signString static method
私钥签名
Implementation
static String signString(String text, String private) {
final RSAPrivateKey privateKey =
RSAKeyParser().parse(private) as RSAPrivateKey;
final Signer signer = Signer(
RSASigner(RSASignDigest.SHA256, privateKey: privateKey),
);
String signerStr = signer.sign(text).base64;
return signerStr;
}