source: trunk/server/source4/heimdal/lib/krb5/transited.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 12.4 KB
Line 
1/*
2 * Copyright (c) 1997 - 2001, 2003 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35
36/* this is an attempt at one of the most horrible `compression'
37 schemes that has ever been invented; it's so amazingly brain-dead
38 that words can not describe it, and all this just to save a few
39 silly bytes */
40
41struct tr_realm {
42 char *realm;
43 unsigned leading_space:1;
44 unsigned leading_slash:1;
45 unsigned trailing_dot:1;
46 struct tr_realm *next;
47};
48
49static void
50free_realms(struct tr_realm *r)
51{
52 struct tr_realm *p;
53 while(r){
54 p = r;
55 r = r->next;
56 free(p->realm);
57 free(p);
58 }
59}
60
61static int
62make_path(krb5_context context, struct tr_realm *r,
63 const char *from, const char *to)
64{
65 struct tr_realm *tmp;
66 const char *p;
67
68 if(strlen(from) < strlen(to)){
69 const char *str;
70 str = from;
71 from = to;
72 to = str;
73 }
74
75 if(strcmp(from + strlen(from) - strlen(to), to) == 0){
76 p = from;
77 while(1){
78 p = strchr(p, '.');
79 if(p == NULL) {
80 krb5_clear_error_message (context);
81 return KRB5KDC_ERR_POLICY;
82 }
83 p++;
84 if(strcmp(p, to) == 0)
85 break;
86 tmp = calloc(1, sizeof(*tmp));
87 if(tmp == NULL){
88 krb5_set_error_message(context, ENOMEM,
89 N_("malloc: out of memory", ""));
90 return ENOMEM;
91 }
92 tmp->next = r->next;
93 r->next = tmp;
94 tmp->realm = strdup(p);
95 if(tmp->realm == NULL){
96 r->next = tmp->next;
97 free(tmp);
98 krb5_set_error_message(context, ENOMEM,
99 N_("malloc: out of memory", ""));
100 return ENOMEM;;
101 }
102 }
103 }else if(strncmp(from, to, strlen(to)) == 0){
104 p = from + strlen(from);
105 while(1){
106 while(p >= from && *p != '/') p--;
107 if(p == from)
108 return KRB5KDC_ERR_POLICY;
109
110 if(strncmp(to, from, p - from) == 0)
111 break;
112 tmp = calloc(1, sizeof(*tmp));
113 if(tmp == NULL){
114 krb5_set_error_message(context, ENOMEM,
115 N_("malloc: out of memory", ""));
116 return ENOMEM;
117 }
118 tmp->next = r->next;
119 r->next = tmp;
120 tmp->realm = malloc(p - from + 1);
121 if(tmp->realm == NULL){
122 r->next = tmp->next;
123 free(tmp);
124 krb5_set_error_message(context, ENOMEM,
125 N_("malloc: out of memory", ""));
126 return ENOMEM;
127 }
128 memcpy(tmp->realm, from, p - from);
129 tmp->realm[p - from] = '\0';
130 p--;
131 }
132 } else {
133 krb5_clear_error_message (context);
134 return KRB5KDC_ERR_POLICY;
135 }
136
137 return 0;
138}
139
140static int
141make_paths(krb5_context context,
142 struct tr_realm *realms, const char *client_realm,
143 const char *server_realm)
144{
145 struct tr_realm *r;
146 int ret;
147 const char *prev_realm = client_realm;
148 const char *next_realm = NULL;
149 for(r = realms; r; r = r->next){
150 /* it *might* be that you can have more than one empty
151 component in a row, at least that's how I interpret the
152 "," exception in 1510 */
153 if(r->realm[0] == '\0'){
154 while(r->next && r->next->realm[0] == '\0')
155 r = r->next;
156 if(r->next)
157 next_realm = r->next->realm;
158 else
159 next_realm = server_realm;
160 ret = make_path(context, r, prev_realm, next_realm);
161 if(ret){
162 free_realms(realms);
163 return ret;
164 }
165 }
166 prev_realm = r->realm;
167 }
168 return 0;
169}
170
171static int
172expand_realms(krb5_context context,
173 struct tr_realm *realms, const char *client_realm)
174{
175 struct tr_realm *r;
176 const char *prev_realm = NULL;
177 for(r = realms; r; r = r->next){
178 if(r->trailing_dot){
179 char *tmp;
180 size_t len;
181
182 if(prev_realm == NULL)
183 prev_realm = client_realm;
184
185 len = strlen(r->realm) + strlen(prev_realm) + 1;
186
187 tmp = realloc(r->realm, len);
188 if(tmp == NULL){
189 free_realms(realms);
190 krb5_set_error_message(context, ENOMEM,
191 N_("malloc: out of memory", ""));
192 return ENOMEM;
193 }
194 r->realm = tmp;
195 strlcat(r->realm, prev_realm, len);
196 }else if(r->leading_slash && !r->leading_space && prev_realm){
197 /* yet another exception: if you use x500-names, the
198 leading realm doesn't have to be "quoted" with a space */
199 char *tmp;
200 size_t len = strlen(r->realm) + strlen(prev_realm) + 1;
201
202 tmp = malloc(len);
203 if(tmp == NULL){
204 free_realms(realms);
205 krb5_set_error_message(context, ENOMEM,
206 N_("malloc: out of memory", ""));
207 return ENOMEM;
208 }
209 strlcpy(tmp, prev_realm, len);
210 strlcat(tmp, r->realm, len);
211 free(r->realm);
212 r->realm = tmp;
213 }
214 prev_realm = r->realm;
215 }
216 return 0;
217}
218
219static struct tr_realm *
220make_realm(char *realm)
221{
222 struct tr_realm *r;
223 char *p, *q;
224 int quote = 0;
225 r = calloc(1, sizeof(*r));
226 if(r == NULL){
227 free(realm);
228 return NULL;
229 }
230 r->realm = realm;
231 for(p = q = r->realm; *p; p++){
232 if(p == r->realm && *p == ' '){
233 r->leading_space = 1;
234 continue;
235 }
236 if(q == r->realm && *p == '/')
237 r->leading_slash = 1;
238 if(quote){
239 *q++ = *p;
240 quote = 0;
241 continue;
242 }
243 if(*p == '\\'){
244 quote = 1;
245 continue;
246 }
247 if(p[0] == '.' && p[1] == '\0')
248 r->trailing_dot = 1;
249 *q++ = *p;
250 }
251 *q = '\0';
252 return r;
253}
254
255static struct tr_realm*
256append_realm(struct tr_realm *head, struct tr_realm *r)
257{
258 struct tr_realm *p;
259 if(head == NULL){
260 r->next = NULL;
261 return r;
262 }
263 p = head;
264 while(p->next) p = p->next;
265 p->next = r;
266 return head;
267}
268
269static int
270decode_realms(krb5_context context,
271 const char *tr, int length, struct tr_realm **realms)
272{
273 struct tr_realm *r = NULL;
274
275 char *tmp;
276 int quote = 0;
277 const char *start = tr;
278 int i;
279
280 for(i = 0; i < length; i++){
281 if(quote){
282 quote = 0;
283 continue;
284 }
285 if(tr[i] == '\\'){
286 quote = 1;
287 continue;
288 }
289 if(tr[i] == ','){
290 tmp = malloc(tr + i - start + 1);
291 if(tmp == NULL){
292 krb5_set_error_message(context, ENOMEM,
293 N_("malloc: out of memory", ""));
294 return ENOMEM;
295 }
296 memcpy(tmp, start, tr + i - start);
297 tmp[tr + i - start] = '\0';
298 r = make_realm(tmp);
299 if(r == NULL){
300 free_realms(*realms);
301 krb5_set_error_message(context, ENOMEM,
302 N_("malloc: out of memory", ""));
303 return ENOMEM;
304 }
305 *realms = append_realm(*realms, r);
306 start = tr + i + 1;
307 }
308 }
309 tmp = malloc(tr + i - start + 1);
310 if(tmp == NULL){
311 free(*realms);
312 krb5_set_error_message(context, ENOMEM,
313 N_("malloc: out of memory", ""));
314 return ENOMEM;
315 }
316 memcpy(tmp, start, tr + i - start);
317 tmp[tr + i - start] = '\0';
318 r = make_realm(tmp);
319 if(r == NULL){
320 free_realms(*realms);
321 krb5_set_error_message(context, ENOMEM,
322 N_("malloc: out of memory", ""));
323 return ENOMEM;
324 }
325 *realms = append_realm(*realms, r);
326
327 return 0;
328}
329
330
331KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
332krb5_domain_x500_decode(krb5_context context,
333 krb5_data tr, char ***realms, unsigned int *num_realms,
334 const char *client_realm, const char *server_realm)
335{
336 struct tr_realm *r = NULL;
337 struct tr_realm *p, **q;
338 int ret;
339
340 if(tr.length == 0) {
341 *realms = NULL;
342 *num_realms = 0;
343 return 0;
344 }
345
346 /* split string in components */
347 ret = decode_realms(context, tr.data, tr.length, &r);
348 if(ret)
349 return ret;
350
351 /* apply prefix rule */
352 ret = expand_realms(context, r, client_realm);
353 if(ret)
354 return ret;
355
356 ret = make_paths(context, r, client_realm, server_realm);
357 if(ret)
358 return ret;
359
360 /* remove empty components and count realms */
361 *num_realms = 0;
362 for(q = &r; *q; ){
363 if((*q)->realm[0] == '\0'){
364 p = *q;
365 *q = (*q)->next;
366 free(p->realm);
367 free(p);
368 }else{
369 q = &(*q)->next;
370 (*num_realms)++;
371 }
372 }
373 if (*num_realms < 0 || *num_realms + 1 > UINT_MAX/sizeof(**realms))
374 return ERANGE;
375
376 {
377 char **R;
378 R = malloc((*num_realms + 1) * sizeof(*R));
379 if (R == NULL)
380 return ENOMEM;
381 *realms = R;
382 while(r){
383 *R++ = r->realm;
384 p = r->next;
385 free(r);
386 r = p;
387 }
388 }
389 return 0;
390}
391
392KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
393krb5_domain_x500_encode(char **realms, unsigned int num_realms,
394 krb5_data *encoding)
395{
396 char *s = NULL;
397 int len = 0;
398 unsigned int i;
399 krb5_data_zero(encoding);
400 if (num_realms == 0)
401 return 0;
402 for(i = 0; i < num_realms; i++){
403 len += strlen(realms[i]);
404 if(realms[i][0] == '/')
405 len++;
406 }
407 len += num_realms - 1;
408 s = malloc(len + 1);
409 if (s == NULL)
410 return ENOMEM;
411 *s = '\0';
412 for(i = 0; i < num_realms; i++){
413 if(i && i < num_realms - 1)
414 strlcat(s, ",", len + 1);
415 if(realms[i][0] == '/')
416 strlcat(s, " ", len + 1);
417 strlcat(s, realms[i], len + 1);
418 }
419 encoding->data = s;
420 encoding->length = strlen(s);
421 return 0;
422}
423
424KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
425krb5_check_transited(krb5_context context,
426 krb5_const_realm client_realm,
427 krb5_const_realm server_realm,
428 krb5_realm *realms,
429 unsigned int num_realms,
430 int *bad_realm)
431{
432 char **tr_realms;
433 char **p;
434 int i;
435
436 if(num_realms == 0)
437 return 0;
438
439 tr_realms = krb5_config_get_strings(context, NULL,
440 "capaths",
441 client_realm,
442 server_realm,
443 NULL);
444 for(i = 0; i < num_realms; i++) {
445 for(p = tr_realms; p && *p; p++) {
446 if(strcmp(*p, realms[i]) == 0)
447 break;
448 }
449 if(p == NULL || *p == NULL) {
450 krb5_config_free_strings(tr_realms);
451 krb5_set_error_message (context, KRB5KRB_AP_ERR_ILL_CR_TKT,
452 N_("no transit allowed "
453 "through realm %s", ""),
454 realms[i]);
455 if(bad_realm)
456 *bad_realm = i;
457 return KRB5KRB_AP_ERR_ILL_CR_TKT;
458 }
459 }
460 krb5_config_free_strings(tr_realms);
461 return 0;
462}
463
464KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
465krb5_check_transited_realms(krb5_context context,
466 const char *const *realms,
467 unsigned int num_realms,
468 int *bad_realm)
469{
470 int i;
471 int ret = 0;
472 char **bad_realms = krb5_config_get_strings(context, NULL,
473 "libdefaults",
474 "transited_realms_reject",
475 NULL);
476 if(bad_realms == NULL)
477 return 0;
478
479 for(i = 0; i < num_realms; i++) {
480 char **p;
481 for(p = bad_realms; *p; p++)
482 if(strcmp(*p, realms[i]) == 0) {
483 ret = KRB5KRB_AP_ERR_ILL_CR_TKT;
484 krb5_set_error_message (context, ret,
485 N_("no transit allowed "
486 "through realm %s", ""),
487 *p);
488 if(bad_realm)
489 *bad_realm = i;
490 break;
491 }
492 }
493 krb5_config_free_strings(bad_realms);
494 return ret;
495}
496
497#if 0
498int
499main(int argc, char **argv)
500{
501 krb5_data x;
502 char **r;
503 int num, i;
504 x.data = argv[1];
505 x.length = strlen(x.data);
506 if(domain_expand(x, &r, &num, argv[2], argv[3]))
507 exit(1);
508 for(i = 0; i < num; i++)
509 printf("%s\n", r[i]);
510 return 0;
511}
512#endif
513
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