public virtual void Exchange(byte[] clientEcdhPubkey, byte[] cRandomUnused, byte[] sRandomUnused, object privateParameters)
{
// "TLS1.3 ciphersuite does not include KeyExchange methods"
// just for shared_secret calculation here
var shared_secret = new byte[32];
if (privateParameters is Parameters.X25519PrivateKeyParameters x25519Prv)
{
var clientPub = new Parameters.X25519PublicKeyParameters(clientEcdhPubkey, 0);
x25519Prv.GenerateSecret(clientPub, shared_secret, 0);
}
else if (privateParameters is Parameters.X448PrivateKeyParameters x448Prv)
{
var clientPub = new Parameters.X448PublicKeyParameters(clientEcdhPubkey, 0);
x448Prv.GenerateSecret(clientPub, shared_secret, 0);
}
else if (privateParameters is Parameters.ECPrivateKeyParameters serverPrv)
{
var ecDomainParam = serverPrv.Parameters;
var clientQ = TlsEccUtilities.DeserializeECPoint(new byte[] { 0x04 }, ecDomainParam.Curve, clientEcdhPubkey);
var clientPub = new Parameters.ECPublicKeyParameters(clientQ, ecDomainParam);
shared_secret = TlsEccUtilities.CalculateECDHBasicAgreement(clientPub, serverPrv);
}
else
{
throw new NotSupportedException("Unsupported KeyShare Group");
}
SharedSecret = shared_secret;
}
protected override void GenerateMasterSecret(byte[] clientEcdhPubkey, byte[] clientRandom, byte[] serverRandom, object privateParameters)
{
var pre_master = new byte[32];
if (privateParameters is Parameters.X25519PrivateKeyParameters x25519Prv)
{
var clientPub = new Parameters.X25519PublicKeyParameters(clientEcdhPubkey, 0);
x25519Prv.GenerateSecret(clientPub, pre_master, 0);
}
else if (privateParameters is Parameters.X448PrivateKeyParameters x448Prv)
{
var clientPub = new Parameters.X448PublicKeyParameters(clientEcdhPubkey, 0);
x448Prv.GenerateSecret(clientPub, pre_master, 0);
}
else if (privateParameters is Parameters.ECPrivateKeyParameters serverPrv)
{
var ecDomainParam = serverPrv.Parameters;
var clientQ = TlsEccUtilities.DeserializeECPoint(new byte[] { 0x04 }, ecDomainParam.Curve, clientEcdhPubkey);
var clientPub = new Parameters.ECPublicKeyParameters(clientQ, ecDomainParam);
pre_master = TlsEccUtilities.CalculateECDHBasicAgreement(clientPub, serverPrv);
}
MasterSecret = RandomFunction.PRF.GetBytes_HMACSHA256(pre_master, "master secret", clientRandom.Concat(serverRandom).ToArray(), 48);
}