217 lines
8.4 KiB
Diff
217 lines
8.4 KiB
Diff
From ed19b0008b5802505a6ccb05e5bac05baf90c418 Mon Sep 17 00:00:00 2001
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rom: Pauli <pauli@openssl.org>
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Date: Wed, 8 Mar 2023 15:28:20 +1100
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Subject: [PATCH] x509: excessive resource use verifying policy
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constraints
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A security vulnerability has been identified in all supported versions
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of OpenSSL related to the verification of X.509 certificate chains
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that include policy constraints. Attackers may be able to exploit this
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vulnerability by creating a malicious certificate chain that triggers
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exponential use of computational resources, leading to a
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denial-of-service
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(DoS) attack on affected systems.
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Fixes CVE-2023-0464
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Reviewed-by: Tomas Mraz <tomas@openssl.org>
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Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
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(Merged from https://github.com/openssl/openssl/pull/20569)
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---
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Cryptlib/OpenSSL/crypto/x509v3/pcy_int.h | 8 +++++-
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Cryptlib/OpenSSL/crypto/x509v3/pcy_node.c | 11 +++++++--
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Cryptlib/OpenSSL/crypto/x509v3/pcy_tree.c | 30 ++++++++++++++---------
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3 files changed, 35 insertions(+), 14 deletions(-)
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diff --git a/Cryptlib/OpenSSL/crypto/x509v3/pcy_int.h b/Cryptlib/OpenSSL/crypto/x509v3/pcy_int.h
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index b5075f9..0ed2349 100644
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--- a/Cryptlib/OpenSSL/crypto/x509v3/pcy_int.h
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+++ b/Cryptlib/OpenSSL/crypto/x509v3/pcy_int.h
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@@ -161,6 +161,11 @@ struct X509_POLICY_LEVEL_st {
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};
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struct X509_POLICY_TREE_st {
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+ /* The number of nodes in the tree */
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+ size_t node_count;
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+ /* The maximum number of nodes in the tree */
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+ size_t node_maximum;
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+
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/* This is the tree 'level' data */
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X509_POLICY_LEVEL *levels;
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int nlevel;
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@@ -209,7 +214,8 @@ X509_POLICY_NODE *tree_find_sk(STACK_OF(X509_POLICY_NODE) *sk,
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X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
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const X509_POLICY_DATA *data,
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X509_POLICY_NODE *parent,
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- X509_POLICY_TREE *tree);
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+ X509_POLICY_TREE *tree,
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+ int extra_data);
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void policy_node_free(X509_POLICY_NODE *node);
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int policy_node_match(const X509_POLICY_LEVEL *lvl,
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const X509_POLICY_NODE *node, const ASN1_OBJECT *oid);
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diff --git a/Cryptlib/OpenSSL/crypto/x509v3/pcy_node.c b/Cryptlib/OpenSSL/crypto/x509v3/pcy_node.c
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index d6c9176..75b3791 100644
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--- a/Cryptlib/OpenSSL/crypto/x509v3/pcy_node.c
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+++ b/Cryptlib/OpenSSL/crypto/x509v3/pcy_node.c
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@@ -111,9 +111,15 @@ X509_POLICY_NODE *level_find_node(const X509_POLICY_LEVEL *level,
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X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
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const X509_POLICY_DATA *data,
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X509_POLICY_NODE *parent,
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- X509_POLICY_TREE *tree)
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+ X509_POLICY_TREE *tree,
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+ int extra_data)
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{
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X509_POLICY_NODE *node;
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+
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+ /* Verify that the tree isn't too large. this mitigates CVE-2023-0464 */
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+ if (tree->node_maximum > 0 && tree->node_count >= tree->node_maximum)
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+ return NULL;
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+
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node = OPENSSL_malloc(sizeof(X509_POLICY_NODE));
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if (!node)
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return NULL;
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@@ -136,7 +142,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
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}
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}
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- if (tree) {
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+ if (extra_data) {
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if (!tree->extra_data)
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tree->extra_data = sk_X509_POLICY_DATA_new_null();
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if (!tree->extra_data)
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@@ -145,6 +151,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
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goto node_error;
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}
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+ tree->node_count++;
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if (parent)
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parent->nchild++;
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diff --git a/Cryptlib/OpenSSL/crypto/x509v3/pcy_tree.c b/Cryptlib/OpenSSL/crypto/x509v3/pcy_tree.c
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index 09b8691..fb9a616 100644
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--- a/Cryptlib/OpenSSL/crypto/x509v3/pcy_tree.c
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+++ b/Cryptlib/OpenSSL/crypto/x509v3/pcy_tree.c
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@@ -63,6 +63,10 @@
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#include "pcy_int.h"
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+#ifndef OPENSSL_POLICY_TREE_NODES_MAX
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+# define OPENSSL_POLICY_TREE_NODES_MAX 1000
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+#endif
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+
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/*
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* Enable this to print out the complete policy tree at various point during
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* evaluation.
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@@ -225,6 +229,8 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
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if (!tree)
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return 0;
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+ /* Limit the groeth of the tree to mitigate CVE-2023-0464 */
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+ tree->node_maximum = OPENSSL_POLICY_TREE_NODES_MAX;
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tree->flags = 0;
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tree->levels = OPENSSL_malloc(sizeof(X509_POLICY_LEVEL) * n);
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tree->nlevel = 0;
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@@ -247,7 +253,7 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
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data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0);
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- if (!data || !level_add_node(level, data, NULL, tree))
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+ if (!data || !level_add_node(level, data, NULL, tree, 1))
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goto bad_tree;
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for (i = n - 2; i >= 0; i--) {
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@@ -304,7 +310,8 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
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}
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static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
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- const X509_POLICY_DATA *data)
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+ const X509_POLICY_DATA *data,
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+ X509_POLICY_TREE *tree)
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{
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X509_POLICY_LEVEL *last = curr - 1;
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X509_POLICY_NODE *node;
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@@ -313,13 +320,13 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
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for (i = 0; i < sk_X509_POLICY_NODE_num(last->nodes); i++) {
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node = sk_X509_POLICY_NODE_value(last->nodes, i);
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if (policy_node_match(last, node, data->valid_policy)) {
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- if (!level_add_node(curr, data, node, NULL))
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+ if (!level_add_node(curr, data, node, tree, 0))
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return 0;
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matched = 1;
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}
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}
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if (!matched && last->anyPolicy) {
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- if (!level_add_node(curr, data, last->anyPolicy, NULL))
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+ if (!level_add_node(curr, data, last->anyPolicy, tree, 0))
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return 0;
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}
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return 1;
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@@ -331,7 +338,8 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
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*/
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static int tree_link_nodes(X509_POLICY_LEVEL *curr,
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- const X509_POLICY_CACHE *cache)
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+ const X509_POLICY_CACHE *cache,
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+ X509_POLICY_TREE *tree)
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{
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int i;
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X509_POLICY_DATA *data;
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@@ -352,7 +360,7 @@ static int tree_link_nodes(X509_POLICY_LEVEL *curr,
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continue;
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#endif
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/* Look for matching nodes in previous level */
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- if (!tree_link_matching_nodes(curr, data))
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+ if (!tree_link_matching_nodes(curr, data, tree))
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return 0;
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}
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return 1;
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@@ -382,7 +390,7 @@ static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
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/* Curr may not have anyPolicy */
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data->qualifier_set = cache->anyPolicy->qualifier_set;
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data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
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- if (!level_add_node(curr, data, node, tree)) {
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+ if (!level_add_node(curr, data, node, tree, 1)) {
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policy_data_free(data);
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return 0;
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}
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@@ -464,7 +472,7 @@ static int tree_link_any(X509_POLICY_LEVEL *curr,
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/* Curr may not have anyPolicy */
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data->qualifier_set = cache->anyPolicy->qualifier_set;
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data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
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- if (!level_add_node(curr, data, node, tree)) {
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+ if (!level_add_node(curr, data, node, tree, 1)) {
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policy_data_free(data);
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return 0;
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}
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@@ -473,7 +481,7 @@ static int tree_link_any(X509_POLICY_LEVEL *curr,
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}
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/* Finally add link to anyPolicy */
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if (last->anyPolicy) {
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- if (!level_add_node(curr, cache->anyPolicy, last->anyPolicy, NULL))
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+ if (!level_add_node(curr, cache->anyPolicy, last->anyPolicy, tree, 0))
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return 0;
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}
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return 1;
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@@ -646,7 +654,7 @@ static int tree_calculate_user_set(X509_POLICY_TREE *tree,
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extra->qualifier_set = anyPolicy->data->qualifier_set;
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extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
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| POLICY_DATA_FLAG_EXTRA_NODE;
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- node = level_add_node(NULL, extra, anyPolicy->parent, tree);
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+ node = level_add_node(NULL, extra, anyPolicy->parent, tree, 1);
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}
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if (!tree->user_policies) {
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tree->user_policies = sk_X509_POLICY_NODE_new_null();
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@@ -668,7 +676,7 @@ static int tree_evaluate(X509_POLICY_TREE *tree)
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for (i = 1; i < tree->nlevel; i++, curr++) {
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cache = policy_cache_set(curr->cert);
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- if (!tree_link_nodes(curr, cache))
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+ if (!tree_link_nodes(curr, cache, tree))
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return 0;
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if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)
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--
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2.27.0
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