Mitigate nodejs/node#17523.

Author: SaltwaterC

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 0.1.3
+ * Emit an error event from AES-256-GCM Decrypt if the tag length isn't the default 16 bytes / 128 bits.
+
 ## v0.1.2
  * Add length attribute for gcm.encrypt to simplify the MAC slicing when appendMac is on
 

lib/aes256gcm.js

@@ -47,6 +47,11 @@ function Decrypt(options) {
     return new Decrypt(options);
   }
   this._decipher = crypto.createDecipheriv('aes-256-gcm', options.key, options.iv);
+  if (options.mac.length !== 16) {
+    var message = util.format('Expecting a tag length of 16 bytes / 128 bits rather than %d.', options.mac.length);
+    var err = new Error(message);
+    this.emit('error', err);
+  }
   this._decipher.setAuthTag(options.mac);
   Transform.call(this, options);
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "envelope-encryption-tools",
-  "version": "0.1.2",
+  "version": "0.1.3",
   "main": "lib/main.js",
   "description": "Lightweight encryption toolkit to support envelope encryption schemes",
   "license": "MIT",