Simple Digital Signature Example : RSA algorithm « Security « Java Tutorial





import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Signature;

import sun.misc.BASE64Encoder;

public class MainClass {
  public static void main(String[] args) throws Exception {
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(1024);
    KeyPair keyPair = kpg.genKeyPair();

    byte[] data = "test".getBytes("UTF8");

    Signature sig = Signature.getInstance("MD5WithRSA");
    sig.initSign(keyPair.getPrivate());
    sig.update(data);
    byte[] signatureBytes = sig.sign();
    System.out.println("Singature:" + new BASE64Encoder().encode(signatureBytes));

    sig.initVerify(keyPair.getPublic());
    sig.update(data);

    System.out.println(sig.verify(signatureBytes));
  }
}










36.38.RSA algorithm
36.38.1.Basic RSA example.
36.38.2.RSA example with random key generation.
36.38.3.RSA example with PKCS #1 Padding.
36.38.4.RSA example with OAEP Padding and random key generation.
36.38.5.An example of using RSA to encrypt a single asymmetric key.
36.38.6.Simple Digital Signature Example
36.38.7.Creates a 1024 bit RSA key pair and stores it to the filesystem as two files
36.38.8.RSA Signature Generation
36.38.9.An RSA sample application