Fix Device Metadata migration used for Device Tracking if an aliased userId was used.

Author: tylerjroach

aws-auth-cognito/src/main/java/com/amplifyframework/auth/cognito/actions/CredentialStoreCognitoActions.kt

@@ -36,13 +36,26 @@ internal object CredentialStoreCognitoActions : CredentialStoreActions {
                     legacyCredentialStore.deleteCredential()
                 }
 
-                // migrate device data
-                val lastAuthUserId = legacyCredentialStore.retrieveLastAuthUserId()
-                lastAuthUserId?.let {
-                    val deviceMetaData = legacyCredentialStore.retrieveDeviceMetadata(lastAuthUserId)
+                /*
+                Migrate Device Metadata
+                1. We first need to get the list of userIds that contain device metadata on the device.
+                2. For each userId, we check to see if the current credential store has device metadata for that user.
+                3. If the current user does not have device metadata in the current store, migrate from legacy.
+                This is a possibility because of a bug where we were previously attempting to migrate using an aliased
+                userId lookup. This situation would happen if a user migrated, signed out, then signed back in. Upon
+                signing back in, they would be granted new device metadata. Since that new metadata is what is
+                associated with the refresh token, we do not want to overwrite it.
+                4. If the current user has device metadata in the current credential store, do not migrate from legacy.
+                5. Upon migration completion, we delete the legacy device metadata.
+                 */
+                legacyCredentialStore.retrieveDeviceMetadataUserIdList().forEach { userId ->
+                    val deviceMetaData = legacyCredentialStore.retrieveDeviceMetadata(userId)
                     if (deviceMetaData != DeviceMetadata.Empty) {
-                        credentialStore.saveDeviceMetadata(lastAuthUserId, deviceMetaData)
-                        legacyCredentialStore.deleteDeviceKeyCredential(lastAuthUserId)
+                        credentialStore.retrieveDeviceMetadata(userId)
+                        if (credentialStore.retrieveDeviceMetadata(userId) == DeviceMetadata.Empty) {
+                            credentialStore.saveDeviceMetadata(userId, deviceMetaData)
+                        }
+                        legacyCredentialStore.deleteDeviceKeyCredential(userId)
                     }
                 }
 

aws-auth-cognito/src/main/java/com/amplifyframework/auth/cognito/data/AWSCognitoLegacyCredentialStore.kt

@@ -29,6 +29,7 @@ import com.amplifyframework.statemachine.codegen.data.DeviceMetadata
 import com.amplifyframework.statemachine.codegen.data.FederatedToken
 import com.amplifyframework.statemachine.codegen.data.SignInMethod
 import com.amplifyframework.statemachine.codegen.data.SignedInData
+import java.io.File
 import java.time.Instant
 import java.time.temporal.ChronoUnit
 import java.util.Date
@@ -74,6 +75,7 @@ internal class AWSCognitoLegacyCredentialStore(
         const val TOKEN_KEY = "token"
     }
 
+    private val userDeviceDetailsCacheKeyPrefix = "$APP_DEVICE_INFO_CACHE.${authConfiguration.userPool?.poolId}."
     private val userDeviceDetailsCacheKey = "$APP_DEVICE_INFO_CACHE.${authConfiguration.userPool?.poolId}.%s"
 
     private val idAndCredentialsKeyValue: KeyValueRepository by lazy {
@@ -229,6 +231,22 @@ internal class AWSCognitoLegacyCredentialStore(
         )
     }
 
+    /*
+    During migration away from the legacy credential store, we need to find all shared preference files that store
+    device metadata. These filenames contain the real userId (not aliased) for the tracked device metadata.
+     */
+    fun retrieveDeviceMetadataUserIdList(): List<String> {
+        return try {
+            val sharedPrefsSuffix = ".xml"
+            File(context.dataDir, "shared_prefs").listFiles { _, filename ->
+                filename.startsWith(userDeviceDetailsCacheKeyPrefix) && filename.endsWith(sharedPrefsSuffix)
+            }?.map { it.name.substringAfter(userDeviceDetailsCacheKeyPrefix).substringBefore(sharedPrefsSuffix) }
+                ?.filter { it.isNotBlank() } ?: emptyList()
+        } catch (e: Exception) {
+            return emptyList()
+        }
+    }
+
     @Synchronized
     override fun retrieveDeviceMetadata(username: String): DeviceMetadata {
         val deviceDetailsCacheKey = String.format(userDeviceDetailsCacheKey, username)