ZeroMQ_TestPlain.java

	// the error will occur after a couple of seconds. It seems that the ZAP-Request to configure 
	// plain is not processed before the sockets start with their work. 
	// this will show that loadpasswords throws a nullpointer-exception because it assumes the password file is already
	// loaded.
	// Adding a sleep after auth.configurePlain(..) helps but is very hacky.

package org.tt.zmq.security;

import java.io.FileWriter;
import java.io.IOException;
import java.nio.charset.Charset;

import org.zeromq.ZAuth;
import org.zeromq.ZContext;
import org.zeromq.ZMQ;

public class TestPlain {
	private static final boolean VERBOSE_MODE=true;
	private static final boolean SHOW_ERROR = false;
	
	public static String woodhouse() {
	    //  Create context
		ZContext ctx = new ZContext();
		
	    //  Start an authentication engine for this context. This engine
	    //  allows or denies incoming connections (talking to the libzmq
	    //  core over a protocol called ZAP).
		ZAuth auth = new ZAuth(ctx);
		

	    //  Get some indication of what the authenticator is deciding
	    auth.setVerbose(VERBOSE_MODE);
	    //  Whitelist our address; any other address will be rejected
	    auth.allow("127.0.0.1");
	    auth.configurePlain("*", "passwords");
		
	    if (!SHOW_ERROR){
		    try {
				Thread.sleep(50);
			}
			catch (Exception e) {
				e.printStackTrace();
			}
	    }
	        
	    //  Create and bind server socket
	    ZMQ.Socket server = ctx.createSocket(ZMQ.PUSH);
	    server.setPlainServer(true);
	    server.setZAPDomain("global".getBytes());
	    server.bind("tcp://*:9000");
		System.out.println("wh5");
	     
	    //  Create and connect client socket
	    ZMQ.Socket client = ctx.createSocket(ZMQ.PULL);
	    client.setPlainUsername("admin".getBytes());
	    client.setPlainPassword("secret".getBytes());
	    client.connect("tcp://127.0.0.1:9000");
		System.out.println("wh6");
	    
	    //  Send a single message from server to client
	    server.send("Hello");
		System.out.println("wh7");
	    String message = client.recvStr(0,Charset.defaultCharset());
	    auth.destroy();
	    ctx.close();
	    return message;
	}
	
	
	public static void main(String[] args) {
	    try {
			FileWriter write = new FileWriter("passwords");
			write.write("guest=guest\n"); 
			write.write("tourist=1234\n");
			write.write("admin=secret\n");
			write.close();
		} catch (IOException e) {
			e.printStackTrace();
		}			

	    while (true) {
			String result = woodhouse();
			System.out.println(System.currentTimeMillis()+":"+result);
		}
	}
}