protected override Result Fragment_ClientCertificateVerify(Fragments.CertificateVerify frag)
{
if (State == TLSSessionState.Client_Certificate)
{
if (_clientCertificates != null && _clientCertificates.Length > 0)
{
var clientHello_clientCert = GetHandshakeMessages(true); // without CertificateVerify message itself
var valid = ClientCertificateSignatureVerify(clientHello_clientCert, frag);
if (!valid)
{
return(Result.FatalAlert(AlertDescription.bad_certificate, "Client Certificate Signature Verify failure"));
}
State = TLSSessionState.Client_CertificateVerify;
return(null);
}
else
{
return(Result.FatalAlert(AlertDescription.unexpected_message, "Client Certificate Empty but sent CertificateVerify message"));
}
}
else
{
return(Result.FatalAlert(AlertDescription.unexpected_message, $"State [{State}] check failed on Client_CertificateVerify message"));
}
}
bool ClientCertificateSignatureVerify(byte[] handshakeMsg, Fragments.CertificateVerify frag)
{
var handshakeHash = (_params.Cipher as Ciphers.CipherSuiteBase13).GetHashAlgorithm().ComputeHash(handshakeMsg);
var contextString = "TLS 1.3, client CertificateVerify";
var dataToSign = new List <byte>
{
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
};
dataToSign.AddRange(Encoding.ASCII.GetBytes(contextString));
dataToSign.Add(0x00);
dataToSign.AddRange(handshakeHash);
return(VerifyWithClientCertificate(dataToSign.ToArray(), frag.Signature, frag.SignatureAlgorithm));
}
protected virtual Result Fragment_ClientCertificateVerify(Fragments.CertificateVerify frag)
{
if (State == TLSSessionState.Client_Key_Exchange)
{
if (_clientCertificates != null && _clientCertificates.Length > 0)
{
var clientHello_clientKeyEx = GetHandshakeMessages(true); // without CertificateVerify message itself
var valid = VerifyWithClientCertificate(clientHello_clientKeyEx, frag.Signature, frag.SignatureAlgorithm);
if (!valid)
{
return(Result.FatalAlert(AlertDescription.bad_certificate, "Client Certificate Signature Verify failure"));
}
return(null);
}
else
{
return(Result.FatalAlert(AlertDescription.unexpected_message, "Client Certificate Empty but sent CertificateVerify message"));
}
}
else
{
return(Result.FatalAlert(AlertDescription.unexpected_message, $"State [{State}] check failed on Client_CertificateVerify message"));
}
}
