public static bool TryRecover(Context ctx, SecpRecoverableECDSASignature recoverableSig, ReadOnlySpan <byte> msg32, out ECPubKey?pubkey)
{
if (recoverableSig == null)
{
throw new ArgumentNullException(nameof(recoverableSig));
}
ctx ??= Context.Instance;
GE q;
Scalar r, s;
Scalar m;
int recid;
if (msg32.Length != 32)
{
throw new ArgumentException(paramName: nameof(msg32), message: "msg32 should be 32 bytes");
}
(r, s, recid) = recoverableSig;
VERIFY_CHECK(recid >= 0 && recid < 4); /* should have been caught in parse_compact */
m = new Scalar(msg32, out _);
if (secp256k1_ecdsa_sig_recover(ctx.EcMultContext, r, s, out q, m, recid))
{
pubkey = new ECPubKey(q, ctx);
return(true);
}
else
{
pubkey = null;
return(false);
}
}
public static bool TryCreateFromCompact(ReadOnlySpan <byte> in64, int recid, out SecpRecoverableECDSASignature?sig)
{
sig = null;
if (SecpECDSASignature.TryCreateFromCompact(in64, out var compact) && compact is SecpECDSASignature)
{
sig = new SecpRecoverableECDSASignature(compact, recid);
return(true);
}
return(false);
}
public bool TrySignRecoverable(ReadOnlySpan <byte> msg32, INonceFunction?nonceFunction, out SecpRecoverableECDSASignature?recoverableSignature)
{
if (msg32.Length != 32)
{
throw new ArgumentException(paramName: nameof(msg32), message: "msg32 should be 32 bytes");
}
if (this.TrySignECDSA(msg32, nonceFunction, out int recid, out SecpECDSASignature? sig) && sig is SecpECDSASignature)
{
recoverableSignature = new SecpRecoverableECDSASignature(sig, recid);
return(true);
}
recoverableSignature = null;
return(false);
}