2 * Copyright 2004-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
10 #include "internal/cryptlib.h"
11 #include <openssl/x509.h>
12 #include <openssl/x509v3.h>
17 * Enable this to print out the complete policy tree at various point during
22 * #define OPENSSL_POLICY_DEBUG
25 #ifdef OPENSSL_POLICY_DEBUG
27 static void expected_print(BIO *err, X509_POLICY_LEVEL *lev,
28 X509_POLICY_NODE *node, int indent)
30 if ((lev->flags & X509_V_FLAG_INHIBIT_MAP)
31 || !(node->data->flags & POLICY_DATA_FLAG_MAP_MASK))
32 BIO_puts(err, " Not Mapped\n");
35 STACK_OF(ASN1_OBJECT) *pset = node->data->expected_policy_set;
37 BIO_puts(err, " Expected: ");
38 for (i = 0; i < sk_ASN1_OBJECT_num(pset); i++) {
39 oid = sk_ASN1_OBJECT_value(pset, i);
42 i2a_ASN1_OBJECT(err, oid);
48 static void tree_print(char *str, X509_POLICY_TREE *tree,
49 X509_POLICY_LEVEL *curr)
51 BIO *err = BIO_new_fp(stderr, BIO_NOCLOSE);
52 X509_POLICY_LEVEL *plev;
57 curr = tree->levels + tree->nlevel;
61 BIO_printf(err, "Level print after %s\n", str);
62 BIO_printf(err, "Printing Up to Level %ld\n", curr - tree->levels);
63 for (plev = tree->levels; plev != curr; plev++) {
66 BIO_printf(err, "Level %ld, flags = %x\n",
67 (long)(plev - tree->levels), plev->flags);
68 for (i = 0; i < sk_X509_POLICY_NODE_num(plev->nodes); i++) {
69 X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(plev->nodes, i);
71 X509_POLICY_NODE_print(err, node, 2);
72 expected_print(err, plev, node, 2);
73 BIO_printf(err, " Flags: %x\n", node->data->flags);
76 X509_POLICY_NODE_print(err, plev->anyPolicy, 2);
83 * Return value: <= 0 on error, or positive bit mask:
85 * X509_PCY_TREE_VALID: valid tree
86 * X509_PCY_TREE_EMPTY: empty tree (including bare TA case)
87 * X509_PCY_TREE_EXPLICIT: explicit policy required
89 static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
92 X509_POLICY_TREE *tree;
93 X509_POLICY_LEVEL *level;
94 const X509_POLICY_CACHE *cache;
95 X509_POLICY_DATA *data = NULL;
96 int ret = X509_PCY_TREE_VALID;
97 int n = sk_X509_num(certs) - 1; /* RFC5280 paths omit the TA */
98 int explicit_policy = (flags & X509_V_FLAG_EXPLICIT_POLICY) ? 0 : n+1;
99 int any_skip = (flags & X509_V_FLAG_INHIBIT_ANY) ? 0 : n+1;
100 int map_skip = (flags & X509_V_FLAG_INHIBIT_MAP) ? 0 : n+1;
105 /* Can't do anything with just a trust anchor */
107 return X509_PCY_TREE_EMPTY;
110 * First setup the policy cache in all n non-TA certificates, this will be
111 * used in X509_verify_cert() which will invoke the verify callback for all
112 * certificates with invalid policy extensions.
114 for (i = n - 1; i >= 0; i--) {
115 X509 *x = sk_X509_value(certs, i);
117 /* Call for side-effect of computing hash and caching extensions */
118 X509_check_purpose(x, -1, 0);
120 /* If cache is NULL, likely ENOMEM: return immediately */
121 if (policy_cache_set(x) == NULL)
122 return X509_PCY_TREE_INTERNAL;
126 * At this point check for invalid policies and required explicit policy.
127 * Note that the explicit_policy counter is a count-down to zero, with the
128 * requirement kicking in if and once it does that. The counter is
129 * decremented for every non-self-issued certificate in the path, but may
130 * be further reduced by policy constraints in a non-leaf certificate.
132 * The ultimate policy set is the intersection of all the policies along
133 * the path, if we hit a certificate with an empty policy set, and explicit
134 * policy is required we're done.
137 i >= 0 && (explicit_policy > 0 || (ret & X509_PCY_TREE_EMPTY) == 0);
139 X509 *x = sk_X509_value(certs, i);
140 uint32_t ex_flags = X509_get_extension_flags(x);
142 /* All the policies are already cached, we can return early */
143 if (ex_flags & EXFLAG_INVALID_POLICY)
144 return X509_PCY_TREE_INVALID;
146 /* Access the cache which we now know exists */
147 cache = policy_cache_set(x);
149 if ((ret & X509_PCY_TREE_VALID) && cache->data == NULL)
150 ret = X509_PCY_TREE_EMPTY;
151 if (explicit_policy > 0) {
152 if (!(ex_flags & EXFLAG_SI))
154 if ((cache->explicit_skip >= 0)
155 && (cache->explicit_skip < explicit_policy))
156 explicit_policy = cache->explicit_skip;
160 if (explicit_policy == 0)
161 ret |= X509_PCY_TREE_EXPLICIT;
162 if ((ret & X509_PCY_TREE_VALID) == 0)
165 /* If we get this far initialize the tree */
166 if ((tree = OPENSSL_zalloc(sizeof(*tree))) == NULL) {
167 X509V3err(X509V3_F_TREE_INIT, ERR_R_MALLOC_FAILURE);
168 return X509_PCY_TREE_INTERNAL;
172 * http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
174 * The top level is implicitly for the trust anchor with valid expected
175 * policies of anyPolicy. (RFC 5280 has the TA at depth 0 and the leaf at
176 * depth n, we have the leaf at depth 0 and the TA at depth n).
178 if ((tree->levels = OPENSSL_zalloc(sizeof(*tree->levels)*(n+1))) == NULL) {
180 X509V3err(X509V3_F_TREE_INIT, ERR_R_MALLOC_FAILURE);
181 return X509_PCY_TREE_INTERNAL;
184 level = tree->levels;
185 if ((data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0)) == NULL)
187 if (level_add_node(level, data, NULL, tree) == NULL) {
188 policy_data_free(data);
193 * In this pass initialize all the tree levels and whether anyPolicy and
194 * policy mapping are inhibited at each level.
196 for (i = n - 1; i >= 0; i--) {
197 X509 *x = sk_X509_value(certs, i);
198 uint32_t ex_flags = X509_get_extension_flags(x);
200 /* Access the cache which we now know exists */
201 cache = policy_cache_set(x);
206 if (!cache->anyPolicy)
207 level->flags |= X509_V_FLAG_INHIBIT_ANY;
209 /* Determine inhibit any and inhibit map flags */
212 * Any matching allowed only if certificate is self issued and not
213 * the last in the chain.
215 if (!(ex_flags & EXFLAG_SI) || (i == 0))
216 level->flags |= X509_V_FLAG_INHIBIT_ANY;
218 if (!(ex_flags & EXFLAG_SI))
220 if ((cache->any_skip >= 0) && (cache->any_skip < any_skip))
221 any_skip = cache->any_skip;
225 level->flags |= X509_V_FLAG_INHIBIT_MAP;
227 if (!(ex_flags & EXFLAG_SI))
229 if ((cache->map_skip >= 0) && (cache->map_skip < map_skip))
230 map_skip = cache->map_skip;
238 X509_policy_tree_free(tree);
239 return X509_PCY_TREE_INTERNAL;
243 * Return value: 1 on success, 0 otherwise
245 static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
246 X509_POLICY_DATA *data)
248 X509_POLICY_LEVEL *last = curr - 1;
251 /* Iterate through all in nodes linking matches */
252 for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
253 X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
255 if (policy_node_match(last, node, data->valid_policy)) {
256 if (level_add_node(curr, data, node, NULL) == NULL)
261 if (!matched && last->anyPolicy) {
262 if (level_add_node(curr, data, last->anyPolicy, NULL) == NULL)
269 * This corresponds to RFC3280 6.1.3(d)(1): link any data from
270 * CertificatePolicies onto matching parent or anyPolicy if no match.
272 * Return value: 1 on success, 0 otherwise.
274 static int tree_link_nodes(X509_POLICY_LEVEL *curr,
275 const X509_POLICY_CACHE *cache)
279 for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++) {
280 X509_POLICY_DATA *data = sk_X509_POLICY_DATA_value(cache->data, i);
282 /* Look for matching nodes in previous level */
283 if (!tree_link_matching_nodes(curr, data))
290 * This corresponds to RFC3280 6.1.3(d)(2): Create new data for any unmatched
291 * policies in the parent and link to anyPolicy.
293 * Return value: 1 on success, 0 otherwise.
295 static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
296 const X509_POLICY_CACHE *cache,
297 const ASN1_OBJECT *id,
298 X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
300 X509_POLICY_DATA *data;
303 id = node->data->valid_policy;
305 * Create a new node with qualifiers from anyPolicy and id from unmatched
308 if ((data = policy_data_new(NULL, id, node_critical(node))) == NULL)
311 /* Curr may not have anyPolicy */
312 data->qualifier_set = cache->anyPolicy->qualifier_set;
313 data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
314 if (level_add_node(curr, data, node, tree) == NULL) {
315 policy_data_free(data);
322 * Return value: 1 on success, 0 otherwise.
324 static int tree_link_unmatched(X509_POLICY_LEVEL *curr,
325 const X509_POLICY_CACHE *cache,
326 X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
328 const X509_POLICY_LEVEL *last = curr - 1;
331 if ((last->flags & X509_V_FLAG_INHIBIT_MAP)
332 || !(node->data->flags & POLICY_DATA_FLAG_MAPPED)) {
333 /* If no policy mapping: matched if one child present */
336 if (!tree_add_unmatched(curr, cache, NULL, node, tree))
340 /* If mapping: matched if one child per expected policy set */
341 STACK_OF(ASN1_OBJECT) *expset = node->data->expected_policy_set;
342 if (node->nchild == sk_ASN1_OBJECT_num(expset))
344 /* Locate unmatched nodes */
345 for (i = 0; i < sk_ASN1_OBJECT_num(expset); i++) {
346 ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(expset, i);
347 if (level_find_node(curr, node, oid))
349 if (!tree_add_unmatched(curr, cache, oid, node, tree))
358 * Return value: 1 on success, 0 otherwise
360 static int tree_link_any(X509_POLICY_LEVEL *curr,
361 const X509_POLICY_CACHE *cache,
362 X509_POLICY_TREE *tree)
365 X509_POLICY_NODE *node;
366 X509_POLICY_LEVEL *last = curr - 1;
368 for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
369 node = sk_X509_POLICY_NODE_value(last->nodes, i);
371 if (!tree_link_unmatched(curr, cache, node, tree))
374 /* Finally add link to anyPolicy */
375 if (last->anyPolicy &&
376 level_add_node(curr, cache->anyPolicy, last->anyPolicy, NULL) == NULL)
382 * Prune the tree: delete any child mapped child data on the current level then
383 * proceed up the tree deleting any data with no children. If we ever have no
384 * data on a level we can halt because the tree will be empty.
386 * Return value: <= 0 error, otherwise one of:
388 * X509_PCY_TREE_VALID: valid tree
389 * X509_PCY_TREE_EMPTY: empty tree
391 static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
393 STACK_OF(X509_POLICY_NODE) *nodes;
394 X509_POLICY_NODE *node;
397 if (curr->flags & X509_V_FLAG_INHIBIT_MAP) {
398 for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
399 node = sk_X509_POLICY_NODE_value(nodes, i);
400 /* Delete any mapped data: see RFC3280 XXXX */
401 if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK) {
402 node->parent->nchild--;
404 (void)sk_X509_POLICY_NODE_delete(nodes, i);
412 for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
413 node = sk_X509_POLICY_NODE_value(nodes, i);
414 if (node->nchild == 0) {
415 node->parent->nchild--;
417 (void)sk_X509_POLICY_NODE_delete(nodes, i);
420 if (curr->anyPolicy && !curr->anyPolicy->nchild) {
421 if (curr->anyPolicy->parent)
422 curr->anyPolicy->parent->nchild--;
423 OPENSSL_free(curr->anyPolicy);
424 curr->anyPolicy = NULL;
426 if (curr == tree->levels) {
427 /* If we zapped anyPolicy at top then tree is empty */
428 if (!curr->anyPolicy)
429 return X509_PCY_TREE_EMPTY;
433 return X509_PCY_TREE_VALID;
437 * Return value: 1 on success, 0 otherwise.
439 static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
440 X509_POLICY_NODE *pcy)
442 if (*pnodes == NULL &&
443 (*pnodes = policy_node_cmp_new()) == NULL)
445 if (sk_X509_POLICY_NODE_find(*pnodes, pcy) != -1)
447 return sk_X509_POLICY_NODE_push(*pnodes, pcy) != 0;
450 #define TREE_CALC_FAILURE 0
451 #define TREE_CALC_OK_NOFREE 1
452 #define TREE_CALC_OK_DOFREE 2
455 * Calculate the authority set based on policy tree. The 'pnodes' parameter is
456 * used as a store for the set of policy nodes used to calculate the user set.
457 * If the authority set is not anyPolicy then pnodes will just point to the
458 * authority set. If however the authority set is anyPolicy then the set of
459 * valid policies (other than anyPolicy) is store in pnodes.
462 * TREE_CALC_FAILURE on failure,
463 * TREE_CALC_OK_NOFREE on success and pnodes need not be freed,
464 * TREE_CALC_OK_DOFREE on success and pnodes needs to be freed
466 static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
467 STACK_OF(X509_POLICY_NODE) **pnodes)
469 X509_POLICY_LEVEL *curr;
470 X509_POLICY_NODE *node, *anyptr;
471 STACK_OF(X509_POLICY_NODE) **addnodes;
473 curr = tree->levels + tree->nlevel - 1;
475 /* If last level contains anyPolicy set is anyPolicy */
476 if (curr->anyPolicy) {
477 if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
478 return TREE_CALC_FAILURE;
481 /* Add policies to authority set */
482 addnodes = &tree->auth_policies;
485 for (i = 1; i < tree->nlevel; i++) {
487 * If no anyPolicy node on this this level it can't appear on lower
488 * levels so end search.
490 if ((anyptr = curr->anyPolicy) == NULL)
493 for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++) {
494 node = sk_X509_POLICY_NODE_value(curr->nodes, j);
495 if ((node->parent == anyptr)
496 && !tree_add_auth_node(addnodes, node)) {
497 if (addnodes == pnodes) {
498 sk_X509_POLICY_NODE_free(*pnodes);
501 return TREE_CALC_FAILURE;
505 if (addnodes == pnodes)
506 return TREE_CALC_OK_DOFREE;
508 *pnodes = tree->auth_policies;
509 return TREE_CALC_OK_NOFREE;
513 * Return value: 1 on success, 0 otherwise.
515 static int tree_calculate_user_set(X509_POLICY_TREE *tree,
516 STACK_OF(ASN1_OBJECT) *policy_oids,
517 STACK_OF(X509_POLICY_NODE) *auth_nodes)
520 X509_POLICY_NODE *node;
522 X509_POLICY_NODE *anyPolicy;
523 X509_POLICY_DATA *extra;
526 * Check if anyPolicy present in authority constrained policy set: this
527 * will happen if it is a leaf node.
529 if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
532 anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
534 for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
535 oid = sk_ASN1_OBJECT_value(policy_oids, i);
536 if (OBJ_obj2nid(oid) == NID_any_policy) {
537 tree->flags |= POLICY_FLAG_ANY_POLICY;
542 for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
543 oid = sk_ASN1_OBJECT_value(policy_oids, i);
544 node = tree_find_sk(auth_nodes, oid);
549 * Create a new node with policy ID from user set and qualifiers
552 extra = policy_data_new(NULL, oid, node_critical(anyPolicy));
555 extra->qualifier_set = anyPolicy->data->qualifier_set;
556 extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
557 | POLICY_DATA_FLAG_EXTRA_NODE;
558 node = level_add_node(NULL, extra, anyPolicy->parent, tree);
560 if (!tree->user_policies) {
561 tree->user_policies = sk_X509_POLICY_NODE_new_null();
562 if (!tree->user_policies)
565 if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))
572 * Return value: <= 0 error, otherwise one of:
573 * X509_PCY_TREE_VALID: valid tree
574 * X509_PCY_TREE_EMPTY: empty tree
575 * (see tree_prune()).
577 static int tree_evaluate(X509_POLICY_TREE *tree)
580 X509_POLICY_LEVEL *curr = tree->levels + 1;
581 const X509_POLICY_CACHE *cache;
583 for (i = 1; i < tree->nlevel; i++, curr++) {
584 cache = policy_cache_set(curr->cert);
585 if (!tree_link_nodes(curr, cache))
586 return X509_PCY_TREE_INTERNAL;
588 if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
589 && !tree_link_any(curr, cache, tree))
590 return X509_PCY_TREE_INTERNAL;
591 #ifdef OPENSSL_POLICY_DEBUG
592 tree_print("before tree_prune()", tree, curr);
594 ret = tree_prune(tree, curr);
595 if (ret != X509_PCY_TREE_VALID)
598 return X509_PCY_TREE_VALID;
601 static void exnode_free(X509_POLICY_NODE *node)
603 if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
607 void X509_policy_tree_free(X509_POLICY_TREE *tree)
609 X509_POLICY_LEVEL *curr;
615 sk_X509_POLICY_NODE_free(tree->auth_policies);
616 sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
618 for (i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++) {
619 X509_free(curr->cert);
620 sk_X509_POLICY_NODE_pop_free(curr->nodes, policy_node_free);
621 policy_node_free(curr->anyPolicy);
624 sk_X509_POLICY_DATA_pop_free(tree->extra_data, policy_data_free);
625 OPENSSL_free(tree->levels);
631 * Application policy checking function.
633 * X509_PCY_TREE_FAILURE: Failure to satisfy explicit policy
634 * X509_PCY_TREE_INVALID: Inconsistent or invalid extensions
635 * X509_PCY_TREE_INTERNAL: Internal error, most likely malloc
636 * X509_PCY_TREE_VALID: Success (null tree if empty or bare TA)
638 int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
639 STACK_OF(X509) *certs,
640 STACK_OF(ASN1_OBJECT) *policy_oids, unsigned int flags)
645 X509_POLICY_TREE *tree = NULL;
646 STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
649 *pexplicit_policy = 0;
650 init_ret = tree_init(&tree, certs, flags);
655 if ((init_ret & X509_PCY_TREE_EXPLICIT) == 0) {
656 if (init_ret & X509_PCY_TREE_EMPTY) {
657 X509_policy_tree_free(tree);
658 return X509_PCY_TREE_VALID;
661 *pexplicit_policy = 1;
662 /* Tree empty and requireExplicit True: Error */
663 if (init_ret & X509_PCY_TREE_EMPTY)
664 return X509_PCY_TREE_FAILURE;
667 ret = tree_evaluate(tree);
668 #ifdef OPENSSL_POLICY_DEBUG
669 tree_print("tree_evaluate()", tree, NULL);
674 if (ret == X509_PCY_TREE_EMPTY) {
675 X509_policy_tree_free(tree);
676 if (init_ret & X509_PCY_TREE_EXPLICIT)
677 return X509_PCY_TREE_FAILURE;
678 return X509_PCY_TREE_VALID;
681 /* Tree is not empty: continue */
683 if ((calc_ret = tree_calculate_authority_set(tree, &auth_nodes)) == 0)
685 ret = tree_calculate_user_set(tree, policy_oids, auth_nodes);
686 if (calc_ret == TREE_CALC_OK_DOFREE)
687 sk_X509_POLICY_NODE_free(auth_nodes);
693 if (init_ret & X509_PCY_TREE_EXPLICIT) {
694 nodes = X509_policy_tree_get0_user_policies(tree);
695 if (sk_X509_POLICY_NODE_num(nodes) <= 0)
696 return X509_PCY_TREE_FAILURE;
698 return X509_PCY_TREE_VALID;
701 X509_policy_tree_free(tree);
702 return X509_PCY_TREE_INTERNAL;