void ServerAuthModule::OnMessageVerifyClient(RawMessage& rawMessage)
{
if (m_bIsVerifiedClient)
throw AuthException(AuthException::authInternalError, _T("client already verified"), __FILE__, __LINE__);
if (m_spServer == NULL)
throw AuthException(AuthException::authInternalError, _T("server == NULL"), __FILE__, __LINE__);
SRPAuthVerifyClientMessage verifyClientMessage;
ConstVectorRefStream stream(rawMessage.Data());
verifyClientMessage.Deserialize(stream);
HighResolutionTimer timer;
timer.Start();
// check client; when failed, client doesn't know password
TByteArray Ms;
try
{
Ms = m_spServer->VerifyClient(verifyClientMessage.GetHc());
}
catch(std::runtime_error& ex)
{
throw AuthException(
AuthException::authFailed, _T("couldn't verify client") + CString(ex.what()),
__FILE__, __LINE__);
}
m_bIsVerifiedClient = true;
// log
CString cszText;
cszText.Format(_T("verifying client took %u ms"), unsigned(timer.Elapsed()*1000.0));
LOG_INFO(cszText, Log::Server::AuthSRP);
// send server our hash
SRPAuthVerifyServerMessage verifyServerMessage(Ms);
SendMessage(verifyServerMessage);
// get server session key
TByteArray K = m_spServer->GetK();
m_spServer.reset(); // no longer needed
// set up RC4 encryption
m_spEncryptModule.reset(new RC4::EncryptModule(K));
}
void ServerAuthModule::OnMessageAuthRequest(RawMessage& rawMessage)
{
if (m_bIsVerifiedClient)
throw AuthException(AuthException::authInternalError, _T("client already verified"), __FILE__, __LINE__);
if (m_spServer != NULL)
throw AuthException(AuthException::authInternalError, _T("server == NULL"), __FILE__, __LINE__);
AuthRequestMessage authMessage;
ConstVectorRefStream stream(rawMessage.Data());
authMessage.Deserialize(stream);
// get server infos
ATLASSERT(m_fnGetServerAuthInfo != NULL);
TByteArray vecPasswordKey, vecSalt;
try
{
m_fnGetServerAuthInfo(authMessage.GetUsername(), vecPasswordKey, vecSalt, m_iAccountId);
}
catch(const Exception& ex)
{
LOG_WARN(_T("caught exception during GetServerAuthInfo(): ") + ex.Message(), Log::Server::AuthSRP);
throw AuthException(
AuthException::authFailed, _T("couldn't get auth info: ") + ex.Message(),
__FILE__, __LINE__);
}
catch(...)
{
throw AuthException(
AuthException::authFailed, _T("couldn't get auth info"), __FILE__, __LINE__);
}
HighResolutionTimer timer;
timer.Start();
SRP::GroupParameter gp = SRP::Helper::GetPresetGroupParameter(c_uiDefaultPresetGroupParameter);
m_spServer.reset(new SRP::Server(gp));
// generate b
BigInteger b = SRP::Helper::GenerateRandomBits(1024);
BigInteger PassVerifier = SRP::Helper::ToInteger<BigInteger>(vecPasswordKey);
// calculate B
BigInteger B = m_spServer->GetB(PassVerifier, b);
TByteArray Bbin;
SRP::Helper::ToBinaryData(B, Bbin);
// calculate session key
TByteArray Abin = authMessage.GetA();
BigInteger A = SRP::Helper::ToInteger<BigInteger>(Abin);
BigInteger s = SRP::Helper::ToInteger<BigInteger>(vecSalt);
USES_CONVERSION;
std::string strUsername(T2CA(authMessage.GetUsername()));
m_spServer->CalcSessionKey(A, s, strUsername, PassVerifier);
// log
CString cszText;
cszText.Format(_T("calculating session key took %u ms"), unsigned(timer.Elapsed()*1000.0));
LOG_INFO(cszText, Log::Server::AuthSRP);
// send response
SRPAuthResponseMessage authResponseMessage(vecSalt, Bbin);
SendMessage(authResponseMessage);
}