comparison src/net/sourceforge/jsocks/server/ServerAuthenticatorNone.java @ 0:0ce5cc452d02

initial version
author Carl Byington <carl@five-ten-sg.com>
date Thu, 22 May 2014 10:41:19 -0700
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children 205ee2873330
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-1:000000000000 0:0ce5cc452d02
1 package net.sourceforge.jsocks.server;
2 import java.io.IOException;
3 import java.io.InputStream;
4 import java.io.OutputStream;
5 import java.io.PushbackInputStream;
6 import java.net.Socket;
7
8 import net.sourceforge.jsocks.ProxyMessage;
9 import net.sourceforge.jsocks.UDPEncapsulation;
10
11 /**
12 An implementation of ServerAuthenticator, which does <b>not</b> do
13 any authentication.
14 <P>
15 <FONT size="+3" color ="FF0000"> Warning!!</font><br> Should not be
16 used on machines which are not behind the firewall.
17 <p>
18 It is only provided to make implementing other authentication schemes
19 easier.<br>
20 For Example: <tt><pre>
21 class MyAuth extends socks.server.ServerAuthenticator{
22 ...
23 public ServerAuthenticator startSession(java.net.Socket s){
24 if(!checkHost(s.getInetAddress()) return null;
25 return super.startSession(s);
26 }
27
28 boolean checkHost(java.net.Inetaddress addr){
29 boolean allow;
30 //Do it somehow
31 return allow;
32 }
33 }
34 </pre></tt>
35 */
36 public class ServerAuthenticatorNone implements ServerAuthenticator {
37
38 static final byte[] socks5response = {5, 0};
39
40 InputStream in;
41 OutputStream out;
42
43 /**
44 Creates new instance of the ServerAuthenticatorNone.
45 */
46 public ServerAuthenticatorNone() {
47 this.in = null;
48 this.out = null;
49 }
50 /**
51 Constructs new ServerAuthenticatorNone object suitable for returning
52 from the startSession function.
53 @param in Input stream to return from getInputStream method.
54 @param out Output stream to return from getOutputStream method.
55 */
56 public ServerAuthenticatorNone(InputStream in, OutputStream out) {
57 this.in = in;
58 this.out = out;
59 }
60 /**
61 Grants access to everyone.Removes authentication related bytes from
62 the stream, when a SOCKS5 connection is being made, selects an
63 authentication NONE.
64 */
65 public ServerAuthenticator startSession(Socket s)
66 throws IOException {
67 PushbackInputStream in = new PushbackInputStream(s.getInputStream());
68 OutputStream out = s.getOutputStream();
69 int version = in.read();
70
71 if (version == 5) {
72 if (!selectSocks5Authentication(in, out, 0))
73 return null;
74 }
75 else if (version == 4) {
76 //Else it is the request message allready, version 4
77 in.unread(version);
78 }
79 else
80 return null;
81
82 return new ServerAuthenticatorNone(in, out);
83 }
84
85 /**
86 Get input stream.
87 @return Input stream speciefied in the constructor.
88 */
89 public InputStream getInputStream() {
90 return in;
91 }
92 /**
93 Get output stream.
94 @return Output stream speciefied in the constructor.
95 */
96 public OutputStream getOutputStream() {
97 return out;
98 }
99 /**
100 Allways returns null.
101 @return null
102 */
103 public UDPEncapsulation getUdpEncapsulation() {
104 return null;
105 }
106
107 /**
108 Allways returns true.
109 */
110 public boolean checkRequest(ProxyMessage msg) {
111 return true;
112 }
113
114 /**
115 Allways returns true.
116 */
117 public boolean checkRequest(java.net.DatagramPacket dp, boolean out) {
118 return true;
119 }
120
121 /**
122 Does nothing.
123 */
124 public void endSession() {
125 }
126
127 /**
128 Convinience routine for selecting SOCKSv5 authentication.
129 <p>
130 This method reads in authentication methods that client supports,
131 checks wether it supports given method. If it does, the notification
132 method is written back to client, that this method have been chosen
133 for authentication. If given method was not found, authentication
134 failure message is send to client ([5,FF]).
135 @param in Input stream, version byte should be removed from the stream
136 before calling this method.
137 @param out Output stream.
138 @param methodId Method which should be selected.
139 @return true if methodId was found, false otherwise.
140 */
141 static public boolean selectSocks5Authentication(InputStream in,
142 OutputStream out,
143 int methodId)
144 throws IOException {
145 int num_methods = in.read();
146
147 if (num_methods <= 0) return false;
148
149 byte method_ids[] = new byte[num_methods];
150 byte response[] = new byte[2];
151 boolean found = false;
152 response[0] = (byte) 5; //SOCKS version
153 response[1] = (byte) 0xFF; //Not found, we are pessimistic
154 int bread = 0; //bytes read so far
155
156 while (bread < num_methods)
157 bread += in.read(method_ids, bread, num_methods - bread);
158
159 for (int i = 0; i < num_methods; ++i)
160 if (method_ids[i] == methodId) {
161 found = true;
162 response[1] = (byte) methodId;
163 break;
164 }
165
166 out.write(response);
167 return found;
168 }
169 }