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);
}
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.");
}