Merge pull request #13 from jeskew/fix/cast-lambda-messages-to-http-style

Replace Lambda-specific handling with a Lambda -> HTTP-style message converter

Author: jeskew

.travis.yml

@@ -2,13 +2,12 @@ language: node_js
 node_js:
   - "0.10"
   - "0.12"
-  - "4.0"
-  - "4.1"
   - "4.2"
-  - "4.3"
   - "4.4"
-  - "6.0"
-  - "6.1"
+  - "5"
+  - "6"
+  - "7"
+  - "8"
 
 script:
   - npm test

index.js

@@ -39,21 +39,15 @@ var url = require('url'),
         'Token',
         'TopicArn',
         'Type'
-    ];
-
-var hashHasKey = function (hash, key) {
-    if (!(key in hash)) {
-        if (/URL$/.test(key) && key.replace(/URL$/, 'Url') in hash) {
-            return true;
-        }
-        return false;
-    }
-    return true;
-};
+    ],
+    lambdaMessageKeys = {
+        'SigningCertUrl': 'SigningCertURL',
+        'UnsubscribeUrl': 'UnsubscribeURL'
+    };
 
 var hashHasKeys = function (hash, keys) {
     for (var i = 0; i < keys.length; i++) {
-        if (!hashHasKey(hash, keys[i])) {
+        if (!(keys[i] in hash)) {
             return false;
         }
     }
@@ -71,6 +65,20 @@ var indexOf = function (array, value) {
     return -1;
 };
 
+function convertLambdaMessage(message) {
+    for (var key in lambdaMessageKeys) {
+        if (key in message) {
+            message[lambdaMessageKeys[key]] = message[key];
+        }
+    }
+
+    if ('Subject' in message && message.Subject === null) {
+        delete message.Subject;
+    }
+
+    return message;
+}
+
 var validateMessageStructure = function (message) {
     var valid = hashHasKeys(message, requiredKeys);
 
@@ -182,13 +190,14 @@ function MessageValidator(hostPattern, encoding) {
  */
 MessageValidator.prototype.validate = function (hash, cb) {
     var hostPattern = this.hostPattern;
+    hash = convertLambdaMessage(hash);
 
     if (!validateMessageStructure(hash)) {
         cb(new Error('Message missing required keys.'));
         return;
     }
 
-    if (!validateUrl(hash['SigningCertURL'] || hash['SigningCertUrl'], hostPattern)) {
+    if (!validateUrl(hash['SigningCertURL'], hostPattern)) {
         cb(new Error('The certificate is located on an invalid domain.'));
         return;
     }

test/validator.js

@@ -25,6 +25,7 @@ var chai = require('chai'),
         Type: 'Notification',
         MessageId: '1',
         TopicArn: 'arn',
+        Subject: null,
         Message: 'A Lambda message for you!',
         Timestamp: (new Date).toISOString(),
         SignatureVersion: '1',
@@ -66,6 +67,14 @@ describe('Message Validator', function () {
 
                 for (var j = 0; j < signableKeysForSubscription.length; j++) {
                     if (signableKeysForSubscription[j] in validMessages[i]) {
+                        // skip signing null Subject fields to match Lambda behavior
+                        if (
+                            signableKeysForSubscription[j] === 'Subject' &&
+                            validMessages[i][signableKeysForSubscription[j]] === null
+                        ) {
+                            continue;
+                        }
+
                         signer.update(signableKeysForSubscription[j] + "\n"
                             + validMessages[i][signableKeysForSubscription[j]] + "\n", 'utf8');
                     }