/// Determines the public key for which `sig` is a valid signature for
/// `msg`. Requires a verify-capable context.
public PublicKey Recover(Message msg, RecoverableSigniture sig)
{
if (Caps == ContextFlag.SignOnly || Caps == ContextFlag.None)
{
throw new Exception("IncapableContext");
}
var pkBytes = new byte[64];
if (Proxy.secp256k1_ecdsa_recover(Ctx, pkBytes, sig.Value, msg.Value) != 1)
{
throw new Exception("InvalidSignature");
}
return(PublicKey.From(pkBytes));
}
/// Constructs a signature for `msg` using the secret key `sk` and RFC6979 nonce
/// Requires a signing-capable context.
public RecoverableSigniture sign_recoverable(Message msg, SecretKey sk)
{
if (Caps == ContextFlag.VerifyOnly || Caps == ContextFlag.None)
{
throw new Exception("IncapableContext");
}
var ret = new byte[65];
// We can assume the return value because it's not possible to construct
// an invalid signature from a valid `Message` and `SecretKey`
if (Proxy.secp256k1_ecdsa_sign_recoverable(Ctx, ret, msg.Value, sk.Value, IntPtr.Zero /*Proxy.secp256k1_nonce_function_rfc6979()*/, IntPtr.Zero) == 1)
{
return(RecoverableSigniture.From(ret));
}
throw new Exception("This should never happen!");
}
