[PM-27150] React to device changes on device screen unlock method (#6103)

Author: andrebispo5

app/src/main/kotlin/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSource.kt

@@ -211,7 +211,7 @@ interface AuthDiskSource : AppIdProvider {
     /**
      * Gets the flow for the biometrics key for the given [userId].
      */
-    fun getUserBiometicUnlockKeyFlow(userId: String): Flow<String?>
+    fun getUserBiometricUnlockKeyFlow(userId: String): Flow<String?>
 
     /**
      * Retrieves a pin-protected user key for the given [userId].

app/src/main/kotlin/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSourceImpl.kt

@@ -331,7 +331,7 @@ class AuthDiskSourceImpl(
         getMutableBiometricUnlockKeyFlow(userId).tryEmit(biometricsKey)
     }
 
-    override fun getUserBiometicUnlockKeyFlow(userId: String): Flow<String?> =
+    override fun getUserBiometricUnlockKeyFlow(userId: String): Flow<String?> =
         getMutableBiometricUnlockKeyFlow(userId)
             .onSubscription { emit(getUserBiometricUnlockKey(userId = userId)) }
 

app/src/main/kotlin/com/x8bit/bitwarden/data/platform/repository/SettingsRepositoryImpl.kt

@@ -279,7 +279,7 @@ class SettingsRepositoryImpl(
         get() = activeUserId
             ?.let { userId ->
                 authDiskSource
-                    .getUserBiometicUnlockKeyFlow(userId)
+                    .getUserBiometricUnlockKeyFlow(userId)
                     .map { it != null }
             }
             ?: flowOf(false)

app/src/test/kotlin/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSourceTest.kt

@@ -721,6 +721,25 @@ class AuthDiskSourceTest {
         assertEquals(biometricsKey, actual)
     }
 
+    @Test
+    fun `getUserBiometricUnlockKeyFlow should react to changes in getUserBiometricUnlockKey`() =
+        runTest {
+            val mockUserId = "mockUserId"
+            val biometricsKey = "1234"
+            authDiskSource.getUserBiometricUnlockKeyFlow(userId = mockUserId).test {
+                // The initial values of the Flow and the property are in sync
+                assertNull(authDiskSource.getUserBiometricUnlockKey(userId = mockUserId))
+                assertNull(awaitItem())
+
+                // Updating the disk source updates shared preferences
+                authDiskSource.storeUserBiometricUnlockKey(
+                    userId = mockUserId,
+                    biometricsKey = biometricsKey,
+                )
+                assertEquals(biometricsKey, awaitItem())
+            }
+        }
+
     @Test
     fun `storeUserBiometricInitVector for non-null values should update SharedPreferences`() {
         val biometricsInitVectorBaseKey = "bwSecureStorage:biometricInitializationVector"
@@ -783,11 +802,11 @@ class AuthDiskSourceTest {
 
     @Suppress("MaxLineLength")
     @Test
-    fun `storeUserBiometricUnlockKey should update the resulting flow from getUserBiometicUnlockKeyFlow`() =
+    fun `storeUserBiometricUnlockKey should update the resulting flow from getUserBiometricUnlockKeyFlow`() =
         runTest {
             val topSecretKey = "topsecret"
             val mockUserId = "mockUserId"
-            authDiskSource.getUserBiometicUnlockKeyFlow(mockUserId).test {
+            authDiskSource.getUserBiometricUnlockKeyFlow(mockUserId).test {
                 assertNull(awaitItem())
                 authDiskSource.storeUserBiometricUnlockKey(
                     userId = mockUserId,

app/src/test/kotlin/com/x8bit/bitwarden/data/auth/datasource/disk/util/FakeAuthDiskSource.kt

@@ -274,7 +274,7 @@ class FakeAuthDiskSource : AuthDiskSource {
         getMutableBiometricUnlockKeyFlow(userId).tryEmit(biometricsKey)
     }
 
-    override fun getUserBiometicUnlockKeyFlow(userId: String): Flow<String?> =
+    override fun getUserBiometricUnlockKeyFlow(userId: String): Flow<String?> =
         getMutableBiometricUnlockKeyFlow(userId)
             .onSubscription { emit(getUserBiometricUnlockKey(userId)) }
 

authenticator/src/main/kotlin/com/bitwarden/authenticator/data/auth/datasource/disk/AuthDiskSource.kt

@@ -1,12 +1,18 @@
 package com.bitwarden.authenticator.data.auth.datasource.disk
 
 import com.bitwarden.network.provider.AppIdProvider
+import kotlinx.coroutines.flow.Flow
 
 /**
  * Primary access point for disk information.
  */
 interface AuthDiskSource : AppIdProvider {
 
+    /**
+     * Tracks the biometrics key.
+     */
+    val userBiometricUnlockKeyFlow: Flow<String?>
+
     /**
      * Retrieves the "last active time".
      *

authenticator/src/main/kotlin/com/bitwarden/authenticator/data/auth/datasource/disk/AuthDiskSourceImpl.kt

@@ -1,7 +1,10 @@
 package com.bitwarden.authenticator.data.auth.datasource.disk
 
 import android.content.SharedPreferences
+import com.bitwarden.core.data.repository.util.bufferedMutableSharedFlow
 import com.bitwarden.data.datasource.disk.BaseEncryptedDiskSource
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.onSubscription
 import java.util.UUID
 
 private const val AUTHENTICATOR_SYNC_SYMMETRIC_KEY = "authenticatorSyncSymmetricKey"
@@ -20,6 +23,7 @@ class AuthDiskSourceImpl(
     sharedPreferences = sharedPreferences,
 ),
     AuthDiskSource {
+    private val mutableUserBiometricUnlockKeyFlow = bufferedMutableSharedFlow<String?>(replay = 1)
 
     override val uniqueAppId: String
         get() = getString(key = UNIQUE_APP_ID_KEY) ?: generateAndStoreUniqueAppId()
@@ -39,13 +43,21 @@ class AuthDiskSourceImpl(
     override fun getUserBiometricUnlockKey(): String? =
         getEncryptedString(key = BIOMETRICS_UNLOCK_KEY)
 
+    override val userBiometricUnlockKeyFlow: Flow<String?>
+        get() =
+            mutableUserBiometricUnlockKeyFlow
+                .onSubscription {
+                    emit(getUserBiometricUnlockKey())
+                }
+
     override fun storeUserBiometricUnlockKey(
         biometricsKey: String?,
     ) {
         putEncryptedString(
             key = BIOMETRICS_UNLOCK_KEY,
             value = biometricsKey,
         )
+        mutableUserBiometricUnlockKeyFlow.tryEmit(biometricsKey)
     }
 
     override var authenticatorBridgeSymmetricSyncKey: ByteArray?

authenticator/src/main/kotlin/com/bitwarden/authenticator/data/platform/repository/SettingsRepository.kt

@@ -57,6 +57,11 @@ interface SettingsRepository {
      */
     val isUnlockWithBiometricsEnabled: Boolean
 
+    /**
+     * Tracks whether or not biometric unlocking is enabled for the current user.
+     */
+    val isUnlockWithBiometricsEnabledFlow: StateFlow<Boolean>
+
     /**
      * Tracks changes to the expiration alert threshold.
      */

authenticator/src/main/kotlin/com/bitwarden/authenticator/data/platform/repository/SettingsRepositoryImpl.kt

@@ -66,6 +66,17 @@ class SettingsRepositoryImpl(
     override val isUnlockWithBiometricsEnabled: Boolean
         get() = authDiskSource.getUserBiometricUnlockKey() != null
 
+    override val isUnlockWithBiometricsEnabledFlow: StateFlow<Boolean>
+        get() =
+            authDiskSource
+                .userBiometricUnlockKeyFlow
+                .map { it != null }
+                .stateIn(
+                    scope = unconfinedScope,
+                    started = SharingStarted.Eagerly,
+                    initialValue = isUnlockWithBiometricsEnabled,
+                )
+
     override val appThemeStateFlow: StateFlow<AppTheme>
         get() = settingsDiskSource
             .appThemeFlow

authenticator/src/main/kotlin/com/bitwarden/authenticator/ui/platform/components/biometrics/BiometricChanges.kt

@@ -0,0 +1,38 @@
+package com.bitwarden.authenticator.ui.platform.components.biometrics
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.lifecycle.Lifecycle
+import com.bitwarden.authenticator.ui.platform.manager.biometrics.BiometricsManager
+import com.bitwarden.ui.platform.base.util.LifecycleEventEffect
+
+/**
+ * Tracks changes in biometric support and notifies when the app resumes.
+ *
+ * This composable monitors lifecycle events and checks biometric support status
+ * whenever the app returns to the foreground ([Lifecycle.Event.ON_RESUME]) or
+ * biometric support status changes (via [LaunchedEffect]).
+ *
+ * @param biometricsManager Manager to check current biometric support status.
+ * @param onBiometricSupportChange Callback invoked with the current biometric
+ * support status.
+ */
+@Composable
+fun BiometricChanges(
+    biometricsManager: BiometricsManager,
+    onBiometricSupportChange: (isSupported: Boolean) -> Unit,
+) {
+    LaunchedEffect(biometricsManager.isBiometricsSupported) {
+        onBiometricSupportChange(biometricsManager.isBiometricsSupported)
+    }
+
+    LifecycleEventEffect { _, event ->
+        when (event) {
+            Lifecycle.Event.ON_RESUME -> {
+                onBiometricSupportChange(biometricsManager.isBiometricsSupported)
+            }
+
+            else -> Unit
+        }
+    }
+}