openssl/crypto/x509/pcy_tree.c
Richard Levitte 878dc8dd95 Join the x509 and x509v3 directories
This has been long overdue.

Note that this does not join the X509 and X509V3 error modules, that
will be too many macro changes at this stage.

Fixes #8919

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8925)
2019-05-29 09:32:50 +02:00

695 lines
22 KiB
C

/*
* Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "internal/cryptlib.h"
#include <openssl/trace.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include "pcy_int.h"
static void expected_print(BIO *channel,
X509_POLICY_LEVEL *lev, X509_POLICY_NODE *node,
int indent)
{
if ((lev->flags & X509_V_FLAG_INHIBIT_MAP)
|| !(node->data->flags & POLICY_DATA_FLAG_MAP_MASK))
BIO_puts(channel, " Not Mapped\n");
else {
int i;
STACK_OF(ASN1_OBJECT) *pset = node->data->expected_policy_set;
ASN1_OBJECT *oid;
BIO_puts(channel, " Expected: ");
for (i = 0; i < sk_ASN1_OBJECT_num(pset); i++) {
oid = sk_ASN1_OBJECT_value(pset, i);
if (i)
BIO_puts(channel, ", ");
i2a_ASN1_OBJECT(channel, oid);
}
BIO_puts(channel, "\n");
}
}
static void tree_print(BIO *channel,
char *str, X509_POLICY_TREE *tree,
X509_POLICY_LEVEL *curr)
{
X509_POLICY_LEVEL *plev;
if (!curr)
curr = tree->levels + tree->nlevel;
else
curr++;
BIO_printf(channel, "Level print after %s\n", str);
BIO_printf(channel, "Printing Up to Level %ld\n",
curr - tree->levels);
for (plev = tree->levels; plev != curr; plev++) {
int i;
BIO_printf(channel, "Level %ld, flags = %x\n",
(long)(plev - tree->levels), plev->flags);
for (i = 0; i < sk_X509_POLICY_NODE_num(plev->nodes); i++) {
X509_POLICY_NODE *node =
sk_X509_POLICY_NODE_value(plev->nodes, i);
X509_POLICY_NODE_print(channel, node, 2);
expected_print(channel, plev, node, 2);
BIO_printf(channel, " Flags: %x\n", node->data->flags);
}
if (plev->anyPolicy)
X509_POLICY_NODE_print(channel, plev->anyPolicy, 2);
}
}
#define TREE_PRINT(str, tree, curr) \
OSSL_TRACE_BEGIN(X509V3_POLICY) { \
tree_print(trc_out, "before tree_prune()", tree, curr); \
} OSSL_TRACE_END(X509V3_POLICY)
/*-
* Return value: <= 0 on error, or positive bit mask:
*
* X509_PCY_TREE_VALID: valid tree
* X509_PCY_TREE_EMPTY: empty tree (including bare TA case)
* X509_PCY_TREE_EXPLICIT: explicit policy required
*/
static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
unsigned int flags)
{
X509_POLICY_TREE *tree;
X509_POLICY_LEVEL *level;
const X509_POLICY_CACHE *cache;
X509_POLICY_DATA *data = NULL;
int ret = X509_PCY_TREE_VALID;
int n = sk_X509_num(certs) - 1; /* RFC5280 paths omit the TA */
int explicit_policy = (flags & X509_V_FLAG_EXPLICIT_POLICY) ? 0 : n+1;
int any_skip = (flags & X509_V_FLAG_INHIBIT_ANY) ? 0 : n+1;
int map_skip = (flags & X509_V_FLAG_INHIBIT_MAP) ? 0 : n+1;
int i;
*ptree = NULL;
/* Can't do anything with just a trust anchor */
if (n == 0)
return X509_PCY_TREE_EMPTY;
/*
* First setup the policy cache in all n non-TA certificates, this will be
* used in X509_verify_cert() which will invoke the verify callback for all
* certificates with invalid policy extensions.
*/
for (i = n - 1; i >= 0; i--) {
X509 *x = sk_X509_value(certs, i);
/* Call for side-effect of computing hash and caching extensions */
X509_check_purpose(x, -1, 0);
/* If cache is NULL, likely ENOMEM: return immediately */
if (policy_cache_set(x) == NULL)
return X509_PCY_TREE_INTERNAL;
}
/*
* At this point check for invalid policies and required explicit policy.
* Note that the explicit_policy counter is a count-down to zero, with the
* requirement kicking in if and once it does that. The counter is
* decremented for every non-self-issued certificate in the path, but may
* be further reduced by policy constraints in a non-leaf certificate.
*
* The ultimate policy set is the intersection of all the policies along
* the path, if we hit a certificate with an empty policy set, and explicit
* policy is required we're done.
*/
for (i = n - 1;
i >= 0 && (explicit_policy > 0 || (ret & X509_PCY_TREE_EMPTY) == 0);
i--) {
X509 *x = sk_X509_value(certs, i);
uint32_t ex_flags = X509_get_extension_flags(x);
/* All the policies are already cached, we can return early */
if (ex_flags & EXFLAG_INVALID_POLICY)
return X509_PCY_TREE_INVALID;
/* Access the cache which we now know exists */
cache = policy_cache_set(x);
if ((ret & X509_PCY_TREE_VALID) && cache->data == NULL)
ret = X509_PCY_TREE_EMPTY;
if (explicit_policy > 0) {
if (!(ex_flags & EXFLAG_SI))
explicit_policy--;
if ((cache->explicit_skip >= 0)
&& (cache->explicit_skip < explicit_policy))
explicit_policy = cache->explicit_skip;
}
}
if (explicit_policy == 0)
ret |= X509_PCY_TREE_EXPLICIT;
if ((ret & X509_PCY_TREE_VALID) == 0)
return ret;
/* If we get this far initialize the tree */
if ((tree = OPENSSL_zalloc(sizeof(*tree))) == NULL) {
X509V3err(X509V3_F_TREE_INIT, ERR_R_MALLOC_FAILURE);
return X509_PCY_TREE_INTERNAL;
}
/*
* http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
*
* The top level is implicitly for the trust anchor with valid expected
* policies of anyPolicy. (RFC 5280 has the TA at depth 0 and the leaf at
* depth n, we have the leaf at depth 0 and the TA at depth n).
*/
if ((tree->levels = OPENSSL_zalloc(sizeof(*tree->levels)*(n+1))) == NULL) {
OPENSSL_free(tree);
X509V3err(X509V3_F_TREE_INIT, ERR_R_MALLOC_FAILURE);
return X509_PCY_TREE_INTERNAL;
}
tree->nlevel = n+1;
level = tree->levels;
if ((data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0)) == NULL)
goto bad_tree;
if (level_add_node(level, data, NULL, tree) == NULL) {
policy_data_free(data);
goto bad_tree;
}
/*
* In this pass initialize all the tree levels and whether anyPolicy and
* policy mapping are inhibited at each level.
*/
for (i = n - 1; i >= 0; i--) {
X509 *x = sk_X509_value(certs, i);
uint32_t ex_flags = X509_get_extension_flags(x);
/* Access the cache which we now know exists */
cache = policy_cache_set(x);
X509_up_ref(x);
(++level)->cert = x;
if (!cache->anyPolicy)
level->flags |= X509_V_FLAG_INHIBIT_ANY;
/* Determine inhibit any and inhibit map flags */
if (any_skip == 0) {
/*
* Any matching allowed only if certificate is self issued and not
* the last in the chain.
*/
if (!(ex_flags & EXFLAG_SI) || (i == 0))
level->flags |= X509_V_FLAG_INHIBIT_ANY;
} else {
if (!(ex_flags & EXFLAG_SI))
any_skip--;
if ((cache->any_skip >= 0) && (cache->any_skip < any_skip))
any_skip = cache->any_skip;
}
if (map_skip == 0)
level->flags |= X509_V_FLAG_INHIBIT_MAP;
else {
if (!(ex_flags & EXFLAG_SI))
map_skip--;
if ((cache->map_skip >= 0) && (cache->map_skip < map_skip))
map_skip = cache->map_skip;
}
}
*ptree = tree;
return ret;
bad_tree:
X509_policy_tree_free(tree);
return X509_PCY_TREE_INTERNAL;
}
/*
* Return value: 1 on success, 0 otherwise
*/
static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
X509_POLICY_DATA *data)
{
X509_POLICY_LEVEL *last = curr - 1;
int i, matched = 0;
/* Iterate through all in nodes linking matches */
for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
if (policy_node_match(last, node, data->valid_policy)) {
if (level_add_node(curr, data, node, NULL) == NULL)
return 0;
matched = 1;
}
}
if (!matched && last->anyPolicy) {
if (level_add_node(curr, data, last->anyPolicy, NULL) == NULL)
return 0;
}
return 1;
}
/*
* This corresponds to RFC3280 6.1.3(d)(1): link any data from
* CertificatePolicies onto matching parent or anyPolicy if no match.
*
* Return value: 1 on success, 0 otherwise.
*/
static int tree_link_nodes(X509_POLICY_LEVEL *curr,
const X509_POLICY_CACHE *cache)
{
int i;
for (i = 0; i < sk_X509_POLICY_DATA_num(cache->data); i++) {
X509_POLICY_DATA *data = sk_X509_POLICY_DATA_value(cache->data, i);
/* Look for matching nodes in previous level */
if (!tree_link_matching_nodes(curr, data))
return 0;
}
return 1;
}
/*
* This corresponds to RFC3280 6.1.3(d)(2): Create new data for any unmatched
* policies in the parent and link to anyPolicy.
*
* Return value: 1 on success, 0 otherwise.
*/
static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
const X509_POLICY_CACHE *cache,
const ASN1_OBJECT *id,
X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
{
X509_POLICY_DATA *data;
if (id == NULL)
id = node->data->valid_policy;
/*
* Create a new node with qualifiers from anyPolicy and id from unmatched
* node.
*/
if ((data = policy_data_new(NULL, id, node_critical(node))) == NULL)
return 0;
/* Curr may not have anyPolicy */
data->qualifier_set = cache->anyPolicy->qualifier_set;
data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
if (level_add_node(curr, data, node, tree) == NULL) {
policy_data_free(data);
return 0;
}
return 1;
}
/*
* Return value: 1 on success, 0 otherwise.
*/
static int tree_link_unmatched(X509_POLICY_LEVEL *curr,
const X509_POLICY_CACHE *cache,
X509_POLICY_NODE *node, X509_POLICY_TREE *tree)
{
const X509_POLICY_LEVEL *last = curr - 1;
int i;
if ((last->flags & X509_V_FLAG_INHIBIT_MAP)
|| !(node->data->flags & POLICY_DATA_FLAG_MAPPED)) {
/* If no policy mapping: matched if one child present */
if (node->nchild)
return 1;
if (!tree_add_unmatched(curr, cache, NULL, node, tree))
return 0;
/* Add it */
} else {
/* If mapping: matched if one child per expected policy set */
STACK_OF(ASN1_OBJECT) *expset = node->data->expected_policy_set;
if (node->nchild == sk_ASN1_OBJECT_num(expset))
return 1;
/* Locate unmatched nodes */
for (i = 0; i < sk_ASN1_OBJECT_num(expset); i++) {
ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(expset, i);
if (level_find_node(curr, node, oid))
continue;
if (!tree_add_unmatched(curr, cache, oid, node, tree))
return 0;
}
}
return 1;
}
/*
* Return value: 1 on success, 0 otherwise
*/
static int tree_link_any(X509_POLICY_LEVEL *curr,
const X509_POLICY_CACHE *cache,
X509_POLICY_TREE *tree)
{
int i;
X509_POLICY_NODE *node;
X509_POLICY_LEVEL *last = curr - 1;
for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
node = sk_X509_POLICY_NODE_value(last->nodes, i);
if (!tree_link_unmatched(curr, cache, node, tree))
return 0;
}
/* Finally add link to anyPolicy */
if (last->anyPolicy &&
level_add_node(curr, cache->anyPolicy, last->anyPolicy, NULL) == NULL)
return 0;
return 1;
}
/*-
* Prune the tree: delete any child mapped child data on the current level then
* proceed up the tree deleting any data with no children. If we ever have no
* data on a level we can halt because the tree will be empty.
*
* Return value: <= 0 error, otherwise one of:
*
* X509_PCY_TREE_VALID: valid tree
* X509_PCY_TREE_EMPTY: empty tree
*/
static int tree_prune(X509_POLICY_TREE *tree, X509_POLICY_LEVEL *curr)
{
STACK_OF(X509_POLICY_NODE) *nodes;
X509_POLICY_NODE *node;
int i;
nodes = curr->nodes;
if (curr->flags & X509_V_FLAG_INHIBIT_MAP) {
for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
node = sk_X509_POLICY_NODE_value(nodes, i);
/* Delete any mapped data: see RFC3280 XXXX */
if (node->data->flags & POLICY_DATA_FLAG_MAP_MASK) {
node->parent->nchild--;
OPENSSL_free(node);
(void)sk_X509_POLICY_NODE_delete(nodes, i);
}
}
}
for (;;) {
--curr;
nodes = curr->nodes;
for (i = sk_X509_POLICY_NODE_num(nodes) - 1; i >= 0; i--) {
node = sk_X509_POLICY_NODE_value(nodes, i);
if (node->nchild == 0) {
node->parent->nchild--;
OPENSSL_free(node);
(void)sk_X509_POLICY_NODE_delete(nodes, i);
}
}
if (curr->anyPolicy && !curr->anyPolicy->nchild) {
if (curr->anyPolicy->parent)
curr->anyPolicy->parent->nchild--;
OPENSSL_free(curr->anyPolicy);
curr->anyPolicy = NULL;
}
if (curr == tree->levels) {
/* If we zapped anyPolicy at top then tree is empty */
if (!curr->anyPolicy)
return X509_PCY_TREE_EMPTY;
break;
}
}
return X509_PCY_TREE_VALID;
}
/*
* Return value: 1 on success, 0 otherwise.
*/
static int tree_add_auth_node(STACK_OF(X509_POLICY_NODE) **pnodes,
X509_POLICY_NODE *pcy)
{
if (*pnodes == NULL &&
(*pnodes = policy_node_cmp_new()) == NULL)
return 0;
if (sk_X509_POLICY_NODE_find(*pnodes, pcy) >= 0)
return 1;
return sk_X509_POLICY_NODE_push(*pnodes, pcy) != 0;
}
#define TREE_CALC_FAILURE 0
#define TREE_CALC_OK_NOFREE 1
#define TREE_CALC_OK_DOFREE 2
/*-
* Calculate the authority set based on policy tree. The 'pnodes' parameter is
* used as a store for the set of policy nodes used to calculate the user set.
* If the authority set is not anyPolicy then pnodes will just point to the
* authority set. If however the authority set is anyPolicy then the set of
* valid policies (other than anyPolicy) is store in pnodes.
*
* Return value:
* TREE_CALC_FAILURE on failure,
* TREE_CALC_OK_NOFREE on success and pnodes need not be freed,
* TREE_CALC_OK_DOFREE on success and pnodes needs to be freed
*/
static int tree_calculate_authority_set(X509_POLICY_TREE *tree,
STACK_OF(X509_POLICY_NODE) **pnodes)
{
X509_POLICY_LEVEL *curr;
X509_POLICY_NODE *node, *anyptr;
STACK_OF(X509_POLICY_NODE) **addnodes;
int i, j;
curr = tree->levels + tree->nlevel - 1;
/* If last level contains anyPolicy set is anyPolicy */
if (curr->anyPolicy) {
if (!tree_add_auth_node(&tree->auth_policies, curr->anyPolicy))
return TREE_CALC_FAILURE;
addnodes = pnodes;
} else
/* Add policies to authority set */
addnodes = &tree->auth_policies;
curr = tree->levels;
for (i = 1; i < tree->nlevel; i++) {
/*
* If no anyPolicy node on this this level it can't appear on lower
* levels so end search.
*/
if ((anyptr = curr->anyPolicy) == NULL)
break;
curr++;
for (j = 0; j < sk_X509_POLICY_NODE_num(curr->nodes); j++) {
node = sk_X509_POLICY_NODE_value(curr->nodes, j);
if ((node->parent == anyptr)
&& !tree_add_auth_node(addnodes, node)) {
if (addnodes == pnodes) {
sk_X509_POLICY_NODE_free(*pnodes);
*pnodes = NULL;
}
return TREE_CALC_FAILURE;
}
}
}
if (addnodes == pnodes)
return TREE_CALC_OK_DOFREE;
*pnodes = tree->auth_policies;
return TREE_CALC_OK_NOFREE;
}
/*
* Return value: 1 on success, 0 otherwise.
*/
static int tree_calculate_user_set(X509_POLICY_TREE *tree,
STACK_OF(ASN1_OBJECT) *policy_oids,
STACK_OF(X509_POLICY_NODE) *auth_nodes)
{
int i;
X509_POLICY_NODE *node;
ASN1_OBJECT *oid;
X509_POLICY_NODE *anyPolicy;
X509_POLICY_DATA *extra;
/*
* Check if anyPolicy present in authority constrained policy set: this
* will happen if it is a leaf node.
*/
if (sk_ASN1_OBJECT_num(policy_oids) <= 0)
return 1;
anyPolicy = tree->levels[tree->nlevel - 1].anyPolicy;
for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
oid = sk_ASN1_OBJECT_value(policy_oids, i);
if (OBJ_obj2nid(oid) == NID_any_policy) {
tree->flags |= POLICY_FLAG_ANY_POLICY;
return 1;
}
}
for (i = 0; i < sk_ASN1_OBJECT_num(policy_oids); i++) {
oid = sk_ASN1_OBJECT_value(policy_oids, i);
node = tree_find_sk(auth_nodes, oid);
if (!node) {
if (!anyPolicy)
continue;
/*
* Create a new node with policy ID from user set and qualifiers
* from anyPolicy.
*/
extra = policy_data_new(NULL, oid, node_critical(anyPolicy));
if (extra == NULL)
return 0;
extra->qualifier_set = anyPolicy->data->qualifier_set;
extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
| POLICY_DATA_FLAG_EXTRA_NODE;
node = level_add_node(NULL, extra, anyPolicy->parent, tree);
}
if (!tree->user_policies) {
tree->user_policies = sk_X509_POLICY_NODE_new_null();
if (!tree->user_policies)
return 1;
}
if (!sk_X509_POLICY_NODE_push(tree->user_policies, node))
return 0;
}
return 1;
}
/*-
* Return value: <= 0 error, otherwise one of:
* X509_PCY_TREE_VALID: valid tree
* X509_PCY_TREE_EMPTY: empty tree
* (see tree_prune()).
*/
static int tree_evaluate(X509_POLICY_TREE *tree)
{
int ret, i;
X509_POLICY_LEVEL *curr = tree->levels + 1;
const X509_POLICY_CACHE *cache;
for (i = 1; i < tree->nlevel; i++, curr++) {
cache = policy_cache_set(curr->cert);
if (!tree_link_nodes(curr, cache))
return X509_PCY_TREE_INTERNAL;
if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
&& !tree_link_any(curr, cache, tree))
return X509_PCY_TREE_INTERNAL;
TREE_PRINT("before tree_prune()", tree, curr);
ret = tree_prune(tree, curr);
if (ret != X509_PCY_TREE_VALID)
return ret;
}
return X509_PCY_TREE_VALID;
}
static void exnode_free(X509_POLICY_NODE *node)
{
if (node->data && (node->data->flags & POLICY_DATA_FLAG_EXTRA_NODE))
OPENSSL_free(node);
}
void X509_policy_tree_free(X509_POLICY_TREE *tree)
{
X509_POLICY_LEVEL *curr;
int i;
if (!tree)
return;
sk_X509_POLICY_NODE_free(tree->auth_policies);
sk_X509_POLICY_NODE_pop_free(tree->user_policies, exnode_free);
for (i = 0, curr = tree->levels; i < tree->nlevel; i++, curr++) {
X509_free(curr->cert);
sk_X509_POLICY_NODE_pop_free(curr->nodes, policy_node_free);
policy_node_free(curr->anyPolicy);
}
sk_X509_POLICY_DATA_pop_free(tree->extra_data, policy_data_free);
OPENSSL_free(tree->levels);
OPENSSL_free(tree);
}
/*-
* Application policy checking function.
* Return codes:
* X509_PCY_TREE_FAILURE: Failure to satisfy explicit policy
* X509_PCY_TREE_INVALID: Inconsistent or invalid extensions
* X509_PCY_TREE_INTERNAL: Internal error, most likely malloc
* X509_PCY_TREE_VALID: Success (null tree if empty or bare TA)
*/
int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy,
STACK_OF(X509) *certs,
STACK_OF(ASN1_OBJECT) *policy_oids, unsigned int flags)
{
int init_ret;
int ret;
int calc_ret;
X509_POLICY_TREE *tree = NULL;
STACK_OF(X509_POLICY_NODE) *nodes, *auth_nodes = NULL;
*ptree = NULL;
*pexplicit_policy = 0;
init_ret = tree_init(&tree, certs, flags);
if (init_ret <= 0)
return init_ret;
if ((init_ret & X509_PCY_TREE_EXPLICIT) == 0) {
if (init_ret & X509_PCY_TREE_EMPTY) {
X509_policy_tree_free(tree);
return X509_PCY_TREE_VALID;
}
} else {
*pexplicit_policy = 1;
/* Tree empty and requireExplicit True: Error */
if (init_ret & X509_PCY_TREE_EMPTY)
return X509_PCY_TREE_FAILURE;
}
ret = tree_evaluate(tree);
TREE_PRINT("tree_evaluate()", tree, NULL);
if (ret <= 0)
goto error;
if (ret == X509_PCY_TREE_EMPTY) {
X509_policy_tree_free(tree);
if (init_ret & X509_PCY_TREE_EXPLICIT)
return X509_PCY_TREE_FAILURE;
return X509_PCY_TREE_VALID;
}
/* Tree is not empty: continue */
if ((calc_ret = tree_calculate_authority_set(tree, &auth_nodes)) == 0)
goto error;
ret = tree_calculate_user_set(tree, policy_oids, auth_nodes);
if (calc_ret == TREE_CALC_OK_DOFREE)
sk_X509_POLICY_NODE_free(auth_nodes);
if (!ret)
goto error;
*ptree = tree;
if (init_ret & X509_PCY_TREE_EXPLICIT) {
nodes = X509_policy_tree_get0_user_policies(tree);
if (sk_X509_POLICY_NODE_num(nodes) <= 0)
return X509_PCY_TREE_FAILURE;
}
return X509_PCY_TREE_VALID;
error:
X509_policy_tree_free(tree);
return X509_PCY_TREE_INTERNAL;
}