Merge pull request #1 from topcoder-platform/issue-125

For #125: AWS handshake

Author: jmgasper

DLPTrigger/handlers/options.ts

@@ -0,0 +1,17 @@
+import * as aws from 'aws-lambda'
+import { createHash } from 'crypto'
+
+/**
+ * Handles HTTP get event.
+ * @param event
+ * @param context
+ */
+export default async function handleGetRequest(event: aws.APIGatewayEvent, context: aws.Context) {
+  const handshakeRequestData = event.headers['x-handshake-request-data']
+  if (!handshakeRequestData) {
+    return {}
+  }
+  const digest = createHash('sha256').update(handshakeRequestData).digest('hex')
+  const responseHeaders = { 'x-handshake-response-data': digest }
+  return responseHeaders
+}

DLPTrigger/lambda.ts

@@ -1,14 +1,15 @@
 import handleGetRequest from './handlers/get'
 import * as aws from 'aws-lambda'
 import handlePostRequest from './handlers/post'
+import handleOptionsRequest from './handlers/options'
 
 /**
  * HTTP headers to be always returned to the client.
  */
 const commonHeaders = {
   'Access-Control-Allow-Credentials': 'true',
   'Access-Control-Allow-Origin': '*',
-  'Access-Control-Allow-Methods': 'GET, POST, OPTIONS, HANDSHAKE',
+  'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
   'Access-Control-Allow-Headers': '*',
   'Access-Control-Max-Age': '86400',
   // eslint-disable-next-line quote-props
@@ -25,6 +26,10 @@ export async function handle (event: aws.APIGatewayEvent, context: aws.Context)
   const headers = commonHeaders
   let statusCode = 200
   let body: any = null
+  // Store lower-case version of the headers
+  for (const key in event.headers) {
+    event.headers[key.toLowerCase()] = event.headers[key];
+  }
 
   try {
     switch (event.httpMethod) {
@@ -37,7 +42,8 @@ export async function handle (event: aws.APIGatewayEvent, context: aws.Context)
         break
       }
       case 'OPTIONS':
-        // Nothing to do for OPTIONS method.
+        const additionalHeaders = await handleOptionsRequest(event, context)
+        Object.assign(headers, additionalHeaders)
         break
       default:
         statusCode = 405