public static bool TryRecover(Context ctx, Secp256k1.SecpRecoverableECDSASignature recoverableSig, ReadOnlySpan <byte> msg32, [MaybeNullWhen(false)] 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 void ReadWrite(BitcoinStream stream)
{
#if HAS_SPAN
if (stream.Serializing)
{
Span <byte> tmp = stackalloc byte[65];
_ECKey.WriteToSpan(compressed, tmp, out var l);
tmp = tmp.Slice(0, l);
stream.ReadWrite(ref tmp);
}
else
{
Span <byte> tmp = stackalloc byte[compressed ? 33 : 65];
stream.ReadWrite(ref tmp);
if (NBitcoinContext.Instance.TryCreatePubKey(tmp, out var p) && p is Secp256k1.ECPubKey)
{
_ECKey = p;
}
else
{
throw new FormatException("Deserializing invalid pubkey");
}
}
#else
stream.ReadWrite(ref vch);
if (!stream.Serializing)
{
_ECKey = new ECKey(vch, false);
}
#endif
}
internal PubKey(Secp256k1.ECPubKey pubkey, bool compressed)
{
if (pubkey == null)
{
throw new ArgumentNullException(nameof(pubkey));
}
this._ECKey = pubkey;
this.compressed = compressed;
}