Exemplo n.º 1
0
        private OcbBlockCipher InitCipher(bool forEncryption, AeadParameters parameters)
        {
            OcbBlockCipher c = new OcbBlockCipher(new AesFastEngine(), new AesFastEngine());

            c.Init(forEncryption, parameters);
            return(c);
        }
Exemplo n.º 2
0
        private void RunTestCase(string testName, string[] testVector, int macLengthBits)
        {
            byte[] key   = Hex.Decode(K);
            byte[] nonce = Hex.Decode(N);

            int pos = 0;

            byte[] A = Hex.Decode(testVector[pos++]);
            byte[] P = Hex.Decode(testVector[pos++]);
            byte[] C = Hex.Decode(testVector[pos++]);

            int macLengthBytes = macLengthBits / 8;

            // TODO Variations processing AAD and cipher bytes incrementally

            KeyParameter   keyParameter   = new KeyParameter(key);
            AeadParameters aeadParameters = new AeadParameters(keyParameter, macLengthBits, nonce, A);

            OcbBlockCipher encCipher = InitCipher(true, aeadParameters);
            OcbBlockCipher decCipher = InitCipher(false, aeadParameters);

            CheckTestCase(encCipher, decCipher, testName, macLengthBytes, P, C);
            CheckTestCase(encCipher, decCipher, testName + " (reused)", macLengthBytes, P, C);

            // TODO Key reuse
        }
Exemplo n.º 3
0
        private void DoTestExceptions()
        {
            IAeadBlockCipher ocb = CreateOcbCipher();

            try
            {
                ocb = new OcbBlockCipher(new DesEngine(), new DesEngine());
                Fail("incorrect block size not picked up");
            }
            catch (ArgumentException)
            {
                // expected
            }

            try
            {
                ocb.Init(false, new KeyParameter(new byte[16]));
                Fail("illegal argument not picked up");
            }
            catch (ArgumentException)
            {
                // expected
            }

            // TODO
            //AEADTestUtil.testReset(this, createOCBCipher(), createOCBCipher(), new AEADParameters(new KeyParameter(new byte[16]), 128, new byte[15]));
            //AEADTestUtil.testTampering(this, ocb, new AEADParameters(new KeyParameter(new byte[16]), 128, new byte[15]));
        }
Exemplo n.º 4
0
        private void CheckTestCase(OcbBlockCipher encCipher, OcbBlockCipher decCipher, string testName,
                                   int macLengthBytes, byte[] P, byte[] C)
        {
            byte[] tag = Arrays.Copy(C, C.Length - macLengthBytes, macLengthBytes);

            {
                byte[] enc = new byte[encCipher.GetOutputSize(P.Length)];
                int    len = encCipher.ProcessBytes(P, 0, P.Length, enc, 0);
                len += encCipher.DoFinal(enc, len);

                if (enc.Length != len)
                {
                    Fail("encryption reported incorrect length: " + testName);
                }

                if (!AreEqual(C, enc))
                {
                    Fail("incorrect encrypt in: " + testName);
                }

                if (!AreEqual(tag, encCipher.GetMac()))
                {
                    Fail("getMac() not the same as the appended tag: " + testName);
                }
            }

            {
                byte[] dec = new byte[decCipher.GetOutputSize(C.Length)];
                int    len = decCipher.ProcessBytes(C, 0, C.Length, dec, 0);
                len += decCipher.DoFinal(dec, len);

                if (dec.Length != len)
                {
                    Fail("decryption reported incorrect length: " + testName);
                }

                if (!AreEqual(P, dec))
                {
                    Fail("incorrect decrypt in: " + testName);
                }

                if (!AreEqual(tag, decCipher.GetMac()))
                {
                    Fail("getMac() not the same as the appended tag: " + testName);
                }
            }
        }
Exemplo n.º 5
0
        private void RunLongerTestCase(int aesKeySize, int tagLen, byte[] expectedOutput)
        {
            KeyParameter key = new KeyParameter(new byte[aesKeySize / 8]);

            byte[] N = new byte[12];

            IAeadBlockCipher c1 = new OcbBlockCipher(new AesFastEngine(), new AesFastEngine());

            c1.Init(true, new AeadParameters(key, tagLen, N));

            IAeadBlockCipher c2 = new OcbBlockCipher(new AesFastEngine(), new AesFastEngine());

            long total = 0;

            byte[] S = new byte[128];

            for (int i = 0; i < 128; ++i)
            {
                N[11] = (byte)i;

                c2.Init(true, new AeadParameters(key, tagLen, N));

                total += UpdateCiphers(c1, c2, S, i, true, true);
                total += UpdateCiphers(c1, c2, S, i, false, true);
                total += UpdateCiphers(c1, c2, S, i, true, false);
            }

            long expectedTotal = 16256 + (48 * tagLen);

            if (total != expectedTotal)
            {
                Fail("test generated the wrong amount of input: " + total);
            }

            byte[] output = new byte[c1.GetOutputSize(0)];
            c1.DoFinal(output, 0);

            if (!AreEqual(expectedOutput, output))
            {
                Fail("incorrect encrypt in long-form test");
            }
        }
Exemplo n.º 6
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.");
        }
Exemplo n.º 7
0
        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.");
        }