Example #1
0
        public static IBufferedCipher GetCipher(
            string algorithm)
        {
            if (algorithm == null)
            {
                throw new ArgumentNullException("algorithm");
            }

            algorithm = Platform.ToUpperInvariant(algorithm);

            {
                string aliased = (string)algorithms[algorithm];

                if (aliased != null)
                {
                    algorithm = aliased;
                }
            }

            IBasicAgreement iesAgreement = null;

            if (algorithm == "IES")
            {
                iesAgreement = new DHBasicAgreement();
            }
            else if (algorithm == "ECIES")
            {
                iesAgreement = new ECDHBasicAgreement();
            }

            if (iesAgreement != null)
            {
                return(new BufferedIesCipher(
                           new IesEngine(
                               iesAgreement,
                               new Kdf2BytesGenerator(
                                   new Sha1Digest()),
                               new HMac(
                                   new Sha1Digest()))));
            }



            if (Platform.StartsWith(algorithm, "PBE"))
            {
                if (Platform.EndsWith(algorithm, "-CBC"))
                {
                    if (algorithm == "PBEWITHSHA1ANDDES-CBC")
                    {
                        return(new PaddedBufferedBlockCipher(
                                   new CbcBlockCipher(new DesEngine())));
                    }
                    else if (algorithm == "PBEWITHSHA1ANDRC2-CBC")
                    {
                        return(new PaddedBufferedBlockCipher(
                                   new CbcBlockCipher(new RC2Engine())));
                    }
                    else if (Strings.IsOneOf(algorithm,
                                             "PBEWITHSHAAND2-KEYTRIPLEDES-CBC", "PBEWITHSHAAND3-KEYTRIPLEDES-CBC"))
                    {
                        return(new PaddedBufferedBlockCipher(
                                   new CbcBlockCipher(new DesEdeEngine())));
                    }
                    else if (Strings.IsOneOf(algorithm,
                                             "PBEWITHSHAAND128BITRC2-CBC", "PBEWITHSHAAND40BITRC2-CBC"))
                    {
                        return(new PaddedBufferedBlockCipher(
                                   new CbcBlockCipher(new RC2Engine())));
                    }
                }
                else if (Platform.EndsWith(algorithm, "-BC") || Platform.EndsWith(algorithm, "-OPENSSL"))
                {
                    if (Strings.IsOneOf(algorithm,
                                        "PBEWITHSHAAND128BITAES-CBC-BC",
                                        "PBEWITHSHAAND192BITAES-CBC-BC",
                                        "PBEWITHSHAAND256BITAES-CBC-BC",
                                        "PBEWITHSHA256AND128BITAES-CBC-BC",
                                        "PBEWITHSHA256AND192BITAES-CBC-BC",
                                        "PBEWITHSHA256AND256BITAES-CBC-BC",
                                        "PBEWITHMD5AND128BITAES-CBC-OPENSSL",
                                        "PBEWITHMD5AND192BITAES-CBC-OPENSSL",
                                        "PBEWITHMD5AND256BITAES-CBC-OPENSSL"))
                    {
                        return(new PaddedBufferedBlockCipher(
                                   new CbcBlockCipher(new AesFastEngine())));
                    }
                }
            }



            string[] parts = algorithm.Split('/');

            IBlockCipher           blockCipher     = null;
            IAsymmetricBlockCipher asymBlockCipher = null;
            IStreamCipher          streamCipher    = null;

            string algorithmName = parts[0];

            {
                string aliased = (string)algorithms[algorithmName];

                if (aliased != null)
                {
                    algorithmName = aliased;
                }
            }

            CipherAlgorithm cipherAlgorithm;

            try
            {
                cipherAlgorithm = (CipherAlgorithm)Enums.GetEnumValue(typeof(CipherAlgorithm), algorithmName);
            }
            catch (ArgumentException)
            {
                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
            }

            switch (cipherAlgorithm)
            {
            case CipherAlgorithm.AES:
                blockCipher = new AesFastEngine();
                break;

            case CipherAlgorithm.ARC4:
                streamCipher = new RC4Engine();
                break;

            case CipherAlgorithm.BLOWFISH:
                blockCipher = new BlowfishEngine();
                break;

            case CipherAlgorithm.CAMELLIA:
                blockCipher = new CamelliaEngine();
                break;

            case CipherAlgorithm.CAST5:
                blockCipher = new Cast5Engine();
                break;

            case CipherAlgorithm.CAST6:
                blockCipher = new Cast6Engine();
                break;

            case CipherAlgorithm.DES:
                blockCipher = new DesEngine();
                break;

            case CipherAlgorithm.DESEDE:
                blockCipher = new DesEdeEngine();
                break;

            case CipherAlgorithm.ELGAMAL:
                asymBlockCipher = new ElGamalEngine();
                break;

            case CipherAlgorithm.GOST28147:
                blockCipher = new Gost28147Engine();
                break;

            case CipherAlgorithm.HC128:
                streamCipher = new HC128Engine();
                break;

            case CipherAlgorithm.HC256:
                streamCipher = new HC256Engine();
                break;

            case CipherAlgorithm.IDEA:
                blockCipher = new IdeaEngine();
                break;

            case CipherAlgorithm.NOEKEON:
                blockCipher = new NoekeonEngine();
                break;

            case CipherAlgorithm.PBEWITHSHAAND128BITRC4:
            case CipherAlgorithm.PBEWITHSHAAND40BITRC4:
                streamCipher = new RC4Engine();
                break;

            case CipherAlgorithm.RC2:
                blockCipher = new RC2Engine();
                break;

            case CipherAlgorithm.RC5:
                blockCipher = new RC532Engine();
                break;

            case CipherAlgorithm.RC5_64:
                blockCipher = new RC564Engine();
                break;

            case CipherAlgorithm.RC6:
                blockCipher = new RC6Engine();
                break;

            case CipherAlgorithm.RIJNDAEL:
                blockCipher = new RijndaelEngine();
                break;

            case CipherAlgorithm.RSA:
                asymBlockCipher = new RsaBlindedEngine();
                break;

            case CipherAlgorithm.SALSA20:
                streamCipher = new Salsa20Engine();
                break;

            case CipherAlgorithm.SEED:
                blockCipher = new SeedEngine();
                break;

            case CipherAlgorithm.SERPENT:
                blockCipher = new SerpentEngine();
                break;

            case CipherAlgorithm.SKIPJACK:
                blockCipher = new SkipjackEngine();
                break;

            case CipherAlgorithm.TEA:
                blockCipher = new TeaEngine();
                break;

            case CipherAlgorithm.THREEFISH_256:
                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_256);
                break;

            case CipherAlgorithm.THREEFISH_512:
                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_512);
                break;

            case CipherAlgorithm.THREEFISH_1024:
                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_1024);
                break;

            case CipherAlgorithm.TNEPRES:
                blockCipher = new TnepresEngine();
                break;

            case CipherAlgorithm.TWOFISH:
                blockCipher = new TwofishEngine();
                break;

            case CipherAlgorithm.VMPC:
                streamCipher = new VmpcEngine();
                break;

            case CipherAlgorithm.VMPC_KSA3:
                streamCipher = new VmpcKsa3Engine();
                break;

            case CipherAlgorithm.XTEA:
                blockCipher = new XteaEngine();
                break;

            default:
                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
            }

            if (streamCipher != null)
            {
                if (parts.Length > 1)
                {
                    throw new ArgumentException("Modes and paddings not used for stream ciphers");
                }

                return(new BufferedStreamCipher(streamCipher));
            }


            bool cts    = false;
            bool padded = true;
            IBlockCipherPadding padding         = null;
            IAeadBlockCipher    aeadBlockCipher = null;

            if (parts.Length > 2)
            {
                if (streamCipher != null)
                {
                    throw new ArgumentException("Paddings not used for stream ciphers");
                }

                string paddingName = parts[2];

                CipherPadding cipherPadding;
                if (paddingName == "")
                {
                    cipherPadding = CipherPadding.RAW;
                }
                else if (paddingName == "X9.23PADDING")
                {
                    cipherPadding = CipherPadding.X923PADDING;
                }
                else
                {
                    try
                    {
                        cipherPadding = (CipherPadding)Enums.GetEnumValue(typeof(CipherPadding), paddingName);
                    }
                    catch (ArgumentException)
                    {
                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                    }
                }

                switch (cipherPadding)
                {
                case CipherPadding.NOPADDING:
                    padded = false;
                    break;

                case CipherPadding.RAW:
                    break;

                case CipherPadding.ISO10126PADDING:
                case CipherPadding.ISO10126D2PADDING:
                case CipherPadding.ISO10126_2PADDING:
                    padding = new ISO10126d2Padding();
                    break;

                case CipherPadding.ISO7816_4PADDING:
                case CipherPadding.ISO9797_1PADDING:
                    padding = new ISO7816d4Padding();
                    break;

                case CipherPadding.ISO9796_1:
                case CipherPadding.ISO9796_1PADDING:
                    asymBlockCipher = new ISO9796d1Encoding(asymBlockCipher);
                    break;

                case CipherPadding.OAEP:
                case CipherPadding.OAEPPADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher);
                    break;

                case CipherPadding.OAEPWITHMD5ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new MD5Digest());
                    break;

                case CipherPadding.OAEPWITHSHA1ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_1ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha1Digest());
                    break;

                case CipherPadding.OAEPWITHSHA224ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_224ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha224Digest());
                    break;

                case CipherPadding.OAEPWITHSHA256ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_256ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest());
                    break;

                case CipherPadding.OAEPWITHSHA384ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_384ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha384Digest());
                    break;

                case CipherPadding.OAEPWITHSHA512ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_512ANDMGF1PADDING:
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha512Digest());
                    break;

                case CipherPadding.PKCS1:
                case CipherPadding.PKCS1PADDING:
                    asymBlockCipher = new Pkcs1Encoding(asymBlockCipher);
                    break;

                case CipherPadding.PKCS5:
                case CipherPadding.PKCS5PADDING:
                case CipherPadding.PKCS7:
                case CipherPadding.PKCS7PADDING:
                    padding = new Pkcs7Padding();
                    break;

                case CipherPadding.TBCPADDING:
                    padding = new TbcPadding();
                    break;

                case CipherPadding.WITHCTS:
                    cts = true;
                    break;

                case CipherPadding.X923PADDING:
                    padding = new X923Padding();
                    break;

                case CipherPadding.ZEROBYTEPADDING:
                    padding = new ZeroBytePadding();
                    break;

                default:
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                }
            }

            string mode = "";

            if (parts.Length > 1)
            {
                mode = parts[1];

                int    di       = GetDigitIndex(mode);
                string modeName = di >= 0 ? mode.Substring(0, di) : mode;

                try
                {
                    CipherMode cipherMode = modeName == ""
                        ? CipherMode.NONE
                        : (CipherMode)Enums.GetEnumValue(typeof(CipherMode), modeName);

                    switch (cipherMode)
                    {
                    case CipherMode.ECB:
                    case CipherMode.NONE:
                        break;

                    case CipherMode.CBC:
                        blockCipher = new CbcBlockCipher(blockCipher);
                        break;

                    case CipherMode.CCM:
                        aeadBlockCipher = new CcmBlockCipher(blockCipher);
                        break;

                    case CipherMode.CFB:
                    {
                        int bits = (di < 0)
                                ?       8 * blockCipher.GetBlockSize()
                                :       int.Parse(mode.Substring(di));

                        blockCipher = new CfbBlockCipher(blockCipher, bits);
                        break;
                    }

                    case CipherMode.CTR:
                        blockCipher = new SicBlockCipher(blockCipher);
                        break;

                    case CipherMode.CTS:
                        cts         = true;
                        blockCipher = new CbcBlockCipher(blockCipher);
                        break;

                    case CipherMode.EAX:
                        aeadBlockCipher = new EaxBlockCipher(blockCipher);
                        break;

                    case CipherMode.GCM:
                        aeadBlockCipher = new GcmBlockCipher(blockCipher);
                        break;

                    case CipherMode.GOFB:
                        blockCipher = new GOfbBlockCipher(blockCipher);
                        break;

                    case CipherMode.OCB:
                        aeadBlockCipher = new OcbBlockCipher(blockCipher, CreateBlockCipher(cipherAlgorithm));
                        break;

                    case CipherMode.OFB:
                    {
                        int bits = (di < 0)
                                ?       8 * blockCipher.GetBlockSize()
                                :       int.Parse(mode.Substring(di));

                        blockCipher = new OfbBlockCipher(blockCipher, bits);
                        break;
                    }

                    case CipherMode.OPENPGPCFB:
                        blockCipher = new OpenPgpCfbBlockCipher(blockCipher);
                        break;

                    case CipherMode.SIC:
                        if (blockCipher.GetBlockSize() < 16)
                        {
                            throw new ArgumentException("Warning: SIC-Mode can become a twotime-pad if the blocksize of the cipher is too small. Use a cipher with a block size of at least 128 bits (e.g. AES)");
                        }
                        blockCipher = new SicBlockCipher(blockCipher);
                        break;

                    default:
                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                    }
                }
                catch (ArgumentException)
                {
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                }
            }

            if (aeadBlockCipher != null)
            {
                if (cts)
                {
                    throw new SecurityUtilityException("CTS mode not valid for AEAD ciphers.");
                }
                if (padded && parts.Length > 2 && parts[2] != "")
                {
                    throw new SecurityUtilityException("Bad padding specified for AEAD cipher.");
                }

                return(new BufferedAeadBlockCipher(aeadBlockCipher));
            }

            if (blockCipher != null)
            {
                if (cts)
                {
                    return(new CtsBlockCipher(blockCipher));
                }

                if (padding != null)
                {
                    return(new PaddedBufferedBlockCipher(blockCipher, padding));
                }

                if (!padded || blockCipher.IsPartialBlockOkay)
                {
                    return(new BufferedBlockCipher(blockCipher));
                }

                return(new PaddedBufferedBlockCipher(blockCipher));
            }

            if (asymBlockCipher != null)
            {
                return(new BufferedAsymmetricBlockCipher(asymBlockCipher));
            }

            throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
        }
        public static IBufferedCipher GetCipher(
            string algorithm)
        {
            if (algorithm == null)
            {
                throw new ArgumentNullException("algorithm");
            }

            algorithm = algorithm.ToUpper(CultureInfo.InvariantCulture);

            string aliased = (string)algorithms[algorithm];

            if (aliased != null)
            {
                algorithm = aliased;
            }



            IBasicAgreement iesAgreement = null;

            if (algorithm == "IES")
            {
                iesAgreement = new DHBasicAgreement();
            }
            else if (algorithm == "ECIES")
            {
                iesAgreement = new ECDHBasicAgreement();
            }

            if (iesAgreement != null)
            {
                return(new BufferedIesCipher(
                           new IesEngine(
                               iesAgreement,
                               new Kdf2BytesGenerator(
                                   new Sha1Digest()),
                               new HMac(
                                   new Sha1Digest()))));
            }



            if (algorithm.StartsWith("PBE"))
            {
                switch (algorithm)
                {
                case "PBEWITHSHAAND2-KEYTRIPLEDES-CBC":
                case "PBEWITHSHAAND3-KEYTRIPLEDES-CBC":
                    return(new PaddedBufferedBlockCipher(
                               new CbcBlockCipher(new DesEdeEngine())));

                case "PBEWITHSHAAND128BITRC2-CBC":
                case "PBEWITHSHAAND40BITRC2-CBC":
                    return(new PaddedBufferedBlockCipher(
                               new CbcBlockCipher(new RC2Engine())));

                case "PBEWITHSHAAND128BITAES-CBC-BC":
                case "PBEWITHSHAAND192BITAES-CBC-BC":
                case "PBEWITHSHAAND256BITAES-CBC-BC":
                case "PBEWITHSHA256AND128BITAES-CBC-BC":
                case "PBEWITHSHA256AND192BITAES-CBC-BC":
                case "PBEWITHSHA256AND256BITAES-CBC-BC":
                case "PBEWITHMD5AND128BITAES-CBC-OPENSSL":
                case "PBEWITHMD5AND192BITAES-CBC-OPENSSL":
                case "PBEWITHMD5AND256BITAES-CBC-OPENSSL":
                    return(new PaddedBufferedBlockCipher(
                               new CbcBlockCipher(new AesFastEngine())));

                case "PBEWITHSHA1ANDDES-CBC":
                    return(new PaddedBufferedBlockCipher(
                               new CbcBlockCipher(new DesEngine())));

                case "PBEWITHSHA1ANDRC2-CBC":
                    return(new PaddedBufferedBlockCipher(
                               new CbcBlockCipher(new RC2Engine())));
                }
            }



            string[] parts = algorithm.Split('/');

            IBlockCipher           blockCipher     = null;
            IAsymmetricBlockCipher asymBlockCipher = null;
            IStreamCipher          streamCipher    = null;

            switch (parts[0])
            {
            case "AES":
                blockCipher = new AesFastEngine();
                break;

            case "ARC4":
                streamCipher = new RC4Engine();
                break;

            case "BLOWFISH":
                blockCipher = new BlowfishEngine();
                break;

            case "CAMELLIA":
                blockCipher = new CamelliaEngine();
                break;

            case "CAST5":
                blockCipher = new Cast5Engine();
                break;

            case "CAST6":
                blockCipher = new Cast6Engine();
                break;

            case "DES":
                blockCipher = new DesEngine();
                break;

            case "DESEDE":
                blockCipher = new DesEdeEngine();
                break;

            case "ELGAMAL":
                asymBlockCipher = new ElGamalEngine();
                break;

            case "GOST28147":
                blockCipher = new Gost28147Engine();
                break;

            case "HC128":
                streamCipher = new HC128Engine();
                break;

            case "HC256":
                streamCipher = new HC256Engine();
                break;

#if INCLUDE_IDEA
            case "IDEA":
                blockCipher = new IdeaEngine();
                break;
#endif
            case "NOEKEON":
                blockCipher = new NoekeonEngine();
                break;

            case "PBEWITHSHAAND128BITRC4":
            case "PBEWITHSHAAND40BITRC4":
                streamCipher = new RC4Engine();
                break;

            case "RC2":
                blockCipher = new RC2Engine();
                break;

            case "RC5":
                blockCipher = new RC532Engine();
                break;

            case "RC5-64":
                blockCipher = new RC564Engine();
                break;

            case "RC6":
                blockCipher = new RC6Engine();
                break;

            case "RIJNDAEL":
                blockCipher = new RijndaelEngine();
                break;

            case "RSA":
                asymBlockCipher = new RsaBlindedEngine();
                break;

            case "SALSA20":
                streamCipher = new Salsa20Engine();
                break;

            case "SEED":
                blockCipher = new SeedEngine();
                break;

            case "SERPENT":
                blockCipher = new SerpentEngine();
                break;

            case "SKIPJACK":
                blockCipher = new SkipjackEngine();
                break;

            case "TEA":
                blockCipher = new TeaEngine();
                break;

            case "TWOFISH":
                blockCipher = new TwofishEngine();
                break;

            case "VMPC":
                streamCipher = new VmpcEngine();
                break;

            case "VMPC-KSA3":
                streamCipher = new VmpcKsa3Engine();
                break;

            case "XTEA":
                blockCipher = new XteaEngine();
                break;

            default:
                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
            }

            if (streamCipher != null)
            {
                if (parts.Length > 1)
                {
                    throw new ArgumentException("Modes and paddings not used for stream ciphers");
                }

                return(new BufferedStreamCipher(streamCipher));
            }


            bool cts    = false;
            bool padded = true;
            IBlockCipherPadding padding         = null;
            IAeadBlockCipher    aeadBlockCipher = null;

            if (parts.Length > 2)
            {
                if (streamCipher != null)
                {
                    throw new ArgumentException("Paddings not used for stream ciphers");
                }

                switch (parts[2])
                {
                case "NOPADDING":
                    padded = false;
                    break;

                case "":
                case "RAW":
                    break;

                case "ISO10126PADDING":
                case "ISO10126D2PADDING":
                case "ISO10126-2PADDING":
                    padding = new ISO10126d2Padding();
                    break;

                case "ISO7816-4PADDING":
                case "ISO9797-1PADDING":
                    padding = new ISO7816d4Padding();
                    break;

                case "ISO9796-1":
                case "ISO9796-1PADDING":
                    asymBlockCipher = new ISO9796d1Encoding(asymBlockCipher);
                    break;

                case "OAEP":
                case "OAEPPADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher);
                    break;

                case "OAEPWITHMD5ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new MD5Digest());
                    break;

                case "OAEPWITHSHA1ANDMGF1PADDING":
                case "OAEPWITHSHA-1ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha1Digest());
                    break;

                case "OAEPWITHSHA224ANDMGF1PADDING":
                case "OAEPWITHSHA-224ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha224Digest());
                    break;

                case "OAEPWITHSHA256ANDMGF1PADDING":
                case "OAEPWITHSHA-256ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest());
                    break;

                case "OAEPWITHSHA384ANDMGF1PADDING":
                case "OAEPWITHSHA-384ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha384Digest());
                    break;

                case "OAEPWITHSHA512ANDMGF1PADDING":
                case "OAEPWITHSHA-512ANDMGF1PADDING":
                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha512Digest());
                    break;

                case "PKCS1":
                case "PKCS1PADDING":
                    asymBlockCipher = new Pkcs1Encoding(asymBlockCipher);
                    break;

                case "PKCS5":
                case "PKCS5PADDING":
                case "PKCS7":
                case "PKCS7PADDING":
                    // NB: Padding defaults to Pkcs7Padding already
                    break;

                case "TBCPADDING":
                    padding = new TbcPadding();
                    break;

                case "WITHCTS":
                    cts = true;
                    break;

                case "X9.23PADDING":
                case "X923PADDING":
                    padding = new X923Padding();
                    break;

                case "ZEROBYTEPADDING":
                    padding = new ZeroBytePadding();
                    break;

                default:
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                }
            }

            string mode = "";
            if (parts.Length > 1)
            {
                mode = parts[1];

                int    di       = GetDigitIndex(mode);
                string modeName = di >= 0 ? mode.Substring(0, di) : mode;

                switch (modeName)
                {
                case "":
                case "ECB":
                case "NONE":
                    break;

                case "CBC":
                    blockCipher = new CbcBlockCipher(blockCipher);
                    break;

                case "CCM":
                    aeadBlockCipher = new CcmBlockCipher(blockCipher);
                    break;

                case "CFB":
                {
                    int bits = (di < 0)
                                                        ?       8 * blockCipher.GetBlockSize()
                                                        :       int.Parse(mode.Substring(di));

                    blockCipher = new CfbBlockCipher(blockCipher, bits);
                    break;
                }

                case "CTR":
                    blockCipher = new SicBlockCipher(blockCipher);
                    break;

                case "CTS":
                    cts         = true;
                    blockCipher = new CbcBlockCipher(blockCipher);
                    break;

                case "EAX":
                    aeadBlockCipher = new EaxBlockCipher(blockCipher);
                    break;

                case "GCM":
                    aeadBlockCipher = new GcmBlockCipher(blockCipher);
                    break;

                case "GOFB":
                    blockCipher = new GOfbBlockCipher(blockCipher);
                    break;

                case "OFB":
                {
                    int bits = (di < 0)
                                                        ?       8 * blockCipher.GetBlockSize()
                                                        :       int.Parse(mode.Substring(di));

                    blockCipher = new OfbBlockCipher(blockCipher, bits);
                    break;
                }

                case "OPENPGPCFB":
                    blockCipher = new OpenPgpCfbBlockCipher(blockCipher);
                    break;

                case "SIC":
                    if (blockCipher.GetBlockSize() < 16)
                    {
                        throw new ArgumentException("Warning: SIC-Mode can become a twotime-pad if the blocksize of the cipher is too small. Use a cipher with a block size of at least 128 bits (e.g. AES)");
                    }
                    blockCipher = new SicBlockCipher(blockCipher);
                    break;

                default:
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                }
            }

            if (aeadBlockCipher != null)
            {
                if (cts)
                {
                    throw new SecurityUtilityException("CTS mode not valid for AEAD ciphers.");
                }
                if (padded && parts.Length > 1 && parts[2] != "")
                {
                    throw new SecurityUtilityException("Bad padding specified for AEAD cipher.");
                }

                return(new BufferedAeadBlockCipher(aeadBlockCipher));
            }

            if (blockCipher != null)
            {
                if (cts)
                {
                    return(new CtsBlockCipher(blockCipher));
                }

                if (!padded || blockCipher.IsPartialBlockOkay)
                {
                    return(new BufferedBlockCipher(blockCipher));
                }

                if (padding != null)
                {
                    return(new PaddedBufferedBlockCipher(blockCipher, padding));
                }

                return(new PaddedBufferedBlockCipher(blockCipher));
            }

            if (asymBlockCipher != null)
            {
                return(new BufferedAsymmetricBlockCipher(asymBlockCipher));
            }

            throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
        }
        /// <summary>
        /// Build the engine
        /// </summary>
        /// <param name="algorithm">SymmetricBlockAlgorithm enum, algorithm name</param>
        /// <returns>IBlockCipher with the algorithm Engine</returns>
        internal IBlockCipher getCipherEngine(SymmetricBlockAlgorithm algorithm)
        {
            IBlockCipher engine = null;

            switch (algorithm)
            {
            case SymmetricBlockAlgorithm.AES:
                engine = new AesEngine();
                break;

            case SymmetricBlockAlgorithm.BLOWFISH:
                engine = new BlowfishEngine();
                break;

            case SymmetricBlockAlgorithm.CAMELLIA:
                engine = new CamelliaEngine();
                break;

            case SymmetricBlockAlgorithm.CAST5:
                engine = new Cast5Engine();
                break;

            case SymmetricBlockAlgorithm.CAST6:
                engine = new Cast6Engine();
                break;

            case SymmetricBlockAlgorithm.DES:
                engine = new DesEngine();
                break;

            case SymmetricBlockAlgorithm.TRIPLEDES:
                engine = new DesEdeEngine();
                break;

            case SymmetricBlockAlgorithm.DSTU7624_128:
                engine = new Dstu7624Engine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.DSTU7624_128, this.error));
                break;

            case SymmetricBlockAlgorithm.DSTU7624_256:
                engine = new Dstu7624Engine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.DSTU7624_256, this.error));
                break;

            case SymmetricBlockAlgorithm.DSTU7624_512:
                engine = new Dstu7624Engine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.DSTU7624_512, this.error));
                break;

            case SymmetricBlockAlgorithm.GOST28147:
                engine = new Gost28147Engine();
                break;

            case SymmetricBlockAlgorithm.NOEKEON:
                engine = new NoekeonEngine();
                break;

            case SymmetricBlockAlgorithm.RC2:
                engine = new RC2Engine();
                break;

            case SymmetricBlockAlgorithm.RC532:
                engine = new RC532Engine();
                break;

            case SymmetricBlockAlgorithm.RC564:
                engine = new RC564Engine();
                break;

            case SymmetricBlockAlgorithm.RC6:
                engine = new RC6Engine();
                break;

            case SymmetricBlockAlgorithm.RIJNDAEL_128:
                engine = new RijndaelEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.RIJNDAEL_128, this.error));
                break;

            case SymmetricBlockAlgorithm.RIJNDAEL_160:
                engine = new RijndaelEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.RIJNDAEL_160, this.error));
                break;

            case SymmetricBlockAlgorithm.RIJNDAEL_192:
                engine = new RijndaelEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.RIJNDAEL_192, this.error));
                break;

            case SymmetricBlockAlgorithm.RIJNDAEL_224:
                engine = new RijndaelEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.RIJNDAEL_224, this.error));
                break;

            case SymmetricBlockAlgorithm.RIJNDAEL_256:
                engine = new RijndaelEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.RIJNDAEL_256, this.error));
                break;

            case SymmetricBlockAlgorithm.SEED:
                engine = new SeedEngine();
                break;

            case SymmetricBlockAlgorithm.SERPENT:
                engine = new SerpentEngine();
                break;

            case SymmetricBlockAlgorithm.SKIPJACK:
                engine = new SkipjackEngine();
                break;

            case SymmetricBlockAlgorithm.SM4:
                engine = new SM4Engine();
                break;

            case SymmetricBlockAlgorithm.TEA:
                engine = new TeaEngine();
                break;

            case SymmetricBlockAlgorithm.THREEFISH_256:
                engine = new ThreefishEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.THREEFISH_256, this.error));
                break;

            case SymmetricBlockAlgorithm.THREEFISH_512:
                engine = new ThreefishEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.THREEFISH_512, this.error));
                break;

            case SymmetricBlockAlgorithm.THREEFISH_1024:
                engine = new ThreefishEngine(SymmetricBlockAlgorithmUtils.getBlockSize(SymmetricBlockAlgorithm.THREEFISH_1024, this.error));
                break;

            case SymmetricBlockAlgorithm.TWOFISH:
                engine = new TwofishEngine();
                break;

            case SymmetricBlockAlgorithm.XTEA:
                engine = new XteaEngine();
                break;

            default:
                this.error.setError("SB020", "Cipher " + algorithm + " not recognised.");
                break;
            }
            return(engine);
        }
Example #4
0
        public override void Decode(byte[] data)
        {
            if (this.Info == null)
            {
                throw new DecodeException("File info must be set before decoding binary file.");
            }

            var dataReader = new BinaryReader(new MemoryStream(data));

            this.Info.CompressionType = (CompressionType)dataReader.ReadByte();
            var dataLength = dataReader.ReadInt32BigEndian();

            // Total length includes already read bytes and the extra bytes read because of compression
            var totalLength = (this.Info.CompressionType == CompressionType.None ? 5 : 9) + dataLength;

            // Decrypt the data if a key is given
            if (this.Info.EncryptionKey != null)
            {
                var xtea = new XteaEngine();
                xtea.Init(false, new KeyParameter(this.Info.EncryptionKey));
                var decrypted = new byte[totalLength];
                xtea.ProcessBlock(dataReader.ReadBytes(totalLength), 5, decrypted, 0);

                dataReader = new BinaryReader(new MemoryStream(decrypted));
            }

            // Check if we should decompress the data or not
            if (this.Info.CompressionType == CompressionType.None)
            {
                this.Info.UncompressedSize = dataLength;
                this.Data = dataReader.ReadBytes(dataLength);
            }
            else
            {
                // Decompress the data
                this.Info.CompressedSize   = dataLength;
                this.Info.UncompressedSize = dataReader.ReadInt32BigEndian();
                var compressedBytes   = dataReader.ReadBytes(dataLength);
                var uncompressedBytes = new byte[this.Info.UncompressedSize.Value];

                switch (this.Info.CompressionType)
                {
                case CompressionType.Bzip2:
                    // Add the bzip2 header as it is missing from the cache for whatever reason
                    var bzipCompressedBytes = new byte[compressedBytes.Length + 4];
                    bzipCompressedBytes[0] = (byte)'B';
                    bzipCompressedBytes[1] = (byte)'Z';
                    bzipCompressedBytes[2] = (byte)'h';
                    bzipCompressedBytes[3] = (byte)'1';
                    Array.Copy(compressedBytes, 0, bzipCompressedBytes, 4, compressedBytes.Length);

                    using (var bzip2Stream = new BZip2InputStream(new MemoryStream(bzipCompressedBytes)))
                    {
                        var readBzipBytes = bzip2Stream.Read(uncompressedBytes, 0, this.Info.UncompressedSize.Value);

                        if (readBzipBytes != this.Info.UncompressedSize)
                        {
                            throw new DecodeException("Uncompressed container data length does not match obtained length.");
                        }
                    }
                    break;

                case CompressionType.Gzip:
                    using (var gzipStream = new GZipInputStream(new MemoryStream(compressedBytes)))
                    {
                        var readGzipBytes = gzipStream.Read(uncompressedBytes, 0, this.Info.UncompressedSize.Value);

                        if (readGzipBytes != this.Info.UncompressedSize)
                        {
                            throw new DecodeException("Uncompressed container data length does not match obtained length.");
                        }
                    }
                    break;

                case CompressionType.Lzma:
                    using (var compressedStream = new MemoryStream(compressedBytes))
                        using (var uncompressedStream = new MemoryStream(uncompressedBytes))
                        {
                            var lzmaDecoder = new SevenZip.Compression.LZMA.Decoder();
                            lzmaDecoder.Code(compressedStream, uncompressedStream, compressedStream.Length, -1, null);

                            if (uncompressedStream.Length != this.Info.UncompressedSize)
                            {
                                throw new DecodeException("Uncompressed container data length does not match obtained length.");
                            }

                            uncompressedBytes = uncompressedStream.ToArray();
                        }
                    break;

                default:
                    throw new DecodeException("Invalid compression type given.");
                }

                this.Data = uncompressedBytes;
            }

            // Update and verify obtained info
            // Read and verify the version of the file
            var versionRead = false;

            if (dataReader.BaseStream.Length - dataReader.BaseStream.Position >= 2)
            {
                var version = dataReader.ReadUInt16BigEndian();

                if (this.Info.Version != null)
                {
                    // The version is truncated to 2 bytes, so only the least significant 2 bytes are compared
                    var truncatedInfoVersion = (int)(ushort)this.Info.Version;
                    if (version != truncatedInfoVersion)
                    {
                        throw new DecodeException($"Obtained version part ({version}) did not match expected ({truncatedInfoVersion}).");
                    }
                }
                else
                {
                    // Set obtained version if previously unset
                    this.Info.Version = version;
                }

                versionRead = true;
            }

            // Calculate and verify CRC
            // CRC excludes the version of the file added to the end
            // There is no way to know if the CRC is zero or unset
            var crcHasher = new Crc32();

            crcHasher.Update(data.Take(data.Length - (versionRead ? 2 : 0)).ToArray());
            var crc = (int)crcHasher.Value;

            if (this.Info.Crc != null && crc != this.Info.Crc)
            {
                throw new DecodeException($"Calculated checksum (0x{crc:X}) did not match expected (0x{this.Info.Crc:X}).");
            }

            this.Info.Crc = crc;

            // Calculate and verify the whirlpool digest
            var whirlpoolHasher = new WhirlpoolDigest();

            whirlpoolHasher.BlockUpdate(data, 0, data.Length - (versionRead ? 2 : 0));

            var whirlpoolDigest = new byte[whirlpoolHasher.GetDigestSize()];

            whirlpoolHasher.DoFinal(whirlpoolDigest, 0);

            if (this.Info.WhirlpoolDigest != null && !whirlpoolDigest.SequenceEqual(this.Info.WhirlpoolDigest))
            {
                throw new DecodeException("Calculated whirlpool digest did not match expected.");
            }

            this.Info.WhirlpoolDigest = whirlpoolDigest;

            if (dataReader.BaseStream.Position < dataReader.BaseStream.Length)
            {
                throw new DecodeException($"Input data not fully consumed while decoding binary file. {dataReader.BaseStream.Length - dataReader.BaseStream.Position} bytes remain.");
            }
        }
        public static IBufferedCipher GetCipher(string algorithm)
        {
            //IL_0008: Unknown result type (might be due to invalid IL or missing references)
            //IL_0469: Unknown result type (might be due to invalid IL or missing references)
            //IL_0495: Unknown result type (might be due to invalid IL or missing references)
            //IL_07f1: Unknown result type (might be due to invalid IL or missing references)
            if (algorithm == null)
            {
                throw new ArgumentNullException("algorithm");
            }
            algorithm = Platform.ToUpperInvariant(algorithm);
            string text = (string)algorithms.get_Item((object)algorithm);

            if (text != null)
            {
                algorithm = text;
            }
            IBasicAgreement basicAgreement = null;

            if (algorithm == "IES")
            {
                basicAgreement = new DHBasicAgreement();
            }
            else if (algorithm == "ECIES")
            {
                basicAgreement = new ECDHBasicAgreement();
            }
            if (basicAgreement != null)
            {
                return(new BufferedIesCipher(new IesEngine(basicAgreement, new Kdf2BytesGenerator(new Sha1Digest()), new HMac(new Sha1Digest()))));
            }
            if (Platform.StartsWith(algorithm, "PBE"))
            {
                if (Platform.EndsWith(algorithm, "-CBC"))
                {
                    if (algorithm == "PBEWITHSHA1ANDDES-CBC")
                    {
                        return(new PaddedBufferedBlockCipher(new CbcBlockCipher(new DesEngine())));
                    }
                    if (algorithm == "PBEWITHSHA1ANDRC2-CBC")
                    {
                        return(new PaddedBufferedBlockCipher(new CbcBlockCipher(new RC2Engine())));
                    }
                    if (Strings.IsOneOf(algorithm, "PBEWITHSHAAND2-KEYTRIPLEDES-CBC", "PBEWITHSHAAND3-KEYTRIPLEDES-CBC"))
                    {
                        return(new PaddedBufferedBlockCipher(new CbcBlockCipher(new DesEdeEngine())));
                    }
                    if (Strings.IsOneOf(algorithm, "PBEWITHSHAAND128BITRC2-CBC", "PBEWITHSHAAND40BITRC2-CBC"))
                    {
                        return(new PaddedBufferedBlockCipher(new CbcBlockCipher(new RC2Engine())));
                    }
                }
                else if ((Platform.EndsWith(algorithm, "-BC") || Platform.EndsWith(algorithm, "-OPENSSL")) && Strings.IsOneOf(algorithm, "PBEWITHSHAAND128BITAES-CBC-BC", "PBEWITHSHAAND192BITAES-CBC-BC", "PBEWITHSHAAND256BITAES-CBC-BC", "PBEWITHSHA256AND128BITAES-CBC-BC", "PBEWITHSHA256AND192BITAES-CBC-BC", "PBEWITHSHA256AND256BITAES-CBC-BC", "PBEWITHMD5AND128BITAES-CBC-OPENSSL", "PBEWITHMD5AND192BITAES-CBC-OPENSSL", "PBEWITHMD5AND256BITAES-CBC-OPENSSL"))
                {
                    return(new PaddedBufferedBlockCipher(new CbcBlockCipher(new AesFastEngine())));
                }
            }
            string[] array = algorithm.Split(new char[1] {
                '/'
            });
            IBlockCipher           blockCipher           = null;
            IAsymmetricBlockCipher asymmetricBlockCipher = null;
            IStreamCipher          streamCipher          = null;
            string text2 = array[0];
            string text3 = (string)algorithms.get_Item((object)text2);

            if (text3 != null)
            {
                text2 = text3;
            }
            CipherAlgorithm cipherAlgorithm;

            try
            {
                cipherAlgorithm = (CipherAlgorithm)Enums.GetEnumValue(typeof(CipherAlgorithm), text2);
            }
            catch (ArgumentException)
            {
                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
            }
            switch (cipherAlgorithm)
            {
            case CipherAlgorithm.AES:
                blockCipher = new AesFastEngine();
                break;

            case CipherAlgorithm.ARC4:
                streamCipher = new RC4Engine();
                break;

            case CipherAlgorithm.BLOWFISH:
                blockCipher = new BlowfishEngine();
                break;

            case CipherAlgorithm.CAMELLIA:
                blockCipher = new CamelliaEngine();
                break;

            case CipherAlgorithm.CAST5:
                blockCipher = new Cast5Engine();
                break;

            case CipherAlgorithm.CAST6:
                blockCipher = new Cast6Engine();
                break;

            case CipherAlgorithm.DES:
                blockCipher = new DesEngine();
                break;

            case CipherAlgorithm.DESEDE:
                blockCipher = new DesEdeEngine();
                break;

            case CipherAlgorithm.ELGAMAL:
                asymmetricBlockCipher = new ElGamalEngine();
                break;

            case CipherAlgorithm.GOST28147:
                blockCipher = new Gost28147Engine();
                break;

            case CipherAlgorithm.HC128:
                streamCipher = new HC128Engine();
                break;

            case CipherAlgorithm.HC256:
                streamCipher = new HC256Engine();
                break;

            case CipherAlgorithm.IDEA:
                blockCipher = new IdeaEngine();
                break;

            case CipherAlgorithm.NOEKEON:
                blockCipher = new NoekeonEngine();
                break;

            case CipherAlgorithm.PBEWITHSHAAND128BITRC4:
            case CipherAlgorithm.PBEWITHSHAAND40BITRC4:
                streamCipher = new RC4Engine();
                break;

            case CipherAlgorithm.RC2:
                blockCipher = new RC2Engine();
                break;

            case CipherAlgorithm.RC5:
                blockCipher = new RC532Engine();
                break;

            case CipherAlgorithm.RC5_64:
                blockCipher = new RC564Engine();
                break;

            case CipherAlgorithm.RC6:
                blockCipher = new RC6Engine();
                break;

            case CipherAlgorithm.RIJNDAEL:
                blockCipher = new RijndaelEngine();
                break;

            case CipherAlgorithm.RSA:
                asymmetricBlockCipher = new RsaBlindedEngine();
                break;

            case CipherAlgorithm.SALSA20:
                streamCipher = new Salsa20Engine();
                break;

            case CipherAlgorithm.SEED:
                blockCipher = new SeedEngine();
                break;

            case CipherAlgorithm.SERPENT:
                blockCipher = new SerpentEngine();
                break;

            case CipherAlgorithm.SKIPJACK:
                blockCipher = new SkipjackEngine();
                break;

            case CipherAlgorithm.TEA:
                blockCipher = new TeaEngine();
                break;

            case CipherAlgorithm.THREEFISH_256:
                blockCipher = new ThreefishEngine(256);
                break;

            case CipherAlgorithm.THREEFISH_512:
                blockCipher = new ThreefishEngine(512);
                break;

            case CipherAlgorithm.THREEFISH_1024:
                blockCipher = new ThreefishEngine(1024);
                break;

            case CipherAlgorithm.TNEPRES:
                blockCipher = new TnepresEngine();
                break;

            case CipherAlgorithm.TWOFISH:
                blockCipher = new TwofishEngine();
                break;

            case CipherAlgorithm.VMPC:
                streamCipher = new VmpcEngine();
                break;

            case CipherAlgorithm.VMPC_KSA3:
                streamCipher = new VmpcKsa3Engine();
                break;

            case CipherAlgorithm.XTEA:
                blockCipher = new XteaEngine();
                break;

            default:
                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
            }
            if (streamCipher != null)
            {
                if (array.Length > 1)
                {
                    throw new ArgumentException("Modes and paddings not used for stream ciphers");
                }
                return(new BufferedStreamCipher(streamCipher));
            }
            bool flag  = false;
            bool flag2 = true;
            IBlockCipherPadding blockCipherPadding = null;
            IAeadBlockCipher    aeadBlockCipher    = null;

            if (array.Length > 2)
            {
                if (streamCipher != null)
                {
                    throw new ArgumentException("Paddings not used for stream ciphers");
                }
                string        text4 = array[2];
                CipherPadding cipherPadding;
                if (text4 == "")
                {
                    cipherPadding = CipherPadding.RAW;
                }
                else if (text4 == "X9.23PADDING")
                {
                    cipherPadding = CipherPadding.X923PADDING;
                }
                else
                {
                    try
                    {
                        cipherPadding = (CipherPadding)Enums.GetEnumValue(typeof(CipherPadding), text4);
                    }
                    catch (ArgumentException)
                    {
                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                    }
                }
                switch (cipherPadding)
                {
                case CipherPadding.NOPADDING:
                    flag2 = false;
                    break;

                case CipherPadding.ISO10126PADDING:
                case CipherPadding.ISO10126D2PADDING:
                case CipherPadding.ISO10126_2PADDING:
                    blockCipherPadding = new ISO10126d2Padding();
                    break;

                case CipherPadding.ISO7816_4PADDING:
                case CipherPadding.ISO9797_1PADDING:
                    blockCipherPadding = new ISO7816d4Padding();
                    break;

                case CipherPadding.ISO9796_1:
                case CipherPadding.ISO9796_1PADDING:
                    asymmetricBlockCipher = new ISO9796d1Encoding(asymmetricBlockCipher);
                    break;

                case CipherPadding.OAEP:
                case CipherPadding.OAEPPADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher);
                    break;

                case CipherPadding.OAEPWITHMD5ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new MD5Digest());
                    break;

                case CipherPadding.OAEPWITHSHA1ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_1ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new Sha1Digest());
                    break;

                case CipherPadding.OAEPWITHSHA224ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_224ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new Sha224Digest());
                    break;

                case CipherPadding.OAEPWITHSHA256ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_256ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new Sha256Digest());
                    break;

                case CipherPadding.OAEPWITHSHA384ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_384ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new Sha384Digest());
                    break;

                case CipherPadding.OAEPWITHSHA512ANDMGF1PADDING:
                case CipherPadding.OAEPWITHSHA_512ANDMGF1PADDING:
                    asymmetricBlockCipher = new OaepEncoding(asymmetricBlockCipher, new Sha512Digest());
                    break;

                case CipherPadding.PKCS1:
                case CipherPadding.PKCS1PADDING:
                    asymmetricBlockCipher = new Pkcs1Encoding(asymmetricBlockCipher);
                    break;

                case CipherPadding.PKCS5:
                case CipherPadding.PKCS5PADDING:
                case CipherPadding.PKCS7:
                case CipherPadding.PKCS7PADDING:
                    blockCipherPadding = new Pkcs7Padding();
                    break;

                case CipherPadding.TBCPADDING:
                    blockCipherPadding = new TbcPadding();
                    break;

                case CipherPadding.WITHCTS:
                    flag = true;
                    break;

                case CipherPadding.X923PADDING:
                    blockCipherPadding = new X923Padding();
                    break;

                case CipherPadding.ZEROBYTEPADDING:
                    blockCipherPadding = new ZeroBytePadding();
                    break;

                default:
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");

                case CipherPadding.RAW:
                    break;
                }
            }
            string text5 = "";

            if (array.Length > 1)
            {
                text5 = array[1];
                int    digitIndex = GetDigitIndex(text5);
                string text6      = ((digitIndex >= 0) ? text5.Substring(0, digitIndex) : text5);
                try
                {
                    switch ((text6 == "") ? CipherMode.NONE : ((CipherMode)Enums.GetEnumValue(typeof(CipherMode), text6)))
                    {
                    case CipherMode.CBC:
                        blockCipher = new CbcBlockCipher(blockCipher);
                        break;

                    case CipherMode.CCM:
                        aeadBlockCipher = new CcmBlockCipher(blockCipher);
                        break;

                    case CipherMode.CFB:
                    {
                        int bitBlockSize = ((digitIndex < 0) ? (8 * blockCipher.GetBlockSize()) : int.Parse(text5.Substring(digitIndex)));
                        blockCipher = new CfbBlockCipher(blockCipher, bitBlockSize);
                        break;
                    }

                    case CipherMode.CTR:
                        blockCipher = new SicBlockCipher(blockCipher);
                        break;

                    case CipherMode.CTS:
                        flag        = true;
                        blockCipher = new CbcBlockCipher(blockCipher);
                        break;

                    case CipherMode.EAX:
                        aeadBlockCipher = new EaxBlockCipher(blockCipher);
                        break;

                    case CipherMode.GCM:
                        aeadBlockCipher = new GcmBlockCipher(blockCipher);
                        break;

                    case CipherMode.GOFB:
                        blockCipher = new GOfbBlockCipher(blockCipher);
                        break;

                    case CipherMode.OCB:
                        aeadBlockCipher = new OcbBlockCipher(blockCipher, CreateBlockCipher(cipherAlgorithm));
                        break;

                    case CipherMode.OFB:
                    {
                        int blockSize = ((digitIndex < 0) ? (8 * blockCipher.GetBlockSize()) : int.Parse(text5.Substring(digitIndex)));
                        blockCipher = new OfbBlockCipher(blockCipher, blockSize);
                        break;
                    }

                    case CipherMode.OPENPGPCFB:
                        blockCipher = new OpenPgpCfbBlockCipher(blockCipher);
                        break;

                    case CipherMode.SIC:
                        if (blockCipher.GetBlockSize() < 16)
                        {
                            throw new ArgumentException("Warning: SIC-Mode can become a twotime-pad if the blocksize of the cipher is too small. Use a cipher with a block size of at least 128 bits (e.g. AES)");
                        }
                        blockCipher = new SicBlockCipher(blockCipher);
                        break;

                    default:
                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");

                    case CipherMode.ECB:
                    case CipherMode.NONE:
                        break;
                    }
                }
                catch (ArgumentException)
                {
                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                }
            }
            if (aeadBlockCipher != null)
            {
                if (flag)
                {
                    throw new SecurityUtilityException("CTS mode not valid for AEAD ciphers.");
                }
                if (flag2 && array.Length > 2 && array[2] != "")
                {
                    throw new SecurityUtilityException("Bad padding specified for AEAD cipher.");
                }
                return(new BufferedAeadBlockCipher(aeadBlockCipher));
            }
            if (blockCipher != null)
            {
                if (flag)
                {
                    return(new CtsBlockCipher(blockCipher));
                }
                if (blockCipherPadding != null)
                {
                    return(new PaddedBufferedBlockCipher(blockCipher, blockCipherPadding));
                }
                if (!flag2 || blockCipher.IsPartialBlockOkay)
                {
                    return(new BufferedBlockCipher(blockCipher));
                }
                return(new PaddedBufferedBlockCipher(blockCipher));
            }
            if (asymmetricBlockCipher != null)
            {
                return(new BufferedAsymmetricBlockCipher(asymmetricBlockCipher));
            }
            throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
        }