Java Create KeyPair hangs on VM but works on physical system [duplicate]

Question

I have some Java code which is creating a KeyPair using JCS and Bouncey Castle. When I create a keypair on a physical Linux system like my desktop it works fine. The key generation takes a second or two. When I run the same code on a VM the key gen usually "hangs" (I leave it running for up to 5 minutes). Sometimes it works in under 30 seconds but that's rare.

I'm guessing that this has something to do with not enough randomness being available on the VM, but I don't know how to work around this.

Here is the test code which is pulled from my actual program code and condensed:

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

public class KeyPairCreateTester {
    private static final String RANDOM_ALGO = "SHA1PRNG";

    public static void main(String[] args) {
        final String keyAlgo = "RSA";
        final int keySize = 2048;

        try {
            System.out.printf("Creating random instance using %s\n", RANDOM_ALGO);
            SecureRandom random = SecureRandom.getInstance(RANDOM_ALGO);
            System.out.printf("Creating key using algo %s size %d\n", keyAlgo, keySize);
            KeyPairGenerator keygen = KeyPairGenerator.getInstance(keyAlgo);
            System.out.printf("Initialize\n");
            keygen.initialize(keySize, random);
            System.out.printf("Generating key\n");
            KeyPair keyPair = keygen.generateKeyPair();
            System.out.println("Success");
        } catch (NoSuchAlgorithmException e) {
            System.err.println("No such algo");
        }
    }

}

The "hang" occurs after "Generating key".

Adjusting the keySize down to even 512 has only minimal effect. At 512 the key is generated a few times more often but it still hangs most of the time for at least 5 minutes.

The physical machine and the VM are both Ubuntu 16.04.

Java is 1.8.0_72 + 1.8.0_101 (I tried both).

Would REALLY appreciate some pointers on this one. It's driving me crazy!

Answer 1

Solved the problem by installing the haveged package and starting that service (systemctl start haveged).