1 /* pcy_tree.c */
2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
3 * project 2004.
4 */
5 /* ====================================================================
6 * Copyright (c) 2004 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59 #include "cryptlib.h"
60 #include <openssl/x509.h>
61 #include <openssl/x509v3.h>
62
63 #include "pcy_int.h"
64
65 /* Initialize policy tree. Return values:
66 * 0 Some internal error occured.
67 * -1 Inconsistent or invalid extensions in certificates.
68 * 1 Tree initialized OK.
69 * 2 Policy tree is empty.
70 * 5 Tree OK and requireExplicitPolicy true.
71 * 6 Tree empty and requireExplicitPolicy true.
72 */
73
tree_init(X509_POLICY_TREE ** ptree,STACK_OF (X509)* certs,unsigned int flags)74 static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
75 unsigned int flags)
76 {
77 X509_POLICY_TREE *tree;
78 X509_POLICY_LEVEL *level;
79 const X509_POLICY_CACHE *cache;
80 X509_POLICY_DATA *data = NULL;
81 X509 *x;
82 int ret = 1;
83 int i, n;
84 int explicit_policy;
85 int any_skip;
86 int map_skip;
87 *ptree = NULL;
88 n = sk_X509_num(certs);
89
90 /* Disable policy mapping for now... */
91 flags |= X509_V_FLAG_INHIBIT_MAP;
92
93 if (flags & X509_V_FLAG_EXPLICIT_POLICY)
94 explicit_policy = 0;
95 else
96 explicit_policy = n + 1;
97
98 if (flags & X509_V_FLAG_INHIBIT_ANY)
99 any_skip = 0;
100 else
101 any_skip = n + 1;
102
103 if (flags & X509_V_FLAG_INHIBIT_MAP)
104 map_skip = 0;
105 else
106 map_skip = n + 1;
107
108 /* Can't do anything with just a trust anchor */
109 if (n == 1)
110 return 1;
111 /* First setup policy cache in all certificates apart from the
112 * trust anchor. Note any bad cache results on the way. Also can
113 * calculate explicit_policy value at this point.
114 */
115 for (i = n - 2; i >= 0; i--)
116 {
117 x = sk_X509_value(certs, i);
118 X509_check_purpose(x, -1, -1);
119 cache = policy_cache_set(x);
120 /* If cache NULL something bad happened: return immediately */
121 if (cache == NULL)
122 return 0;
123 /* If inconsistent extensions keep a note of it but continue */
124 if (x->ex_flags & EXFLAG_INVALID_POLICY)
125 ret = -1;
126 /* Otherwise if we have no data (hence no CertificatePolicies)
127 * and haven't already set an inconsistent code note it.
128 */
129 else if ((ret == 1) && !cache->data)
130 ret = 2;
131 if (explicit_policy > 0)
132 {
133 explicit_policy--;
134 if (!(x->ex_flags & EXFLAG_SS)
135 && (cache->explicit_skip != -1)
136 && (cache->explicit_skip < explicit_policy))
137 explicit_policy = cache->explicit_skip;
138 }
139 }
140
141 if (ret != 1)
142 {
143 if (ret == 2 && !explicit_policy)
144 return 6;
145 return ret;
146 }
147
148
149 /* If we get this far initialize the tree */
150
151 tree = OPENSSL_malloc(sizeof(X509_POLICY_TREE));
152
153 if (!tree)
154 return 0;
155
156 tree->flags = 0;
157 tree->levels = OPENSSL_malloc(sizeof(X509_POLICY_LEVEL) * n);
158 tree->nlevel = 0;
159 tree->extra_data = NULL;
160 tree->auth_policies = NULL;
161 tree->user_policies = NULL;
162
163 if (!tree)
164 {
165 OPENSSL_free(tree);
166 return 0;
167 }
168
169 memset(tree->levels, 0, n * sizeof(X509_POLICY_LEVEL));
170
171 tree->nlevel = n;
172
173 level = tree->levels;
174
175 /* Root data: initialize to anyPolicy */
176
177 data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0);
178
179 if (!data || !level_add_node(level, data, NULL, tree))
180 goto bad_tree;
181
182 for (i = n - 2; i >= 0; i--)
183 {
184 level++;
185 x = sk_X509_value(certs, i);
186 cache = policy_cache_set(x);
187
188 CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
189 level->cert = x;
190
191 if (!cache->anyPolicy)
192 level->flags |= X509_V_FLAG_INHIBIT_ANY;
193
194 /* Determine inhibit any and inhibit map flags */
195 if (any_skip == 0)
196 {
197 /* Any matching allowed if certificate is self
198 * issued and not the last in the chain.
199 */
200 if (!(x->ex_flags & EXFLAG_SS) || (i == 0))
201 level->flags |= X509_V_FLAG_INHIBIT_ANY;
202 }
203 else
204 {
205 any_skip--;
206 if ((cache->any_skip > 0)
207 && (cache->any_skip < any_skip))
208 any_skip = cache->any_skip;
209 }
210
211 if (map_skip == 0)
212 level->flags |= X509_V_FLAG_INHIBIT_MAP;
213 else
214 {
215 map_skip--;
216 if ((cache->map_skip > 0)
217 && (cache->map_skip < map_skip))
218 map_skip = cache->map_skip;
219 }
220
221
222 }
223
224 *ptree = tree;
225
226 if (explicit_policy)
227 return 1;
228 else
229 return 5;
230
231 bad_tree:
232
233 X509_policy_tree_free(tree);
234
235 return 0;
236
237 }
238
239 /* This corresponds to RFC3280 XXXX XXXXX:
240 * link any data from CertificatePolicies onto matching parent
241 * or anyPolicy if no match.
242 */
243
tree_link_nodes(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache)244 static int tree_link_nodes(X509_POLICY_LEVEL *curr,
245 const X509_POLICY_CACHE *cache)
246 {
247 int i;
248 X509_POLICY_LEVEL *last;
249 X509_POLICY_DATA *data;
250 X509_POLICY_NODE *parent;
251 last = curr - 1;
252 for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++)
253 {
254 data = sk_X509_POLICY_DATA_value(cache->data, i);
255 /* If a node is mapped any it doesn't have a corresponding
256 * CertificatePolicies entry.
257 * However such an identical node would be created
258 * if anyPolicy matching is enabled because there would be
259 * no match with the parent valid_policy_set. So we create
260 * link because then it will have the mapping flags
261 * right and we can prune it later.
262 */
263 if ((data->flags & POLICY_DATA_FLAG_MAPPED_ANY)
264 && !(curr->flags & X509_V_FLAG_INHIBIT_ANY))
265 continue;
266 /* Look for matching node in parent */
267 parent = level_find_node(last, data->valid_policy);
268 /* If no match link to anyPolicy */
269 if (!parent)
270 parent = last->anyPolicy;
271 if (parent && !level_add_node(curr, data, parent, NULL))
272 return 0;
273 }
274 return 1;
275 }
276
277 /* This corresponds to RFC3280 XXXX XXXXX:
278 * Create new data for any unmatched policies in the parent and link
279 * to anyPolicy.
280 */
281
tree_link_any(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_TREE * tree)282 static int tree_link_any(X509_POLICY_LEVEL *curr,
283 const X509_POLICY_CACHE *cache,
284 X509_POLICY_TREE *tree)
285 {
286 int i;
287 X509_POLICY_DATA *data;
288 X509_POLICY_NODE *node;
289 X509_POLICY_LEVEL *last;
290
291 last = curr - 1;
292
293 for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++)
294 {
295 node = sk_X509_POLICY_NODE_value(last->nodes, i);
296
297 /* Skip any node with any children: we only want unmathced
298 * nodes.
299 *
300 * Note: need something better for policy mapping
301 * because each node may have multiple children
302 */
303 if (node->nchild)
304 continue;
305 /* Create a new node with qualifiers from anyPolicy and
306 * id from unmatched node.
307 */
308 data = policy_data_new(NULL, node->data->valid_policy,
309 node_critical(node));
310
311 if (data == NULL)
312 return 0;
313 data->qualifier_set = curr->anyPolicy->data->qualifier_set;
314 data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
315 if (!level_add_node(curr, data, node, tree))
316 {
317 policy_data_free(data);
318 return 0;
319 }
320 }
321 /* Finally add link to anyPolicy */
322 if (last->anyPolicy)
323 {
324 if (!level_add_node(curr, cache->anyPolicy,
325 last->anyPolicy, NULL))
326 return 0;
327 }
328 return 1;
329 }
330
331 /* Prune the tree: delete any child mapped child data on the current level
332 * then proceed up the tree deleting any data with no children. If we ever
333 * have no data on a level we can halt because the tree will be empty.
334 */
335
tree_prune(X509_POLICY_TREE * tree,X509_POLICY_LEVEL * curr)336 static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
337 {
338 X509_POLICY_NODE *node;
339 int i;
340 for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)
341 {
342 node = sk_X509_POLICY_NODE_value(curr->nodes, i);
343 /* Delete any mapped data: see RFC3280 XXXX */
344 if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK)
345 {
346 node->parent->nchild--;
347 OPENSSL_free(node);
348 (void)sk_X509_POLICY_NODE_delete(curr->nodes, i);
349 }
350 }
351
352 for(;;) {
353 --curr;
354 for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)
355 {
356 node = sk_X509_POLICY_NODE_value(curr->nodes, i);
357 if (node->nchild == 0)
358 {
359 node->parent->nchild--;
360 OPENSSL_free(node);
361 (void)sk_X509_POLICY_NODE_delete(curr->nodes, i);
362 }
363 }
364 if (curr->anyPolicy && !curr->anyPolicy->nchild)
365 {
366 if (curr->anyPolicy->parent)
367 curr->anyPolicy->parent->nchild--;
368 OPENSSL_free(curr->anyPolicy);
369 curr->anyPolicy = NULL;
370 }
371 if (curr == tree->levels)
372 {
373 /* If we zapped anyPolicy at top then tree is empty */
374 if (!curr->anyPolicy)
375 return 2;
376 return 1;
377 }
378 }
379
380 return 1;
381
382 }
383
tree_add_auth_node(STACK_OF (X509_POLICY_NODE)** pnodes,X509_POLICY_NODE * pcy)384 static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
385 X509_POLICY_NODE *pcy)
386 {
387 if (!*pnodes)
388 {
389 *pnodes = policy_node_cmp_new();
390 if (!*pnodes)
391 return 0;
392 }
393 else if (sk_X509_POLICY_NODE_find(*pnodes, pcy) != -1)
394 return 1;
395
396 if (!sk_X509_POLICY_NODE_push(*pnodes, pcy))
397 return 0;
398
399 return 1;
400
401 }
402
403 /* Calculate the authority set based on policy tree.
404 * The 'pnodes' parameter is used as a store for the set of policy nodes
405 * used to calculate the user set. If the authority set is not anyPolicy
406 * then pnodes will just point to the authority set. If however the authority
407 * set is anyPolicy then the set of valid policies (other than anyPolicy)
408 * is store in pnodes. The return value of '2' is used in this case to indicate
409 * that pnodes should be freed.
410 */
411
tree_calculate_authority_set(X509_POLICY_TREE * tree,STACK_OF (X509_POLICY_NODE)** pnodes)412 static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
413 STACK_OF(X509_POLICY_NODE) **pnodes)
414 {
415 X509_POLICY_LEVEL *curr;
416 X509_POLICY_NODE *node, *anyptr;
417 STACK_OF(X509_POLICY_NODE) **addnodes;
418 int i, j;
419 curr = tree->levels + tree->nlevel - 1;
420
421 /* If last level contains anyPolicy set is anyPolicy */
422 if (curr->anyPolicy)
423 {
424 if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
425 return 0;
426 addnodes = pnodes;
427 }
428 else
429 /* Add policies to authority set */
430 addnodes = &tree->auth_policies;
431
432 curr = tree->levels;
433 for (i = 1; i < tree->nlevel; i++)
434 {
435 /* If no anyPolicy node on this this level it can't
436 * appear on lower levels so end search.
437 */
438 if (!(anyptr = curr->anyPolicy))
439 break;
440 curr++;
441 for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++)
442 {
443 node = sk_X509_POLICY_NODE_value(curr->nodes, j);
444 if ((node->parent == anyptr)
445 && !tree_add_auth_node(addnodes, node))
446 return 0;
447 }
448 }
449
450 if (addnodes == pnodes)
451 return 2;
452
453 *pnodes = tree->auth_policies;
454
455 return 1;
456 }
457
tree_calculate_user_set(X509_POLICY_TREE * tree,STACK_OF (ASN1_OBJECT)* policy_oids,STACK_OF (X509_POLICY_NODE)* auth_nodes)458 static int tree_calculate_user_set(X509_POLICY_TREE *tree,
459 STACK_OF(ASN1_OBJECT) *policy_oids,
460 STACK_OF(X509_POLICY_NODE) *auth_nodes)
461 {
462 int i;
463 X509_POLICY_NODE *node;
464 ASN1_OBJECT *oid;
465
466 X509_POLICY_NODE *anyPolicy;
467 X509_POLICY_DATA *extra;
468
469 /* Check if anyPolicy present in authority constrained policy set:
470 * this will happen if it is a leaf node.
471 */
472
473 if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
474 return 1;
475
476 anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
477
478 for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)
479 {
480 oid = sk_ASN1_OBJECT_value(policy_oids, i);
481 if (OBJ_obj2nid(oid) == NID_any_policy)
482 {
483 tree->flags |= POLICY_FLAG_ANY_POLICY;
484 return 1;
485 }
486 }
487
488 for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)
489 {
490 oid = sk_ASN1_OBJECT_value(policy_oids, i);
491 node = tree_find_sk(auth_nodes, oid);
492 if (!node)
493 {
494 if (!anyPolicy)
495 continue;
496 /* Create a new node with policy ID from user set
497 * and qualifiers from anyPolicy.
498 */
499 extra = policy_data_new(NULL, oid,
500 node_critical(anyPolicy));
501 if (!extra)
502 return 0;
503 extra->qualifier_set = anyPolicy->data->qualifier_set;
504 extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
505 | POLICY_DATA_FLAG_EXTRA_NODE;
506 node = level_add_node(NULL, extra, anyPolicy->parent,
507 tree);
508 }
509 if (!tree->user_policies)
510 {
511 tree->user_policies = sk_X509_POLICY_NODE_new_null();
512 if (!tree->user_policies)
513 return 1;
514 }
515 if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))
516 return 0;
517 }
518 return 1;
519
520 }
521
tree_evaluate(X509_POLICY_TREE * tree)522 static int tree_evaluate(X509_POLICY_TREE *tree)
523 {
524 int ret, i;
525 X509_POLICY_LEVEL *curr = tree->levels + 1;
526 const X509_POLICY_CACHE *cache;
527
528 for(i = 1; i < tree->nlevel; i++, curr++)
529 {
530 cache = policy_cache_set(curr->cert);
531 if (!tree_link_nodes(curr, cache))
532 return 0;
533
534 if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
535 && !tree_link_any(curr, cache, tree))
536 return 0;
537 ret = tree_prune(tree, curr);
538 if (ret != 1)
539 return ret;
540 }
541
542 return 1;
543
544 }
545
exnode_free(X509_POLICY_NODE * node)546 static void exnode_free(X509_POLICY_NODE *node)
547 {
548 if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
549 OPENSSL_free(node);
550 }
551
552
X509_policy_tree_free(X509_POLICY_TREE * tree)553 void X509_policy_tree_free(X509_POLICY_TREE *tree)
554 {
555 X509_POLICY_LEVEL *curr;
556 int i;
557
558 if (!tree)
559 return;
560
561 sk_X509_POLICY_NODE_free(tree->auth_policies);
562 sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
563
564 for(i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++)
565 {
566 if (curr->cert)
567 X509_free(curr->cert);
568 if (curr->nodes)
569 sk_X509_POLICY_NODE_pop_free(curr->nodes,
570 policy_node_free);
571 if (curr->anyPolicy)
572 policy_node_free(curr->anyPolicy);
573 }
574
575 if (tree->extra_data)
576 sk_X509_POLICY_DATA_pop_free(tree->extra_data,
577 policy_data_free);
578
579 OPENSSL_free(tree->levels);
580 OPENSSL_free(tree);
581
582 }
583
584 /* Application policy checking function.
585 * Return codes:
586 * 0 Internal Error.
587 * 1 Successful.
588 * -1 One or more certificates contain invalid or inconsistent extensions
589 * -2 User constrained policy set empty and requireExplicit true.
590 */
591
X509_policy_check(X509_POLICY_TREE ** ptree,int * pexplicit_policy,STACK_OF (X509)* certs,STACK_OF (ASN1_OBJECT)* policy_oids,unsigned int flags)592 int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
593 STACK_OF(X509) *certs,
594 STACK_OF(ASN1_OBJECT) *policy_oids,
595 unsigned int flags)
596 {
597 int ret;
598 X509_POLICY_TREE *tree = NULL;
599 STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
600 *ptree = NULL;
601
602 *pexplicit_policy = 0;
603 ret = tree_init(&tree, certs, flags);
604
605
606 switch (ret)
607 {
608
609 /* Tree empty requireExplicit False: OK */
610 case 2:
611 return 1;
612
613 /* Some internal error */
614 case 0:
615 return 0;
616
617 /* Tree empty requireExplicit True: Error */
618
619 case 6:
620 *pexplicit_policy = 1;
621 return -2;
622
623 /* Tree OK requireExplicit True: OK and continue */
624 case 5:
625 *pexplicit_policy = 1;
626 break;
627
628 /* Tree OK: continue */
629
630 case 1:
631 if (!tree)
632 /*
633 * tree_init() returns success and a null tree
634 * if it's just looking at a trust anchor.
635 * I'm not sure that returning success here is
636 * correct, but I'm sure that reporting this
637 * as an internal error which our caller
638 * interprets as a malloc failure is wrong.
639 */
640 return 1;
641 break;
642 }
643
644 if (!tree) goto error;
645 ret = tree_evaluate(tree);
646
647 if (ret <= 0)
648 goto error;
649
650 /* Return value 2 means tree empty */
651 if (ret == 2)
652 {
653 X509_policy_tree_free(tree);
654 if (*pexplicit_policy)
655 return -2;
656 else
657 return 1;
658 }
659
660 /* Tree is not empty: continue */
661
662 ret = tree_calculate_authority_set(tree, &auth_nodes);
663
664 if (!ret)
665 goto error;
666
667 if (!tree_calculate_user_set(tree, policy_oids, auth_nodes))
668 goto error;
669
670 if (ret == 2)
671 sk_X509_POLICY_NODE_free(auth_nodes);
672
673 if (tree)
674 *ptree = tree;
675
676 if (*pexplicit_policy)
677 {
678 nodes = X509_policy_tree_get0_user_policies(tree);
679 if (sk_X509_POLICY_NODE_num(nodes) <= 0)
680 return -2;
681 }
682
683 return 1;
684
685 error:
686
687 X509_policy_tree_free(tree);
688
689 return 0;
690
691 }
692
693