fix(apigateway): CORS OPTIONS method should not require auth (aws#22402)

When you create a RestApi and you provide `defaultCorsPreflightOptions` we automatically create a CORS OPTIONS method for each method. If you also provide `defaultMethodOptions` then those default options get passed through to the CORS OPTION method as well. In the case of authentication options this should not be the case.

This PR explicitly sets the authentication related options to NONE values which overrides whatever is provided in `defaultMethodOptions`.

I've updated an integration tests to assert that an OPTIONS call is successful (I also tested before the fix to assert that it failed).

fixes aws#8615


----

### All Submissions:

* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/main/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: corymhall

packages/@aws-cdk/aws-apigateway/README.md

@@ -740,7 +740,51 @@ books.addMethod('GET', new apigateway.HttpIntegration('http://amazon.com'), {
 
 A full working example is shown below.
 
-[Full token authorizer example](test/authorizers/integ.token-authorizer.lit.ts).
+```ts
+import * as path from 'path';
+import * as lambda from '@aws-cdk/aws-lambda';
+import { App, Stack } from '@aws-cdk/core';
+import { MockIntegration, PassthroughBehavior, RestApi, TokenAuthorizer, Cors } from '../../lib';
+
+/// !show
+const app = new App();
+const stack = new Stack(app, 'TokenAuthorizerInteg');
+
+const authorizerFn = new lambda.Function(stack, 'MyAuthorizerFunction', {
+  runtime: lambda.Runtime.NODEJS_14_X,
+  handler: 'index.handler',
+  code: lambda.AssetCode.fromAsset(path.join(__dirname, 'integ.token-authorizer.handler')),
+});
+
+const authorizer = new TokenAuthorizer(stack, 'MyAuthorizer', {
+  handler: authorizerFn,
+});
+
+const restapi = new RestApi(stack, 'MyRestApi', {
+  cloudWatchRole: true,
+  defaultMethodOptions: {
+    authorizer,
+  },
+  defaultCorsPreflightOptions: {
+    allowOrigins: Cors.ALL_ORIGINS,
+  },
+});
+
+
+restapi.root.addMethod('ANY', new MockIntegration({
+  integrationResponses: [
+    { statusCode: '200' },
+  ],
+  passthroughBehavior: PassthroughBehavior.NEVER,
+  requestTemplates: {
+    'application/json': '{ "statusCode": 200 }',
+  },
+}), {
+  methodResponses: [
+    { statusCode: '200' },
+  ],
+});
+```
 
 By default, the `TokenAuthorizer` looks for the authorization token in the request header with the key 'Authorization'. This can,
 however, be modified by changing the `identitySource` property.

packages/@aws-cdk/aws-apigateway/lib/method.ts

@@ -186,7 +186,7 @@ export class Method extends Resource {
 
     const defaultMethodOptions = props.resource.defaultMethodOptions || {};
     const authorizer = options.authorizer || defaultMethodOptions.authorizer;
-    const authorizerId = authorizer?.authorizerId;
+    const authorizerId = authorizer?.authorizerId ? authorizer.authorizerId : undefined;
 
     const authorizationTypeOption = options.authorizationType || defaultMethodOptions.authorizationType;
     const authorizationType = authorizer?.authorizationType || authorizationTypeOption || AuthorizationType.NONE;

packages/@aws-cdk/aws-apigateway/lib/resource.ts

@@ -4,7 +4,7 @@ import { CfnResource, CfnResourceProps } from './apigateway.generated';
 import { Cors, CorsOptions } from './cors';
 import { Integration } from './integration';
 import { MockIntegration } from './integrations';
-import { Method, MethodOptions } from './method';
+import { Method, MethodOptions, AuthorizationType } from './method';
 import { IRestApi, RestApi } from './restapi';
 
 export interface IResource extends IResourceBase {
@@ -296,6 +296,12 @@ export abstract class ResourceBase extends ResourceConstruct implements IResourc
         { statusCode: `${statusCode}`, responseParameters: integrationResponseParams, responseTemplates: renderResponseTemplate() },
       ],
     }), {
+      authorizer: {
+        authorizerId: '',
+        authorizationType: AuthorizationType.NONE,
+      },
+      apiKeyRequired: false,
+      authorizationType: AuthorizationType.NONE,
       methodResponses: [
         { statusCode: `${statusCode}`, responseParameters: methodResponseParams },
       ],

packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.lit.ts

@@ -0,0 +1,127 @@
+import * as path from 'path';
+import * as lambda from '@aws-cdk/aws-lambda';
+import { App, Stack, Duration } from '@aws-cdk/core';
+import { IntegTest, ExpectedResult, Match } from '@aws-cdk/integ-tests';
+import { MockIntegration, PassthroughBehavior, RestApi, TokenAuthorizer, Cors } from '../../lib';
+
+const app = new App();
+const stack = new Stack(app, 'TokenAuthorizerInteg');
+
+const authorizerFn = new lambda.Function(stack, 'MyAuthorizerFunction', {
+  runtime: lambda.Runtime.NODEJS_14_X,
+  handler: 'index.handler',
+  code: lambda.AssetCode.fromAsset(path.join(__dirname, 'integ.token-authorizer.handler')),
+});
+
+const authorizer = new TokenAuthorizer(stack, 'MyAuthorizer', {
+  handler: authorizerFn,
+});
+
+const restapi = new RestApi(stack, 'MyRestApi', {
+  cloudWatchRole: true,
+  defaultMethodOptions: {
+    authorizer,
+  },
+  defaultCorsPreflightOptions: {
+    allowOrigins: Cors.ALL_ORIGINS,
+  },
+});
+
+
+restapi.root.addMethod('ANY', new MockIntegration({
+  integrationResponses: [
+    { statusCode: '200' },
+  ],
+  passthroughBehavior: PassthroughBehavior.NEVER,
+  requestTemplates: {
+    'application/json': '{ "statusCode": 200 }',
+  },
+}), {
+  methodResponses: [
+    { statusCode: '200' },
+  ],
+});
+
+const integ = new IntegTest(app, 'apigw-token-auth', {
+  testCases: [stack],
+});
+const hostName = `${restapi.restApiId}.execute-api.${stack.region}.${stack.urlSuffix}`;
+const testFunc = new lambda.Function(stack, 'InvokeFunction', {
+  memorySize: 250,
+  timeout: Duration.seconds(10),
+  code: lambda.Code.fromInline(`
+const https = require('https');
+const options = {
+  hostname: '${hostName}',
+  path: '/${restapi.deploymentStage.stageName}',
+};
+exports.handler = async function(event) {
+  console.log(event);
+  options.method = event.method;
+  if ('authorization' in event) {
+    options.headers = {
+      Authorization: event.authorization,
+    };
+  }
+  let dataString = '';
+  const response = await new Promise((resolve, reject) => {
+    const req = https.request(options, (res) => {
+      res.on('data', data => {
+        dataString += data;
+      })
+      res.on('end', () => {
+        resolve({
+          statusCode: res.statusCode,
+          body: dataString,
+        });
+      })
+    });
+    req.on('error', err => {
+      reject({
+        statusCode: 500,
+        body: JSON.stringify({
+          cause: 'Something went wrong',
+          error: err,
+        })
+      });
+    });
+    req.end();
+  });
+  return response;
+}
+`),
+  handler: 'index.handler',
+  runtime: lambda.Runtime.NODEJS_16_X,
+});
+
+const invokeGet = integ.assertions.invokeFunction({
+  functionName: testFunc.functionName,
+  payload: JSON.stringify({
+    method: 'GET',
+    authorization: 'allow',
+  }),
+});
+invokeGet.expect(ExpectedResult.objectLike({
+  Payload: Match.stringLikeRegexp('200'),
+}));
+
+const invokeGetDeny = integ.assertions.invokeFunction({
+  functionName: testFunc.functionName,
+  payload: JSON.stringify({
+    method: 'GET',
+    authorization: 'deny',
+  }),
+});
+invokeGetDeny.expect(ExpectedResult.objectLike({
+  Payload: Match.stringLikeRegexp('User is not authorized to access this resource with an explicit deny'),
+}));
+
+const invokeOptions = integ.assertions.invokeFunction({
+  functionName: testFunc.functionName,
+  payload: JSON.stringify({
+    method: 'OPTIONS',
+  }),
+});
+invokeOptions.expect(ExpectedResult.objectLike({
+  Payload: Match.stringLikeRegexp('204'),
+}));

packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.ts

@@ -1,5 +1,5 @@
 {
-  "version": "20.0.0",
+  "version": "21.0.0",
   "files": {
     "fec8e8354e12687c5a4b843b4e269741f53dec634946869b276f7fd1017845c3": {
       "source": {
@@ -14,15 +14,15 @@
         }
       }
     },
-    "d121ee9744a20c9af43e516c8fb4fe93d1ed9b26130e2db68ed9534c7104c866": {
+    "d48b90b340d35b9bc726b78e652d17148e2449f6f756e4377428635071f68d09": {
       "source": {
         "path": "TokenAuthorizerInteg.template.json",
         "packaging": "file"
       },
       "destinations": {
         "current_account-current_region": {
           "bucketName": "cdk-hnb659fds-assets-${AWS::AccountId}-${AWS::Region}",
-          "objectKey": "d121ee9744a20c9af43e516c8fb4fe93d1ed9b26130e2db68ed9534c7104c866.json",
+          "objectKey": "d48b90b340d35b9bc726b78e652d17148e2449f6f756e4377428635071f68d09.json",
           "assumeRoleArn": "arn:${AWS::Partition}:iam::${AWS::AccountId}:role/cdk-hnb659fds-file-publishing-role-${AWS::AccountId}-${AWS::Region}"
         }
       }