private Boolean CompareHash(Type hashAlgorithmType, Byte[] plainText, Byte[] hashedBytes, Int32 saltLength = 16)
{
var hashAlgorithm = Activator.CreateInstance(hashAlgorithmType, true) as HashAlgorithm;
if (hashAlgorithm == null)
{
throw new InvalidOperationException(String.Format("Could not create instance of type {0}.", hashAlgorithmType));
}
var salt = CryptographyUtility.GetBytes(hashedBytes, saltLength);
var targetHash = CryptographyUtility.CombineBytes(salt, hashAlgorithm.ComputeHash(CryptographyUtility.CombineBytes(salt, plainText)));
return(CryptographyUtility.CompareBytes(hashedBytes, targetHash));
}
private Boolean CompareHash(Type keyedHashAlgorithmType, Byte[] symmetricKey, Byte[] plainText, Byte[] hashedText, Boolean saltEnabled = true, DataProtectionScope dataProtectionScope = DataProtectionScope.LocalMachine)
{
if (symmetricKey == null || plainText == null || hashedText == null)
{
return(false);
}
var keyedHashAlgorithm = Activator.CreateInstance(keyedHashAlgorithmType, true) as KeyedHashAlgorithm;
if (keyedHashAlgorithm == null)
{
throw new InvalidOperationException(String.Format("Could not create instance of type {0}.", keyedHashAlgorithmType));
}
keyedHashAlgorithm.Key = symmetricKey;
var hashedPlainText = keyedHashAlgorithm.ComputeHash(plainText);
// TODO: (DG) Support SALT!
return(CryptographyUtility.CompareBytes(hashedPlainText, hashedText));
}
private Byte[] CreateHash(Type hashAlgorithmType, Byte[] plainText, Int32 saltLength = 16)
{
var hashAlgorithm = Activator.CreateInstance(hashAlgorithmType, true) as HashAlgorithm;
if (hashAlgorithm == null)
{
throw new InvalidOperationException(String.Format("Could not create instance of type {0}.", hashAlgorithmType));
}
// Generate salt
var salt = new Byte[saltLength];
_RngCryptoServiceProvider.GetNonZeroBytes(salt);
// Compute hash
var hashedText = hashAlgorithm.ComputeHash(CryptographyUtility.CombineBytes(salt, plainText));
// Randomize plain text
_RngCryptoServiceProvider.GetBytes(plainText);
return(CryptographyUtility.CombineBytes(salt, hashedText));
}
