/**
* @return <c>true</c> if the keyDigest is compatible with the specified saltData and saltHash
*/
public bool Validate(byte[] saltData, byte[] saltHash)
{
Check16Bytes(saltData, "saltData");
Check16Bytes(saltHash, "saltHash");
// validation uses the RC4 for block zero
RC4 rc4 = CreateRC4(0);
byte[] saltDataPrime = new byte[saltData.Length];
Array.Copy(saltData, saltDataPrime, saltData.Length);
rc4.Encrypt(saltDataPrime);
byte[] saltHashPrime = new byte[saltHash.Length];
Array.Copy(saltHash, saltHashPrime, saltHash.Length);
rc4.Encrypt(saltHashPrime);
using (MD5 md5 = new MD5CryptoServiceProvider())
{
byte[] finalSaltResult = md5.ComputeHash(saltDataPrime);
//if (false)
//{ // set true to see a valid saltHash value
// byte[] saltHashThatWouldWork = xor(saltHash, xor(saltHashPrime, finalSaltResult));
// Console.WriteLine(HexDump.ToHex(saltHashThatWouldWork));
//}
return(Arrays.Equals(saltHashPrime, finalSaltResult));
}
}
private void RekeyForNextBlock()
{
_currentKeyIndex = _streamPos / RC4_REKEYING_INTERVAL;
_rc4 = _key.CreateRC4(_currentKeyIndex);
_nextRC4BlockStart = (_currentKeyIndex + 1) * RC4_REKEYING_INTERVAL;
}