🌱 Use aes-256-gcm for passphrase encryption

Closes #452

src/crypto/encrypt.js

@@ -88,45 +88,49 @@ export const decryptMessageWithSecret = (
 };
 
 /**
- * @method encryptAES256CBCWithPassword
+ * @method encryptAES256GCMWithPassword
  * @param {String} plainText utf8 - any utf8 string
  * @param {String} password utf8 - the password used to encrypt the passphrase
  *
- * @return {Object} - { cipher: '...', iv: '...' }
+ * @return {Object} - { cipher: '...', iv: '...', tag: '...' }
  */
 
-const encryptAES256CBCWithPassword = (plainText, password) => {
+const encryptAES256GCMWithPassword = (plainText, password) => {
 	const iv = crypto.randomBytes(16);
 	const passwordHash = hash(password, 'utf8');
-	const cipher = crypto.createCipheriv('aes-256-cbc', passwordHash, iv);
+	const cipher = crypto.createCipheriv('aes-256-gcm', passwordHash, iv);
 	const firstBlock = cipher.update(plainText, 'utf8');
 	const encrypted = Buffer.concat([firstBlock, cipher.final()]);
+	const tag = cipher.getAuthTag();
 
 	return {
 		cipher: encrypted.toString('hex'),
 		iv: iv.toString('hex'),
+		tag: tag.toString('hex'),
 	};
 };
 
 /**
- * @method decryptAES256CBCWithPassword
- * @param {Object} Object - Object with cipher and iv as hex strings
- * @param {String} Object.cipher - hex string AES-256-CBC cipher
+ * @method decryptAES256GCMWithPassword
+ * @param {Object} Object - Object with cipher, iv and tag as hex strings
+ * @param {String} Object.cipher - hex string AES-256-GCM cipher
  * @param {String} Object.iv - hex string for the initialisation vector
+ * @param {String} Object.tag - hex string for the tag
  * @param {String} password utf8 - the password used to encrypt the passphrase
  *
  * @return {String} utf8
  */
 
-const decryptAES256CBCWithPassword = ({ cipher, iv }, password) => {
+const decryptAES256GCMWithPassword = ({ cipher, iv, tag }, password) => {
 	const passwordHash = hash(password, 'utf8');
-	const decipherInit = crypto.createDecipheriv(
-		'aes-256-cbc',
+	const decipher = crypto.createDecipheriv(
+		'aes-256-gcm',
 		passwordHash,
 		hexToBuffer(iv),
 	);
-	const firstBlock = decipherInit.update(hexToBuffer(cipher));
-	const decrypted = Buffer.concat([firstBlock, decipherInit.final()]);
+	decipher.setAuthTag(hexToBuffer(tag));
+	const firstBlock = decipher.update(hexToBuffer(cipher));
+	const decrypted = Buffer.concat([firstBlock, decipher.final()]);
 
 	return decrypted.toString();
 };
@@ -136,17 +140,20 @@ const decryptAES256CBCWithPassword = ({ cipher, iv }, password) => {
  * @param {String} passphrase utf8 - twelve word secret passphrase
  * @param {String} password utf8 - the password used to encrypt the passphrase
  *
- * @return {Object} - { cipher: '...', iv: '...' }
+ * @return {Object} - { cipher: '...', iv: '...', tag: '...' }
  */
 
-export const encryptPassphraseWithPassword = encryptAES256CBCWithPassword;
+export const encryptPassphraseWithPassword = encryptAES256GCMWithPassword;
 
 /**
  * @method decryptPassphraseWithPassword
- * @param {Object} cipherAndIv - Object containing the encryption cipher and the iv
+ * @param {Object} Object - Object with cipher, iv and tag as hex strings
+ * @param {String} Object.cipher - hex string AES-256-GCM cipher
+ * @param {String} Object.iv - hex string for the initialisation vector
+ * @param {String} Object.tag - hex string for the tag
  * @param {String} password utf8 - the password used to encrypt the passphrase
  *
  * @return {String}
  */
 
-export const decryptPassphraseWithPassword = decryptAES256CBCWithPassword;
+export const decryptPassphraseWithPassword = decryptAES256GCMWithPassword;

test/crypto/encrypt.js

@@ -161,17 +161,26 @@ describe('encrypt', () => {
 					.and.be.hexString()
 					.and.have.length(32);
 			});
+
+			it('should output the tag', () => {
+				cipher.should.be
+					.type('object')
+					.and.have.property('tag')
+					.and.be.hexString()
+					.and.have.length(32);
+			});
 		});
 
 		describe('#decryptPassphraseWithPassword', () => {
 			it('should decrypt a text with a password', () => {
-				const cipherAndNonce = {
+				const cipherNonceAndTag = {
 					cipher:
-						'1c527b9408e77ae79e2ceb1ad5907ec523cd957d30c6a08dc922686e62ed98271910ca5b605f95aec98c438b6214fa7e83e3689f3fba89bfcaee937b35a3d931640afe79c353499a500f14c35bd3fd08',
-					iv: '89d0fa0b955219a0e6239339fbb8239f',
+						'331a80ab5f9cdd21e16f60c73e9b8f3c3d7f6b44dc79f60985234fde36077080726e577cb5596ab0c885bc321efc4f6cce52f5cae134b48e1b5308232563b6180858323bcb',
+					iv: 'e249a35bb2c2fa529fdbe349496d30ac',
+					tag: 'eb318b7feaa7a7540e599984bd1bb298',
 				};
 				const decrypted = decryptPassphraseWithPassword(
-					cipherAndNonce,
+					cipherNonceAndTag,
 					defaultPassword,
 				);
 				decrypted.should.be.eql(defaultSecret);