public Session ProcessChallenge(VerificationChallenge challenge)
{
_s = challenge.ServerKey;
_B = challenge.PublicEphemeralKey.ToBigInteger();
if (_B % _parameter.PrimeNumber == 0)
{
throw new Exception("Mod B % PrimeNumber could not be 0");
}
_u = _hashAlgorithm.ComputeHash(_A.Concat(_B.ToBytes()).ToArray()).ToBigInteger();
if (_u == 0)
{
throw new Exception("u could not be 0");
}
_x = Compute_x(_s, _username, _password).ToBigInteger();
_v = BigInteger.ModPow(_parameter.Generator, _x, _parameter.PrimeNumber);
_S = Compute_S(_B, _k, _u, _a, _x);
_K = Compute_K(_S.ToBytes());
_M = Compute_M(_username, _s, _A, _B.ToBytes(), _K);
_HMAK = Compute_HAMK(_A, _M, _K);
var session = new Session()
{
Key = _M
};
#if DEBUG
Console.WriteLine("================ User Challenge ==============");
Console.WriteLine("_s = {0}", _s.ToBigInteger());
Console.WriteLine("_B = {0}", _B);
Console.WriteLine("_A = {0}", _A.ToBigInteger());
Console.WriteLine("_a = {0}", _a);
Console.WriteLine("_u = {0}", _u);
Console.WriteLine("_x = {0}", _x);
Console.WriteLine("_k = {0}", _k);
Console.WriteLine("_v = {0}", _v);
Console.WriteLine("_S = {0}", _S);
Console.WriteLine("_K = {0}", _K.ToBigInteger());
Console.WriteLine("_M = {0}", _M.ToBigInteger());
Console.WriteLine("=============================================");
#endif
return(session);
}
public VerificationChallenge GetChallenge()
{
VerificationChallenge challenge = new VerificationChallenge();
if ((_A % _parameter.PrimeNumber) == BigInteger.Zero)
{
challenge.ServerKey = null;
challenge.PublicEphemeralKey = null;
}
else
{
challenge.ServerKey = _s.ToBytes();
challenge.PublicEphemeralKey = _B.ToBytes();
}
return(challenge);
}
