+++ /dev/null
-From 959c59c7a0164117e7f8366466a32bb1f8d77ff1 Mon Sep 17 00:00:00 2001
-From: Pauli <pauli@openssl.org>
-Date: Wed, 8 Mar 2023 15:28:20 +1100
-Subject: [PATCH] x509: excessive resource use verifying policy constraints
-
-A security vulnerability has been identified in all supported versions
-of OpenSSL related to the verification of X.509 certificate chains
-that include policy constraints. Attackers may be able to exploit this
-vulnerability by creating a malicious certificate chain that triggers
-exponential use of computational resources, leading to a denial-of-service
-(DoS) attack on affected systems.
-
-Fixes CVE-2023-0464
-
-Reviewed-by: Tomas Mraz <tomas@openssl.org>
-Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
-(Merged from https://github.com/openssl/openssl/pull/20568)
-
---- a/crypto/x509/pcy_local.h
-+++ b/crypto/x509/pcy_local.h
-@@ -111,6 +111,11 @@ struct X509_POLICY_LEVEL_st {
- };
-
- struct X509_POLICY_TREE_st {
-+ /* The number of nodes in the tree */
-+ size_t node_count;
-+ /* The maximum number of nodes in the tree */
-+ size_t node_maximum;
-+
- /* This is the tree 'level' data */
- X509_POLICY_LEVEL *levels;
- int nlevel;
-@@ -157,7 +162,8 @@ X509_POLICY_NODE *ossl_policy_tree_find_
- X509_POLICY_NODE *ossl_policy_level_add_node(X509_POLICY_LEVEL *level,
- X509_POLICY_DATA *data,
- X509_POLICY_NODE *parent,
-- X509_POLICY_TREE *tree);
-+ X509_POLICY_TREE *tree,
-+ int extra_data);
- void ossl_policy_node_free(X509_POLICY_NODE *node);
- int ossl_policy_node_match(const X509_POLICY_LEVEL *lvl,
- const X509_POLICY_NODE *node, const ASN1_OBJECT *oid);
---- a/crypto/x509/pcy_node.c
-+++ b/crypto/x509/pcy_node.c
-@@ -59,10 +59,15 @@ X509_POLICY_NODE *ossl_policy_level_find
- X509_POLICY_NODE *ossl_policy_level_add_node(X509_POLICY_LEVEL *level,
- X509_POLICY_DATA *data,
- X509_POLICY_NODE *parent,
-- X509_POLICY_TREE *tree)
-+ X509_POLICY_TREE *tree,
-+ int extra_data)
- {
- X509_POLICY_NODE *node;
-
-+ /* Verify that the tree isn't too large. This mitigates CVE-2023-0464 */
-+ if (tree->node_maximum > 0 && tree->node_count >= tree->node_maximum)
-+ return NULL;
-+
- node = OPENSSL_zalloc(sizeof(*node));
- if (node == NULL) {
- ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
-@@ -70,7 +75,7 @@ X509_POLICY_NODE *ossl_policy_level_add_
- }
- node->data = data;
- node->parent = parent;
-- if (level) {
-+ if (level != NULL) {
- if (OBJ_obj2nid(data->valid_policy) == NID_any_policy) {
- if (level->anyPolicy)
- goto node_error;
-@@ -90,7 +95,7 @@ X509_POLICY_NODE *ossl_policy_level_add_
- }
- }
-
-- if (tree) {
-+ if (extra_data) {
- if (tree->extra_data == NULL)
- tree->extra_data = sk_X509_POLICY_DATA_new_null();
- if (tree->extra_data == NULL){
-@@ -103,6 +108,7 @@ X509_POLICY_NODE *ossl_policy_level_add_
- }
- }
-
-+ tree->node_count++;
- if (parent)
- parent->nchild++;
-
---- a/crypto/x509/pcy_tree.c
-+++ b/crypto/x509/pcy_tree.c
-@@ -14,6 +14,17 @@
-
- #include "pcy_local.h"
-
-+/*
-+ * If the maximum number of nodes in the policy tree isn't defined, set it to
-+ * a generous default of 1000 nodes.
-+ *
-+ * Defining this to be zero means unlimited policy tree growth which opens the
-+ * door on CVE-2023-0464.
-+ */
-+#ifndef OPENSSL_POLICY_TREE_NODES_MAX
-+# define OPENSSL_POLICY_TREE_NODES_MAX 1000
-+#endif
-+
- static void expected_print(BIO *channel,
- X509_POLICY_LEVEL *lev, X509_POLICY_NODE *node,
- int indent)
-@@ -163,6 +174,9 @@ static int tree_init(X509_POLICY_TREE **
- return X509_PCY_TREE_INTERNAL;
- }
-
-+ /* Limit the growth of the tree to mitigate CVE-2023-0464 */
-+ tree->node_maximum = OPENSSL_POLICY_TREE_NODES_MAX;
-+
- /*
- * http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
- *
-@@ -180,7 +194,7 @@ static int tree_init(X509_POLICY_TREE **
- if ((data = ossl_policy_data_new(NULL,
- OBJ_nid2obj(NID_any_policy), 0)) == NULL)
- goto bad_tree;
-- if (ossl_policy_level_add_node(level, data, NULL, tree) == NULL) {
-+ if (ossl_policy_level_add_node(level, data, NULL, tree, 1) == NULL) {
- ossl_policy_data_free(data);
- goto bad_tree;
- }
-@@ -239,7 +253,8 @@ static int tree_init(X509_POLICY_TREE **
- * Return value: 1 on success, 0 otherwise
- */
- static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
-- X509_POLICY_DATA *data)
-+ X509_POLICY_DATA *data,
-+ X509_POLICY_TREE *tree)
- {
- X509_POLICY_LEVEL *last = curr - 1;
- int i, matched = 0;
-@@ -249,13 +264,13 @@ static int tree_link_matching_nodes(X509
- X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
-
- if (ossl_policy_node_match(last, node, data->valid_policy)) {
-- if (ossl_policy_level_add_node(curr, data, node, NULL) == NULL)
-+ if (ossl_policy_level_add_node(curr, data, node, tree, 0) == NULL)
- return 0;
- matched = 1;
- }
- }
- if (!matched && last->anyPolicy) {
-- if (ossl_policy_level_add_node(curr, data, last->anyPolicy, NULL) == NULL)
-+ if (ossl_policy_level_add_node(curr, data, last->anyPolicy, tree, 0) == NULL)
- return 0;
- }
- return 1;
-@@ -268,7 +283,8 @@ static int tree_link_matching_nodes(X509
- * Return value: 1 on success, 0 otherwise.
- */
- static int tree_link_nodes(X509_POLICY_LEVEL *curr,
-- const X509_POLICY_CACHE *cache)
-+ const X509_POLICY_CACHE *cache,
-+ X509_POLICY_TREE *tree)
- {
- int i;
-
-@@ -276,7 +292,7 @@ static int tree_link_nodes(X509_POLICY_L
- 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))
-+ if (!tree_link_matching_nodes(curr, data, tree))
- return 0;
- }
- return 1;
-@@ -307,7 +323,7 @@ static int tree_add_unmatched(X509_POLIC
- /* Curr may not have anyPolicy */
- data->qualifier_set = cache->anyPolicy->qualifier_set;
- data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
-- if (ossl_policy_level_add_node(curr, data, node, tree) == NULL) {
-+ if (ossl_policy_level_add_node(curr, data, node, tree, 1) == NULL) {
- ossl_policy_data_free(data);
- return 0;
- }
-@@ -370,7 +386,7 @@ static int tree_link_any(X509_POLICY_LEV
- /* Finally add link to anyPolicy */
- if (last->anyPolicy &&
- ossl_policy_level_add_node(curr, cache->anyPolicy,
-- last->anyPolicy, NULL) == NULL)
-+ last->anyPolicy, tree, 0) == NULL)
- return 0;
- return 1;
- }
-@@ -553,7 +569,7 @@ static int tree_calculate_user_set(X509_
- extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
- | POLICY_DATA_FLAG_EXTRA_NODE;
- node = ossl_policy_level_add_node(NULL, extra, anyPolicy->parent,
-- tree);
-+ tree, 1);
- }
- if (!tree->user_policies) {
- tree->user_policies = sk_X509_POLICY_NODE_new_null();
-@@ -580,7 +596,7 @@ static int tree_evaluate(X509_POLICY_TRE
-
- for (i = 1; i < tree->nlevel; i++, curr++) {
- cache = ossl_policy_cache_set(curr->cert);
-- if (!tree_link_nodes(curr, cache))
-+ if (!tree_link_nodes(curr, cache, tree))
- return X509_PCY_TREE_INTERNAL;
-
- if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
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