--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/net/sourceforge/jsocks/Socks4Message.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,157 @@
+package net.sourceforge.jsocks;
+import java.io.*;
+import java.net.*;
+
+/**
+  SOCKS4 Reply/Request message.
+*/
+
+public class Socks4Message extends ProxyMessage{
+
+   private byte[] msgBytes;
+   private int msgLength;
+
+   /**
+    * Server failed reply, cmd command for failed request
+    */
+   public Socks4Message(int cmd){
+      super(cmd,null,0);
+      this.user    = null;
+
+      msgLength = 2;
+      msgBytes = new byte[2];
+
+      msgBytes[0] = (byte) 0;
+      msgBytes[1] = (byte) command;
+   }
+
+   /**
+    *  Server successfull reply
+    */
+   public Socks4Message(int cmd,InetAddress ip,int port){
+      this(0,cmd,ip,port,null);
+   }
+
+   /**
+    *  Client request
+    */
+   public Socks4Message(int cmd,InetAddress ip,int port,String user){
+      this(SOCKS_VERSION,cmd,ip,port,user);
+   }
+
+   /**
+    * Most general constructor
+    */
+   public Socks4Message(int version, int cmd,
+                        InetAddress ip,int port,String user){
+      super(cmd,ip,port);
+      this.user    = user;
+      this.version = version;
+
+      msgLength = user == null?8:9+user.length();
+      msgBytes = new byte[msgLength];
+
+      msgBytes[0] = (byte) version;
+      msgBytes[1] = (byte) command;
+      msgBytes[2] = (byte) (port >> 8);
+      msgBytes[3] = (byte) port;
+
+      byte[] addr;
+
+      if(ip != null)
+        addr = ip.getAddress();
+      else{
+        addr = new byte[4];
+        addr[0]=addr[1]=addr[2]=addr[3]=0;
+      }
+      System.arraycopy(addr,0,msgBytes,4,4);
+
+      if(user != null){
+         byte[] buf = user.getBytes();
+         System.arraycopy(buf,0,msgBytes,8,buf.length);
+         msgBytes[msgBytes.length -1 ] = 0;
+      }
+   }
+
+   /**
+    *Initialise from the stream
+    *If clientMode is true attempts to read a server response
+    *otherwise reads a client request
+    *see read for more detail
+    */
+   public Socks4Message(InputStream in, boolean clientMode) throws IOException{
+      msgBytes = null;
+      read(in,clientMode);
+   }
+
+   public void read(InputStream in) throws IOException{
+        read(in,true);
+   }
+
+   public void read(InputStream in, boolean clientMode) throws IOException{
+       DataInputStream d_in = new DataInputStream(in);
+       version= d_in.readUnsignedByte();
+       command = d_in.readUnsignedByte();
+       if(clientMode && command != REPLY_OK){
+          String errMsg;
+          if(command >REPLY_OK && command < REPLY_BAD_IDENTD)
+             errMsg = replyMessage[command-REPLY_OK];
+          else
+             errMsg = "Unknown Reply Code";
+          throw new SocksException(command,errMsg);
+       }
+       port = d_in.readUnsignedShort();
+       byte[] addr = new byte[4];
+       d_in.readFully(addr);
+       ip=bytes2IP(addr);
+       host = ip.getHostName();
+       if(!clientMode){
+          int b = in.read();
+          //Hope there are no idiots with user name bigger than this
+          byte[] userBytes = new byte[256];
+          int i = 0;
+          for(i =0;i<userBytes.length && b>0;++i){
+             userBytes[i] = (byte) b;
+             b = in.read();
+          }
+          user = new String(userBytes,0,i);
+       }
+   }
+   public void write(OutputStream out) throws IOException{
+      if(msgBytes == null){
+         Socks4Message msg = new Socks4Message(version,command,ip,port,user);
+         msgBytes = msg.msgBytes;
+         msgLength = msg.msgLength;
+      }
+      out.write(msgBytes);
+   }
+
+   //Class methods
+   static InetAddress bytes2IP(byte[] addr){
+      String s = bytes2IPV4(addr,0);
+      try{
+         return InetAddress.getByName(s);
+      }catch(UnknownHostException uh_ex){
+        return null;
+      }
+   }
+
+   //Constants
+
+   static final String[] replyMessage ={
+          "Request Granted",
+          "Request Rejected or Failed",
+          "Failed request, can't connect to Identd",
+          "Failed request, bad user name"};
+
+   static final int SOCKS_VERSION = 4;
+
+   public final static int REQUEST_CONNECT		= 1;
+   public final static int REQUEST_BIND   		= 2;
+
+   public final static int REPLY_OK 			= 90;
+   public final static int REPLY_REJECTED		= 91;
+   public final static int REPLY_NO_CONNECT		= 92;
+   public final static int REPLY_BAD_IDENTD		= 93;
+
+}