feat(auth,api): cognito user pools auth provider & auth mode for API HTTP requests

packages/api/amplify_api/lib/src/decorators/authorize_http_request.dart

@@ -64,8 +64,15 @@ Future<http.BaseRequest> authorizeHttpRequest(http.BaseRequest request,
       return authorizedRequest.httpRequest;
     case APIAuthorizationType.function:
     case APIAuthorizationType.oidc:
-    case APIAuthorizationType.userPools:
       throw UnimplementedError('${authType.name} not implemented.');
+    case APIAuthorizationType.userPools:
+      final authProvider = _validateAuthProvider(
+        authProviderRepo.getAuthProvider(authType.authProviderToken),
+        authType,
+      );
+      final authorizedRequest =
+          await authProvider.authorizeRequest(_httpToAWSRequest(request));
+      return authorizedRequest.httpRequest;
     case APIAuthorizationType.none:
       return request;
   }

packages/api/amplify_api/test/authorize_http_request_test.dart

@@ -33,11 +33,19 @@ void main() {
   final authProviderRepo = AmplifyAuthProviderRepository();
 
   setUpAll(() {
-    authProviderRepo.registerAuthProvider(
+    authProviderRepo
+      ..registerAuthProvider(
         APIAuthorizationType.apiKey.authProviderToken,
-        AppSyncApiKeyAuthProvider());
-    authProviderRepo.registerAuthProvider(
-        APIAuthorizationType.iam.authProviderToken, TestIamAuthProvider());
+        AppSyncApiKeyAuthProvider(),
+      )
+      ..registerAuthProvider(
+        APIAuthorizationType.iam.authProviderToken,
+        TestIamAuthProvider(),
+      )
+      ..registerAuthProvider(
+        APIAuthorizationType.userPools.authProviderToken,
+        TestTokenAuthProvider(),
+      );
   });
 
   group('authorizeHttpRequest', () {
@@ -132,7 +140,23 @@ void main() {
           throwsA(isA<ApiException>()));
     });
 
-    test('authorizes with Cognito User Pools auth mode', () {}, skip: true);
+    test('authorizes with Cognito User Pools auth mode', () async {
+      const endpointConfig = AWSApiConfig(
+          authorizationType: APIAuthorizationType.userPools,
+          endpoint: _gqlEndpoint,
+          endpointType: EndpointType.graphQL,
+          region: _region);
+      final inputRequest = _generateTestRequest(endpointConfig.endpoint);
+      final authorizedRequest = await authorizeHttpRequest(
+        inputRequest,
+        endpointConfig: endpointConfig,
+        authProviderRepo: authProviderRepo,
+      );
+      expect(
+        authorizedRequest.headers[AWSHeaders.authorization],
+        testAccessToken,
+      );
+    });
 
     test('authorizes with OIDC auth mode', () {}, skip: true);
 

packages/api/amplify_api/test/util.dart

@@ -17,6 +17,8 @@ import 'package:aws_signature_v4/aws_signature_v4.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:http/http.dart' as http;
 
+const testAccessToken = 'test-access-token-123';
+
 class TestIamAuthProvider extends AWSIamAmplifyAuthProvider {
   @override
   Future<AWSCredentials> retrieve() async {
@@ -43,6 +45,13 @@ class TestIamAuthProvider extends AWSIamAmplifyAuthProvider {
   }
 }
 
+class TestTokenAuthProvider extends TokenAmplifyAuthProvider {
+  @override
+  Future<String> getLatestAuthToken() async {
+    return testAccessToken;
+  }
+}
+
 void validateSignedRequest(http.BaseRequest request) {
   const userAgentHeader =
       zIsWeb ? AWSHeaders.amzUserAgent : AWSHeaders.userAgent;

packages/auth/amplify_auth_cognito_dart/lib/src/auth_plugin_impl.dart

@@ -51,6 +51,7 @@ import 'package:amplify_auth_cognito_dart/src/sdk/cognito_identity_provider.dart
 import 'package:amplify_auth_cognito_dart/src/sdk/sdk_bridge.dart';
 import 'package:amplify_auth_cognito_dart/src/state/state.dart';
 import 'package:amplify_auth_cognito_dart/src/util/cognito_iam_auth_provider.dart';
+import 'package:amplify_auth_cognito_dart/src/util/cognito_user_pools_auth_provider.dart';
 import 'package:amplify_core/amplify_core.dart';
 import 'package:amplify_secure_storage_dart/amplify_secure_storage_dart.dart';
 import 'package:built_collection/built_collection.dart';
@@ -180,10 +181,15 @@ class AmplifyAuthCognitoDart extends AuthPluginInterface
 
     // Register auth providers to provide auth functionality to other plugins
     // without requiring other plugins to call `Amplify.Auth...` directly.
-    authProviderRepo.registerAuthProvider(
-      APIAuthorizationType.iam.authProviderToken,
-      CognitoIamAuthProvider(),
-    );
+    authProviderRepo
+      ..registerAuthProvider(
+        APIAuthorizationType.iam.authProviderToken,
+        CognitoIamAuthProvider(),
+      )
+      ..registerAuthProvider(
+        APIAuthorizationType.userPools.authProviderToken,
+        CognitoUserPoolsAuthProvider(),
+      );
 
     if (_stateMachine.getOrCreate(AuthStateMachine.type).currentState.type !=
         AuthStateType.notConfigured) {

packages/auth/amplify_auth_cognito_dart/lib/src/util/cognito_user_pools_auth_provider.dart

@@ -0,0 +1,37 @@
+// Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'dart:async';
+
+import 'package:amplify_auth_cognito_dart/amplify_auth_cognito_dart.dart';
+import 'package:amplify_core/amplify_core.dart';
+import 'package:meta/meta.dart';
+
+/// [AmplifyAuthProvider] implementation that adds access token to request headers.
+@internal
+class CognitoUserPoolsAuthProvider extends TokenAmplifyAuthProvider {
+  /// Get access token from `Amplify.Auth.fetchAuthSession()`.
+  @override
+  Future<String> getLatestAuthToken() async {
+    final authSession =
+        await Amplify.Auth.fetchAuthSession() as CognitoAuthSession;
+    final token = authSession.userPoolTokens?.accessToken.raw;
+    if (token == null) {
+      throw const AuthException(
+        'Unable to fetch access token while authorizing with Cognito User Pools.',
+      );
+    }
+    return token;
+  }
+}