code: public static boolean checkpw(String plaintext, String hashed) {
          return (hashed.compareTo(hashpw(plaintext, hashed)) == 0);
      }
docs: Check that a plaintext password matches a previously hashed
  one
  @param plaintext	the plaintext password to verify
  @param hashed	the previously-hashed password
  @return	true if the passwords match, false otherwise