message: invalid tag length causes deprecation message
diff: @@ -41,8 +41,12 @@ class Encryptor {
  throw new Error("Not a valid signed message");
  }
  let [ciphertext, iv, authTag] = parts;
  + let authTagBuffer = Buffer.from(authTag, 'base64');
  + if(authTagBuffer.length !== 16){
  + throw new Error("Not a valid signed message");
  + }
  let decipher = crypto.createDecipheriv('aes-256-gcm', this.key, Buffer.from(iv, 'base64'));
  - decipher.setAuthTag(Buffer.from(authTag, 'base64'));
  + decipher.setAuthTag(authTagBuffer);
  let decrypted = decipher.update(ciphertext, 'base64', 'utf8');
  decrypted += decipher.final('utf8');
  return JSON.parse(decrypted);
  