private void ComputeHashWorker(string plainText, SupportedHashAlgorithm algorithm, int complexityThrottle = 1,
byte[] saltBytes = null)
{
if (saltBytes == null)
{
saltBytes = _saltProvider.GetNonZeroBytes(SALT_BYTE_LENGTH);
}
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
var algoBytes = Encoding.UTF8.GetBytes(GetAlgoIdentifier(algorithm));
byte[] hashBytes;
var hasComplexityThrottle = false;
_complexityThrottle = complexityThrottle;
switch (algorithm)
{
case SupportedHashAlgorithm.SHA1:
hashBytes = CryptoHashAlgorithmComputeBytes(plainTextBytes, saltBytes, new SHA1Managed());
break;
case SupportedHashAlgorithm.SHA256:
hashBytes = CryptoHashAlgorithmComputeBytes(plainTextBytes, saltBytes, new SHA256Managed());
break;
case SupportedHashAlgorithm.SHA384:
hashBytes = CryptoHashAlgorithmComputeBytes(plainTextBytes, saltBytes, new SHA384Managed());
break;
case SupportedHashAlgorithm.SHA512:
hashBytes = CryptoHashAlgorithmComputeBytes(plainTextBytes, saltBytes, new SHA512Managed());
break;
case SupportedHashAlgorithm.PBKDF2:
complexityThrottle = complexityThrottle * 1000;
hashBytes = new Rfc2898DeriveBytes(plainTextBytes, saltBytes, complexityThrottle).GetBytes(24);
hasComplexityThrottle = true;
break;
default:
hashBytes = CryptoHashAlgorithmComputeBytes(plainTextBytes, saltBytes,
new MD5CryptoServiceProvider());
break;
}
_saltBytes = saltBytes;
if (hasComplexityThrottle)
{
saltBytes = saltBytes.Concat(BitConverter.GetBytes(_complexityThrottle)).ToArray();
}
saltBytes = saltBytes.Concat(algoBytes).ToArray();
// append the salt bytes to the end of the hash
IEnumerable <byte> hashWithSaltBytes = hashBytes.Concat(saltBytes);
HashString = Convert.ToBase64String(hashWithSaltBytes.ToArray());
_inited = true;
}