Upgrade openssl from 1.1.0e to 1.1.1b, with source code. 4.0.78

trunk/3rdparty/openssl-1.1-fit/crypto/x509v3/pcy_tree.c

@@ -0,0 +1,703 @@
+/*
+ * Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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/x509.h>
+#include <openssl/x509v3.h>
+
+#include "pcy_int.h"
+
+/*
+ * Enable this to print out the complete policy tree at various point during
+ * evaluation.
+ */
+
+/*
+ * #define OPENSSL_POLICY_DEBUG
+ */
+
+#ifdef OPENSSL_POLICY_DEBUG
+
+static void expected_print(BIO *err, 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(err, "  Not Mapped\n");
+    else {
+        int i;
+        STACK_OF(ASN1_OBJECT) *pset = node->data->expected_policy_set;
+        ASN1_OBJECT *oid;
+        BIO_puts(err, "  Expected: ");
+        for (i = 0; i < sk_ASN1_OBJECT_num(pset); i++) {
+            oid = sk_ASN1_OBJECT_value(pset, i);
+            if (i)
+                BIO_puts(err, ", ");
+            i2a_ASN1_OBJECT(err, oid);
+        }
+        BIO_puts(err, "\n");
+    }
+}
+
+static void tree_print(char *str, X509_POLICY_TREE *tree,
+                       X509_POLICY_LEVEL *curr)
+{
+    BIO *err = BIO_new_fp(stderr, BIO_NOCLOSE);
+    X509_POLICY_LEVEL *plev;
+
+    if (err == NULL)
+        return;
+    if (!curr)
+        curr = tree->levels + tree->nlevel;
+    else
+        curr++;
+
+    BIO_printf(err, "Level print after %s\n", str);
+    BIO_printf(err, "Printing Up to Level %ld\n", curr - tree->levels);
+    for (plev = tree->levels; plev != curr; plev++) {
+        int i;
+
+        BIO_printf(err, "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(err, node, 2);
+            expected_print(err, plev, node, 2);
+            BIO_printf(err, "  Flags: %x\n", node->data->flags);
+        }
+        if (plev->anyPolicy)
+            X509_POLICY_NODE_print(err, plev->anyPolicy, 2);
+    }
+    BIO_free(err);
+}
+#endif
+
+/*-
+ * 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;
+#ifdef OPENSSL_POLICY_DEBUG
+        tree_print("before tree_prune()", tree, curr);
+#endif
+        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);
+#ifdef OPENSSL_POLICY_DEBUG
+    tree_print("tree_evaluate()", tree, NULL);
+#endif
+    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;
+}