-loaded by esp32_improv only: nothing to find until Improv asks for it
+        ("improv_only.yaml", False),
+        # The configuration defines a service clients are meant to connect to
+        ("own_service.yaml", True),
+        # Manufacturer data is only useful if it is actually broadcast
+        ("manufacturer_data_only.yaml", True),
+    ],
+)
+def test_advertising_required(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+    config_file: str,
+    required: bool,
+) -> None:
+    """The server only requests advertising when the configuration needs it."""
+    main_cpp = generate_main(component_config_path(config_file))
+
+    assert f"set_advertising_required({str(required).lower()})" in main_cpp