Can't generate random KeyPair

Question

Hi all,
i tried with the following code to generate a random RSA KeyPair.
But it is always the same keypair generated. What i'm doing wrong?
SecureRandom random = new SecureRandom();
random.setSeed(System.currentTimeMillis());
KeyPairGenerator pairGen = KeyPairGenerator.getInstance("RSA", "BC");
pairGen.initialize(1024, random);
KeyPair keyPair = pairGen.generateKeyPair();
I tried also this way to create a SecureRandom, but with same result:
SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
Thanks for Help!
Regards turjalei

Answer 1

To check RSA keys for equality, you need to see if their modulus and exponent are the same. Comparing keyPair.toString() will NOT do that - and I'm not sure that keyPair.equals() will do it either.
Here's a quick-and-dirty way to eyeball generated keys and see that they are, in fact, different:import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import org.bouncycastle.util.encoders.Base64;
public class CipherHandler {
    public static void main(String[] args) {
        try {
            SecureRandom random = new SecureRandom();
            random.setSeed(System.currentTimeMillis());
            KeyPairGenerator pairGen =
                KeyPairGenerator.getInstance("RSA", "BC");
            pairGen.initialize(1024, random);
            KeyPair keyPair = pairGen.generateKeyPair();
            byte[] pubEnc = keyPair.getPublic().getEncoded();
            String b64Str = new String(Base64.encode(pubEnc), "ASCII");
            System.out.println("pub one = " + b64Str);
            keyPair = pairGen.generateKeyPair();
            pubEnc = keyPair.getPublic().getEncoded();
            b64Str = new String(Base64.encode(pubEnc), "ASCII");
            System.out.println("pub two = " + b64Str);
        } catch (Exception e) {
            e.printStackTrace();
}When you compare the resulting Base64'd strings, you'll note that they are in fact different...
Good luck!
Grant