1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
|
<?php
/** * Pure-PHP ssh-agent client. * * PHP versions 4 and 5 * * Here are some examples of how to use this library: * <code> * <?php * include 'System/SSH/Agent.php'; * include 'Net/SSH2.php'; * * $agent = new System_SSH_Agent(); * * $ssh = new Net_SSH2('www.domain.tld'); * if (!$ssh->login('username', $agent)) { * exit('Login Failed'); * } * * echo $ssh->exec('pwd'); * echo $ssh->exec('ls -la'); * ?> * </code> * * LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * * @category System * @package System_SSH_Agent * @author Jim Wigginton <terrafrost@php.net> * @copyright 2014 Jim Wigginton * @license http://www.opensource.org/licenses/mit-license.html MIT License * @link http://phpseclib.sourceforge.net * @internal See http://api.libssh.org/rfc/PROTOCOL.agent */
/**#@+ * Message numbers * * @access private */ // to request SSH1 keys you have to use SSH_AGENTC_REQUEST_RSA_IDENTITIES (1) define('SYSTEM_SSH_AGENTC_REQUEST_IDENTITIES', 11); // this is the SSH2 response; the SSH1 response is SSH_AGENT_RSA_IDENTITIES_ANSWER (2). define('SYSTEM_SSH_AGENT_IDENTITIES_ANSWER', 12); define('SYSTEM_SSH_AGENT_FAILURE', 5); // the SSH1 request is SSH_AGENTC_RSA_CHALLENGE (3) define('SYSTEM_SSH_AGENTC_SIGN_REQUEST', 13); // the SSH1 response is SSH_AGENT_RSA_RESPONSE (4) define('SYSTEM_SSH_AGENT_SIGN_RESPONSE', 14);
/**@+ * Agent forwarding status * * @access private */ // no forwarding requested and not active define('SYSTEM_SSH_AGENT_FORWARD_NONE', 0); // request agent forwarding when opportune define('SYSTEM_SSH_AGENT_FORWARD_REQUEST', 1); // forwarding has been request and is active define('SYSTEM_SSH_AGENT_FORWARD_ACTIVE', 2);
/**#@-*/
/** * Pure-PHP ssh-agent client identity object * * Instantiation should only be performed by System_SSH_Agent class. * This could be thought of as implementing an interface that Crypt_RSA * implements. ie. maybe a Net_SSH_Auth_PublicKey interface or something. * The methods in this interface would be getPublicKey, setSignatureMode * and sign since those are the methods phpseclib looks for to perform * public key authentication. * * @package System_SSH_Agent * @author Jim Wigginton <terrafrost@php.net> * @access internal */ class System_SSH_Agent_Identity { /** * Key Object * * @var Crypt_RSA * @access private * @see self::getPublicKey() */ var $key;
/** * Key Blob * * @var string * @access private * @see self::sign() */ var $key_blob;
/** * Socket Resource * * @var resource * @access private * @see self::sign() */ var $fsock;
/** * Default Constructor. * * @param resource $fsock * @return System_SSH_Agent_Identity * @access private */ function System_SSH_Agent_Identity($fsock) { $this->fsock = $fsock; }
/** * Set Public Key * * Called by System_SSH_Agent::requestIdentities() * * @param Crypt_RSA $key * @access private */ function setPublicKey($key) { $this->key = $key; $this->key->setPublicKey(); }
/** * Set Public Key * * Called by System_SSH_Agent::requestIdentities(). The key blob could be extracted from $this->key * but this saves a small amount of computation. * * @param string $key_blob * @access private */ function setPublicKeyBlob($key_blob) { $this->key_blob = $key_blob; }
/** * Get Public Key * * Wrapper for $this->key->getPublicKey() * * @param int $format optional * @return mixed * @access public */ function getPublicKey($format = null) { return !isset($format) ? $this->key->getPublicKey() : $this->key->getPublicKey($format); }
/** * Set Signature Mode * * Doesn't do anything as ssh-agent doesn't let you pick and choose the signature mode. ie. * ssh-agent's only supported mode is CRYPT_RSA_SIGNATURE_PKCS1 * * @param int $mode * @access public */ function setSignatureMode($mode) { }
/** * Create a signature * * See "2.6.2 Protocol 2 private key signature request" * * @param string $message * @return string * @access public */ function sign($message) { // the last parameter (currently 0) is for flags and ssh-agent only defines one flag (for ssh-dss): SSH_AGENT_OLD_SIGNATURE $packet = pack('CNa*Na*N', SYSTEM_SSH_AGENTC_SIGN_REQUEST, strlen($this->key_blob), $this->key_blob, strlen($message), $message, 0); $packet = pack('Na*', strlen($packet), $packet); if (strlen($packet) != fputs($this->fsock, $packet)) { user_error('Connection closed during signing'); }
$length = current(unpack('N', fread($this->fsock, 4))); $type = ord(fread($this->fsock, 1)); if ($type != SYSTEM_SSH_AGENT_SIGN_RESPONSE) { user_error('Unable to retreive signature'); }
$signature_blob = fread($this->fsock, $length - 1); // the only other signature format defined - ssh-dss - is the same length as ssh-rsa // the + 12 is for the other various SSH added length fields return substr($signature_blob, strlen('ssh-rsa') + 12); } }
/** * Pure-PHP ssh-agent client identity factory * * requestIdentities() method pumps out System_SSH_Agent_Identity objects * * @package System_SSH_Agent * @author Jim Wigginton <terrafrost@php.net> * @access internal */ class System_SSH_Agent { /** * Socket Resource * * @var resource * @access private */ var $fsock;
/** * Agent forwarding status * * @access private */ var $forward_status = SYSTEM_SSH_AGENT_FORWARD_NONE;
/** * Buffer for accumulating forwarded authentication * agent data arriving on SSH data channel destined * for agent unix socket * * @access private */ var $socket_buffer = '';
/** * Tracking the number of bytes we are expecting * to arrive for the agent socket on the SSH data * channel */ var $expected_bytes = 0;
/** * Default Constructor * * @return System_SSH_Agent * @access public */ function System_SSH_Agent() { switch (true) { case isset($_SERVER['SSH_AUTH_SOCK']): $address = $_SERVER['SSH_AUTH_SOCK']; break; case isset($_ENV['SSH_AUTH_SOCK']): $address = $_ENV['SSH_AUTH_SOCK']; break; default: user_error('SSH_AUTH_SOCK not found'); return false; }
$this->fsock = fsockopen('unix://' . $address, 0, $errno, $errstr); if (!$this->fsock) { user_error("Unable to connect to ssh-agent (Error $errno: $errstr)"); } }
/** * Request Identities * * See "2.5.2 Requesting a list of protocol 2 keys" * Returns an array containing zero or more System_SSH_Agent_Identity objects * * @return array * @access public */ function requestIdentities() { if (!$this->fsock) { return array(); }
$packet = pack('NC', 1, SYSTEM_SSH_AGENTC_REQUEST_IDENTITIES); if (strlen($packet) != fputs($this->fsock, $packet)) { user_error('Connection closed while requesting identities'); }
$length = current(unpack('N', fread($this->fsock, 4))); $type = ord(fread($this->fsock, 1)); if ($type != SYSTEM_SSH_AGENT_IDENTITIES_ANSWER) { user_error('Unable to request identities'); }
$identities = array(); $keyCount = current(unpack('N', fread($this->fsock, 4))); for ($i = 0; $i < $keyCount; $i++) { $length = current(unpack('N', fread($this->fsock, 4))); $key_blob = fread($this->fsock, $length); $length = current(unpack('N', fread($this->fsock, 4))); if ($length) { $key_comment = fread($this->fsock, $length); } $length = current(unpack('N', substr($key_blob, 0, 4))); $key_type = substr($key_blob, 4, $length); switch ($key_type) { case 'ssh-rsa': if (!class_exists('Crypt_RSA')) { include_once 'Crypt/RSA.php'; } $key = new Crypt_RSA(); $key->loadKey('ssh-rsa ' . base64_encode($key_blob) . ' ' . $key_comment); break; case 'ssh-dss': // not currently supported break; } // resources are passed by reference by default if (isset($key)) { $identity = new System_SSH_Agent_Identity($this->fsock); $identity->setPublicKey($key); $identity->setPublicKeyBlob($key_blob); $identities[] = $identity; unset($key); } }
return $identities; }
/** * Signal that agent forwarding should * be requested when a channel is opened * * @param Net_SSH2 $ssh * @return bool * @access public */ function startSSHForwarding($ssh) { if ($this->forward_status == SYSTEM_SSH_AGENT_FORWARD_NONE) { $this->forward_status = SYSTEM_SSH_AGENT_FORWARD_REQUEST; } }
/** * Request agent forwarding of remote server * * @param Net_SSH2 $ssh * @return bool * @access private */ function _request_forwarding($ssh) { $request_channel = $ssh->_get_open_channel(); if ($request_channel === false) { return false; }
$packet = pack( 'CNNa*C', NET_SSH2_MSG_CHANNEL_REQUEST, $ssh->server_channels[$request_channel], strlen('auth-agent-req@openssh.com'), 'auth-agent-req@openssh.com', 1 );
$ssh->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_REQUEST;
if (!$ssh->_send_binary_packet($packet)) { return false; }
$response = $ssh->_get_channel_packet($request_channel); if ($response === false) { return false; }
$ssh->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_OPEN; $this->forward_status = SYSTEM_SSH_AGENT_FORWARD_ACTIVE;
return true; }
/** * On successful channel open * * This method is called upon successful channel * open to give the SSH Agent an opportunity * to take further action. i.e. request agent forwarding * * @param Net_SSH2 $ssh * @access private */ function _on_channel_open($ssh) { if ($this->forward_status == SYSTEM_SSH_AGENT_FORWARD_REQUEST) { $this->_request_forwarding($ssh); } }
/** * Forward data to SSH Agent and return data reply * * @param string $data * @return data from SSH Agent * @access private */ function _forward_data($data) { if ($this->expected_bytes > 0) { $this->socket_buffer.= $data; $this->expected_bytes -= strlen($data); } else { $agent_data_bytes = current(unpack('N', $data)); $current_data_bytes = strlen($data); $this->socket_buffer = $data; if ($current_data_bytes != $agent_data_bytes + 4) { $this->expected_bytes = ($agent_data_bytes + 4) - $current_data_bytes; return false; } }
if (strlen($this->socket_buffer) != fwrite($this->fsock, $this->socket_buffer)) { user_error('Connection closed attempting to forward data to SSH agent'); }
$this->socket_buffer = ''; $this->expected_bytes = 0;
$agent_reply_bytes = current(unpack('N', fread($this->fsock, 4)));
$agent_reply_data = fread($this->fsock, $agent_reply_bytes); $agent_reply_data = current(unpack('a*', $agent_reply_data));
return pack('Na*', $agent_reply_bytes, $agent_reply_data); } }
|