2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
11 */
12
13#include "includes.h"
14
15#include <sys/types.h>
16
17#include <netdb.h>
18#include <pwd.h>
19#include <string.h>
20#include <stdio.h>
21#include <stdarg.h>
22
23#include "openbsd-compat/sys-queue.h"
24#include "xmalloc.h"
25#include "match.h"
26#include "log.h"
27#include "canohost.h"
28#include "buffer.h"
29#include "channels.h"
30#include "servconf.h"
31#include "misc.h"
32#include "key.h"
33#include "auth-options.h"
34#include "hostfile.h"
35#include "auth.h"
36#ifdef GSSAPI
37#include "ssh-gss.h"
38#endif
39#include "monitor_wrap.h"
40
41/* Flags set authorized_keys flags */
42int no_port_forwarding_flag = 0;
43int no_agent_forwarding_flag = 0;
44int no_x11_forwarding_flag = 0;
45int no_pty_flag = 0;
46int no_user_rc = 0;
47int key_is_cert_authority = 0;
48
49/* "command=" option. */
50char *forced_command = NULL;
51
52/* "environment=" options. */
53struct envstring *custom_environment = NULL;
54
55/* "tunnel=" option. */
56int forced_tun_device = -1;
57
58/* "principals=" option. */
59char *authorized_principals = NULL;
60
61extern ServerOptions options;
62
63void
64auth_clear_options(void)
65{
66 no_agent_forwarding_flag = 0;
67 no_port_forwarding_flag = 0;
68 no_pty_flag = 0;
69 no_x11_forwarding_flag = 0;
70 no_user_rc = 0;
71 key_is_cert_authority = 0;
72 while (custom_environment) {
73 struct envstring *ce = custom_environment;
74 custom_environment = ce->next;
75 free(ce->s);
76 free(ce);
77 }
78 if (forced_command) {
79 free(forced_command);
80 forced_command = NULL;
81 }
82 if (authorized_principals) {
83 free(authorized_principals);
84 authorized_principals = NULL;
85 }
86 forced_tun_device = -1;
87 channel_clear_permitted_opens();
88}
89
90/*
91 * return 1 if access is granted, 0 if not.
92 * side effect: sets key option flags
93 */
94int
95auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
96{
97 const char *cp;
98 int i;
99
100 /* reset options */
101 auth_clear_options();
102
103 if (!opts)
104 return 1;
105
106 while (*opts && *opts != ' ' && *opts != '\t') {
107 cp = "cert-authority";
108 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
109 key_is_cert_authority = 1;
110 opts += strlen(cp);
111 goto next_option;
112 }
113 cp = "no-port-forwarding";
114 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
115 auth_debug_add("Port forwarding disabled.");
116 no_port_forwarding_flag = 1;
117 opts += strlen(cp);
118 goto next_option;
119 }
120 cp = "no-agent-forwarding";
121 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
122 auth_debug_add("Agent forwarding disabled.");
123 no_agent_forwarding_flag = 1;
124 opts += strlen(cp);
125 goto next_option;
126 }
127 cp = "no-X11-forwarding";
128 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
129 auth_debug_add("X11 forwarding disabled.");
130 no_x11_forwarding_flag = 1;
131 opts += strlen(cp);
132 goto next_option;
133 }
134 cp = "no-pty";
135 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
136 auth_debug_add("Pty allocation disabled.");
137 no_pty_flag = 1;
138 opts += strlen(cp);
139 goto next_option;
140 }
141 cp = "no-user-rc";
142 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
143 auth_debug_add("User rc file execution disabled.");
144 no_user_rc = 1;
145 opts += strlen(cp);
146 goto next_option;
147 }
148 cp = "command=\"";
149 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
150 opts += strlen(cp);
151 if (forced_command != NULL)
152 free(forced_command);
153 forced_command = xmalloc(strlen(opts) + 1);
154 i = 0;
155 while (*opts) {
156 if (*opts == '"')
157 break;
158 if (*opts == '\\' && opts[1] == '"') {
159 opts += 2;
160 forced_command[i++] = '"';
161 continue;
162 }
163 forced_command[i++] = *opts++;
164 }
165 if (!*opts) {
166 debug("%.100s, line %lu: missing end quote",
167 file, linenum);
168 auth_debug_add("%.100s, line %lu: missing end quote",
169 file, linenum);
170 free(forced_command);
171 forced_command = NULL;
172 goto bad_option;
173 }
174 forced_command[i] = '\0';
175 auth_debug_add("Forced command.");
176 opts++;
177 goto next_option;
178 }
179 cp = "principals=\"";
180 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
181 opts += strlen(cp);
182 if (authorized_principals != NULL)
183 free(authorized_principals);
184 authorized_principals = xmalloc(strlen(opts) + 1);
185 i = 0;
186 while (*opts) {
187 if (*opts == '"')
188 break;
189 if (*opts == '\\' && opts[1] == '"') {
190 opts += 2;
191 authorized_principals[i++] = '"';
192 continue;
193 }
194 authorized_principals[i++] = *opts++;
195 }
196 if (!*opts) {
197 debug("%.100s, line %lu: missing end quote",
198 file, linenum);
199 auth_debug_add("%.100s, line %lu: missing end quote",
200 file, linenum);
201 free(authorized_principals);
202 authorized_principals = NULL;
203 goto bad_option;
204 }
205 authorized_principals[i] = '\0';
206 auth_debug_add("principals: %.900s",
207 authorized_principals);
208 opts++;
209 goto next_option;
210 }
211 cp = "environment=\"";
212 if (options.permit_user_env &&
213 strncasecmp(opts, cp, strlen(cp)) == 0) {
214 char *s;
215 struct envstring *new_envstring;
216
217 opts += strlen(cp);
218 s = xmalloc(strlen(opts) + 1);
219 i = 0;
220 while (*opts) {
221 if (*opts == '"')
222 break;
223 if (*opts == '\\' && opts[1] == '"') {
224 opts += 2;
225 s[i++] = '"';
226 continue;
227 }
228 s[i++] = *opts++;
229 }
230 if (!*opts) {
231 debug("%.100s, line %lu: missing end quote",
232 file, linenum);
233 auth_debug_add("%.100s, line %lu: missing end quote",
234 file, linenum);
235 free(s);
236 goto bad_option;
237 }
238 s[i] = '\0';
239 auth_debug_add("Adding to environment: %.900s", s);
240 debug("Adding to environment: %.900s", s);
241 opts++;
| 2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
11 */
12
13#include "includes.h"
14
15#include <sys/types.h>
16
17#include <netdb.h>
18#include <pwd.h>
19#include <string.h>
20#include <stdio.h>
21#include <stdarg.h>
22
23#include "openbsd-compat/sys-queue.h"
24#include "xmalloc.h"
25#include "match.h"
26#include "log.h"
27#include "canohost.h"
28#include "buffer.h"
29#include "channels.h"
30#include "servconf.h"
31#include "misc.h"
32#include "key.h"
33#include "auth-options.h"
34#include "hostfile.h"
35#include "auth.h"
36#ifdef GSSAPI
37#include "ssh-gss.h"
38#endif
39#include "monitor_wrap.h"
40
41/* Flags set authorized_keys flags */
42int no_port_forwarding_flag = 0;
43int no_agent_forwarding_flag = 0;
44int no_x11_forwarding_flag = 0;
45int no_pty_flag = 0;
46int no_user_rc = 0;
47int key_is_cert_authority = 0;
48
49/* "command=" option. */
50char *forced_command = NULL;
51
52/* "environment=" options. */
53struct envstring *custom_environment = NULL;
54
55/* "tunnel=" option. */
56int forced_tun_device = -1;
57
58/* "principals=" option. */
59char *authorized_principals = NULL;
60
61extern ServerOptions options;
62
63void
64auth_clear_options(void)
65{
66 no_agent_forwarding_flag = 0;
67 no_port_forwarding_flag = 0;
68 no_pty_flag = 0;
69 no_x11_forwarding_flag = 0;
70 no_user_rc = 0;
71 key_is_cert_authority = 0;
72 while (custom_environment) {
73 struct envstring *ce = custom_environment;
74 custom_environment = ce->next;
75 free(ce->s);
76 free(ce);
77 }
78 if (forced_command) {
79 free(forced_command);
80 forced_command = NULL;
81 }
82 if (authorized_principals) {
83 free(authorized_principals);
84 authorized_principals = NULL;
85 }
86 forced_tun_device = -1;
87 channel_clear_permitted_opens();
88}
89
90/*
91 * return 1 if access is granted, 0 if not.
92 * side effect: sets key option flags
93 */
94int
95auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
96{
97 const char *cp;
98 int i;
99
100 /* reset options */
101 auth_clear_options();
102
103 if (!opts)
104 return 1;
105
106 while (*opts && *opts != ' ' && *opts != '\t') {
107 cp = "cert-authority";
108 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
109 key_is_cert_authority = 1;
110 opts += strlen(cp);
111 goto next_option;
112 }
113 cp = "no-port-forwarding";
114 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
115 auth_debug_add("Port forwarding disabled.");
116 no_port_forwarding_flag = 1;
117 opts += strlen(cp);
118 goto next_option;
119 }
120 cp = "no-agent-forwarding";
121 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
122 auth_debug_add("Agent forwarding disabled.");
123 no_agent_forwarding_flag = 1;
124 opts += strlen(cp);
125 goto next_option;
126 }
127 cp = "no-X11-forwarding";
128 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
129 auth_debug_add("X11 forwarding disabled.");
130 no_x11_forwarding_flag = 1;
131 opts += strlen(cp);
132 goto next_option;
133 }
134 cp = "no-pty";
135 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
136 auth_debug_add("Pty allocation disabled.");
137 no_pty_flag = 1;
138 opts += strlen(cp);
139 goto next_option;
140 }
141 cp = "no-user-rc";
142 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
143 auth_debug_add("User rc file execution disabled.");
144 no_user_rc = 1;
145 opts += strlen(cp);
146 goto next_option;
147 }
148 cp = "command=\"";
149 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
150 opts += strlen(cp);
151 if (forced_command != NULL)
152 free(forced_command);
153 forced_command = xmalloc(strlen(opts) + 1);
154 i = 0;
155 while (*opts) {
156 if (*opts == '"')
157 break;
158 if (*opts == '\\' && opts[1] == '"') {
159 opts += 2;
160 forced_command[i++] = '"';
161 continue;
162 }
163 forced_command[i++] = *opts++;
164 }
165 if (!*opts) {
166 debug("%.100s, line %lu: missing end quote",
167 file, linenum);
168 auth_debug_add("%.100s, line %lu: missing end quote",
169 file, linenum);
170 free(forced_command);
171 forced_command = NULL;
172 goto bad_option;
173 }
174 forced_command[i] = '\0';
175 auth_debug_add("Forced command.");
176 opts++;
177 goto next_option;
178 }
179 cp = "principals=\"";
180 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
181 opts += strlen(cp);
182 if (authorized_principals != NULL)
183 free(authorized_principals);
184 authorized_principals = xmalloc(strlen(opts) + 1);
185 i = 0;
186 while (*opts) {
187 if (*opts == '"')
188 break;
189 if (*opts == '\\' && opts[1] == '"') {
190 opts += 2;
191 authorized_principals[i++] = '"';
192 continue;
193 }
194 authorized_principals[i++] = *opts++;
195 }
196 if (!*opts) {
197 debug("%.100s, line %lu: missing end quote",
198 file, linenum);
199 auth_debug_add("%.100s, line %lu: missing end quote",
200 file, linenum);
201 free(authorized_principals);
202 authorized_principals = NULL;
203 goto bad_option;
204 }
205 authorized_principals[i] = '\0';
206 auth_debug_add("principals: %.900s",
207 authorized_principals);
208 opts++;
209 goto next_option;
210 }
211 cp = "environment=\"";
212 if (options.permit_user_env &&
213 strncasecmp(opts, cp, strlen(cp)) == 0) {
214 char *s;
215 struct envstring *new_envstring;
216
217 opts += strlen(cp);
218 s = xmalloc(strlen(opts) + 1);
219 i = 0;
220 while (*opts) {
221 if (*opts == '"')
222 break;
223 if (*opts == '\\' && opts[1] == '"') {
224 opts += 2;
225 s[i++] = '"';
226 continue;
227 }
228 s[i++] = *opts++;
229 }
230 if (!*opts) {
231 debug("%.100s, line %lu: missing end quote",
232 file, linenum);
233 auth_debug_add("%.100s, line %lu: missing end quote",
234 file, linenum);
235 free(s);
236 goto bad_option;
237 }
238 s[i] = '\0';
239 auth_debug_add("Adding to environment: %.900s", s);
240 debug("Adding to environment: %.900s", s);
241 opts++;
|
243 new_envstring->s = s;
244 new_envstring->next = custom_environment;
245 custom_environment = new_envstring;
246 goto next_option;
247 }
248 cp = "from=\"";
249 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
250 const char *remote_ip = get_remote_ipaddr();
251 const char *remote_host = get_canonical_hostname(
252 options.use_dns);
253 char *patterns = xmalloc(strlen(opts) + 1);
254
255 opts += strlen(cp);
256 i = 0;
257 while (*opts) {
258 if (*opts == '"')
259 break;
260 if (*opts == '\\' && opts[1] == '"') {
261 opts += 2;
262 patterns[i++] = '"';
263 continue;
264 }
265 patterns[i++] = *opts++;
266 }
267 if (!*opts) {
268 debug("%.100s, line %lu: missing end quote",
269 file, linenum);
270 auth_debug_add("%.100s, line %lu: missing end quote",
271 file, linenum);
272 free(patterns);
273 goto bad_option;
274 }
275 patterns[i] = '\0';
276 opts++;
277 switch (match_host_and_ip(remote_host, remote_ip,
278 patterns)) {
279 case 1:
280 free(patterns);
281 /* Host name matches. */
282 goto next_option;
283 case -1:
284 debug("%.100s, line %lu: invalid criteria",
285 file, linenum);
286 auth_debug_add("%.100s, line %lu: "
287 "invalid criteria", file, linenum);
288 /* FALLTHROUGH */
289 case 0:
290 free(patterns);
291 logit("Authentication tried for %.100s with "
292 "correct key but not from a permitted "
293 "host (host=%.200s, ip=%.200s).",
294 pw->pw_name, remote_host, remote_ip);
295 auth_debug_add("Your host '%.200s' is not "
296 "permitted to use this key for login.",
297 remote_host);
298 break;
299 }
300 /* deny access */
301 return 0;
302 }
303 cp = "permitopen=\"";
304 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
305 char *host, *p;
306 int port;
307 char *patterns = xmalloc(strlen(opts) + 1);
308
309 opts += strlen(cp);
310 i = 0;
311 while (*opts) {
312 if (*opts == '"')
313 break;
314 if (*opts == '\\' && opts[1] == '"') {
315 opts += 2;
316 patterns[i++] = '"';
317 continue;
318 }
319 patterns[i++] = *opts++;
320 }
321 if (!*opts) {
322 debug("%.100s, line %lu: missing end quote",
323 file, linenum);
324 auth_debug_add("%.100s, line %lu: missing "
325 "end quote", file, linenum);
326 free(patterns);
327 goto bad_option;
328 }
329 patterns[i] = '\0';
330 opts++;
331 p = patterns;
332 host = hpdelim(&p);
333 if (host == NULL || strlen(host) >= NI_MAXHOST) {
334 debug("%.100s, line %lu: Bad permitopen "
335 "specification <%.100s>", file, linenum,
336 patterns);
337 auth_debug_add("%.100s, line %lu: "
338 "Bad permitopen specification", file,
339 linenum);
340 free(patterns);
341 goto bad_option;
342 }
343 host = cleanhostname(host);
344 if (p == NULL || (port = permitopen_port(p)) < 0) {
345 debug("%.100s, line %lu: Bad permitopen port "
346 "<%.100s>", file, linenum, p ? p : "");
347 auth_debug_add("%.100s, line %lu: "
348 "Bad permitopen port", file, linenum);
349 free(patterns);
350 goto bad_option;
351 }
352 if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0)
353 channel_add_permitted_opens(host, port);
354 free(patterns);
355 goto next_option;
356 }
357 cp = "tunnel=\"";
358 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
359 char *tun = NULL;
360 opts += strlen(cp);
361 tun = xmalloc(strlen(opts) + 1);
362 i = 0;
363 while (*opts) {
364 if (*opts == '"')
365 break;
366 tun[i++] = *opts++;
367 }
368 if (!*opts) {
369 debug("%.100s, line %lu: missing end quote",
370 file, linenum);
371 auth_debug_add("%.100s, line %lu: missing end quote",
372 file, linenum);
373 free(tun);
374 forced_tun_device = -1;
375 goto bad_option;
376 }
377 tun[i] = '\0';
378 forced_tun_device = a2tun(tun, NULL);
379 free(tun);
380 if (forced_tun_device == SSH_TUNID_ERR) {
381 debug("%.100s, line %lu: invalid tun device",
382 file, linenum);
383 auth_debug_add("%.100s, line %lu: invalid tun device",
384 file, linenum);
385 forced_tun_device = -1;
386 goto bad_option;
387 }
388 auth_debug_add("Forced tun device: %d", forced_tun_device);
389 opts++;
390 goto next_option;
391 }
392next_option:
393 /*
394 * Skip the comma, and move to the next option
395 * (or break out if there are no more).
396 */
397 if (!*opts)
398 fatal("Bugs in auth-options.c option processing.");
399 if (*opts == ' ' || *opts == '\t')
400 break; /* End of options. */
401 if (*opts != ',')
402 goto bad_option;
403 opts++;
404 /* Process the next option. */
405 }
406
407 /* grant access */
408 return 1;
409
410bad_option:
411 logit("Bad options in %.100s file, line %lu: %.50s",
412 file, linenum, opts);
413 auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
414 file, linenum, opts);
415
416 /* deny access */
417 return 0;
418}
419
420#define OPTIONS_CRITICAL 1
421#define OPTIONS_EXTENSIONS 2
422static int
423parse_option_list(u_char *optblob, size_t optblob_len, struct passwd *pw,
424 u_int which, int crit,
425 int *cert_no_port_forwarding_flag,
426 int *cert_no_agent_forwarding_flag,
427 int *cert_no_x11_forwarding_flag,
428 int *cert_no_pty_flag,
429 int *cert_no_user_rc,
430 char **cert_forced_command,
431 int *cert_source_address_done)
432{
433 char *command, *allowed;
434 const char *remote_ip;
435 char *name = NULL;
436 u_char *data_blob = NULL;
437 u_int nlen, dlen, clen;
438 Buffer c, data;
439 int ret = -1, found;
440
441 buffer_init(&data);
442
443 /* Make copy to avoid altering original */
444 buffer_init(&c);
445 buffer_append(&c, optblob, optblob_len);
446
447 while (buffer_len(&c) > 0) {
448 if ((name = buffer_get_cstring_ret(&c, &nlen)) == NULL ||
449 (data_blob = buffer_get_string_ret(&c, &dlen)) == NULL) {
450 error("Certificate options corrupt");
451 goto out;
452 }
453 buffer_append(&data, data_blob, dlen);
454 debug3("found certificate option \"%.100s\" len %u",
455 name, dlen);
456 found = 0;
457 if ((which & OPTIONS_EXTENSIONS) != 0) {
458 if (strcmp(name, "permit-X11-forwarding") == 0) {
459 *cert_no_x11_forwarding_flag = 0;
460 found = 1;
461 } else if (strcmp(name,
462 "permit-agent-forwarding") == 0) {
463 *cert_no_agent_forwarding_flag = 0;
464 found = 1;
465 } else if (strcmp(name,
466 "permit-port-forwarding") == 0) {
467 *cert_no_port_forwarding_flag = 0;
468 found = 1;
469 } else if (strcmp(name, "permit-pty") == 0) {
470 *cert_no_pty_flag = 0;
471 found = 1;
472 } else if (strcmp(name, "permit-user-rc") == 0) {
473 *cert_no_user_rc = 0;
474 found = 1;
475 }
476 }
477 if (!found && (which & OPTIONS_CRITICAL) != 0) {
478 if (strcmp(name, "force-command") == 0) {
479 if ((command = buffer_get_cstring_ret(&data,
480 &clen)) == NULL) {
481 error("Certificate constraint \"%s\" "
482 "corrupt", name);
483 goto out;
484 }
485 if (*cert_forced_command != NULL) {
486 error("Certificate has multiple "
487 "force-command options");
488 free(command);
489 goto out;
490 }
491 *cert_forced_command = command;
492 found = 1;
493 }
494 if (strcmp(name, "source-address") == 0) {
495 if ((allowed = buffer_get_cstring_ret(&data,
496 &clen)) == NULL) {
497 error("Certificate constraint "
498 "\"%s\" corrupt", name);
499 goto out;
500 }
501 if ((*cert_source_address_done)++) {
502 error("Certificate has multiple "
503 "source-address options");
504 free(allowed);
505 goto out;
506 }
507 remote_ip = get_remote_ipaddr();
508 switch (addr_match_cidr_list(remote_ip,
509 allowed)) {
510 case 1:
511 /* accepted */
512 free(allowed);
513 break;
514 case 0:
515 /* no match */
516 logit("Authentication tried for %.100s "
517 "with valid certificate but not "
518 "from a permitted host "
519 "(ip=%.200s).", pw->pw_name,
520 remote_ip);
521 auth_debug_add("Your address '%.200s' "
522 "is not permitted to use this "
523 "certificate for login.",
524 remote_ip);
525 free(allowed);
526 goto out;
527 case -1:
528 error("Certificate source-address "
529 "contents invalid");
530 free(allowed);
531 goto out;
532 }
533 found = 1;
534 }
535 }
536
537 if (!found) {
538 if (crit) {
539 error("Certificate critical option \"%s\" "
540 "is not supported", name);
541 goto out;
542 } else {
543 logit("Certificate extension \"%s\" "
544 "is not supported", name);
545 }
546 } else if (buffer_len(&data) != 0) {
547 error("Certificate option \"%s\" corrupt "
548 "(extra data)", name);
549 goto out;
550 }
551 buffer_clear(&data);
552 free(name);
553 free(data_blob);
554 name = NULL;
555 data_blob = NULL;
556 }
557 /* successfully parsed all options */
558 ret = 0;
559
560 out:
561 if (ret != 0 &&
562 cert_forced_command != NULL &&
563 *cert_forced_command != NULL) {
564 free(*cert_forced_command);
565 *cert_forced_command = NULL;
566 }
567 if (name != NULL)
568 free(name);
569 if (data_blob != NULL)
570 free(data_blob);
571 buffer_free(&data);
572 buffer_free(&c);
573 return ret;
574}
575
576/*
577 * Set options from critical certificate options. These supersede user key
578 * options so this must be called after auth_parse_options().
579 */
580int
581auth_cert_options(Key *k, struct passwd *pw)
582{
583 int cert_no_port_forwarding_flag = 1;
584 int cert_no_agent_forwarding_flag = 1;
585 int cert_no_x11_forwarding_flag = 1;
586 int cert_no_pty_flag = 1;
587 int cert_no_user_rc = 1;
588 char *cert_forced_command = NULL;
589 int cert_source_address_done = 0;
590
591 if (key_cert_is_legacy(k)) {
592 /* All options are in the one field for v00 certs */
593 if (parse_option_list(buffer_ptr(&k->cert->critical),
594 buffer_len(&k->cert->critical), pw,
595 OPTIONS_CRITICAL|OPTIONS_EXTENSIONS, 1,
596 &cert_no_port_forwarding_flag,
597 &cert_no_agent_forwarding_flag,
598 &cert_no_x11_forwarding_flag,
599 &cert_no_pty_flag,
600 &cert_no_user_rc,
601 &cert_forced_command,
602 &cert_source_address_done) == -1)
603 return -1;
604 } else {
605 /* Separate options and extensions for v01 certs */
606 if (parse_option_list(buffer_ptr(&k->cert->critical),
607 buffer_len(&k->cert->critical), pw,
608 OPTIONS_CRITICAL, 1, NULL, NULL, NULL, NULL, NULL,
609 &cert_forced_command,
610 &cert_source_address_done) == -1)
611 return -1;
612 if (parse_option_list(buffer_ptr(&k->cert->extensions),
613 buffer_len(&k->cert->extensions), pw,
614 OPTIONS_EXTENSIONS, 1,
615 &cert_no_port_forwarding_flag,
616 &cert_no_agent_forwarding_flag,
617 &cert_no_x11_forwarding_flag,
618 &cert_no_pty_flag,
619 &cert_no_user_rc,
620 NULL, NULL) == -1)
621 return -1;
622 }
623
624 no_port_forwarding_flag |= cert_no_port_forwarding_flag;
625 no_agent_forwarding_flag |= cert_no_agent_forwarding_flag;
626 no_x11_forwarding_flag |= cert_no_x11_forwarding_flag;
627 no_pty_flag |= cert_no_pty_flag;
628 no_user_rc |= cert_no_user_rc;
629 /* CA-specified forced command supersedes key option */
630 if (cert_forced_command != NULL) {
631 if (forced_command != NULL)
632 free(forced_command);
633 forced_command = cert_forced_command;
634 }
635 return 0;
636}
637
| 243 new_envstring->s = s;
244 new_envstring->next = custom_environment;
245 custom_environment = new_envstring;
246 goto next_option;
247 }
248 cp = "from=\"";
249 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
250 const char *remote_ip = get_remote_ipaddr();
251 const char *remote_host = get_canonical_hostname(
252 options.use_dns);
253 char *patterns = xmalloc(strlen(opts) + 1);
254
255 opts += strlen(cp);
256 i = 0;
257 while (*opts) {
258 if (*opts == '"')
259 break;
260 if (*opts == '\\' && opts[1] == '"') {
261 opts += 2;
262 patterns[i++] = '"';
263 continue;
264 }
265 patterns[i++] = *opts++;
266 }
267 if (!*opts) {
268 debug("%.100s, line %lu: missing end quote",
269 file, linenum);
270 auth_debug_add("%.100s, line %lu: missing end quote",
271 file, linenum);
272 free(patterns);
273 goto bad_option;
274 }
275 patterns[i] = '\0';
276 opts++;
277 switch (match_host_and_ip(remote_host, remote_ip,
278 patterns)) {
279 case 1:
280 free(patterns);
281 /* Host name matches. */
282 goto next_option;
283 case -1:
284 debug("%.100s, line %lu: invalid criteria",
285 file, linenum);
286 auth_debug_add("%.100s, line %lu: "
287 "invalid criteria", file, linenum);
288 /* FALLTHROUGH */
289 case 0:
290 free(patterns);
291 logit("Authentication tried for %.100s with "
292 "correct key but not from a permitted "
293 "host (host=%.200s, ip=%.200s).",
294 pw->pw_name, remote_host, remote_ip);
295 auth_debug_add("Your host '%.200s' is not "
296 "permitted to use this key for login.",
297 remote_host);
298 break;
299 }
300 /* deny access */
301 return 0;
302 }
303 cp = "permitopen=\"";
304 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
305 char *host, *p;
306 int port;
307 char *patterns = xmalloc(strlen(opts) + 1);
308
309 opts += strlen(cp);
310 i = 0;
311 while (*opts) {
312 if (*opts == '"')
313 break;
314 if (*opts == '\\' && opts[1] == '"') {
315 opts += 2;
316 patterns[i++] = '"';
317 continue;
318 }
319 patterns[i++] = *opts++;
320 }
321 if (!*opts) {
322 debug("%.100s, line %lu: missing end quote",
323 file, linenum);
324 auth_debug_add("%.100s, line %lu: missing "
325 "end quote", file, linenum);
326 free(patterns);
327 goto bad_option;
328 }
329 patterns[i] = '\0';
330 opts++;
331 p = patterns;
332 host = hpdelim(&p);
333 if (host == NULL || strlen(host) >= NI_MAXHOST) {
334 debug("%.100s, line %lu: Bad permitopen "
335 "specification <%.100s>", file, linenum,
336 patterns);
337 auth_debug_add("%.100s, line %lu: "
338 "Bad permitopen specification", file,
339 linenum);
340 free(patterns);
341 goto bad_option;
342 }
343 host = cleanhostname(host);
344 if (p == NULL || (port = permitopen_port(p)) < 0) {
345 debug("%.100s, line %lu: Bad permitopen port "
346 "<%.100s>", file, linenum, p ? p : "");
347 auth_debug_add("%.100s, line %lu: "
348 "Bad permitopen port", file, linenum);
349 free(patterns);
350 goto bad_option;
351 }
352 if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0)
353 channel_add_permitted_opens(host, port);
354 free(patterns);
355 goto next_option;
356 }
357 cp = "tunnel=\"";
358 if (strncasecmp(opts, cp, strlen(cp)) == 0) {
359 char *tun = NULL;
360 opts += strlen(cp);
361 tun = xmalloc(strlen(opts) + 1);
362 i = 0;
363 while (*opts) {
364 if (*opts == '"')
365 break;
366 tun[i++] = *opts++;
367 }
368 if (!*opts) {
369 debug("%.100s, line %lu: missing end quote",
370 file, linenum);
371 auth_debug_add("%.100s, line %lu: missing end quote",
372 file, linenum);
373 free(tun);
374 forced_tun_device = -1;
375 goto bad_option;
376 }
377 tun[i] = '\0';
378 forced_tun_device = a2tun(tun, NULL);
379 free(tun);
380 if (forced_tun_device == SSH_TUNID_ERR) {
381 debug("%.100s, line %lu: invalid tun device",
382 file, linenum);
383 auth_debug_add("%.100s, line %lu: invalid tun device",
384 file, linenum);
385 forced_tun_device = -1;
386 goto bad_option;
387 }
388 auth_debug_add("Forced tun device: %d", forced_tun_device);
389 opts++;
390 goto next_option;
391 }
392next_option:
393 /*
394 * Skip the comma, and move to the next option
395 * (or break out if there are no more).
396 */
397 if (!*opts)
398 fatal("Bugs in auth-options.c option processing.");
399 if (*opts == ' ' || *opts == '\t')
400 break; /* End of options. */
401 if (*opts != ',')
402 goto bad_option;
403 opts++;
404 /* Process the next option. */
405 }
406
407 /* grant access */
408 return 1;
409
410bad_option:
411 logit("Bad options in %.100s file, line %lu: %.50s",
412 file, linenum, opts);
413 auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
414 file, linenum, opts);
415
416 /* deny access */
417 return 0;
418}
419
420#define OPTIONS_CRITICAL 1
421#define OPTIONS_EXTENSIONS 2
422static int
423parse_option_list(u_char *optblob, size_t optblob_len, struct passwd *pw,
424 u_int which, int crit,
425 int *cert_no_port_forwarding_flag,
426 int *cert_no_agent_forwarding_flag,
427 int *cert_no_x11_forwarding_flag,
428 int *cert_no_pty_flag,
429 int *cert_no_user_rc,
430 char **cert_forced_command,
431 int *cert_source_address_done)
432{
433 char *command, *allowed;
434 const char *remote_ip;
435 char *name = NULL;
436 u_char *data_blob = NULL;
437 u_int nlen, dlen, clen;
438 Buffer c, data;
439 int ret = -1, found;
440
441 buffer_init(&data);
442
443 /* Make copy to avoid altering original */
444 buffer_init(&c);
445 buffer_append(&c, optblob, optblob_len);
446
447 while (buffer_len(&c) > 0) {
448 if ((name = buffer_get_cstring_ret(&c, &nlen)) == NULL ||
449 (data_blob = buffer_get_string_ret(&c, &dlen)) == NULL) {
450 error("Certificate options corrupt");
451 goto out;
452 }
453 buffer_append(&data, data_blob, dlen);
454 debug3("found certificate option \"%.100s\" len %u",
455 name, dlen);
456 found = 0;
457 if ((which & OPTIONS_EXTENSIONS) != 0) {
458 if (strcmp(name, "permit-X11-forwarding") == 0) {
459 *cert_no_x11_forwarding_flag = 0;
460 found = 1;
461 } else if (strcmp(name,
462 "permit-agent-forwarding") == 0) {
463 *cert_no_agent_forwarding_flag = 0;
464 found = 1;
465 } else if (strcmp(name,
466 "permit-port-forwarding") == 0) {
467 *cert_no_port_forwarding_flag = 0;
468 found = 1;
469 } else if (strcmp(name, "permit-pty") == 0) {
470 *cert_no_pty_flag = 0;
471 found = 1;
472 } else if (strcmp(name, "permit-user-rc") == 0) {
473 *cert_no_user_rc = 0;
474 found = 1;
475 }
476 }
477 if (!found && (which & OPTIONS_CRITICAL) != 0) {
478 if (strcmp(name, "force-command") == 0) {
479 if ((command = buffer_get_cstring_ret(&data,
480 &clen)) == NULL) {
481 error("Certificate constraint \"%s\" "
482 "corrupt", name);
483 goto out;
484 }
485 if (*cert_forced_command != NULL) {
486 error("Certificate has multiple "
487 "force-command options");
488 free(command);
489 goto out;
490 }
491 *cert_forced_command = command;
492 found = 1;
493 }
494 if (strcmp(name, "source-address") == 0) {
495 if ((allowed = buffer_get_cstring_ret(&data,
496 &clen)) == NULL) {
497 error("Certificate constraint "
498 "\"%s\" corrupt", name);
499 goto out;
500 }
501 if ((*cert_source_address_done)++) {
502 error("Certificate has multiple "
503 "source-address options");
504 free(allowed);
505 goto out;
506 }
507 remote_ip = get_remote_ipaddr();
508 switch (addr_match_cidr_list(remote_ip,
509 allowed)) {
510 case 1:
511 /* accepted */
512 free(allowed);
513 break;
514 case 0:
515 /* no match */
516 logit("Authentication tried for %.100s "
517 "with valid certificate but not "
518 "from a permitted host "
519 "(ip=%.200s).", pw->pw_name,
520 remote_ip);
521 auth_debug_add("Your address '%.200s' "
522 "is not permitted to use this "
523 "certificate for login.",
524 remote_ip);
525 free(allowed);
526 goto out;
527 case -1:
528 error("Certificate source-address "
529 "contents invalid");
530 free(allowed);
531 goto out;
532 }
533 found = 1;
534 }
535 }
536
537 if (!found) {
538 if (crit) {
539 error("Certificate critical option \"%s\" "
540 "is not supported", name);
541 goto out;
542 } else {
543 logit("Certificate extension \"%s\" "
544 "is not supported", name);
545 }
546 } else if (buffer_len(&data) != 0) {
547 error("Certificate option \"%s\" corrupt "
548 "(extra data)", name);
549 goto out;
550 }
551 buffer_clear(&data);
552 free(name);
553 free(data_blob);
554 name = NULL;
555 data_blob = NULL;
556 }
557 /* successfully parsed all options */
558 ret = 0;
559
560 out:
561 if (ret != 0 &&
562 cert_forced_command != NULL &&
563 *cert_forced_command != NULL) {
564 free(*cert_forced_command);
565 *cert_forced_command = NULL;
566 }
567 if (name != NULL)
568 free(name);
569 if (data_blob != NULL)
570 free(data_blob);
571 buffer_free(&data);
572 buffer_free(&c);
573 return ret;
574}
575
576/*
577 * Set options from critical certificate options. These supersede user key
578 * options so this must be called after auth_parse_options().
579 */
580int
581auth_cert_options(Key *k, struct passwd *pw)
582{
583 int cert_no_port_forwarding_flag = 1;
584 int cert_no_agent_forwarding_flag = 1;
585 int cert_no_x11_forwarding_flag = 1;
586 int cert_no_pty_flag = 1;
587 int cert_no_user_rc = 1;
588 char *cert_forced_command = NULL;
589 int cert_source_address_done = 0;
590
591 if (key_cert_is_legacy(k)) {
592 /* All options are in the one field for v00 certs */
593 if (parse_option_list(buffer_ptr(&k->cert->critical),
594 buffer_len(&k->cert->critical), pw,
595 OPTIONS_CRITICAL|OPTIONS_EXTENSIONS, 1,
596 &cert_no_port_forwarding_flag,
597 &cert_no_agent_forwarding_flag,
598 &cert_no_x11_forwarding_flag,
599 &cert_no_pty_flag,
600 &cert_no_user_rc,
601 &cert_forced_command,
602 &cert_source_address_done) == -1)
603 return -1;
604 } else {
605 /* Separate options and extensions for v01 certs */
606 if (parse_option_list(buffer_ptr(&k->cert->critical),
607 buffer_len(&k->cert->critical), pw,
608 OPTIONS_CRITICAL, 1, NULL, NULL, NULL, NULL, NULL,
609 &cert_forced_command,
610 &cert_source_address_done) == -1)
611 return -1;
612 if (parse_option_list(buffer_ptr(&k->cert->extensions),
613 buffer_len(&k->cert->extensions), pw,
614 OPTIONS_EXTENSIONS, 1,
615 &cert_no_port_forwarding_flag,
616 &cert_no_agent_forwarding_flag,
617 &cert_no_x11_forwarding_flag,
618 &cert_no_pty_flag,
619 &cert_no_user_rc,
620 NULL, NULL) == -1)
621 return -1;
622 }
623
624 no_port_forwarding_flag |= cert_no_port_forwarding_flag;
625 no_agent_forwarding_flag |= cert_no_agent_forwarding_flag;
626 no_x11_forwarding_flag |= cert_no_x11_forwarding_flag;
627 no_pty_flag |= cert_no_pty_flag;
628 no_user_rc |= cert_no_user_rc;
629 /* CA-specified forced command supersedes key option */
630 if (cert_forced_command != NULL) {
631 if (forced_command != NULL)
632 free(forced_command);
633 forced_command = cert_forced_command;
634 }
635 return 0;
636}
637
|