sign function
署名
Implementation
String sign({
required String sigContent,
required String jwk,
}) {
final json = jsonDecode(jwk);
final fullJwk = JsonWebKey.fromJson(json);
final sigConBuf = const Utf8Encoder().convert(sigContent);
final sigBuf = fullJwk.sign(sigConBuf);
final sig = base64Encode(sigBuf);
return sig;
}