crypto: support GCM authenticated encryption mode.

This adds two new member functions getAuthTag and setAuthTag that
are useful for AES-GCM encryption modes. Use getAuthTag after
Cipheriv.final, transmit the tag along with the data and use
Decipheriv.setAuthTag to have the encrypted data verified.

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/crypto.js b/lib/crypto.js
index db3ce1c431..add6a79d78 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -322,6 +322,15 @@ Cipheriv.prototype.update = Cipher.prototype.update;
 Cipheriv.prototype.final = Cipher.prototype.final;
 Cipheriv.prototype.setAutoPadding = Cipher.prototype.setAutoPadding;
 
+Cipheriv.prototype.getAuthTag = function() {
+  return this._binding.getAuthTag();
+};
+
+
+Cipheriv.prototype.setAuthTag = function(tagbuf) {
+  this._binding.setAuthTag(tagbuf);
+};
+
 
 
 exports.createDecipher = exports.Decipher = Decipher;
@@ -367,6 +376,8 @@ Decipheriv.prototype.update = Cipher.prototype.update;
 Decipheriv.prototype.final = Cipher.prototype.final;
 Decipheriv.prototype.finaltol = Cipher.prototype.final;
 Decipheriv.prototype.setAutoPadding = Cipher.prototype.setAutoPadding;
+Decipheriv.prototype.getAuthTag = Cipheriv.prototype.getAuthTag;
+Decipheriv.prototype.setAuthTag = Cipheriv.prototype.setAuthTag;