/// <inheritdoc />
public async Task HandleMessage(IPeerSessionMessageContext <AuthenticationServerPayload> context, AuthLogonProofRequest payload)
{
if (Logger.IsDebugEnabled)
{
Logger.Debug($"Recieved {payload.GetType().Name} Id: {context.Details.ConnectionId}");
}
BigInteger A = payload.A.ToBigInteger();
//SRP6 Safeguard from specification: A % N cannot be 0.
if (A % WoWSRP6ServerCryptoServiceProvider.N == 0)
{
//TODO: This can't be 0 or it breaks
}
//Check if we have a challenge entry for this connection
//TODO: Add proper response code
if (!await ChallengeRepository.HasEntry(context.Details.ConnectionId))
{
await context.PayloadSendService.SendMessage(new AuthLogonProofResponse(new LogonProofFailure()));
return;
}
//TODO: Refactor
using (WoWSRP6PublicComponentHashServiceProvider hasher = new WoWSRP6PublicComponentHashServiceProvider())
{
AuthenticationChallengeModel challenge = await ChallengeRepository.Retrieve(context.Details.ConnectionId);
byte[] hash = hasher.Hash(A, challenge.PublicB);
// Both: u = H(A, B)
BigInteger u = hash
.Take(20)
.ToArray()
.ToBigInteger();
BigInteger N = WoWSRP6ServerCryptoServiceProvider.N;
//Host: S = (Av^u) ^ b (computes session key)
BigInteger S = ((A * (challenge.V.ModPow(u, N)))) //TODO: Do we need % N here?
.ModPow(challenge.PrivateB, N);
//Host: K = H(S)
BigInteger K = hasher.HashSessionKey(S);
byte[] preMHash = T3.ToCleanByteArray()
.Concat(hasher.Hash(challenge.Identity.Reinterpret(Encoding.ASCII)).Take(20).ToArray())
.Concat(challenge.Salt.ToCleanByteArray())
.Concat(payload.A)
.Concat(challenge.PublicB.ToCleanByteArray())
.Concat(K.ToCleanByteArray())
.ToArray();
byte[] M = hasher.Hash(preMHash);
Logger.Debug($"M: {M.Aggregate("", (s, b) => $"{s} {b}")}");
Logger.Debug($"M1: {payload.M1.Aggregate("", (s, b) => $"{s} {b}")}");
//TODO: Remove this test code
if (TestClass.CompareBuffers(M, payload.M1, 20) == 0)
{
Logger.Debug($"Auth Proof Success.");
byte[] M2 = hasher.Hash(payload.A.Concat(M).Concat(K.ToCleanByteArray()).ToArray());
//TODO: We also want to update last/login IP and other stuff
await AccountRepository.UpdateSessionKey(challenge.AccountId, K);
await context.PayloadSendService.SendMessage(new AuthLogonProofResponse(new LogonProofSuccess(M2)));
}
else
{
Logger.Debug($"Auth Proof Failure.");
await context.PayloadSendService.SendMessage(new AuthLogonProofResponse(new LogonProofFailure()));
}
}
//TODO: Implement
}