public void Process(MusigPubNonce aggregatedNonce)
{
if (processed_nonce)
{
throw new InvalidOperationException($"Nonce already processed");
}
var agg_pk = this.SigningPubKey;
MusigSessionCache session_cache = new MusigSessionCache();
Span <byte> fin_nonce = stackalloc byte[32];
Span <byte> agg_pk32 = stackalloc byte[32];
Span <GEJ> aggnonce_ptj = stackalloc GEJ[2];
aggnonce_ptj[0] = aggregatedNonce.K1.Q.ToGroupElementJacobian();
aggnonce_ptj[1] = aggregatedNonce.K2.Q.ToGroupElementJacobian();
agg_pk.WriteToSpan(agg_pk32);
/* Add public adaptor to nonce */
if (adaptor != null)
{
aggnonce_ptj[0] = aggnonce_ptj[0].AddVariable(adaptor.Q);
}
secp256k1_musig_nonce_process_internal(this.ctx.EcMultContext, out session_cache.FinalNonceParity, fin_nonce, out session_cache.NonceCoeff, aggnonce_ptj, agg_pk32, msg32);
/* Compute messagehash and store in session cache */
ECXOnlyPubKey.secp256k1_schnorrsig_challenge(out session_cache.Challenge, fin_nonce, msg32, agg_pk32);
/* If there is a tweak then set `msghash` times `tweak` to the `s`-part of the sig template.*/
session_cache.SPart = Scalar.Zero;
if (is_tweaked)
{
Scalar e_tmp = session_cache.Challenge;
if (!ECPrivKey.secp256k1_eckey_privkey_tweak_mul(ref e_tmp, scalar_tweak))
{
throw new InvalidOperationException("Impossible to sign (secp256k1_eckey_privkey_tweak_mul is false)");
}
if (pk_parity)
{
e_tmp = e_tmp.Negate();
}
session_cache.SPart = session_cache.SPart.Add(e_tmp);
}
fin_nonce.CopyTo(session_cache.FinalNonce);
SessionCache = session_cache;
processed_nonce = true;
this.aggregateNonce = aggregatedNonce;
}
