Add re-authentication to BSBLan (#146280)

Co-authored-by: Norbert Rittel <norbert@rittel.de>

homeassistant/components/bsblan/config_flow.py

@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
+from collections.abc import Mapping
 from typing import Any
 
-from bsblan import BSBLAN, BSBLANConfig, BSBLANError
+from bsblan import BSBLAN, BSBLANAuthError, BSBLANConfig, BSBLANError
 import voluptuous as vol
 
 from homeassistant.config_entries import ConfigFlow, ConfigFlowResult
@@ -45,7 +46,7 @@ class BSBLANFlowHandler(ConfigFlow, domain=DOMAIN):
         self.username = user_input.get(CONF_USERNAME)
         self.password = user_input.get(CONF_PASSWORD)
 
-        return await self._validate_and_create()
+        return await self._validate_and_create(user_input)
 
     async def async_step_zeroconf(
         self, discovery_info: ZeroconfServiceInfo
@@ -128,14 +129,29 @@ class BSBLANFlowHandler(ConfigFlow, domain=DOMAIN):
         self.username = user_input.get(CONF_USERNAME)
         self.password = user_input.get(CONF_PASSWORD)
 
-        return await self._validate_and_create(is_discovery=True)
+        return await self._validate_and_create(user_input, is_discovery=True)
 
     async def _validate_and_create(
-        self, is_discovery: bool = False
+        self, user_input: dict[str, Any], is_discovery: bool = False
     ) -> ConfigFlowResult:
         """Validate device connection and create entry."""
         try:
-            await self._get_bsblan_info(is_discovery=is_discovery)
+            await self._get_bsblan_info()
+        except BSBLANAuthError:
+            if is_discovery:
+                return self.async_show_form(
+                    step_id="discovery_confirm",
+                    data_schema=vol.Schema(
+                        {
+                            vol.Optional(CONF_PASSKEY): str,
+                            vol.Optional(CONF_USERNAME): str,
+                            vol.Optional(CONF_PASSWORD): str,
+                        }
+                    ),
+                    errors={"base": "invalid_auth"},
+                    description_placeholders={"host": str(self.host)},
+                )
+            return self._show_setup_form({"base": "invalid_auth"}, user_input)
         except BSBLANError:
             if is_discovery:
                 return self.async_show_form(
@@ -154,18 +170,145 @@ class BSBLANFlowHandler(ConfigFlow, domain=DOMAIN):
 
         return self._async_create_entry()
 
+    async def async_step_reauth(
+        self, entry_data: Mapping[str, Any]
+    ) -> ConfigFlowResult:
+        """Handle reauth flow."""
+        return await self.async_step_reauth_confirm()
+
+    async def async_step_reauth_confirm(
+        self, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
+        """Handle reauth confirmation flow."""
+        existing_entry = self.hass.config_entries.async_get_entry(
+            self.context["entry_id"]
+        )
+        assert existing_entry
+
+        if user_input is None:
+            # Preserve existing values as defaults
+            return self.async_show_form(
+                step_id="reauth_confirm",
+                data_schema=vol.Schema(
+                    {
+                        vol.Optional(
+                            CONF_PASSKEY,
+                            default=existing_entry.data.get(
+                                CONF_PASSKEY, vol.UNDEFINED
+                            ),
+                        ): str,
+                        vol.Optional(
+                            CONF_USERNAME,
+                            default=existing_entry.data.get(
+                                CONF_USERNAME, vol.UNDEFINED
+                            ),
+                        ): str,
+                        vol.Optional(
+                            CONF_PASSWORD,
+                            default=vol.UNDEFINED,
+                        ): str,
+                    }
+                ),
+            )
+
+        # Use existing host and port, update auth credentials
+        self.host = existing_entry.data[CONF_HOST]
+        self.port = existing_entry.data[CONF_PORT]
+        self.passkey = user_input.get(CONF_PASSKEY) or existing_entry.data.get(
+            CONF_PASSKEY
+        )
+        self.username = user_input.get(CONF_USERNAME) or existing_entry.data.get(
+            CONF_USERNAME
+        )
+        self.password = user_input.get(CONF_PASSWORD)
+
+        try:
+            await self._get_bsblan_info(raise_on_progress=False, is_reauth=True)
+        except BSBLANAuthError:
+            return self.async_show_form(
+                step_id="reauth_confirm",
+                data_schema=vol.Schema(
+                    {
+                        vol.Optional(
+                            CONF_PASSKEY,
+                            default=user_input.get(CONF_PASSKEY, vol.UNDEFINED),
+                        ): str,
+                        vol.Optional(
+                            CONF_USERNAME,
+                            default=user_input.get(CONF_USERNAME, vol.UNDEFINED),
+                        ): str,
+                        vol.Optional(
+                            CONF_PASSWORD,
+                            default=vol.UNDEFINED,
+                        ): str,
+                    }
+                ),
+                errors={"base": "invalid_auth"},
+            )
+        except BSBLANError:
+            return self.async_show_form(
+                step_id="reauth_confirm",
+                data_schema=vol.Schema(
+                    {
+                        vol.Optional(
+                            CONF_PASSKEY,
+                            default=user_input.get(CONF_PASSKEY, vol.UNDEFINED),
+                        ): str,
+                        vol.Optional(
+                            CONF_USERNAME,
+                            default=user_input.get(CONF_USERNAME, vol.UNDEFINED),
+                        ): str,
+                        vol.Optional(
+                            CONF_PASSWORD,
+                            default=vol.UNDEFINED,
+                        ): str,
+                    }
+                ),
+                errors={"base": "cannot_connect"},
+            )
+
+        # Update the config entry with new auth data
+        data_updates = {}
+        if self.passkey is not None:
+            data_updates[CONF_PASSKEY] = self.passkey
+        if self.username is not None:
+            data_updates[CONF_USERNAME] = self.username
+        if self.password is not None:
+            data_updates[CONF_PASSWORD] = self.password
+
+        return self.async_update_reload_and_abort(
+            existing_entry, data_updates=data_updates, reason="reauth_successful"
+        )
+
     @callback
-    def _show_setup_form(self, errors: dict | None = None) -> ConfigFlowResult:
+    def _show_setup_form(
+        self, errors: dict | None = None, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
         """Show the setup form to the user."""
+        # Preserve user input if provided, otherwise use defaults
+        defaults = user_input or {}
+
         return self.async_show_form(
             step_id="user",
             data_schema=vol.Schema(
                 {
-                    vol.Required(CONF_HOST): str,
-                    vol.Optional(CONF_PORT, default=DEFAULT_PORT): int,
-                    vol.Optional(CONF_PASSKEY): str,
-                    vol.Optional(CONF_USERNAME): str,
-                    vol.Optional(CONF_PASSWORD): str,
+                    vol.Required(
+                        CONF_HOST, default=defaults.get(CONF_HOST, vol.UNDEFINED)
+                    ): str,
+                    vol.Optional(
+                        CONF_PORT, default=defaults.get(CONF_PORT, DEFAULT_PORT)
+                    ): int,
+                    vol.Optional(
+                        CONF_PASSKEY, default=defaults.get(CONF_PASSKEY, vol.UNDEFINED)
+                    ): str,
+                    vol.Optional(
+                        CONF_USERNAME,
+                        default=defaults.get(CONF_USERNAME, vol.UNDEFINED),
+                    ): str,
+                    vol.Optional(
+                        CONF_PASSWORD,
+                        default=defaults.get(CONF_PASSWORD, vol.UNDEFINED),
+                    ): str,
                 }
             ),
             errors=errors or {},
@@ -186,7 +329,9 @@ class BSBLANFlowHandler(ConfigFlow, domain=DOMAIN):
         )
 
     async def _get_bsblan_info(
-        self, raise_on_progress: bool = True, is_discovery: bool = False
+        self,
+        raise_on_progress: bool = True,
+        is_reauth: bool = False,
     ) -> None:
         """Get device information from a BSBLAN device."""
         config = BSBLANConfig(
@@ -209,11 +354,13 @@ class BSBLANFlowHandler(ConfigFlow, domain=DOMAIN):
                 format_mac(self.mac), raise_on_progress=raise_on_progress
             )
 
-        # Always allow updating host/port for both user and discovery flows
-        # This ensures connectivity is maintained when devices change IP addresses
-        self._abort_if_unique_id_configured(
-            updates={
-                CONF_HOST: self.host,
-                CONF_PORT: self.port,
-            }
-        )
+        # Skip unique_id configuration check during reauth to prevent "already_configured" abort
+        if not is_reauth:
+            # Always allow updating host/port for both user and discovery flows
+            # This ensures connectivity is maintained when devices change IP addresses
+            self._abort_if_unique_id_configured(
+                updates={
+                    CONF_HOST: self.host,
+                    CONF_PORT: self.port,
+                }
+            )

homeassistant/components/bsblan/coordinator.py

@@ -4,11 +4,19 @@ from dataclasses import dataclass
 from datetime import timedelta
 from random import randint
 
-from bsblan import BSBLAN, BSBLANConnectionError, HotWaterState, Sensor, State
+from bsblan import (
+    BSBLAN,
+    BSBLANAuthError,
+    BSBLANConnectionError,
+    HotWaterState,
+    Sensor,
+    State,
+)
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_HOST
 from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import ConfigEntryAuthFailed
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
 
 from .const import DOMAIN, LOGGER, SCAN_INTERVAL
@@ -62,6 +70,10 @@ class BSBLanUpdateCoordinator(DataUpdateCoordinator[BSBLanCoordinatorData]):
             state = await self.client.state()
             sensor = await self.client.sensor()
             dhw = await self.client.hot_water_state()
+        except BSBLANAuthError as err:
+            raise ConfigEntryAuthFailed(
+                "Authentication failed for BSB-Lan device"
+            ) from err
         except BSBLANConnectionError as err:
             host = self.config_entry.data[CONF_HOST] if self.config_entry else "unknown"
             raise UpdateFailed(

homeassistant/components/bsblan/strings.json

@@ -33,14 +33,25 @@
           "username": "[%key:component::bsblan::config::step::user::data_description::username%]",
           "password": "[%key:component::bsblan::config::step::user::data_description::password%]"
         }
+      },
+      "reauth_confirm": {
+        "title": "[%key:common::config_flow::title::reauth%]",
+        "description": "The BSB-Lan integration needs to re-authenticate with {name}",
+        "data": {
+          "passkey": "[%key:component::bsblan::config::step::user::data::passkey%]",
+          "username": "[%key:common::config_flow::data::username%]",
+          "password": "[%key:common::config_flow::data::password%]"
+        }
       }
     },
     "error": {
-      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]"
+      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
+      "invalid_auth": "[%key:common::config_flow::error::invalid_auth%]"
     },
     "abort": {
       "already_configured": "[%key:common::config_flow::abort::already_configured_device%]",
-      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]"
+      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
+      "reauth_successful": "[%key:common::config_flow::abort::reauth_successful%]"
     }
   },
   "exceptions": {

tests/components/bsblan/test_config_flow.py

@@ -3,11 +3,11 @@
 from ipaddress import ip_address
 from unittest.mock import AsyncMock, MagicMock
 
-from bsblan import BSBLANConnectionError
+from bsblan import BSBLANAuthError, BSBLANConnectionError, BSBLANError
 import pytest
 
 from homeassistant.components.bsblan.const import CONF_PASSKEY, DOMAIN
-from homeassistant.config_entries import SOURCE_USER, SOURCE_ZEROCONF
+from homeassistant.config_entries import SOURCE_REAUTH, SOURCE_USER, SOURCE_ZEROCONF
 from homeassistant.const import CONF_HOST, CONF_PASSWORD, CONF_PORT, CONF_USERNAME
 from homeassistant.core import HomeAssistant
 from homeassistant.data_entry_flow import FlowResultType
@@ -129,7 +129,7 @@ async def test_full_user_flow_implementation(
     result = await _init_user_flow(hass)
     _assert_form_result(result, "user")
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -142,7 +142,7 @@ async def test_full_user_flow_implementation(
     )
 
     _assert_create_entry_result(
-        result2,
+        result,
         format_mac("00:80:41:19:69:90"),
         {
             CONF_HOST: "127.0.0.1",
@@ -185,6 +185,94 @@ async def test_connection_error(
     _assert_form_result(result, "user", {"base": "cannot_connect"})
 
 
+async def test_authentication_error(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+) -> None:
+    """Test we show user form on BSBLan authentication error with field preservation."""
+    mock_bsblan.device.side_effect = BSBLANAuthError
+
+    user_input = {
+        CONF_HOST: "192.168.1.100",
+        CONF_PORT: 8080,
+        CONF_PASSKEY: "secret",
+        CONF_USERNAME: "testuser",
+        CONF_PASSWORD: "wrongpassword",
+    }
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_USER},
+        data=user_input,
+    )
+
+    assert result.get("type") is FlowResultType.FORM
+    assert result.get("errors") == {"base": "invalid_auth"}
+    assert result.get("step_id") == "user"
+
+    # Verify that user input is preserved in the form
+    data_schema = result.get("data_schema")
+    assert data_schema is not None
+
+    # Check that the form fields contain the previously entered values
+    host_field = next(
+        field for field in data_schema.schema if field.schema == CONF_HOST
+    )
+    port_field = next(
+        field for field in data_schema.schema if field.schema == CONF_PORT
+    )
+    passkey_field = next(
+        field for field in data_schema.schema if field.schema == CONF_PASSKEY
+    )
+    username_field = next(
+        field for field in data_schema.schema if field.schema == CONF_USERNAME
+    )
+    password_field = next(
+        field for field in data_schema.schema if field.schema == CONF_PASSWORD
+    )
+
+    # The defaults are callable functions, so we need to call them
+    assert host_field.default() == "192.168.1.100"
+    assert port_field.default() == 8080
+    assert passkey_field.default() == "secret"
+    assert username_field.default() == "testuser"
+    assert password_field.default() == "wrongpassword"
+
+
+async def test_authentication_error_vs_connection_error(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+) -> None:
+    """Test that authentication and connection errors are handled differently."""
+    # Test connection error first
+    mock_bsblan.device.side_effect = BSBLANConnectionError
+
+    result = await _init_user_flow(
+        hass,
+        {
+            CONF_HOST: "127.0.0.1",
+            CONF_PORT: 80,
+        },
+    )
+
+    _assert_form_result(result, "user", {"base": "cannot_connect"})
+
+    # Reset and test authentication error
+    mock_bsblan.device.side_effect = BSBLANAuthError
+
+    result = await _init_user_flow(
+        hass,
+        {
+            CONF_HOST: "127.0.0.1",
+            CONF_PORT: 80,
+            CONF_USERNAME: "admin",
+            CONF_PASSWORD: "wrongpass",
+        },
+    )
+
+    _assert_form_result(result, "user", {"base": "invalid_auth"})
+
+
 async def test_user_device_exists_abort(
     hass: HomeAssistant,
     mock_bsblan: MagicMock,
@@ -217,7 +305,7 @@ async def test_zeroconf_discovery(
     result = await _init_zeroconf_flow(hass, zeroconf_discovery_info)
     _assert_form_result(result, "discovery_confirm")
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -228,7 +316,7 @@ async def test_zeroconf_discovery(
     )
 
     _assert_create_entry_result(
-        result2,
+        result,
         format_mac("00:80:41:19:69:90"),
         {
             CONF_HOST: "10.0.2.60",
@@ -285,7 +373,7 @@ async def test_zeroconf_discovery_no_mac_requires_auth(
     # Reset side_effect for the second call to succeed
     mock_bsblan.device.side_effect = None
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -295,7 +383,7 @@ async def test_zeroconf_discovery_no_mac_requires_auth(
     )
 
     _assert_create_entry_result(
-        result2,
+        result,
         "00:80:41:19:69:90",  # MAC from fixture file
         {
             CONF_HOST: "10.0.2.60",
@@ -324,10 +412,10 @@ async def test_zeroconf_discovery_no_mac_no_auth_required(
     _assert_form_result(result, "discovery_confirm")
 
     # User confirms the discovery
-    result2 = await _configure_flow(hass, result["flow_id"], {})
+    result = await _configure_flow(hass, result["flow_id"], {})
 
     _assert_create_entry_result(
-        result2,
+        result,
         "00:80:41:19:69:90",  # MAC from fixture file
         {
             CONF_HOST: "10.0.2.60",
@@ -355,7 +443,7 @@ async def test_zeroconf_discovery_connection_error(
     result = await _init_zeroconf_flow(hass, zeroconf_discovery_info)
     _assert_form_result(result, "discovery_confirm")
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -365,7 +453,7 @@ async def test_zeroconf_discovery_connection_error(
         },
     )
 
-    _assert_form_result(result2, "discovery_confirm", {"base": "cannot_connect"})
+    _assert_form_result(result, "discovery_confirm", {"base": "cannot_connect"})
 
 
 async def test_zeroconf_discovery_updates_host_port_on_existing_entry(
@@ -445,7 +533,7 @@ async def test_zeroconf_discovery_connection_error_recovery(
     result = await _init_zeroconf_flow(hass, zeroconf_discovery_info)
     _assert_form_result(result, "discovery_confirm")
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -455,12 +543,12 @@ async def test_zeroconf_discovery_connection_error_recovery(
         },
     )
 
-    _assert_form_result(result2, "discovery_confirm", {"base": "cannot_connect"})
+    _assert_form_result(result, "discovery_confirm", {"base": "cannot_connect"})
 
     # Second attempt succeeds (connection is fixed)
     mock_bsblan.device.side_effect = None
 
-    result3 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -471,7 +559,7 @@ async def test_zeroconf_discovery_connection_error_recovery(
     )
 
     _assert_create_entry_result(
-        result3,
+        result,
         format_mac("00:80:41:19:69:90"),
         {
             CONF_HOST: "10.0.2.60",
@@ -513,7 +601,7 @@ async def test_connection_error_recovery(
     # Second attempt succeeds (connection is fixed)
     mock_bsblan.device.side_effect = None
 
-    result2 = await _configure_flow(
+    result = await _configure_flow(
         hass,
         result["flow_id"],
         {
@@ -526,7 +614,7 @@ async def test_connection_error_recovery(
     )
 
     _assert_create_entry_result(
-        result2,
+        result,
         format_mac("00:80:41:19:69:90"),
         {
             CONF_HOST: "127.0.0.1",
@@ -567,3 +655,249 @@ async def test_zeroconf_discovery_no_mac_duplicate_host_port(
 
     # Should not call device API since we abort early
     assert len(mock_bsblan.device.mock_calls) == 0
+
+
+async def test_reauth_flow_success(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test successful reauth flow."""
+    mock_config_entry.add_to_hass(hass)
+
+    # Start reauth flow
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={
+            "source": SOURCE_REAUTH,
+            "entry_id": mock_config_entry.entry_id,
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm")
+
+    # Check that the form has the correct description placeholder
+    assert result.get("description_placeholders") == {"name": "BSBLAN Setup"}
+
+    # Check that existing values are preserved as defaults
+    data_schema = result.get("data_schema")
+    assert data_schema is not None
+
+    # Complete reauth with new credentials
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_PASSKEY: "new_passkey",
+            CONF_USERNAME: "new_admin",
+            CONF_PASSWORD: "new_password",
+        },
+    )
+
+    _assert_abort_result(result, "reauth_successful")
+
+    # Verify config entry was updated with new credentials
+    assert mock_config_entry.data[CONF_PASSKEY] == "new_passkey"
+    assert mock_config_entry.data[CONF_USERNAME] == "new_admin"
+    assert mock_config_entry.data[CONF_PASSWORD] == "new_password"
+    # Verify host and port remain unchanged
+    assert mock_config_entry.data[CONF_HOST] == "127.0.0.1"
+    assert mock_config_entry.data[CONF_PORT] == 80
+
+
+async def test_reauth_flow_auth_error(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test reauth flow with authentication error."""
+    mock_config_entry.add_to_hass(hass)
+
+    # Mock authentication error
+    mock_bsblan.device.side_effect = BSBLANAuthError
+
+    # Start reauth flow
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={
+            "source": SOURCE_REAUTH,
+            "entry_id": mock_config_entry.entry_id,
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm")
+
+    # Submit with wrong credentials
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_PASSKEY: "wrong_passkey",
+            CONF_USERNAME: "wrong_admin",
+            CONF_PASSWORD: "wrong_password",
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm", {"base": "invalid_auth"})
+
+    # Verify that user input is preserved in the form after error
+    data_schema = result.get("data_schema")
+    assert data_schema is not None
+
+    # Check that the form fields contain the previously entered values
+    passkey_field = next(
+        field for field in data_schema.schema if field.schema == CONF_PASSKEY
+    )
+    username_field = next(
+        field for field in data_schema.schema if field.schema == CONF_USERNAME
+    )
+
+    assert passkey_field.default() == "wrong_passkey"
+    assert username_field.default() == "wrong_admin"
+
+
+async def test_reauth_flow_connection_error(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test reauth flow with connection error."""
+    mock_config_entry.add_to_hass(hass)
+
+    # Mock connection error
+    mock_bsblan.device.side_effect = BSBLANConnectionError
+
+    # Start reauth flow
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={
+            "source": SOURCE_REAUTH,
+            "entry_id": mock_config_entry.entry_id,
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm")
+
+    # Submit credentials but get connection error
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_PASSKEY: "1234",
+            CONF_USERNAME: "admin",
+            CONF_PASSWORD: "admin1234",
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm", {"base": "cannot_connect"})
+
+
+async def test_reauth_flow_preserves_existing_values(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test that reauth flow preserves existing values when user doesn't change them."""
+    mock_config_entry.add_to_hass(hass)
+
+    # Start reauth flow
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={
+            "source": SOURCE_REAUTH,
+            "entry_id": mock_config_entry.entry_id,
+        },
+    )
+
+    _assert_form_result(result, "reauth_confirm")
+
+    # Submit without changing any credentials (only password is provided)
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_PASSWORD: "new_password_only",
+        },
+    )
+
+    _assert_abort_result(result, "reauth_successful")
+
+    # Verify that existing passkey and username are preserved
+    assert mock_config_entry.data[CONF_PASSKEY] == "1234"  # Original value
+    assert mock_config_entry.data[CONF_USERNAME] == "admin"  # Original value
+    assert mock_config_entry.data[CONF_PASSWORD] == "new_password_only"  # New value
+
+
+async def test_reauth_flow_partial_credentials_update(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test reauth flow with partial credential updates."""
+    mock_config_entry.add_to_hass(hass)
+
+    # Start reauth flow
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={
+            "source": SOURCE_REAUTH,
+            "entry_id": mock_config_entry.entry_id,
+        },
+    )
+
+    # Submit with only username and password changes
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_USERNAME: "new_admin",
+            CONF_PASSWORD: "new_password",
+        },
+    )
+
+    _assert_abort_result(result, "reauth_successful")
+
+    # Verify partial update: passkey preserved, username and password updated
+    assert mock_config_entry.data[CONF_PASSKEY] == "1234"  # Original preserved
+    assert mock_config_entry.data[CONF_USERNAME] == "new_admin"  # Updated
+    assert mock_config_entry.data[CONF_PASSWORD] == "new_password"  # Updated
+    # Host and port should remain unchanged
+    assert mock_config_entry.data[CONF_HOST] == "127.0.0.1"
+    assert mock_config_entry.data[CONF_PORT] == 80
+
+
+async def test_zeroconf_discovery_auth_error_during_confirm(
+    hass: HomeAssistant,
+    mock_bsblan: MagicMock,
+    zeroconf_discovery_info: ZeroconfServiceInfo,
+) -> None:
+    """Test authentication error during discovery_confirm step."""
+    # Remove MAC from discovery to force discovery_confirm step
+    zeroconf_discovery_info.properties.pop("mac", None)
+
+    # Setup device to require authentication during initial discovery
+    mock_bsblan.device.side_effect = BSBLANError
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_ZEROCONF},
+        data=zeroconf_discovery_info,
+    )
+
+    _assert_form_result(result, "discovery_confirm")
+
+    # Now setup auth error for the confirmation step
+    mock_bsblan.device.side_effect = BSBLANAuthError
+
+    result = await _configure_flow(
+        hass,
+        result["flow_id"],
+        {
+            CONF_PASSKEY: "wrong_key",
+            CONF_USERNAME: "admin",
+            CONF_PASSWORD: "wrong_password",
+        },
+    )
+
+    # Should show the discovery_confirm form again with auth error
+    _assert_form_result(result, "discovery_confirm", {"base": "invalid_auth"})

tests/components/bsblan/test_init.py

@@ -2,13 +2,14 @@
 
 from unittest.mock import MagicMock
 
-from bsblan import BSBLANConnectionError
+from bsblan import BSBLANAuthError, BSBLANConnectionError
+from freezegun.api import FrozenDateTimeFactory
 
 from homeassistant.components.bsblan.const import DOMAIN
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.core import HomeAssistant
 
-from tests.common import MockConfigEntry
+from tests.common import MockConfigEntry, async_fire_time_changed
 
 
 async def test_load_unload_config_entry(
@@ -45,3 +46,32 @@ async def test_config_entry_not_ready(
 
     assert len(mock_bsblan.state.mock_calls) == 1
     assert mock_config_entry.state is ConfigEntryState.SETUP_RETRY
+
+
+async def test_config_entry_auth_failed_triggers_reauth(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_bsblan: MagicMock,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test that BSBLANAuthError during coordinator update triggers reauth flow."""
+    # First, set up the integration successfully
+    mock_config_entry.add_to_hass(hass)
+    await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    assert mock_config_entry.state is ConfigEntryState.LOADED
+
+    # Mock BSBLANAuthError during next update
+    mock_bsblan.initialize.side_effect = BSBLANAuthError("Authentication failed")
+
+    # Advance time by the coordinator's update interval to trigger update
+    freezer.tick(delta=20)  # Advance beyond the 12 second scan interval + random offset
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    # Check that a reauth flow has been started
+    flows = hass.config_entries.flow.async_progress()
+    assert len(flows) == 1
+    assert flows[0]["context"]["source"] == "reauth"
+    assert flows[0]["context"]["entry_id"] == mock_config_entry.entry_id