WindowsPRNG

WindowsPRNG.java

package test;

import java.security.Provider;
import java.security.SecureRandom;
import java.security.Security;
import java.util.Optional;

public interface WindowsPRNG {

	static void init() {
		String provider = "SunMSCAPI"; // original provider
		String type = "SecureRandom"; // service type
		String alg = "Windows-PRNG"; // algorithm
		String name = String.format("%s.%s", provider, type); // our provider name
		if (Security.getProvider(name) != null) return; // already registered
		Optional.ofNullable(Security.getProvider(provider)) // only on Windows
				.ifPresent(p -> Optional.ofNullable(p.getService(type, alg)) // should exist but who knows?
						.ifPresent(svc -> Security.insertProviderAt(
								// insert our provider with single SecureRandom service
								new Provider(name, p.getVersionStr(), null) {{
									setProperty(String.format("%s.%s", type, alg), svc.getClassName());
								}}, 1)));
	}

	static void main(String[] args) {
		long started = System.currentTimeMillis();
		WindowsPRNG.init();
		new SecureRandom().generateSeed(20);
		System.out.println(System.currentTimeMillis() - started);
	}

}