sign method
Implementation
@override
List<int> sign(List<int> digest,
{bool hashMessage = true, List<int>? extraEntropy}) {
final hash = hashMessage ? QuickCrypto.blake2b256Hash(digest) : digest;
final signature =
_ecdsaSigningKey.sign(digest: hash, extraEntropy: extraEntropy);
return [
...signature.item1.toBytes(CryptoSignerConst.curveSecp256k1.baselen),
signature.item2
];
}