source: heimdal/vendor/current/lib/krb5/transited.c

Last change on this file was 1, checked in by Paul Smedley, 10 years ago

Initial commit of Heimdal 1.5.3
File size: 11.1 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 return krb5_enomem(context);
89 tmp->next = r->next;
90 r->next = tmp;
91 tmp->realm = strdup(p);
92 if(tmp->realm == NULL){
93 r->next = tmp->next;
94 free(tmp);
95 return krb5_enomem(context);
96 }
97 }
98 }else if(strncmp(from, to, strlen(to)) == 0){
99 p = from + strlen(from);
100 while(1){
101 while(p >= from && *p != '/') p--;
102 if(p == from)
103 return KRB5KDC_ERR_POLICY;
104
105 if(strncmp(to, from, p - from) == 0)
106 break;
107 tmp = calloc(1, sizeof(*tmp));
108 if(tmp == NULL)
109 return krb5_enomem(context);
110 tmp->next = r->next;
111 r->next = tmp;
112 tmp->realm = malloc(p - from + 1);
113 if(tmp->realm == NULL){
114 r->next = tmp->next;
115 free(tmp);
116 return krb5_enomem(context);
117 }
118 memcpy(tmp->realm, from, p - from);
119 tmp->realm[p - from] = '\0';
120 p--;
121 }
122 } else {
123 krb5_clear_error_message (context);
124 return KRB5KDC_ERR_POLICY;
125 }
126
127 return 0;
128}
129
130static int
131make_paths(krb5_context context,
132 struct tr_realm *realms, const char *client_realm,
133 const char *server_realm)
134{
135 struct tr_realm *r;
136 int ret;
137 const char *prev_realm = client_realm;
138 const char *next_realm = NULL;
139 for(r = realms; r; r = r->next){
140 /* it *might* be that you can have more than one empty
141 component in a row, at least that's how I interpret the
142 "," exception in 1510 */
143 if(r->realm[0] == '\0'){
144 while(r->next && r->next->realm[0] == '\0')
145 r = r->next;
146 if(r->next)
147 next_realm = r->next->realm;
148 else
149 next_realm = server_realm;
150 ret = make_path(context, r, prev_realm, next_realm);
151 if(ret){
152 free_realms(realms);
153 return ret;
154 }
155 }
156 prev_realm = r->realm;
157 }
158 return 0;
159}
160
161static int
162expand_realms(krb5_context context,
163 struct tr_realm *realms, const char *client_realm)
164{
165 struct tr_realm *r;
166 const char *prev_realm = NULL;
167 for(r = realms; r; r = r->next){
168 if(r->trailing_dot){
169 char *tmp;
170 size_t len;
171
172 if(prev_realm == NULL)
173 prev_realm = client_realm;
174
175 len = strlen(r->realm) + strlen(prev_realm) + 1;
176
177 tmp = realloc(r->realm, len);
178 if(tmp == NULL){
179 free_realms(realms);
180 return krb5_enomem(context);
181 }
182 r->realm = tmp;
183 strlcat(r->realm, prev_realm, len);
184 }else if(r->leading_slash && !r->leading_space && prev_realm){
185 /* yet another exception: if you use x500-names, the
186 leading realm doesn't have to be "quoted" with a space */
187 char *tmp;
188 size_t len = strlen(r->realm) + strlen(prev_realm) + 1;
189
190 tmp = malloc(len);
191 if(tmp == NULL){
192 free_realms(realms);
193 return krb5_enomem(context);
194 }
195 strlcpy(tmp, prev_realm, len);
196 strlcat(tmp, r->realm, len);
197 free(r->realm);
198 r->realm = tmp;
199 }
200 prev_realm = r->realm;
201 }
202 return 0;
203}
204
205static struct tr_realm *
206make_realm(char *realm)
207{
208 struct tr_realm *r;
209 char *p, *q;
210 int quote = 0;
211 r = calloc(1, sizeof(*r));
212 if(r == NULL){
213 free(realm);
214 return NULL;
215 }
216 r->realm = realm;
217 for(p = q = r->realm; *p; p++){
218 if(p == r->realm && *p == ' '){
219 r->leading_space = 1;
220 continue;
221 }
222 if(q == r->realm && *p == '/')
223 r->leading_slash = 1;
224 if(quote){
225 *q++ = *p;
226 quote = 0;
227 continue;
228 }
229 if(*p == '\\'){
230 quote = 1;
231 continue;
232 }
233 if(p[0] == '.' && p[1] == '\0')
234 r->trailing_dot = 1;
235 *q++ = *p;
236 }
237 *q = '\0';
238 return r;
239}
240
241static struct tr_realm*
242append_realm(struct tr_realm *head, struct tr_realm *r)
243{
244 struct tr_realm *p;
245 if(head == NULL){
246 r->next = NULL;
247 return r;
248 }
249 p = head;
250 while(p->next) p = p->next;
251 p->next = r;
252 return head;
253}
254
255static int
256decode_realms(krb5_context context,
257 const char *tr, int length, struct tr_realm **realms)
258{
259 struct tr_realm *r = NULL;
260
261 char *tmp;
262 int quote = 0;
263 const char *start = tr;
264 int i;
265
266 for(i = 0; i < length; i++){
267 if(quote){
268 quote = 0;
269 continue;
270 }
271 if(tr[i] == '\\'){
272 quote = 1;
273 continue;
274 }
275 if(tr[i] == ','){
276 tmp = malloc(tr + i - start + 1);
277 if(tmp == NULL)
278 return krb5_enomem(context);
279 memcpy(tmp, start, tr + i - start);
280 tmp[tr + i - start] = '\0';
281 r = make_realm(tmp);
282 if(r == NULL){
283 free_realms(*realms);
284 return krb5_enomem(context);
285 }
286 *realms = append_realm(*realms, r);
287 start = tr + i + 1;
288 }
289 }
290 tmp = malloc(tr + i - start + 1);
291 if(tmp == NULL){
292 free(*realms);
293 return krb5_enomem(context);
294 }
295 memcpy(tmp, start, tr + i - start);
296 tmp[tr + i - start] = '\0';
297 r = make_realm(tmp);
298 if(r == NULL){
299 free_realms(*realms);
300 return krb5_enomem(context);
301 }
302 *realms = append_realm(*realms, r);
303
304 return 0;
305}
306
307
308KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
309krb5_domain_x500_decode(krb5_context context,
310 krb5_data tr, char ***realms, unsigned int *num_realms,
311 const char *client_realm, const char *server_realm)
312{
313 struct tr_realm *r = NULL;
314 struct tr_realm *p, **q;
315 int ret;
316
317 if(tr.length == 0) {
318 *realms = NULL;
319 *num_realms = 0;
320 return 0;
321 }
322
323 /* split string in components */
324 ret = decode_realms(context, tr.data, tr.length, &r);
325 if(ret)
326 return ret;
327
328 /* apply prefix rule */
329 ret = expand_realms(context, r, client_realm);
330 if(ret)
331 return ret;
332
333 ret = make_paths(context, r, client_realm, server_realm);
334 if(ret)
335 return ret;
336
337 /* remove empty components and count realms */
338 *num_realms = 0;
339 for(q = &r; *q; ){
340 if((*q)->realm[0] == '\0'){
341 p = *q;
342 *q = (*q)->next;
343 free(p->realm);
344 free(p);
345 }else{
346 q = &(*q)->next;
347 (*num_realms)++;
348 }
349 }
350 if (*num_realms + 1 > UINT_MAX/sizeof(**realms))
351 return ERANGE;
352
353 {
354 char **R;
355 R = malloc((*num_realms + 1) * sizeof(*R));
356 if (R == NULL)
357 return krb5_enomem(context);
358 *realms = R;
359 while(r){
360 *R++ = r->realm;
361 p = r->next;
362 free(r);
363 r = p;
364 }
365 }
366 return 0;
367}
368
369KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
370krb5_domain_x500_encode(char **realms, unsigned int num_realms,
371 krb5_data *encoding)
372{
373 char *s = NULL;
374 int len = 0;
375 unsigned int i;
376 krb5_data_zero(encoding);
377 if (num_realms == 0)
378 return 0;
379 for(i = 0; i < num_realms; i++){
380 len += strlen(realms[i]);
381 if(realms[i][0] == '/')
382 len++;
383 }
384 len += num_realms - 1;
385 s = malloc(len + 1);
386 if (s == NULL)
387 return ENOMEM;
388 *s = '\0';
389 for(i = 0; i < num_realms; i++){
390 if(i)
391 strlcat(s, ",", len + 1);
392 if(realms[i][0] == '/')
393 strlcat(s, " ", len + 1);
394 strlcat(s, realms[i], len + 1);
395 }
396 encoding->data = s;
397 encoding->length = strlen(s);
398 return 0;
399}
400
401KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
402krb5_check_transited(krb5_context context,
403 krb5_const_realm client_realm,
404 krb5_const_realm server_realm,
405 krb5_realm *realms,
406 unsigned int num_realms,
407 int *bad_realm)
408{
409 char **tr_realms;
410 char **p;
411 size_t i;
412
413 if(num_realms == 0)
414 return 0;
415
416 tr_realms = krb5_config_get_strings(context, NULL,
417 "capaths",
418 client_realm,
419 server_realm,
420 NULL);
421 for(i = 0; i < num_realms; i++) {
422 for(p = tr_realms; p && *p; p++) {
423 if(strcmp(*p, realms[i]) == 0)
424 break;
425 }
426 if(p == NULL || *p == NULL) {
427 krb5_config_free_strings(tr_realms);
428 krb5_set_error_message (context, KRB5KRB_AP_ERR_ILL_CR_TKT,
429 N_("no transit allowed "
430 "through realm %s", ""),
431 realms[i]);
432 if(bad_realm)
433 *bad_realm = i;
434 return KRB5KRB_AP_ERR_ILL_CR_TKT;
435 }
436 }
437 krb5_config_free_strings(tr_realms);
438 return 0;
439}
440
441KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
442krb5_check_transited_realms(krb5_context context,
443 const char *const *realms,
444 unsigned int num_realms,
445 int *bad_realm)
446{
447 size_t i;
448 int ret = 0;
449 char **bad_realms = krb5_config_get_strings(context, NULL,
450 "libdefaults",
451 "transited_realms_reject",
452 NULL);
453 if(bad_realms == NULL)
454 return 0;
455
456 for(i = 0; i < num_realms; i++) {
457 char **p;
458 for(p = bad_realms; *p; p++)
459 if(strcmp(*p, realms[i]) == 0) {
460 ret = KRB5KRB_AP_ERR_ILL_CR_TKT;
461 krb5_set_error_message (context, ret,
462 N_("no transit allowed "
463 "through realm %s", ""),
464 *p);
465 if(bad_realm)
466 *bad_realm = i;
467 break;
468 }
469 }
470 krb5_config_free_strings(bad_realms);
471 return ret;
472}
473
474#if 0
475int
476main(int argc, char **argv)
477{
478 krb5_data x;
479 char **r;
480 int num, i;
481 x.data = argv[1];
482 x.length = strlen(x.data);
483 if(domain_expand(x, &r, &num, argv[2], argv[3]))
484 exit(1);
485 for(i = 0; i < num; i++)
486 printf("%s\n", r[i]);
487 return 0;
488}
489#endif
490
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