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1 /*
2  * Copyright 2004-2021 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 
expected_print(BIO * channel,X509_POLICY_LEVEL * lev,X509_POLICY_NODE * node,int indent)28 static void expected_print(BIO *channel,
29                            X509_POLICY_LEVEL *lev, X509_POLICY_NODE *node,
30                            int indent)
31 {
32     if ((lev->flags & X509_V_FLAG_INHIBIT_MAP)
33         || !(node->data->flags & POLICY_DATA_FLAG_MAP_MASK))
34         BIO_puts(channel, "  Not Mapped\n");
35     else {
36         int i;
37 
38         STACK_OF(ASN1_OBJECT) *pset = node->data->expected_policy_set;
39         ASN1_OBJECT *oid;
40         BIO_puts(channel, "  Expected: ");
41         for (i = 0; i < sk_ASN1_OBJECT_num(pset); i++) {
42             oid = sk_ASN1_OBJECT_value(pset, i);
43             if (i)
44                 BIO_puts(channel, ", ");
45             i2a_ASN1_OBJECT(channel, oid);
46         }
47         BIO_puts(channel, "\n");
48     }
49 }
50 
tree_print(BIO * channel,char * str,X509_POLICY_TREE * tree,X509_POLICY_LEVEL * curr)51 static void tree_print(BIO *channel,
52                        char *str, X509_POLICY_TREE *tree,
53                        X509_POLICY_LEVEL *curr)
54 {
55     X509_POLICY_LEVEL *plev;
56 
57     if (!curr)
58         curr = tree->levels + tree->nlevel;
59     else
60         curr++;
61 
62     BIO_printf(channel, "Level print after %s\n", str);
63     BIO_printf(channel, "Printing Up to Level %ld\n",
64                (long)(curr - tree->levels));
65     for (plev = tree->levels; plev != curr; plev++) {
66         int i;
67 
68         BIO_printf(channel, "Level %ld, flags = %x\n",
69                    (long)(plev - tree->levels), plev->flags);
70         for (i = 0; i < sk_X509_POLICY_NODE_num(plev->nodes); i++) {
71             X509_POLICY_NODE *node =
72                 sk_X509_POLICY_NODE_value(plev->nodes, i);
73 
74             X509_POLICY_NODE_print(channel, node, 2);
75             expected_print(channel, plev, node, 2);
76             BIO_printf(channel, "  Flags: %x\n", node->data->flags);
77         }
78         if (plev->anyPolicy)
79             X509_POLICY_NODE_print(channel, plev->anyPolicy, 2);
80     }
81 }
82 
83 #define TREE_PRINT(str, tree, curr) \
84     OSSL_TRACE_BEGIN(X509V3_POLICY) { \
85         tree_print(trc_out, "before tree_prune()", tree, curr); \
86     } OSSL_TRACE_END(X509V3_POLICY)
87 
88 /*-
89  * Return value: <= 0 on error, or positive bit mask:
90  *
91  * X509_PCY_TREE_VALID: valid tree
92  * X509_PCY_TREE_EMPTY: empty tree (including bare TA case)
93  * X509_PCY_TREE_EXPLICIT: explicit policy required
94  */
tree_init(X509_POLICY_TREE ** ptree,STACK_OF (X509)* certs,unsigned int flags)95 static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
96                      unsigned int flags)
97 {
98     X509_POLICY_TREE *tree;
99     X509_POLICY_LEVEL *level;
100     const X509_POLICY_CACHE *cache;
101     X509_POLICY_DATA *data = NULL;
102     int ret = X509_PCY_TREE_VALID;
103     int n = sk_X509_num(certs) - 1; /* RFC5280 paths omit the TA */
104     int explicit_policy = (flags & X509_V_FLAG_EXPLICIT_POLICY) ? 0 : n+1;
105     int any_skip = (flags & X509_V_FLAG_INHIBIT_ANY) ? 0 : n+1;
106     int map_skip = (flags & X509_V_FLAG_INHIBIT_MAP) ? 0 : n+1;
107     int i;
108 
109     *ptree = NULL;
110 
111     /* Can't do anything with just a trust anchor */
112     if (n == 0)
113         return X509_PCY_TREE_EMPTY;
114 
115     /*
116      * First setup the policy cache in all n non-TA certificates, this will be
117      * used in X509_verify_cert() which will invoke the verify callback for all
118      * certificates with invalid policy extensions.
119      */
120     for (i = n - 1; i >= 0; i--) {
121         X509 *x = sk_X509_value(certs, i);
122 
123         /* Call for side-effect of computing hash and caching extensions */
124         X509_check_purpose(x, -1, 0);
125 
126         /* If cache is NULL, likely ENOMEM: return immediately */
127         if (ossl_policy_cache_set(x) == NULL)
128             return X509_PCY_TREE_INTERNAL;
129     }
130 
131     /*
132      * At this point check for invalid policies and required explicit policy.
133      * Note that the explicit_policy counter is a count-down to zero, with the
134      * requirement kicking in if and once it does that.  The counter is
135      * decremented for every non-self-issued certificate in the path, but may
136      * be further reduced by policy constraints in a non-leaf certificate.
137      *
138      * The ultimate policy set is the intersection of all the policies along
139      * the path, if we hit a certificate with an empty policy set, and explicit
140      * policy is required we're done.
141      */
142     for (i = n - 1;
143          i >= 0 && (explicit_policy > 0 || (ret & X509_PCY_TREE_EMPTY) == 0);
144          i--) {
145         X509 *x = sk_X509_value(certs, i);
146         uint32_t ex_flags = X509_get_extension_flags(x);
147 
148         /* All the policies are already cached, we can return early */
149         if (ex_flags & EXFLAG_INVALID_POLICY)
150             return X509_PCY_TREE_INVALID;
151 
152         /* Access the cache which we now know exists */
153         cache = ossl_policy_cache_set(x);
154 
155         if ((ret & X509_PCY_TREE_VALID) && cache->data == NULL)
156             ret = X509_PCY_TREE_EMPTY;
157         if (explicit_policy > 0) {
158             if (!(ex_flags & EXFLAG_SI))
159                 explicit_policy--;
160             if ((cache->explicit_skip >= 0)
161                 && (cache->explicit_skip < explicit_policy))
162                 explicit_policy = cache->explicit_skip;
163         }
164     }
165 
166     if (explicit_policy == 0)
167         ret |= X509_PCY_TREE_EXPLICIT;
168     if ((ret & X509_PCY_TREE_VALID) == 0)
169         return ret;
170 
171     /* If we get this far initialize the tree */
172     if ((tree = OPENSSL_zalloc(sizeof(*tree))) == NULL) {
173         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
174         return X509_PCY_TREE_INTERNAL;
175     }
176 
177     /* Limit the growth of the tree to mitigate CVE-2023-0464 */
178     tree->node_maximum = OPENSSL_POLICY_TREE_NODES_MAX;
179 
180     /*
181      * http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
182      *
183      * The top level is implicitly for the trust anchor with valid expected
184      * policies of anyPolicy.  (RFC 5280 has the TA at depth 0 and the leaf at
185      * depth n, we have the leaf at depth 0 and the TA at depth n).
186      */
187     if ((tree->levels = OPENSSL_zalloc(sizeof(*tree->levels)*(n+1))) == NULL) {
188         OPENSSL_free(tree);
189         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
190         return X509_PCY_TREE_INTERNAL;
191     }
192     tree->nlevel = n+1;
193     level = tree->levels;
194     if ((data = ossl_policy_data_new(NULL,
195                                      OBJ_nid2obj(NID_any_policy), 0)) == NULL)
196         goto bad_tree;
197     if (ossl_policy_level_add_node(level, data, NULL, tree, 1) == NULL) {
198         ossl_policy_data_free(data);
199         goto bad_tree;
200     }
201 
202     /*
203      * In this pass initialize all the tree levels and whether anyPolicy and
204      * policy mapping are inhibited at each level.
205      */
206     for (i = n - 1; i >= 0; i--) {
207         X509 *x = sk_X509_value(certs, i);
208         uint32_t ex_flags = X509_get_extension_flags(x);
209 
210         /* Access the cache which we now know exists */
211         cache = ossl_policy_cache_set(x);
212 
213         X509_up_ref(x);
214         (++level)->cert = x;
215 
216         if (!cache->anyPolicy)
217             level->flags |= X509_V_FLAG_INHIBIT_ANY;
218 
219         /* Determine inhibit any and inhibit map flags */
220         if (any_skip == 0) {
221             /*
222              * Any matching allowed only if certificate is self issued and not
223              * the last in the chain.
224              */
225             if (!(ex_flags & EXFLAG_SI) || (i == 0))
226                 level->flags |= X509_V_FLAG_INHIBIT_ANY;
227         } else {
228             if (!(ex_flags & EXFLAG_SI))
229                 any_skip--;
230             if ((cache->any_skip >= 0) && (cache->any_skip < any_skip))
231                 any_skip = cache->any_skip;
232         }
233 
234         if (map_skip == 0)
235             level->flags |= X509_V_FLAG_INHIBIT_MAP;
236         else {
237             if (!(ex_flags & EXFLAG_SI))
238                 map_skip--;
239             if ((cache->map_skip >= 0) && (cache->map_skip < map_skip))
240                 map_skip = cache->map_skip;
241         }
242     }
243 
244     *ptree = tree;
245     return ret;
246 
247  bad_tree:
248     X509_policy_tree_free(tree);
249     return X509_PCY_TREE_INTERNAL;
250 }
251 
252 /*
253  * Return value: 1 on success, 0 otherwise
254  */
tree_link_matching_nodes(X509_POLICY_LEVEL * curr,X509_POLICY_DATA * data,X509_POLICY_TREE * tree)255 static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
256                                     X509_POLICY_DATA *data,
257                                     X509_POLICY_TREE *tree)
258 {
259     X509_POLICY_LEVEL *last = curr - 1;
260     int i, matched = 0;
261 
262     /* Iterate through all in nodes linking matches */
263     for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
264         X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
265 
266         if (ossl_policy_node_match(last, node, data->valid_policy)) {
267             if (ossl_policy_level_add_node(curr, data, node, tree, 0) == NULL)
268                 return 0;
269             matched = 1;
270         }
271     }
272     if (!matched && last->anyPolicy) {
273         if (ossl_policy_level_add_node(curr, data, last->anyPolicy, tree, 0) == NULL)
274             return 0;
275     }
276     return 1;
277 }
278 
279 /*
280  * This corresponds to RFC3280 6.1.3(d)(1): link any data from
281  * CertificatePolicies onto matching parent or anyPolicy if no match.
282  *
283  * Return value: 1 on success, 0 otherwise.
284  */
tree_link_nodes(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_TREE * tree)285 static int tree_link_nodes(X509_POLICY_LEVEL *curr,
286                            const X509_POLICY_CACHE *cache,
287                            X509_POLICY_TREE *tree)
288 {
289     int i;
290 
291     for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++) {
292         X509_POLICY_DATA *data = sk_X509_POLICY_DATA_value(cache->data, i);
293 
294         /* Look for matching nodes in previous level */
295         if (!tree_link_matching_nodes(curr, data, tree))
296             return 0;
297     }
298     return 1;
299 }
300 
301 /*
302  * This corresponds to RFC3280 6.1.3(d)(2): Create new data for any unmatched
303  * policies in the parent and link to anyPolicy.
304  *
305  * Return value: 1 on success, 0 otherwise.
306  */
tree_add_unmatched(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,const ASN1_OBJECT * id,X509_POLICY_NODE * node,X509_POLICY_TREE * tree)307 static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
308                               const X509_POLICY_CACHE *cache,
309                               const ASN1_OBJECT *id,
310                               X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
311 {
312     X509_POLICY_DATA *data;
313 
314     if (id == NULL)
315         id = node->data->valid_policy;
316     /*
317      * Create a new node with qualifiers from anyPolicy and id from unmatched
318      * node.
319      */
320     if ((data = ossl_policy_data_new(NULL, id, node_critical(node))) == NULL)
321         return 0;
322 
323     /* Curr may not have anyPolicy */
324     data->qualifier_set = cache->anyPolicy->qualifier_set;
325     data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
326     if (ossl_policy_level_add_node(curr, data, node, tree, 1) == NULL) {
327         ossl_policy_data_free(data);
328         return 0;
329     }
330     return 1;
331 }
332 
333 /*
334  * Return value: 1 on success, 0 otherwise.
335  */
tree_link_unmatched(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_NODE * node,X509_POLICY_TREE * tree)336 static int tree_link_unmatched(X509_POLICY_LEVEL *curr,
337                                const X509_POLICY_CACHE *cache,
338                                X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
339 {
340     const X509_POLICY_LEVEL *last = curr - 1;
341     int i;
342 
343     if ((last->flags & X509_V_FLAG_INHIBIT_MAP)
344         || !(node->data->flags & POLICY_DATA_FLAG_MAPPED)) {
345         /* If no policy mapping: matched if one child present */
346         if (node->nchild)
347             return 1;
348         if (!tree_add_unmatched(curr, cache, NULL, node, tree))
349             return 0;
350         /* Add it */
351     } else {
352         /* If mapping: matched if one child per expected policy set */
353         STACK_OF(ASN1_OBJECT) *expset = node->data->expected_policy_set;
354         if (node->nchild == sk_ASN1_OBJECT_num(expset))
355             return 1;
356         /* Locate unmatched nodes */
357         for (i = 0; i < sk_ASN1_OBJECT_num(expset); i++) {
358             ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(expset, i);
359             if (ossl_policy_level_find_node(curr, node, oid))
360                 continue;
361             if (!tree_add_unmatched(curr, cache, oid, node, tree))
362                 return 0;
363         }
364 
365     }
366     return 1;
367 }
368 
369 /*
370  * Return value: 1 on success, 0 otherwise
371  */
tree_link_any(X509_POLICY_LEVEL * curr,const X509_POLICY_CACHE * cache,X509_POLICY_TREE * tree)372 static int tree_link_any(X509_POLICY_LEVEL *curr,
373                          const X509_POLICY_CACHE *cache,
374                          X509_POLICY_TREE *tree)
375 {
376     int i;
377     X509_POLICY_NODE *node;
378     X509_POLICY_LEVEL *last = curr - 1;
379 
380     for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
381         node = sk_X509_POLICY_NODE_value(last->nodes, i);
382 
383         if (!tree_link_unmatched(curr, cache, node, tree))
384             return 0;
385     }
386     /* Finally add link to anyPolicy */
387     if (last->anyPolicy &&
388             ossl_policy_level_add_node(curr, cache->anyPolicy,
389                                        last->anyPolicy, tree, 0) == NULL)
390         return 0;
391     return 1;
392 }
393 
394 /*-
395  * Prune the tree: delete any child mapped child data on the current level then
396  * proceed up the tree deleting any data with no children. If we ever have no
397  * data on a level we can halt because the tree will be empty.
398  *
399  * Return value: <= 0 error, otherwise one of:
400  *
401  * X509_PCY_TREE_VALID: valid tree
402  * X509_PCY_TREE_EMPTY: empty tree
403  */
tree_prune(X509_POLICY_TREE * tree,X509_POLICY_LEVEL * curr)404 static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
405 {
406     STACK_OF(X509_POLICY_NODE) *nodes;
407     X509_POLICY_NODE *node;
408     int i;
409     nodes = curr->nodes;
410     if (curr->flags & X509_V_FLAG_INHIBIT_MAP) {
411         for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
412             node = sk_X509_POLICY_NODE_value(nodes, i);
413             /* Delete any mapped data: see RFC3280 XXXX */
414             if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK) {
415                 node->parent->nchild--;
416                 OPENSSL_free(node);
417                 (void)sk_X509_POLICY_NODE_delete(nodes, i);
418             }
419         }
420     }
421 
422     for (;;) {
423         --curr;
424         nodes = curr->nodes;
425         for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
426             node = sk_X509_POLICY_NODE_value(nodes, i);
427             if (node->nchild == 0) {
428                 node->parent->nchild--;
429                 OPENSSL_free(node);
430                 (void)sk_X509_POLICY_NODE_delete(nodes, i);
431             }
432         }
433         if (curr->anyPolicy && !curr->anyPolicy->nchild) {
434             if (curr->anyPolicy->parent)
435                 curr->anyPolicy->parent->nchild--;
436             OPENSSL_free(curr->anyPolicy);
437             curr->anyPolicy = NULL;
438         }
439         if (curr == tree->levels) {
440             /* If we zapped anyPolicy at top then tree is empty */
441             if (!curr->anyPolicy)
442                 return X509_PCY_TREE_EMPTY;
443             break;
444         }
445     }
446     return X509_PCY_TREE_VALID;
447 }
448 
449 /*
450  * Return value: 1 on success, 0 otherwise.
451  */
tree_add_auth_node(STACK_OF (X509_POLICY_NODE)** pnodes,X509_POLICY_NODE * pcy)452 static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
453                               X509_POLICY_NODE *pcy)
454 {
455     if (*pnodes == NULL &&
456         (*pnodes = ossl_policy_node_cmp_new()) == NULL)
457         return 0;
458     if (sk_X509_POLICY_NODE_find(*pnodes, pcy) >= 0)
459         return 1;
460     return sk_X509_POLICY_NODE_push(*pnodes, pcy) != 0;
461 }
462 
463 #define TREE_CALC_FAILURE 0
464 #define TREE_CALC_OK_NOFREE 1
465 #define TREE_CALC_OK_DOFREE 2
466 
467 /*-
468  * Calculate the authority set based on policy tree. The 'pnodes' parameter is
469  * used as a store for the set of policy nodes used to calculate the user set.
470  * If the authority set is not anyPolicy then pnodes will just point to the
471  * authority set. If however the authority set is anyPolicy then the set of
472  * valid policies (other than anyPolicy) is store in pnodes.
473  *
474  * Return value:
475  *  TREE_CALC_FAILURE on failure,
476  *  TREE_CALC_OK_NOFREE on success and pnodes need not be freed,
477  *  TREE_CALC_OK_DOFREE on success and pnodes needs to be freed
478  */
tree_calculate_authority_set(X509_POLICY_TREE * tree,STACK_OF (X509_POLICY_NODE)** pnodes)479 static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
480                                         STACK_OF(X509_POLICY_NODE) **pnodes)
481 {
482     X509_POLICY_LEVEL *curr;
483     X509_POLICY_NODE *node, *anyptr;
484     STACK_OF(X509_POLICY_NODE) **addnodes;
485     int i, j;
486     curr = tree->levels + tree->nlevel - 1;
487 
488     /* If last level contains anyPolicy set is anyPolicy */
489     if (curr->anyPolicy) {
490         if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
491             return TREE_CALC_FAILURE;
492         addnodes = pnodes;
493     } else
494         /* Add policies to authority set */
495         addnodes = &tree->auth_policies;
496 
497     curr = tree->levels;
498     for (i = 1; i < tree->nlevel; i++) {
499         /*
500          * If no anyPolicy node on this level it can't appear on lower
501          * levels so end search.
502          */
503         if ((anyptr = curr->anyPolicy) == NULL)
504             break;
505         curr++;
506         for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++) {
507             node = sk_X509_POLICY_NODE_value(curr->nodes, j);
508             if ((node->parent == anyptr)
509                 && !tree_add_auth_node(addnodes, node)) {
510                 if (addnodes == pnodes) {
511                     sk_X509_POLICY_NODE_free(*pnodes);
512                     *pnodes = NULL;
513                 }
514                 return TREE_CALC_FAILURE;
515             }
516         }
517     }
518     if (addnodes == pnodes)
519         return TREE_CALC_OK_DOFREE;
520 
521     *pnodes = tree->auth_policies;
522     return TREE_CALC_OK_NOFREE;
523 }
524 
525 /*
526  * Return value: 1 on success, 0 otherwise.
527  */
tree_calculate_user_set(X509_POLICY_TREE * tree,STACK_OF (ASN1_OBJECT)* policy_oids,STACK_OF (X509_POLICY_NODE)* auth_nodes)528 static int tree_calculate_user_set(X509_POLICY_TREE *tree,
529                                    STACK_OF(ASN1_OBJECT) *policy_oids,
530                                    STACK_OF(X509_POLICY_NODE) *auth_nodes)
531 {
532     int i;
533     X509_POLICY_NODE *node;
534     ASN1_OBJECT *oid;
535     X509_POLICY_NODE *anyPolicy;
536     X509_POLICY_DATA *extra;
537 
538     /*
539      * Check if anyPolicy present in authority constrained policy set: this
540      * will happen if it is a leaf node.
541      */
542     if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
543         return 1;
544 
545     anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
546 
547     for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
548         oid = sk_ASN1_OBJECT_value(policy_oids, i);
549         if (OBJ_obj2nid(oid) == NID_any_policy) {
550             tree->flags |= POLICY_FLAG_ANY_POLICY;
551             return 1;
552         }
553     }
554 
555     for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
556         oid = sk_ASN1_OBJECT_value(policy_oids, i);
557         node = ossl_policy_tree_find_sk(auth_nodes, oid);
558         if (!node) {
559             if (!anyPolicy)
560                 continue;
561             /*
562              * Create a new node with policy ID from user set and qualifiers
563              * from anyPolicy.
564              */
565             extra = ossl_policy_data_new(NULL, oid, node_critical(anyPolicy));
566             if (extra == NULL)
567                 return 0;
568             extra->qualifier_set = anyPolicy->data->qualifier_set;
569             extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
570                 | POLICY_DATA_FLAG_EXTRA_NODE;
571             node = ossl_policy_level_add_node(NULL, extra, anyPolicy->parent,
572                                               tree, 1);
573         }
574         if (!tree->user_policies) {
575             tree->user_policies = sk_X509_POLICY_NODE_new_null();
576             if (!tree->user_policies)
577                 return 1;
578         }
579         if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))
580             return 0;
581     }
582     return 1;
583 }
584 
585 /*-
586  * Return value: <= 0 error, otherwise one of:
587  *  X509_PCY_TREE_VALID: valid tree
588  *  X509_PCY_TREE_EMPTY: empty tree
589  * (see tree_prune()).
590  */
tree_evaluate(X509_POLICY_TREE * tree)591 static int tree_evaluate(X509_POLICY_TREE *tree)
592 {
593     int ret, i;
594     X509_POLICY_LEVEL *curr = tree->levels + 1;
595     const X509_POLICY_CACHE *cache;
596 
597     for (i = 1; i < tree->nlevel; i++, curr++) {
598         cache = ossl_policy_cache_set(curr->cert);
599         if (!tree_link_nodes(curr, cache, tree))
600             return X509_PCY_TREE_INTERNAL;
601 
602         if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
603             && !tree_link_any(curr, cache, tree))
604             return X509_PCY_TREE_INTERNAL;
605         TREE_PRINT("before tree_prune()", tree, curr);
606         ret = tree_prune(tree, curr);
607         if (ret != X509_PCY_TREE_VALID)
608             return ret;
609     }
610     return X509_PCY_TREE_VALID;
611 }
612 
exnode_free(X509_POLICY_NODE * node)613 static void exnode_free(X509_POLICY_NODE *node)
614 {
615     if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
616         OPENSSL_free(node);
617 }
618 
X509_policy_tree_free(X509_POLICY_TREE * tree)619 void X509_policy_tree_free(X509_POLICY_TREE *tree)
620 {
621     X509_POLICY_LEVEL *curr;
622     int i;
623 
624     if (!tree)
625         return;
626 
627     sk_X509_POLICY_NODE_free(tree->auth_policies);
628     sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
629 
630     for (i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++) {
631         X509_free(curr->cert);
632         sk_X509_POLICY_NODE_pop_free(curr->nodes, ossl_policy_node_free);
633         ossl_policy_node_free(curr->anyPolicy);
634     }
635 
636     sk_X509_POLICY_DATA_pop_free(tree->extra_data, ossl_policy_data_free);
637     OPENSSL_free(tree->levels);
638     OPENSSL_free(tree);
639 
640 }
641 
642 /*-
643  * Application policy checking function.
644  * Return codes:
645  *  X509_PCY_TREE_FAILURE:  Failure to satisfy explicit policy
646  *  X509_PCY_TREE_INVALID:  Inconsistent or invalid extensions
647  *  X509_PCY_TREE_INTERNAL: Internal error, most likely malloc
648  *  X509_PCY_TREE_VALID:    Success (null tree if empty or bare TA)
649  */
X509_policy_check(X509_POLICY_TREE ** ptree,int * pexplicit_policy,STACK_OF (X509)* certs,STACK_OF (ASN1_OBJECT)* policy_oids,unsigned int flags)650 int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
651                       STACK_OF(X509) *certs,
652                       STACK_OF(ASN1_OBJECT) *policy_oids, unsigned int flags)
653 {
654     int init_ret;
655     int ret;
656     int calc_ret;
657     X509_POLICY_TREE *tree = NULL;
658     STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
659 
660     *ptree = NULL;
661     *pexplicit_policy = 0;
662     init_ret = tree_init(&tree, certs, flags);
663 
664     if (init_ret <= 0)
665         return init_ret;
666 
667     if ((init_ret & X509_PCY_TREE_EXPLICIT) == 0) {
668         if (init_ret & X509_PCY_TREE_EMPTY) {
669             X509_policy_tree_free(tree);
670             return X509_PCY_TREE_VALID;
671         }
672     } else {
673         *pexplicit_policy = 1;
674         /* Tree empty and requireExplicit True: Error */
675         if (init_ret & X509_PCY_TREE_EMPTY)
676             return X509_PCY_TREE_FAILURE;
677     }
678 
679     ret = tree_evaluate(tree);
680     TREE_PRINT("tree_evaluate()", tree, NULL);
681     if (ret <= 0)
682         goto error;
683 
684     if (ret == X509_PCY_TREE_EMPTY) {
685         X509_policy_tree_free(tree);
686         if (init_ret & X509_PCY_TREE_EXPLICIT)
687             return X509_PCY_TREE_FAILURE;
688         return X509_PCY_TREE_VALID;
689     }
690 
691     /* Tree is not empty: continue */
692 
693     if ((calc_ret = tree_calculate_authority_set(tree, &auth_nodes)) == 0)
694         goto error;
695     ret = tree_calculate_user_set(tree, policy_oids, auth_nodes);
696     if (calc_ret == TREE_CALC_OK_DOFREE)
697         sk_X509_POLICY_NODE_free(auth_nodes);
698     if (!ret)
699         goto error;
700 
701     *ptree = tree;
702 
703     if (init_ret & X509_PCY_TREE_EXPLICIT) {
704         nodes = X509_policy_tree_get0_user_policies(tree);
705         if (sk_X509_POLICY_NODE_num(nodes) <= 0)
706             return X509_PCY_TREE_FAILURE;
707     }
708     return X509_PCY_TREE_VALID;
709 
710  error:
711     X509_policy_tree_free(tree);
712     return X509_PCY_TREE_INTERNAL;
713 }
714