public TlsKdfV13EarlySecretResult GetDerivedEarlySecret(bool isExternalPsk, BitString preSharedKey, BitString clientHello)
{
var earlySecret = _hkdf.Extract(_bitstringHashLengthBits, preSharedKey);
var binderKey = DeriveSecret(earlySecret, isExternalPsk ? "ext binder" : "res binder", BitString.Empty());
var clientEarlyTrafficSecret = DeriveSecret(earlySecret, "c e traffic", clientHello);
var earlyExporterMasterSecret = DeriveSecret(earlySecret, "e exp master", clientHello);
var derivedEarlySecret = DeriveSecret(earlySecret, "derived", BitString.Empty());
return(new TlsKdfV13EarlySecretResult()
{
EarlySecret = earlySecret,
BinderKey = binderKey,
ClientEarlyTrafficSecret = clientEarlyTrafficSecret,
EarlyExporterMasterSecret = earlyExporterMasterSecret,
DerivedEarlySecret = derivedEarlySecret,
});
}
