--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/net/sourceforge/jsocks/server/IdentAuthenticator.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,150 @@
+package net.sourceforge.jsocks.server;
+import net.sourceforge.jsocks.InetRange;
+import net.sourceforge.jsocks.ProxyMessage;
+import java.util.Hashtable;
+import java.util.Vector;
+import java.util.Enumeration;
+import java.net.*;
+import java.io.*;
+
+/**
+  An implementation of socks.ServerAuthentication which provides
+  simple authentication based on the host from which the connection
+  is made and the name of the user on the remote machine, as reported
+  by identd daemon on the remote machine.
+  <p>
+  It can also be used to provide authentication based only on the contacting
+  host address.
+*/
+
+public class IdentAuthenticator extends ServerAuthenticatorNone{
+   /** Vector of InetRanges */
+   Vector hosts;
+
+   /** Vector of user hashes*/
+   Vector users;
+
+   String user;
+
+
+   /**
+    Constructs empty IdentAuthenticator.
+   */
+   public IdentAuthenticator(){
+      hosts = new Vector();
+      users = new Vector();
+   }
+   /**
+    Used to create instances returned from startSession.
+    @param in Input stream.
+    @param out OutputStream.
+    @param user Username associated with this connection,could be
+                null if name was not required.
+   */
+   IdentAuthenticator(InputStream in,OutputStream out, String user){
+      super(in,out);
+      this.user = user;
+   }
+
+   /**
+    Adds range of addresses from which connection is allowed. Hashtable
+    users should contain user names as keys and anything as values
+    (value is not used and will be ignored). 
+    @param hostRange Range of ip addresses from which connection is allowed.
+    @param users Hashtable of users for whom connection is allowed, or null
+    to indicate that anybody is allowed to connect from the hosts within given
+    range.
+   */
+   public synchronized void add(InetRange hostRange,Hashtable users){
+      this.hosts.addElement(hostRange);
+      this.users.addElement(users);
+   }
+
+   /**
+     Grants permission only to those users, who connect from one of the
+     hosts registered with add(InetRange,Hashtable) and whose names, as
+     reported by identd daemon, are listed for the host the connection
+     came from.
+    */
+   public ServerAuthenticator startSession(Socket s)
+                              throws IOException{
+
+     int ind = getRangeIndex(s.getInetAddress());
+     String user = null;
+
+     //System.out.println("getRangeReturned:"+ind);
+
+     if(ind < 0) return null; //Host is not on the list.
+
+     ServerAuthenticatorNone auth = (ServerAuthenticatorNone)
+                                    super.startSession(s);
+
+     //System.out.println("super.startSession() returned:"+auth);
+     if(auth == null) return null;
+
+     //do the authentication 
+
+     Hashtable user_names = (Hashtable) users.elementAt(ind); 
+
+     if(user_names != null){ //If need to do authentication
+       Ident ident;
+       ident = new Ident(s);
+       //If can't obtain user name, fail
+       if(!ident.successful) return null;
+       //If user name is not listed for this address, fail
+       if(!user_names.containsKey(ident.userName)) return null;
+       user = ident.userName;
+     }
+     return new IdentAuthenticator(auth.in,auth.out,user);
+
+   }
+   /**
+    For SOCKS5 requests allways returns true. For SOCKS4 requests
+    checks wether the user name supplied in the request corresponds
+    to the name obtained from the ident daemon.
+   */
+   public boolean checkRequest(ProxyMessage msg,java.net.Socket s){
+     //If it's version 5 request, or if anybody is permitted, return true;
+     if(msg.version == 5 || user == null) 
+       return true;
+
+     if(msg.version != 4) return false; //Who knows?
+
+     return user.equals(msg.user);
+   }
+
+  /** Get String representaion of the IdentAuthenticator.*/
+  public String toString(){
+     String s = "";
+
+     for(int i=0;i<hosts.size();++i)
+        s += "Range:"+hosts.elementAt(i)+"\nUsers:"+userNames(i)+"\n";
+     return s;
+  }
+
+//Private Methods
+//////////////////
+  private int getRangeIndex(InetAddress ip){
+     int index = 0;
+     Enumeration eEnum = hosts.elements();
+     while(eEnum.hasMoreElements()){
+       InetRange ir = (InetRange) eEnum.nextElement();
+       if(ir.contains(ip)) return index;
+       index++;
+     }
+     return -1; //Not found
+  }
+
+  private String userNames(int i){
+    if(users.elementAt(i) == null) return "Everybody is permitted.";
+
+    Enumeration eEnum = ((Hashtable)users.elementAt(i)).keys();
+    if(!eEnum.hasMoreElements()) return "";
+    String s = eEnum.nextElement().toString();
+    while(eEnum.hasMoreElements())
+       s += "; "+eEnum.nextElement();
+
+    return s;
+  }
+
+}