Refer to SSL_pending from the man page for SSL_read
[openssl.git] / crypto / x509v3 / pcy_tree.c
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
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_SI)
135                                 && (cache->explicit_skip != -1)
136                                 && (cache->explicit_skip < explicit_policy))
137                                 explicit_policy = cache->explicit_skip + 1;
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_SI) || (i == 0))
201                                 level->flags |= X509_V_FLAG_INHIBIT_ANY;
202                         }
203                 else
204                         {
205                         if (!(x->ex_flags & EXFLAG_SI))
206                                 any_skip--;
207                         if ((cache->any_skip >= 0)
208                                 && (cache->any_skip < any_skip))
209                                 any_skip = cache->any_skip;
210                         }
211
212                 if (map_skip == 0)
213                         level->flags |= X509_V_FLAG_INHIBIT_MAP;
214                 else
215                         {
216                         map_skip--;
217                         if ((cache->map_skip >= 0)
218                                 && (cache->map_skip < map_skip))
219                                 map_skip = cache->map_skip;
220                         }
221
222
223                 }
224
225         *ptree = tree;
226
227         if (explicit_policy)
228                 return 1;
229         else
230                 return 5;
231
232         bad_tree:
233
234         X509_policy_tree_free(tree);
235
236         return 0;
237
238         }
239
240 /* This corresponds to RFC3280 XXXX XXXXX:
241  * link any data from CertificatePolicies onto matching parent
242  * or anyPolicy if no match.
243  */
244
245 static int tree_link_nodes(X509_POLICY_LEVEL *curr,
246                                 const X509_POLICY_CACHE *cache)
247         {
248         int i;
249         X509_POLICY_LEVEL *last;
250         X509_POLICY_DATA *data;
251         X509_POLICY_NODE *parent;
252         last = curr - 1;
253         for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++)
254                 {
255                 data = sk_X509_POLICY_DATA_value(cache->data, i);
256                 /* If a node is mapped any it doesn't have a corresponding
257                  * CertificatePolicies entry. 
258                  * However such an identical node would be created
259                  * if anyPolicy matching is enabled because there would be
260                  * no match with the parent valid_policy_set. So we create
261                  * link because then it will have the mapping flags
262                  * right and we can prune it later.
263                  */
264                 if ((data->flags & POLICY_DATA_FLAG_MAPPED_ANY)
265                         && !(curr->flags & X509_V_FLAG_INHIBIT_ANY))
266                         continue;
267                 /* Look for matching node in parent */
268                 parent = level_find_node(last, data->valid_policy);
269                 /* If no match link to anyPolicy */
270                 if (!parent)
271                         parent = last->anyPolicy;
272                 if (parent && !level_add_node(curr, data, parent, NULL))
273                                 return 0;
274                 }
275         return 1;
276         }
277
278 /* This corresponds to RFC3280 XXXX XXXXX:
279  * Create new data for any unmatched policies in the parent and link
280  * to anyPolicy.
281  */
282
283 static int tree_link_any(X509_POLICY_LEVEL *curr,
284                         const X509_POLICY_CACHE *cache,
285                         X509_POLICY_TREE *tree)
286         {
287         int i;
288         X509_POLICY_DATA *data;
289         X509_POLICY_NODE *node;
290         X509_POLICY_LEVEL *last;
291
292         last = curr - 1;
293
294         for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++)
295                 {
296                 node = sk_X509_POLICY_NODE_value(last->nodes, i);
297
298                 /* Skip any node with any children: we only want unmathced
299                  * nodes.
300                  *
301                  * Note: need something better for policy mapping
302                  * because each node may have multiple children 
303                  */
304                 if (node->nchild)
305                         continue;
306                 /* Create a new node with qualifiers from anyPolicy and
307                  * id from unmatched node.
308                  */
309                 data = policy_data_new(NULL, node->data->valid_policy, 
310                                                 node_critical(node));
311
312                 if (data == NULL)
313                         return 0;
314                 /* Curr may not have anyPolicy */
315                 data->qualifier_set = cache->anyPolicy->qualifier_set;
316                 data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
317                 if (!level_add_node(curr, data, node, tree))
318                         {
319                         policy_data_free(data);
320                         return 0;
321                         }
322                 }
323         /* Finally add link to anyPolicy */
324         if (last->anyPolicy)
325                 {
326                 if (!level_add_node(curr, cache->anyPolicy,
327                                                 last->anyPolicy, NULL))
328                         return 0;
329                 }
330         return 1;
331         }
332
333 /* Prune the tree: delete any child mapped child data on the current level
334  * then proceed up the tree deleting any data with no children. If we ever
335  * have no data on a level we can halt because the tree will be empty.
336  */
337
338 static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
339         {
340         X509_POLICY_NODE *node;
341         int i;
342         for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)
343                 {
344                 node = sk_X509_POLICY_NODE_value(curr->nodes, i);
345                 /* Delete any mapped data: see RFC3280 XXXX */
346                 if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK)
347                         {
348                         node->parent->nchild--;
349                         OPENSSL_free(node);
350                         (void)sk_X509_POLICY_NODE_delete(curr->nodes, i);
351                         }
352                 }
353
354         for(;;) {
355                 --curr;
356                 for (i = sk_X509_POLICY_NODE_num(curr->nodes) - 1; i >= 0; i--)
357                         {
358                         node = sk_X509_POLICY_NODE_value(curr->nodes, i);
359                         if (node->nchild == 0)
360                                 {
361                                 node->parent->nchild--;
362                                 OPENSSL_free(node);
363                                 (void)sk_X509_POLICY_NODE_delete(curr->nodes, i);
364                                 }
365                         }
366                 if (curr->anyPolicy && !curr->anyPolicy->nchild)
367                         {
368                         if (curr->anyPolicy->parent)
369                                 curr->anyPolicy->parent->nchild--;
370                         OPENSSL_free(curr->anyPolicy);
371                         curr->anyPolicy = NULL;
372                         }
373                 if (curr == tree->levels)
374                         {
375                         /* If we zapped anyPolicy at top then tree is empty */
376                         if (!curr->anyPolicy)
377                                         return 2;
378                         return 1;
379                         }
380                 }
381
382         return 1;
383
384         }
385
386 static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
387                                                  X509_POLICY_NODE *pcy)
388         {
389         if (!*pnodes)
390                 {
391                 *pnodes = policy_node_cmp_new();
392                 if (!*pnodes)
393                         return 0;
394                 }
395         else if (sk_X509_POLICY_NODE_find(*pnodes, pcy) != -1)
396                 return 1;
397
398         if (!sk_X509_POLICY_NODE_push(*pnodes, pcy))
399                 return 0;
400
401         return 1;
402
403         }
404
405 /* Calculate the authority set based on policy tree.
406  * The 'pnodes' parameter is used as a store for the set of policy nodes
407  * used to calculate the user set. If the authority set is not anyPolicy
408  * then pnodes will just point to the authority set. If however the authority
409  * set is anyPolicy then the set of valid policies (other than anyPolicy)
410  * is store in pnodes. The return value of '2' is used in this case to indicate
411  * that pnodes should be freed.
412  */
413
414 static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
415                                         STACK_OF(X509_POLICY_NODE) **pnodes)
416         {
417         X509_POLICY_LEVEL *curr;
418         X509_POLICY_NODE *node, *anyptr;
419         STACK_OF(X509_POLICY_NODE) **addnodes;
420         int i, j;
421         curr = tree->levels + tree->nlevel - 1;
422
423         /* If last level contains anyPolicy set is anyPolicy */
424         if (curr->anyPolicy)
425                 {
426                 if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
427                         return 0;
428                 addnodes = pnodes;
429                 }
430         else
431                 /* Add policies to authority set */
432                 addnodes = &tree->auth_policies;
433
434         curr = tree->levels;
435         for (i = 1; i < tree->nlevel; i++)
436                 {
437                 /* If no anyPolicy node on this this level it can't
438                  * appear on lower levels so end search.
439                  */
440                 if (!(anyptr = curr->anyPolicy))
441                         break;
442                 curr++;
443                 for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++)
444                         {
445                         node = sk_X509_POLICY_NODE_value(curr->nodes, j);
446                         if ((node->parent == anyptr)
447                                 && !tree_add_auth_node(addnodes, node))
448                                         return 0;
449                         }
450                 }
451
452         if (addnodes == pnodes)
453                 return 2;
454
455         *pnodes = tree->auth_policies;
456
457         return 1;
458         }
459
460 static int tree_calculate_user_set(X509_POLICY_TREE *tree,
461                                 STACK_OF(ASN1_OBJECT) *policy_oids,
462                                 STACK_OF(X509_POLICY_NODE) *auth_nodes)
463         {
464         int i;
465         X509_POLICY_NODE *node;
466         ASN1_OBJECT *oid;
467
468         X509_POLICY_NODE *anyPolicy;
469         X509_POLICY_DATA *extra;
470
471         /* Check if anyPolicy present in authority constrained policy set:
472          * this will happen if it is a leaf node.
473          */
474
475         if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
476                 return 1;
477
478         anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
479
480         for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)
481                 {
482                 oid = sk_ASN1_OBJECT_value(policy_oids, i);
483                 if (OBJ_obj2nid(oid) == NID_any_policy)
484                         {
485                         tree->flags |= POLICY_FLAG_ANY_POLICY;
486                         return 1;
487                         }
488                 }
489
490         for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++)
491                 {
492                 oid = sk_ASN1_OBJECT_value(policy_oids, i);
493                 node = tree_find_sk(auth_nodes, oid);
494                 if (!node)
495                         {
496                         if (!anyPolicy)
497                                 continue;
498                         /* Create a new node with policy ID from user set
499                          * and qualifiers from anyPolicy.
500                          */
501                         extra = policy_data_new(NULL, oid,
502                                                 node_critical(anyPolicy));
503                         if (!extra)
504                                 return 0;
505                         extra->qualifier_set = anyPolicy->data->qualifier_set;
506                         extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
507                                                 | POLICY_DATA_FLAG_EXTRA_NODE;
508                         node = level_add_node(NULL, extra, anyPolicy->parent,
509                                                 tree);
510                         }
511                 if (!tree->user_policies)
512                         {
513                         tree->user_policies = sk_X509_POLICY_NODE_new_null();
514                         if (!tree->user_policies)
515                                 return 1;
516                         }
517                 if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))
518                         return 0;
519                 }
520         return 1;
521
522         }
523
524 static int tree_evaluate(X509_POLICY_TREE *tree)
525         {
526         int ret, i;
527         X509_POLICY_LEVEL *curr = tree->levels + 1;
528         const X509_POLICY_CACHE *cache;
529
530         for(i = 1; i < tree->nlevel; i++, curr++)
531                 {
532                 cache = policy_cache_set(curr->cert);
533                 if (!tree_link_nodes(curr, cache))
534                         return 0;
535
536                 if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
537                         && !tree_link_any(curr, cache, tree))
538                         return 0;
539                 ret = tree_prune(tree, curr);
540                 if (ret != 1)
541                         return ret;
542                 }
543
544         return 1;
545
546         }
547
548 static void exnode_free(X509_POLICY_NODE *node)
549         {
550         if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
551                 OPENSSL_free(node);
552         }
553
554
555 void X509_policy_tree_free(X509_POLICY_TREE *tree)
556         {
557         X509_POLICY_LEVEL *curr;
558         int i;
559
560         if (!tree)
561                 return;
562
563         sk_X509_POLICY_NODE_free(tree->auth_policies);
564         sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
565
566         for(i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++)
567                 {
568                 if (curr->cert)
569                         X509_free(curr->cert);
570                 if (curr->nodes)
571                         sk_X509_POLICY_NODE_pop_free(curr->nodes,
572                                                 policy_node_free);
573                 if (curr->anyPolicy)
574                         policy_node_free(curr->anyPolicy);
575                 }
576
577         if (tree->extra_data)
578                 sk_X509_POLICY_DATA_pop_free(tree->extra_data,
579                                                 policy_data_free);
580
581         OPENSSL_free(tree->levels);
582         OPENSSL_free(tree);
583
584         }
585
586 /* Application policy checking function.
587  * Return codes:
588  *  0   Internal Error.
589  *  1   Successful.
590  * -1   One or more certificates contain invalid or inconsistent extensions
591  * -2   User constrained policy set empty and requireExplicit true.
592  */
593
594 int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
595                         STACK_OF(X509) *certs,
596                         STACK_OF(ASN1_OBJECT) *policy_oids,
597                         unsigned int flags)
598         {
599         int ret;
600         X509_POLICY_TREE *tree = NULL;
601         STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
602         *ptree = NULL;
603
604         *pexplicit_policy = 0;
605         ret = tree_init(&tree, certs, flags);
606
607
608         switch (ret)
609                 {
610
611                 /* Tree empty requireExplicit False: OK */
612                 case 2:
613                 return 1;
614
615                 /* Some internal error */
616                 case 0:
617                 return 0;
618
619                 /* Tree empty requireExplicit True: Error */
620
621                 case 6:
622                 *pexplicit_policy = 1;
623                 return -2;
624
625                 /* Tree OK requireExplicit True: OK and continue */
626                 case 5:
627                 *pexplicit_policy = 1;
628                 break;
629
630                 /* Tree OK: continue */
631
632                 case 1:
633                 if (!tree)
634                         /*
635                          * tree_init() returns success and a null tree
636                          * if it's just looking at a trust anchor.
637                          * I'm not sure that returning success here is
638                          * correct, but I'm sure that reporting this
639                          * as an internal error which our caller
640                          * interprets as a malloc failure is wrong.
641                          */
642                         return 1;
643                 break;
644                 }
645
646         if (!tree) goto error;
647         ret = tree_evaluate(tree);
648
649         if (ret <= 0)
650                 goto error;
651
652         /* Return value 2 means tree empty */
653         if (ret == 2)
654                 {
655                 X509_policy_tree_free(tree);
656                 if (*pexplicit_policy)
657                         return -2;
658                 else
659                         return 1;
660                 }
661
662         /* Tree is not empty: continue */
663
664         ret = tree_calculate_authority_set(tree, &auth_nodes);
665
666         if (!ret)
667                 goto error;
668
669         if (!tree_calculate_user_set(tree, policy_oids, auth_nodes))
670                 goto error;
671         
672         if (ret == 2)
673                 sk_X509_POLICY_NODE_free(auth_nodes);
674
675         if (tree)
676                 *ptree = tree;
677
678         if (*pexplicit_policy)
679                 {
680                 nodes = X509_policy_tree_get0_user_policies(tree);
681                 if (sk_X509_POLICY_NODE_num(nodes) <= 0)
682                         return -2;
683                 }
684
685         return 1;
686
687         error:
688
689         X509_policy_tree_free(tree);
690
691         return 0;
692
693         }
694