signWithRSAKey method
Implementation
RSASignature signWithRSAKey(Uint8List m) {
RSASigner signer = RSASigner(SHA1Digest(), '06052b0e03021a');
signer.init(
true, PrivateKeyParameter<asymmetric.RSAPrivateKey>(rsaPrivate));
return RSASignature(signer.generateSignature(m).bytes);
}