Developer's Guide to Web Application Security

keyMaker = KeyPairGenerator.getInstance("DSA");

sigGen = Signature.getInstance("DSA");

} catch (NoSuchAlgorithmException na) {}

keyMaker.initialize(512);

System.out.println("Generating keypair...");

KeyPair pair = keyMaker.generateKeyPair();

PrivateKey priv = pair.getPrivate();

String message = "";

for(int i=0;i<args.length;i++)

message = message +""+args[i];

try {

sigGen.initSign(priv);

sigGen.update(message.getBytes());

signature = sigGen.sign();

} catch(Exception e) {}

System.out.print("Signature: ");

for(int j=0;j<signature.length;j++)

System.out.print((signature[j] + 128) + " ");

}

}

This code is basically the same code we used to generate a key-pair, except ...