public static DelegationTokenInformation decodeDelegationTokenInformation(byte[] tokenBytes)
      throws IOException {
    DataInputStream in = new DataInputStream(new ByteArrayInputStream(tokenBytes));
    DelegationTokenInformation token = new DelegationTokenInformation(0, null);
    int len = WritableUtils.readVInt(in);
    token.password = new byte[len];
    in.readFully(token.password);
    token.renewDate = in.readLong();
    return token;
  }
Workaround for serialization of {@link DelegationTokenInformation} through package access.
Future version of Hadoop should add this to DelegationTokenInformation itself.
shims/common/src/main/java/org/apache/hadoop/security/token/delegation/HiveDelegationTokenSupport.java