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1
2 package ch.ethz.ssh2.channel;
3
4 import java.io.IOException  ;
5 import java.io.InputStream ;
6 import java.io.OutputStream ;
7 import java.net.Socket ;
8
9 import ch.ethz.ssh2.log.Logger;
10
11
17 public class RemoteX11AcceptThread extends Thread
18 {
19 private static final Logger log = Logger.getLogger(RemoteX11AcceptThread.class);
20
21 Channel c;
22
23 String remoteOriginatorAddress;
24 int remoteOriginatorPort;
25
26 Socket s;
27
28 public RemoteX11AcceptThread(Channel c, String remoteOriginatorAddress, int remoteOriginatorPort)
29 {
30 this.c = c;
31 this.remoteOriginatorAddress = remoteOriginatorAddress;
32 this.remoteOriginatorPort = remoteOriginatorPort;
33 }
34
35 public void run()
36 {
37 try
38 {
39
40
41 c.cm.sendOpenConfirmation(c);
42
43
44
45 OutputStream remote_os = c.getStdinStream();
46 InputStream remote_is = c.getStdoutStream();
47
48
55
56
79
80
81
82 byte[] header = new byte[6];
83
84 if (remote_is.read(header) != 6)
85 throw new IOException ("Unexpected EOF on X11 startup!");
86
87 if ((header[0] != 0x42) && (header[0] != 0x6c)) throw new IOException ("Unknown endian format in X11 message!");
89
90
91
92 int idxMSB = (header[0] == 0x42) ? 0 : 1;
93
94
95
96 byte[] auth_buff = new byte[6];
97
98 if (remote_is.read(auth_buff) != 6)
99 throw new IOException ("Unexpected EOF on X11 startup!");
100
101 int authProtocolNameLength = ((auth_buff[idxMSB] & 0xff) << 8) | (auth_buff[1 - idxMSB] & 0xff);
102 int authProtocolDataLength = ((auth_buff[2 + idxMSB] & 0xff) << 8) | (auth_buff[3 - idxMSB] & 0xff);
103
104 if ((authProtocolNameLength > 256) || (authProtocolDataLength > 256))
105 throw new IOException ("Buggy X11 authorization data");
106
107 int authProtocolNamePadding = ((4 - (authProtocolNameLength % 4)) % 4);
108 int authProtocolDataPadding = ((4 - (authProtocolDataLength % 4)) % 4);
109
110 byte[] authProtocolName = new byte[authProtocolNameLength];
111 byte[] authProtocolData = new byte[authProtocolDataLength];
112
113 byte[] paddingBuffer = new byte[4];
114
115 if (remote_is.read(authProtocolName) != authProtocolNameLength)
116 throw new IOException ("Unexpected EOF on X11 startup! (authProtocolName)");
117
118 if (remote_is.read(paddingBuffer, 0, authProtocolNamePadding) != authProtocolNamePadding)
119 throw new IOException ("Unexpected EOF on X11 startup! (authProtocolNamePadding)");
120
121 if (remote_is.read(authProtocolData) != authProtocolDataLength)
122 throw new IOException ("Unexpected EOF on X11 startup! (authProtocolData)");
123
124 if (remote_is.read(paddingBuffer, 0, authProtocolDataPadding) != authProtocolDataPadding)
125 throw new IOException ("Unexpected EOF on X11 startup! (authProtocolDataPadding)");
126
127 if ("MIT-MAGIC-COOKIE-1".equals(new String (authProtocolName)) == false)
128 throw new IOException ("Unknown X11 authorization protocol!");
129
130 if (authProtocolDataLength != 16)
131 throw new IOException ("Wrong data length for X11 authorization data!");
132
133 StringBuffer tmp = new StringBuffer (32);
134 for (int i = 0; i < authProtocolData.length; i++)
135 {
136 String digit2 = Integer.toHexString(authProtocolData[i] & 0xff);
137 tmp.append((digit2.length() == 2) ? digit2 : "0" + digit2);
138 }
139 String hexEncodedFakeCookie = tmp.toString();
140
141
144
145 synchronized (c)
146 {
147
148 c.hexX11FakeCookie = hexEncodedFakeCookie;
149 }
150
151
152
153 X11ServerData sd = c.cm.checkX11Cookie(hexEncodedFakeCookie);
154
155 if (sd == null)
156 throw new IOException ("Invalid X11 cookie received.");
157
158
162
163 s = new Socket (sd.hostname, sd.port);
164
165 OutputStream x11_os = s.getOutputStream();
166 InputStream x11_is = s.getInputStream();
167
168
169
170 x11_os.write(header);
171
172 if (sd.x11_magic_cookie == null)
173 {
174 byte[] emptyAuthData = new byte[6];
175
176 x11_os.write(emptyAuthData);
177 }
178 else
179 {
180 if (sd.x11_magic_cookie.length != 16)
181 throw new IOException ("The real X11 cookie has an invalid length!");
182
183
184 x11_os.write(auth_buff);
185 x11_os.write(authProtocolName);
186 x11_os.write(paddingBuffer, 0, authProtocolNamePadding);
187 x11_os.write(sd.x11_magic_cookie);
188 x11_os.write(paddingBuffer, 0, authProtocolDataPadding);
189 }
190
191 x11_os.flush();
192
193
194
195 StreamForwarder r2l = new StreamForwarder(c, null, null, remote_is, x11_os, "RemoteToX11");
196 StreamForwarder l2r = new StreamForwarder(c, null, null, x11_is, remote_os, "X11ToRemote");
197
198
199
200 r2l.setDaemon(true);
201 r2l.start();
202 l2r.run();
203
204 while (r2l.isAlive())
205 {
206 try
207 {
208 r2l.join();
209 }
210 catch (InterruptedException e)
211 {
212 }
213 }
214
215
216
217 c.cm.closeChannel(c, "EOF on both X11 streams reached.", true);
218 s.close();
219 }
220 catch (IOException e)
221 {
222 log.log(50, "IOException in X11 proxy code: " + e.getMessage());
223
224 try
225 {
226 c.cm.closeChannel(c, "IOException in X11 proxy code (" + e.getMessage() + ")", true);
227 }
228 catch (IOException e1)
229 {
230 }
231 try
232 {
233 if (s != null)
234 s.close();
235 }
236 catch (IOException e1)
237 {
238 }
239 }
240 }
241 }
242 |
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