--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/net/sourceforge/jsocks/server/UserPasswordAuthenticator.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,73 @@
+package net.sourceforge.jsocks.server;
+
+import net.sourceforge.jsocks.ProxyMessage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.Socket;
+
+/**
+  This class implements SOCKS5 User/Password authentication scheme as
+  defined in rfc1929,the server side of it.
+*/
+public class UserPasswordAuthenticator extends  ServerAuthenticatorNone{
+
+   static final int METHOD_ID = 2;
+
+   UserValidation validator;
+
+   /**
+    Construct a new UserPasswordAuthentication object, with given
+    UserVlaidation scheme.
+
+    @param v UserValidation to use for validating users.
+   */
+   public UserPasswordAuthenticator(UserValidation validator){
+      this.validator = validator;
+   }
+
+   public ServerAuthenticator startSession(Socket s) throws IOException{
+     InputStream in = s.getInputStream();
+     OutputStream out = s.getOutputStream();
+
+     if(in.read() != 5) return null; //Drop non version 5 messages.
+
+     if(!selectSocks5Authentication(in,out,METHOD_ID)) 
+       return null;
+     if(!doUserPasswordAuthentication(s,in,out))
+       return null;
+
+     return new ServerAuthenticatorNone(in,out);
+   }
+
+
+//Private Methods
+//////////////////
+
+   private boolean doUserPasswordAuthentication(Socket s,
+                                                InputStream in,
+                                                OutputStream out) 
+                                                throws IOException{
+     int version = in.read();
+     if(version != 1) return false;
+     int ulen = in.read();
+     if(ulen < 0) return false;
+     byte[] user = new byte[ulen];
+     in.read(user);
+     int plen = in.read();
+     if(plen < 0) return false;
+     byte[] password = new byte[plen];
+     in.read(password);
+
+     if(validator.isUserValid(new String(user), new String(password),s)){
+       //System.out.println("user valid");
+       out.write(new byte[]{1,0});
+     }else{
+       //System.out.println("user invalid");
+       out.write(new byte[]{1,1});
+       return false;
+     }
+
+     return true;
+   }
+}