PseudoOtp { public static byte[] decrypt(byte[] cipherText, byte[] keyCandidate) { return decrypt(cipherText, keyCandidate, cipherText.length); } private  PseudoOtp(); static byte[] encrypt(byte[] message, byte[] keyCandidate); static byte[] encrypt(byte[] message, byte[] keyCandidate, int messageLength); static byte[] decrypt(byte[] cipherText, byte[] keyCandidate); static byte[] decrypt(byte[] cipherText, byte[] keyCandidate, int messageLength);  }
@Test (expected = NullPointerException.class) public void testDecryptNullCipher() { PseudoOtp.decrypt(null, new byte[] { 0x00 }); }