Skipjack Example [Back] This is a private key encryption algorithm, designed by NSA. [Theory] Message: Key: The results are then: Encrypted (Base-64) Encrypted (Hex) Decrypted

Code Used

        public string SkipjackEngine(string plain, string key)
        {
            
            BCEngine bcEngine = new BCEngine(new BlowfishEngine(), Encoding.ASCII);
            bcEngine.SetPadding(new Pkcs7Padding());
            return bcEngine.Encrypt(plain, key);
        }

        public string SkipjackEngine(string cipher, string key)
        {
            BCEngine bcEngine = new BCEngine(new BlowfishEngine(), Encoding.ASCII);
            bcEngine.SetPadding(new Pkcs7Padding());
            return bcEngine.Decrypt(cipher, key);
        }



   // Based on http://elian.co.uk/post/2009/07/29/Bouncy-Castle-CSharp.aspx
    public class BCEngine
    {
        private readonly Encoding _encoding;
        private readonly IBlockCipher _blockCipher;
        private Org.BouncyCastle.Crypto.Paddings.PaddedBufferedBlockCipher _cipher;
        private Org.BouncyCastle.Crypto.Paddings.IBlockCipherPadding _padding;

        public BCEngine(IBlockCipher blockCipher, Encoding encoding)
        {
            _blockCipher = blockCipher;
            _encoding = encoding;
        }

        public void SetPadding(IBlockCipherPadding padding)
        {
            if (padding != null)
                _padding = padding;
        }

        public string Encrypt(string plain, string key)
        {
            byte[] result = BouncyCastleCrypto(true, _encoding.GetBytes(plain), key);
            return Convert.ToBase64String(result);
        }

        public string Decrypt(string cipher, string key)
        {
            byte[] result = BouncyCastleCrypto(false, Convert.FromBase64String(cipher), key);
            return _encoding.GetString(result);
        }


        private byte[] BouncyCastleCrypto(bool forEncrypt, byte[] input, string key)
        {
            try
            {
                _cipher = _padding == null ? 
                new PaddedBufferedBlockCipher(_blockCipher) : new PaddedBufferedBlockCipher(_blockCipher, _padding);
                
                int paddingchar = 16 - key.Length;
                
                for (int i = 0; i < paddingchar; i++)
                {
                    key += " ";
                }
                key=key.Substring(0,16);

                byte[] keyByte = _encoding.GetBytes(key);

                
                _cipher.Init(forEncrypt, new KeyParameter(keyByte));
                return _cipher.DoFinal(input);
            }
            catch (Org.BouncyCastle.Crypto.CryptoException ex)
            {
               // throw new CryptoException(ex);
            }
            return null;
        }