ASN1Sequence decryptData(
AlgorithmIdentifier algId,
byte[] data,
char[] password)
{
PKCS12PBEParams pbeParams = PKCS12PBEParams.getInstance(algId.getParameters());
CipherParameters keyParameters = PBEUtil.generateCipherParameters(algId.getObjectId(), password, pbeParams);
byte[] encoding = null;
Object engine = PBEUtil.createEngine(algId.getObjectId());
if (engine is BufferedBlockCipher)
{
BufferedBlockCipher cipher = (BufferedBlockCipher)engine;
cipher.init(false, keyParameters);
int encLen = cipher.getOutputSize(data.Length);
encoding = new byte[encLen];
int off = cipher.processBytes(data, 0, data.Length, encoding, 0);
cipher.doFinal(encoding, off);
}
else if (engine is StreamCipher)
{
StreamCipher cipher = (StreamCipher)engine;
cipher.init(false, keyParameters);
encoding = new byte[data.Length];
cipher.processBytes(data, 0, data.Length, encoding, 0);
}
ASN1InputStream bIn = new ASN1InputStream(new MemoryStream(encoding));
return((ASN1Sequence)bIn.readObject());
}
public static CipherParameters generateCipherParameters(
String algorithm,
char[] password,
ASN1Encodable pbeParameters)
{
String mechanism = (string)algorithms[algorithm.ToUpper()];
byte[] key;
CipherParameters parameters = null;
String type = (String)algorithmType[mechanism];
byte[] salt = null;
int iterationCount = 0;
if (isPKCS12(mechanism))
{
PKCS12PBEParams pbeParams = PKCS12PBEParams.getInstance(pbeParameters);
salt = pbeParams.getIV();
iterationCount = pbeParams.getIterations().intValue();
key = PBEParametersGenerator.PKCS12PasswordToBytes(password);
}
else if (isPKCS5Scheme2(mechanism))
{
PBKDF2Params pbeParams = PBKDF2Params.getInstance(pbeParameters);
salt = pbeParams.getSalt();
iterationCount = pbeParams.getIterationCount().intValue();
key = PBEParametersGenerator.PKCS5PasswordToBytes(password);
}
else
{
PBEParameter pbeParams = PBEParameter.getInstance(pbeParameters);
salt = pbeParams.getSalt();
iterationCount = pbeParams.getIterationCount().intValue();
key = PBEParametersGenerator.PKCS5PasswordToBytes(password);
}
if (mechanism.StartsWith("PBEwithSHA-1"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new SHA1Digest(), key, salt, iterationCount);
if (mechanism.Equals("PBEwithSHA-1and128bitRC4"))
{
parameters = generator.generateDerivedParameters(128);
}
else if (mechanism.Equals("PBEwithSHA-1and40bitRC4"))
{
parameters = generator.generateDerivedParameters(40);
}
else if (mechanism.Equals("PBEwithSHA-1and3-keyDESEDE-CBC"))
{
parameters = generator.generateDerivedParameters(192, 64);
}
else if (mechanism.Equals("PBEwithSHA-1and2-keyDESEDE-CBC"))
{
parameters = generator.generateDerivedParameters(128, 64);
}
else if (mechanism.Equals("PBEwithSHA-1and128bitRC2-CBC"))
{
parameters = generator.generateDerivedParameters(128, 64);
}
else if (mechanism.Equals("PBEwithSHA-1and40bitRC2-CBC"))
{
parameters = generator.generateDerivedParameters(40, 64);
}
else if (mechanism.Equals("PBEwithSHA1andDES-CBC"))
{
parameters = generator.generateDerivedParameters(64, 64);
}
else if (mechanism.Equals("PBEwithSHA1andRC2-CBC"))
{
parameters = generator.generateDerivedParameters(128, 64);
}
}
else if (mechanism.StartsWith("PBEwithMD5"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new MD5Digest(), key, salt, iterationCount);
if (mechanism.Equals("PBEwithMD5andDES-CBC"))
{
parameters = generator.generateDerivedParameters(64, 64);
}
else if (mechanism.Equals("PBEwithMD5andRC2-CBC"))
{
parameters = generator.generateDerivedParameters(64, 64);
}
}
else if (mechanism.StartsWith("PBEwithMD2"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new MD2Digest(), key, salt, iterationCount);
if (mechanism.Equals("PBEwithMD2andDES-CBC"))
{
parameters = generator.generateDerivedParameters(64, 64);
}
else if (mechanism.Equals("PBEwithMD2andRC2-CBC"))
{
parameters = generator.generateDerivedParameters(64, 64);
}
}
else if (mechanism.StartsWith("PBEwithHmac"))
{
if (mechanism.Equals("PBEwithHmacSHA-1"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new SHA1Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(160);
}
else if (mechanism.Equals("PBEwithHmacSHA-224"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new SHA224Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(224);
}
else if (mechanism.Equals("PBEwithHmacSHA-256"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new SHA256Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(256);
}
else if (mechanism.Equals("PBEwithHmacRIPEMD128"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new RIPEMD128Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(128);
}
else if (mechanism.Equals("PBEwithHmacRIPEMD160"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new RIPEMD160Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(160);
}
else if (mechanism.Equals("PBEwithHmacRIPEMD256"))
{
PBEParametersGenerator generator = makePBEGenerator((String)algorithmType[mechanism], new RIPEMD256Digest(), key, salt, iterationCount);
parameters = generator.generateDerivedMacParameters(256);
}
}
for (int i = 0; i != key.Length; i++)
{
key[i] = 0;
}
return(parameters);
}