Authenticated HTTP proxy with Java

How can I configure the username and password to authenticate a http proxy server using Java?

I just found the following configuration parameters:

http.proxyHost=<proxyAddress>
http.proxyPort=<proxyPort>
https.proxyHost=<proxyAddress>
https.proxyPort=<proxyPort>

But, my proxy server requires authentication. How can I configure my app to use the proxy server?

(EDIT: As pointed out by the OP, the using a java.net.Authenticator is required too. I'm updating my answer accordingly for the sake of correctness.)

(EDIT#2: As pointed out in another answer, in JDK 8 it's required to remove basic auth scheme from jdk.http.auth.tunneling.disabledSchemes property)

For authentication, use java.net.Authenticator to set proxy's configuration and set the system properties http.proxyUser and http.proxyPassword.

final String authUser = "user";
final String authPassword = "password";
Authenticator.setDefault(
  new Authenticator() {
    @Override
    public PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication(authUser, authPassword.toCharArray());
    }
  }
);
				
System.setProperty("http.proxyUser", authUser);
System.setProperty("http.proxyPassword", authPassword);

System.setProperty("jdk.http.auth.tunneling.disabledSchemes", "");

You're almost there, you just have to append:

-Dhttp.proxyUser=someUserName
-Dhttp.proxyPassword=somePassword

http://rolandtapken.de/blog/2012-04/java-process-httpproxyuser-and-httpproxypassword says:

> Other suggest to use a custom default Authenticator. But that's dangerous because this would send your password to anybody who asks.

This is relevant if some http/https requests don't go through the proxy (which is quite possible depending on configuration). In that case, you would send your credentials directly to some http server, not to your proxy.

He suggests the following fix.

// Java ignores http.proxyUser. Here come's the workaround.
Authenticator.setDefault(new Authenticator() {
    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
        if (getRequestorType() == RequestorType.PROXY) {
            String prot = getRequestingProtocol().toLowerCase();
            String host = System.getProperty(prot + ".proxyHost", "");
            String port = System.getProperty(prot + ".proxyPort", "80");
            String user = System.getProperty(prot + ".proxyUser", "");
            String password = System.getProperty(prot + ".proxyPassword", "");
 
            if (getRequestingHost().equalsIgnoreCase(host)) {
                if (Integer.parseInt(port) == getRequestingPort()) {
                    // Seems to be OK.
                    return new PasswordAuthentication(user, password.toCharArray());  
                }
            }
        }
        return null;
    }  
});

I haven't tried it yet, but it looks good to me.

I modified the original version slightly to use equalsIgnoreCase() instead of equals(host.toLowerCase()) because of this: http://mattryall.net/blog/2009/02/the-infamous-turkish-locale-bug and I added "80" as the default value for port to avoid NumberFormatException in Integer.parseInt(port).

Most of the answer is in existing replies, but for me not quite. This is what works for me with java.net.HttpURLConnection (I have tested all the cases with JDK 7 and JDK 8). Note that you do not have to use the Authenticator class.

Case 1 : Proxy without user authentication, access HTTP resources

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport

Case 2 : Proxy with user authentication, access HTTP resources

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

Case 3 : Proxy without user authentication, access HTTPS resources (SSL)

-Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport 

Case 4 : Proxy with user authentication, access HTTPS resources (SSL)

-Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

Case 5 : Proxy without user authentication, access both HTTP and HTTPS resources (SSL)

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport 

Case 6 : Proxy with user authentication, access both HTTP and HTTPS resources (SSL)

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttp.proxyUser=myuser -Dhttp.proxyPassword=mypass -Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

You can set the properties in the with System.setProperty("key", "value) too.

To access HTTPS resource you may have to trust the resource by downloading the server certificate and saving it in a trust store and then using that trust store. ie

 System.setProperty("javax.net.ssl.trustStore", "c:/temp/cert-factory/my-cacerts");
 System.setProperty("javax.net.ssl.trustStorePassword", "changeit");

For Java 1.8 and higher you must set

> -Djdk.http.auth.tunneling.disabledSchemes=

to make proxies with Basic Authorization working with https along with Authenticator as mentioned in accepted answer

But, setting only that parameters, the authentication don't works.

Are necessary to add to that code the following:

final String authUser = "myuser";
final String authPassword = "secret";

System.setProperty("http.proxyHost", "hostAddress");
System.setProperty("http.proxyPort", "portNumber");
System.setProperty("http.proxyUser", authUser);
System.setProperty("http.proxyPassword", authPassword);

Authenticator.setDefault(
  new Authenticator() {
    public PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication(authUser, authPassword.toCharArray());
    }
  }
);

Try this runner I wrote. It could be helpful.

import java.io.InputStream;
import java.lang.reflect.Method;
import java.net.Authenticator;
import java.net.PasswordAuthentication;
import java.net.URL;
import java.net.URLConnection;
import java.util.Scanner;

public class ProxyAuthHelper {

    public static void main(String[] args) throws Exception {
        String tmp = System.getProperty("http.proxyUser", System.getProperty("https.proxyUser"));
        if (tmp == null) {
            System.out.println("Proxy username: ");
            tmp = new Scanner(System.in).nextLine();
        }
        final String userName = tmp;

        tmp = System.getProperty("http.proxyPassword", System.getProperty("https.proxyPassword"));
        if (tmp == null) {
            System.out.println("Proxy password: ");
            tmp = new Scanner(System.in).nextLine();
        }
        final char[] password = tmp.toCharArray();

        Authenticator.setDefault(new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                System.out.println("\n--------------\nProxy auth: " + userName);
                return new PasswordAuthentication (userName, password);
            }
        
         });

        Class<?> clazz = Class.forName(args[0]);
        Method method = clazz.getMethod("main", String[].class);
        String[] newArgs = new String[args.length - 1];
        System.arraycopy(args, 1, newArgs, 0, newArgs.length);
        method.invoke(null, new Object[]{newArgs});
    }

}