xref: /freebsd/crypto/openssl/crypto/x509/pcy_tree.c (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2004-2025 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include "internal/cryptlib.h"
11 #include <openssl/trace.h>
12 #include <openssl/x509.h>
13 #include <openssl/x509v3.h>
14 
15 #include "pcy_local.h"
16 
17 /*
18  * If the maximum number of nodes in the policy tree isn't defined, set it to
19  * a generous default of 1000 nodes.
20  *
21  * Defining this to be zero means unlimited policy tree growth which opens the
22  * door on CVE-2023-0464.
23  */
24 #ifndef OPENSSL_POLICY_TREE_NODES_MAX
25 # define OPENSSL_POLICY_TREE_NODES_MAX 1000
26 #endif
27 
28 static void exnode_free(X509_POLICY_NODE *node);
29 
expected_print(BIO * channel,X509_POLICY_LEVEL * lev,X509_POLICY_NODE * node,int indent)30 static void expected_print(BIO *channel,
31                            X509_POLICY_LEVEL *lev, X509_POLICY_NODE *node,
32                            int indent)
33 {
34     if ((lev->flags & X509_V_FLAG_INHIBIT_MAP)
35         || !(node->data->flags & POLICY_DATA_FLAG_MAP_MASK))
36         BIO_puts(channel, "  Not Mapped\n");
37     else {
38         int i;
39 
40         STACK_OF(ASN1_OBJECT) *pset = node->data->expected_policy_set;
41         ASN1_OBJECT *oid;
42         BIO_puts(channel, "  Expected: ");
43         for (i = 0; i < sk_ASN1_OBJECT_num(pset); i++) {
44             oid = sk_ASN1_OBJECT_value(pset, i);
45             if (i)
46                 BIO_puts(channel, ", ");
47             i2a_ASN1_OBJECT(channel, oid);
48         }
49         BIO_puts(channel, "\n");
50     }
51 }
52 
tree_print(BIO * channel,char * str,X509_POLICY_TREE * tree,X509_POLICY_LEVEL * curr)53 static void tree_print(BIO *channel,
54                        char *str, X509_POLICY_TREE *tree,
55                        X509_POLICY_LEVEL *curr)
56 {
57     X509_POLICY_LEVEL *plev;
58 
59     if (!curr)
60         curr = tree->levels + tree->nlevel;
61     else
62         curr++;
63 
64     BIO_printf(channel, "Level print after %s\n", str);
65     BIO_printf(channel, "Printing Up to Level %ld\n",
66                (long)(curr - tree->levels));
67     for (plev = tree->levels; plev != curr; plev++) {
68         int i;
69 
70         BIO_printf(channel, "Level %ld, flags = %x\n",
71                    (long)(plev - tree->levels), plev->flags);
72         for (i = 0; i < sk_X509_POLICY_NODE_num(plev->nodes); i++) {
73             X509_POLICY_NODE *node =
74                 sk_X509_POLICY_NODE_value(plev->nodes, i);
75 
76             X509_POLICY_NODE_print(channel, node, 2);
77             expected_print(channel, plev, node, 2);
78             BIO_printf(channel, "  Flags: %x\n", node->data->flags);
79         }
80         if (plev->anyPolicy)
81             X509_POLICY_NODE_print(channel, plev->anyPolicy, 2);
82     }
83 }
84 
85 #define TREE_PRINT(str, tree, curr) \
86     OSSL_TRACE_BEGIN(X509V3_POLICY) { \
87         tree_print(trc_out, "before tree_prune()", tree, curr); \
88     } OSSL_TRACE_END(X509V3_POLICY)
89 
90 /*-
91  * Return value: <= 0 on error, or positive bit mask:
92  *
93  * X509_PCY_TREE_VALID: valid tree
94  * X509_PCY_TREE_EMPTY: empty tree (including bare TA case)
95  * X509_PCY_TREE_EXPLICIT: explicit policy required
96  */
tree_init(X509_POLICY_TREE ** ptree,STACK_OF (X509)* certs,unsigned int flags)97 static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
98                      unsigned int flags)
99 {
100     X509_POLICY_TREE *tree;
101     X509_POLICY_LEVEL *level;
102     const X509_POLICY_CACHE *cache;
103     X509_POLICY_DATA *data = NULL;
104     int ret = X509_PCY_TREE_VALID;
105     int n = sk_X509_num(certs) - 1; /* RFC5280 paths omit the TA */
106     int explicit_policy = (flags & X509_V_FLAG_EXPLICIT_POLICY) ? 0 : n+1;
107     int any_skip = (flags & X509_V_FLAG_INHIBIT_ANY) ? 0 : n+1;
108     int map_skip = (flags & X509_V_FLAG_INHIBIT_MAP) ? 0 : n+1;
109     int i;
110 
111     *ptree = NULL;
112 
113     if (n < 0)
114         return X509_PCY_TREE_INTERNAL;
115     /* Can't do anything with just a trust anchor */
116     if (n == 0)
117         return X509_PCY_TREE_EMPTY;
118 
119     /*
120      * First setup the policy cache in all n non-TA certificates, this will be
121      * used in X509_verify_cert() which will invoke the verify callback for all
122      * certificates with invalid policy extensions.
123      */
124     for (i = n - 1; i >= 0; i--) {
125         X509 *x = sk_X509_value(certs, i);
126 
127         /* Call for side-effect of computing hash and caching extensions */
128         X509_check_purpose(x, -1, 0);
129 
130         /* If cache is NULL, likely ENOMEM: return immediately */
131         if (ossl_policy_cache_set(x) == NULL)
132             return X509_PCY_TREE_INTERNAL;
133     }
134 
135     /*
136      * At this point check for invalid policies and required explicit policy.
137      * Note that the explicit_policy counter is a count-down to zero, with the
138      * requirement kicking in if and once it does that.  The counter is
139      * decremented for every non-self-issued certificate in the path, but may
140      * be further reduced by policy constraints in a non-leaf certificate.
141      *
142      * The ultimate policy set is the intersection of all the policies along
143      * the path, if we hit a certificate with an empty policy set, and explicit
144      * policy is required we're done.
145      */
146     for (i = n - 1;
147          i >= 0 && (explicit_policy > 0 || (ret & X509_PCY_TREE_EMPTY) == 0);
148          i--) {
149         X509 *x = sk_X509_value(certs, i);
150         uint32_t ex_flags = X509_get_extension_flags(x);
151 
152         /* All the policies are already cached, we can return early */
153         if (ex_flags & EXFLAG_INVALID_POLICY)
154             return X509_PCY_TREE_INVALID;
155 
156         /* Access the cache which we now know exists */
157         cache = ossl_policy_cache_set(x);
158 
159         if ((ret & X509_PCY_TREE_VALID) && cache->data == NULL)
160             ret = X509_PCY_TREE_EMPTY;
161         if (explicit_policy > 0) {
162             if (!(ex_flags & EXFLAG_SI))
163                 explicit_policy--;
164             if ((cache->explicit_skip >= 0)
165                 && (cache->explicit_skip < explicit_policy))
166                 explicit_policy = cache->explicit_skip;
167         }
168     }
169 
170     if (explicit_policy == 0)
171         ret |= X509_PCY_TREE_EXPLICIT;
172     if ((ret & X509_PCY_TREE_VALID) == 0)
173         return ret;
174 
175     /* If we get this far initialize the tree */
176     if ((tree = OPENSSL_zalloc(sizeof(*tree))) == NULL)
177         return X509_PCY_TREE_INTERNAL;
178 
179     /* Limit the growth of the tree to mitigate CVE-2023-0464 */
180     tree->node_maximum = OPENSSL_POLICY_TREE_NODES_MAX;
181 
182     /*
183      * http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
184      *
185      * The top level is implicitly for the trust anchor with valid expected
186      * policies of anyPolicy.  (RFC 5280 has the TA at depth 0 and the leaf at
187      * depth n, we have the leaf at depth 0 and the TA at depth n).
188      */
189     if ((tree->levels = OPENSSL_zalloc(sizeof(*tree->levels)*(n+1))) == NULL) {
190         OPENSSL_free(tree);
191         return X509_PCY_TREE_INTERNAL;
192     }
193     tree->nlevel = n+1;
194     level = tree->levels;
195     if ((data = ossl_policy_data_new(NULL,
196                                      OBJ_nid2obj(NID_any_policy), 0)) == NULL)
197         goto bad_tree;
198     if (ossl_policy_level_add_node(level, data, NULL, tree, 1) == NULL) {
199         ossl_policy_data_free(data);
200         goto bad_tree;
201     }
202 
203     /*
204      * In this pass initialize all the tree levels and whether anyPolicy and
205      * policy mapping are inhibited at each level.
206      */
207     for (i = n - 1; i >= 0; i--) {
208         X509 *x = sk_X509_value(certs, i);
209         uint32_t ex_flags = X509_get_extension_flags(x);
210 
211         /* Access the cache which we now know exists */
212         cache = ossl_policy_cache_set(x);
213 
214         if (!X509_up_ref(x))
215             goto bad_tree;
216 
217         (++level)->cert = x;
218 
219         if (!cache->anyPolicy)
220             level->flags |= X509_V_FLAG_INHIBIT_ANY;
221 
222         /* Determine inhibit any and inhibit map flags */
223         if (any_skip == 0) {
224             /*
225              * Any matching allowed only if certificate is self issued and not
226              * the last in the chain.
227              */
228             if (!(ex_flags & EXFLAG_SI) || (i == 0))
229                 level->flags |= X509_V_FLAG_INHIBIT_ANY;
230         } else {
231             if (!(ex_flags & EXFLAG_SI))
232                 any_skip--;
233             if ((cache->any_skip >= 0) && (cache->any_skip < any_skip))
234                 any_skip = cache->any_skip;
235         }
236 
237         if (map_skip == 0)
238             level->flags |= X509_V_FLAG_INHIBIT_MAP;
239         else {
240             if (!(ex_flags & EXFLAG_SI))
241                 map_skip--;
242             if ((cache->map_skip >= 0) && (cache->map_skip < map_skip))
243                 map_skip = cache->map_skip;
244         }
245     }
246 
247     *ptree = tree;
248     return ret;
249 
250  bad_tree:
251     X509_policy_tree_free(tree);
252     return X509_PCY_TREE_INTERNAL;
253 }
254 
255 /*
256  * Return value: 1 on success, 0 otherwise
257  */
tree_link_matching_nodes(X509_POLICY_LEVEL * curr,X509_POLICY_DATA * data,X509_POLICY_TREE * tree)258 static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
259                                     X509_POLICY_DATA *data,
260                                     X509_POLICY_TREE *tree)
261 {
262     X509_POLICY_LEVEL *last = curr - 1;
263     int i, matched = 0;
264 
265     /* Iterate through all in nodes linking matches */
266     for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
267         X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
268 
269         if (ossl_policy_node_match(last, node, data->valid_policy)) {
270             if (ossl_policy_level_add_node(curr, data, node, tree, 0) == NULL)
271                 return 0;
272             matched = 1;
273         }
274     }
275     if (!matched && last->anyPolicy) {
276         if (ossl_policy_level_add_node(curr, data, last->anyPolicy, tree, 0) == NULL)
277             return 0;
278     }
279     return 1;
280 }
281 
282 /*
283  * This corresponds to RFC3280 6.1.3(d)(1): link any data from
284  * CertificatePolicies onto matching parent or anyPolicy if no match.
285  *
286  * Return value: 1 on success, 0 otherwise.
287  */
tree_link_nodes(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_TREE * tree)288 static int tree_link_nodes(X509_POLICY_LEVEL *curr,
289                            const X509_POLICY_CACHE *cache,
290                            X509_POLICY_TREE *tree)
291 {
292     int i;
293 
294     for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++) {
295         X509_POLICY_DATA *data = sk_X509_POLICY_DATA_value(cache->data, i);
296 
297         /* Look for matching nodes in previous level */
298         if (!tree_link_matching_nodes(curr, data, tree))
299             return 0;
300     }
301     return 1;
302 }
303 
304 /*
305  * This corresponds to RFC3280 6.1.3(d)(2): Create new data for any unmatched
306  * policies in the parent and link to anyPolicy.
307  *
308  * Return value: 1 on success, 0 otherwise.
309  */
tree_add_unmatched(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,const ASN1_OBJECT * id,X509_POLICY_NODE * node,X509_POLICY_TREE * tree)310 static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
311                               const X509_POLICY_CACHE *cache,
312                               const ASN1_OBJECT *id,
313                               X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
314 {
315     X509_POLICY_DATA *data;
316 
317     if (id == NULL)
318         id = node->data->valid_policy;
319     /*
320      * Create a new node with qualifiers from anyPolicy and id from unmatched
321      * node.
322      */
323     if ((data = ossl_policy_data_new(NULL, id, node_critical(node))) == NULL)
324         return 0;
325 
326     /* Curr may not have anyPolicy */
327     data->qualifier_set = cache->anyPolicy->qualifier_set;
328     data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
329     if (ossl_policy_level_add_node(curr, data, node, tree, 1) == NULL) {
330         ossl_policy_data_free(data);
331         return 0;
332     }
333     return 1;
334 }
335 
336 /*
337  * Return value: 1 on success, 0 otherwise.
338  */
tree_link_unmatched(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_NODE * node,X509_POLICY_TREE * tree)339 static int tree_link_unmatched(X509_POLICY_LEVEL *curr,
340                                const X509_POLICY_CACHE *cache,
341                                X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
342 {
343     const X509_POLICY_LEVEL *last = curr - 1;
344     int i;
345 
346     if ((last->flags & X509_V_FLAG_INHIBIT_MAP)
347         || !(node->data->flags & POLICY_DATA_FLAG_MAPPED)) {
348         /* If no policy mapping: matched if one child present */
349         if (node->nchild)
350             return 1;
351         if (!tree_add_unmatched(curr, cache, NULL, node, tree))
352             return 0;
353         /* Add it */
354     } else {
355         /* If mapping: matched if one child per expected policy set */
356         STACK_OF(ASN1_OBJECT) *expset = node->data->expected_policy_set;
357         if (node->nchild == sk_ASN1_OBJECT_num(expset))
358             return 1;
359         /* Locate unmatched nodes */
360         for (i = 0; i < sk_ASN1_OBJECT_num(expset); i++) {
361             ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(expset, i);
362             if (ossl_policy_level_find_node(curr, node, oid))
363                 continue;
364             if (!tree_add_unmatched(curr, cache, oid, node, tree))
365                 return 0;
366         }
367 
368     }
369     return 1;
370 }
371 
372 /*
373  * Return value: 1 on success, 0 otherwise
374  */
tree_link_any(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_TREE * tree)375 static int tree_link_any(X509_POLICY_LEVEL *curr,
376                          const X509_POLICY_CACHE *cache,
377                          X509_POLICY_TREE *tree)
378 {
379     int i;
380     X509_POLICY_NODE *node;
381     X509_POLICY_LEVEL *last = curr - 1;
382 
383     for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
384         node = sk_X509_POLICY_NODE_value(last->nodes, i);
385 
386         if (!tree_link_unmatched(curr, cache, node, tree))
387             return 0;
388     }
389     /* Finally add link to anyPolicy */
390     if (last->anyPolicy &&
391             ossl_policy_level_add_node(curr, cache->anyPolicy,
392                                        last->anyPolicy, tree, 0) == NULL)
393         return 0;
394     return 1;
395 }
396 
397 /*-
398  * Prune the tree: delete any child mapped child data on the current level then
399  * proceed up the tree deleting any data with no children. If we ever have no
400  * data on a level we can halt because the tree will be empty.
401  *
402  * Return value: <= 0 error, otherwise one of:
403  *
404  * X509_PCY_TREE_VALID: valid tree
405  * X509_PCY_TREE_EMPTY: empty tree
406  */
tree_prune(X509_POLICY_TREE * tree,X509_POLICY_LEVEL * curr)407 static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
408 {
409     STACK_OF(X509_POLICY_NODE) *nodes;
410     X509_POLICY_NODE *node;
411     int i;
412     nodes = curr->nodes;
413     if (curr->flags & X509_V_FLAG_INHIBIT_MAP) {
414         for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
415             node = sk_X509_POLICY_NODE_value(nodes, i);
416             /* Delete any mapped data: see RFC3280 XXXX */
417             if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK) {
418                 node->parent->nchild--;
419                 OPENSSL_free(node);
420                 (void)sk_X509_POLICY_NODE_delete(nodes, i);
421             }
422         }
423     }
424 
425     for (;;) {
426         --curr;
427         nodes = curr->nodes;
428         for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
429             node = sk_X509_POLICY_NODE_value(nodes, i);
430             if (node->nchild == 0) {
431                 node->parent->nchild--;
432                 OPENSSL_free(node);
433                 (void)sk_X509_POLICY_NODE_delete(nodes, i);
434             }
435         }
436         if (curr->anyPolicy && !curr->anyPolicy->nchild) {
437             if (curr->anyPolicy->parent)
438                 curr->anyPolicy->parent->nchild--;
439             OPENSSL_free(curr->anyPolicy);
440             curr->anyPolicy = NULL;
441         }
442         if (curr == tree->levels) {
443             /* If we zapped anyPolicy at top then tree is empty */
444             if (!curr->anyPolicy)
445                 return X509_PCY_TREE_EMPTY;
446             break;
447         }
448     }
449     return X509_PCY_TREE_VALID;
450 }
451 
452 /*
453  * Return value: 1 on success, 0 otherwise.
454  */
tree_add_auth_node(STACK_OF (X509_POLICY_NODE)** pnodes,X509_POLICY_NODE * pcy)455 static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
456                               X509_POLICY_NODE *pcy)
457 {
458     if (*pnodes == NULL &&
459         (*pnodes = ossl_policy_node_cmp_new()) == NULL)
460         return 0;
461     if (sk_X509_POLICY_NODE_find(*pnodes, pcy) >= 0)
462         return 1;
463     return sk_X509_POLICY_NODE_push(*pnodes, pcy) != 0;
464 }
465 
466 #define TREE_CALC_FAILURE 0
467 #define TREE_CALC_OK_NOFREE 1
468 #define TREE_CALC_OK_DOFREE 2
469 
470 /*-
471  * Calculate the authority set based on policy tree. The 'pnodes' parameter is
472  * used as a store for the set of policy nodes used to calculate the user set.
473  * If the authority set is not anyPolicy then pnodes will just point to the
474  * authority set. If however the authority set is anyPolicy then the set of
475  * valid policies (other than anyPolicy) is store in pnodes.
476  *
477  * Return value:
478  *  TREE_CALC_FAILURE on failure,
479  *  TREE_CALC_OK_NOFREE on success and pnodes need not be freed,
480  *  TREE_CALC_OK_DOFREE on success and pnodes needs to be freed
481  */
tree_calculate_authority_set(X509_POLICY_TREE * tree,STACK_OF (X509_POLICY_NODE)** pnodes)482 static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
483                                         STACK_OF(X509_POLICY_NODE) **pnodes)
484 {
485     X509_POLICY_LEVEL *curr;
486     X509_POLICY_NODE *node, *anyptr;
487     STACK_OF(X509_POLICY_NODE) **addnodes;
488     int i, j;
489     curr = tree->levels + tree->nlevel - 1;
490 
491     /* If last level contains anyPolicy set is anyPolicy */
492     if (curr->anyPolicy) {
493         if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
494             return TREE_CALC_FAILURE;
495         addnodes = pnodes;
496     } else
497         /* Add policies to authority set */
498         addnodes = &tree->auth_policies;
499 
500     curr = tree->levels;
501     for (i = 1; i < tree->nlevel; i++) {
502         /*
503          * If no anyPolicy node on this level it can't appear on lower
504          * levels so end search.
505          */
506         if ((anyptr = curr->anyPolicy) == NULL)
507             break;
508         curr++;
509         for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++) {
510             node = sk_X509_POLICY_NODE_value(curr->nodes, j);
511             if ((node->parent == anyptr)
512                 && !tree_add_auth_node(addnodes, node)) {
513                 if (addnodes == pnodes) {
514                     sk_X509_POLICY_NODE_free(*pnodes);
515                     *pnodes = NULL;
516                 }
517                 return TREE_CALC_FAILURE;
518             }
519         }
520     }
521     if (addnodes == pnodes)
522         return TREE_CALC_OK_DOFREE;
523 
524     *pnodes = tree->auth_policies;
525     return TREE_CALC_OK_NOFREE;
526 }
527 
528 /*
529  * Return value: 1 on success, 0 otherwise.
530  */
tree_calculate_user_set(X509_POLICY_TREE * tree,STACK_OF (ASN1_OBJECT)* policy_oids,STACK_OF (X509_POLICY_NODE)* auth_nodes)531 static int tree_calculate_user_set(X509_POLICY_TREE *tree,
532                                    STACK_OF(ASN1_OBJECT) *policy_oids,
533                                    STACK_OF(X509_POLICY_NODE) *auth_nodes)
534 {
535     int i;
536     X509_POLICY_NODE *node;
537     ASN1_OBJECT *oid;
538     X509_POLICY_NODE *anyPolicy;
539     X509_POLICY_DATA *extra;
540 
541     /*
542      * Check if anyPolicy present in authority constrained policy set: this
543      * will happen if it is a leaf node.
544      */
545     if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
546         return 1;
547 
548     anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
549 
550     for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
551         oid = sk_ASN1_OBJECT_value(policy_oids, i);
552         if (OBJ_obj2nid(oid) == NID_any_policy) {
553             tree->flags |= POLICY_FLAG_ANY_POLICY;
554             return 1;
555         }
556     }
557 
558     for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
559         oid = sk_ASN1_OBJECT_value(policy_oids, i);
560         node = ossl_policy_tree_find_sk(auth_nodes, oid);
561         if (!node) {
562             if (!anyPolicy)
563                 continue;
564             /*
565              * Create a new node with policy ID from user set and qualifiers
566              * from anyPolicy.
567              */
568             extra = ossl_policy_data_new(NULL, oid, node_critical(anyPolicy));
569             if (extra == NULL)
570                 return 0;
571             extra->qualifier_set = anyPolicy->data->qualifier_set;
572             extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
573                 | POLICY_DATA_FLAG_EXTRA_NODE;
574             node = ossl_policy_level_add_node(NULL, extra, anyPolicy->parent,
575                                               tree, 1);
576             if (node == NULL) {
577                 ossl_policy_data_free(extra);
578                 return 0;
579             }
580         }
581         if (!tree->user_policies) {
582             tree->user_policies = sk_X509_POLICY_NODE_new_null();
583             if (!tree->user_policies) {
584                 exnode_free(node);
585                 return 0;
586             }
587         }
588         if (!sk_X509_POLICY_NODE_push(tree->user_policies, node)) {
589             exnode_free(node);
590             return 0;
591         }
592     }
593     return 1;
594 }
595 
596 /*-
597  * Return value: <= 0 error, otherwise one of:
598  *  X509_PCY_TREE_VALID: valid tree
599  *  X509_PCY_TREE_EMPTY: empty tree
600  * (see tree_prune()).
601  */
tree_evaluate(X509_POLICY_TREE * tree)602 static int tree_evaluate(X509_POLICY_TREE *tree)
603 {
604     int ret, i;
605     X509_POLICY_LEVEL *curr = tree->levels + 1;
606     const X509_POLICY_CACHE *cache;
607 
608     for (i = 1; i < tree->nlevel; i++, curr++) {
609         cache = ossl_policy_cache_set(curr->cert);
610         if (!tree_link_nodes(curr, cache, tree))
611             return X509_PCY_TREE_INTERNAL;
612 
613         if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
614             && !tree_link_any(curr, cache, tree))
615             return X509_PCY_TREE_INTERNAL;
616         TREE_PRINT("before tree_prune()", tree, curr);
617         ret = tree_prune(tree, curr);
618         if (ret != X509_PCY_TREE_VALID)
619             return ret;
620     }
621     return X509_PCY_TREE_VALID;
622 }
623 
exnode_free(X509_POLICY_NODE * node)624 static void exnode_free(X509_POLICY_NODE *node)
625 {
626     if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
627         OPENSSL_free(node);
628 }
629 
X509_policy_tree_free(X509_POLICY_TREE * tree)630 void X509_policy_tree_free(X509_POLICY_TREE *tree)
631 {
632     X509_POLICY_LEVEL *curr;
633     int i;
634 
635     if (!tree)
636         return;
637 
638     sk_X509_POLICY_NODE_free(tree->auth_policies);
639     sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
640 
641     for (i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++) {
642         X509_free(curr->cert);
643         sk_X509_POLICY_NODE_pop_free(curr->nodes, ossl_policy_node_free);
644         ossl_policy_node_free(curr->anyPolicy);
645     }
646 
647     sk_X509_POLICY_DATA_pop_free(tree->extra_data, ossl_policy_data_free);
648     OPENSSL_free(tree->levels);
649     OPENSSL_free(tree);
650 
651 }
652 
653 /*-
654  * Application policy checking function.
655  * Return codes:
656  *  X509_PCY_TREE_FAILURE:  Failure to satisfy explicit policy
657  *  X509_PCY_TREE_INVALID:  Inconsistent or invalid extensions
658  *  X509_PCY_TREE_INTERNAL: Internal error, most likely malloc
659  *  X509_PCY_TREE_VALID:    Success (null tree if empty or bare TA)
660  */
X509_policy_check(X509_POLICY_TREE ** ptree,int * pexplicit_policy,STACK_OF (X509)* certs,STACK_OF (ASN1_OBJECT)* policy_oids,unsigned int flags)661 int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
662                       STACK_OF(X509) *certs,
663                       STACK_OF(ASN1_OBJECT) *policy_oids, unsigned int flags)
664 {
665     int init_ret;
666     int ret;
667     int calc_ret;
668     X509_POLICY_TREE *tree = NULL;
669     STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
670 
671     *ptree = NULL;
672     *pexplicit_policy = 0;
673     init_ret = tree_init(&tree, certs, flags);
674 
675     if (init_ret <= 0)
676         return init_ret;
677 
678     if ((init_ret & X509_PCY_TREE_EXPLICIT) == 0) {
679         if (init_ret & X509_PCY_TREE_EMPTY) {
680             X509_policy_tree_free(tree);
681             return X509_PCY_TREE_VALID;
682         }
683     } else {
684         *pexplicit_policy = 1;
685         /* Tree empty and requireExplicit True: Error */
686         if (init_ret & X509_PCY_TREE_EMPTY)
687             return X509_PCY_TREE_FAILURE;
688     }
689 
690     ret = tree_evaluate(tree);
691     TREE_PRINT("tree_evaluate()", tree, NULL);
692     if (ret <= 0)
693         goto error;
694 
695     if (ret == X509_PCY_TREE_EMPTY) {
696         X509_policy_tree_free(tree);
697         if (init_ret & X509_PCY_TREE_EXPLICIT)
698             return X509_PCY_TREE_FAILURE;
699         return X509_PCY_TREE_VALID;
700     }
701 
702     /* Tree is not empty: continue */
703 
704     if ((calc_ret = tree_calculate_authority_set(tree, &auth_nodes)) == 0)
705         goto error;
706     sk_X509_POLICY_NODE_sort(auth_nodes);
707     ret = tree_calculate_user_set(tree, policy_oids, auth_nodes);
708     if (calc_ret == TREE_CALC_OK_DOFREE)
709         sk_X509_POLICY_NODE_free(auth_nodes);
710     if (!ret)
711         goto error;
712 
713     *ptree = tree;
714 
715     if (init_ret & X509_PCY_TREE_EXPLICIT) {
716         nodes = X509_policy_tree_get0_user_policies(tree);
717         if (sk_X509_POLICY_NODE_num(nodes) <= 0)
718             return X509_PCY_TREE_FAILURE;
719     }
720     return X509_PCY_TREE_VALID;
721 
722  error:
723     X509_policy_tree_free(tree);
724     return X509_PCY_TREE_INTERNAL;
725 }
726