signature.verify() Always returns False

Question

 public static void main(String[] args) {
    try{
        String mod = \"q0AwozeUj0VVkoksDQSCTj3QEgODomq4sAr02xMyIrWldZrNHhWfZAIcWt2MuAY3X6S3ZVUfOFXOrVbltRrO3F9Z6R8         


        

Answer 1

Where you sign the message you should have some code like this:

Signature signature = Signature.getInstance("SHA1withRSA");
signature.initSign(privKey);
signature.update(message);
byte[] signatureValue = signature.sign();

Note the byte-array named signatureValue. That is the actual signature on the data. That is what you should provide to the verify()-method. The message that is signed should be provided in a call to the update()-method. I.e.:

Signature signature = Signature.getInstance("SHA1withRSA");
signature.initVerify(pubKey);
signature.update(message);
bool ok = signature.verify(signatureValue);