From 879f7080d7e141f415c79eaa3a8ac4a3dad0348b 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/20569)
---
 crypto/x509v3/pcy_local.h |  8 +++++++-
 crypto/x509v3/pcy_node.c  | 12 +++++++++---
 crypto/x509v3/pcy_tree.c  | 37 +++++++++++++++++++++++++++----------
 3 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/crypto/x509v3/pcy_local.h b/crypto/x509v3/pcy_local.h
index 5daf78de4585..344aa067659c 100644
--- crypto/x509v3/pcy_local.h.orig
+++ crypto/x509v3/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;
@@ -159,7 +164,8 @@ X509_POLICY_NODE *tree_find_sk(STACK_OF(X509_POLICY_NODE) *sk,
 X509_POLICY_NODE *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 policy_node_free(X509_POLICY_NODE *node);
 int policy_node_match(const X509_POLICY_LEVEL *lvl,
                       const X509_POLICY_NODE *node, const ASN1_OBJECT *oid);
diff --git a/crypto/x509v3/pcy_node.c b/crypto/x509v3/pcy_node.c
index e2d7b1532236..d574fb9d665d 100644
--- crypto/x509v3/pcy_node.c.orig
+++ crypto/x509v3/pcy_node.c
@@ -59,10 +59,15 @@ X509_POLICY_NODE *level_find_node(const X509_POLICY_LEVEL *level,
 X509_POLICY_NODE *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) {
         X509V3err(X509V3_F_LEVEL_ADD_NODE, ERR_R_MALLOC_FAILURE);
@@ -70,7 +75,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
     }
     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 *level_add_node(X509_POLICY_LEVEL *level,
         }
     }
 
-    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 *level_add_node(X509_POLICY_LEVEL *level,
         }
     }
 
+    tree->node_count++;
     if (parent)
         parent->nchild++;
 
diff --git a/crypto/x509v3/pcy_tree.c b/crypto/x509v3/pcy_tree.c
index 6e8322cbc5e3..6c7fd3540500 100644
--- crypto/x509v3/pcy_tree.c.orig
+++ crypto/x509v3/pcy_tree.c
@@ -13,6 +13,18 @@
 
 #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
+
 /*
  * Enable this to print out the complete policy tree at various point during
  * evaluation.
@@ -168,6 +180,9 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
         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.
      *
@@ -184,7 +199,7 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
     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) {
+    if (level_add_node(level, data, NULL, tree, 1) == NULL) {
         policy_data_free(data);
         goto bad_tree;
     }
@@ -243,7 +258,8 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
  * 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;
@@ -253,13 +269,13 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
         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)
+            if (level_add_node(curr, data, node, tree, 0) == NULL)
                 return 0;
             matched = 1;
         }
     }
     if (!matched && last->anyPolicy) {
-        if (level_add_node(curr, data, last->anyPolicy, NULL) == NULL)
+        if (level_add_node(curr, data, last->anyPolicy, tree, 0) == NULL)
             return 0;
     }
     return 1;
@@ -272,7 +288,8 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
  * 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;
 
@@ -280,7 +297,7 @@ static int tree_link_nodes(X509_POLICY_LEVEL *curr,
         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;
@@ -311,7 +328,7 @@ static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
     /* 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) {
+    if (level_add_node(curr, data, node, tree, 1) == NULL) {
         policy_data_free(data);
         return 0;
     }
@@ -373,7 +390,7 @@ static int tree_link_any(X509_POLICY_LEVEL *curr,
     }
     /* Finally add link to anyPolicy */
     if (last->anyPolicy &&
-        level_add_node(curr, cache->anyPolicy, last->anyPolicy, NULL) == NULL)
+        level_add_node(curr, cache->anyPolicy, last->anyPolicy, tree, 0) == NULL)
         return 0;
     return 1;
 }
@@ -555,7 +572,7 @@ static int tree_calculate_user_set(X509_POLICY_TREE *tree,
             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);
+            node = level_add_node(NULL, extra, anyPolicy->parent, tree, 1);
         }
         if (!tree->user_policies) {
             tree->user_policies = sk_X509_POLICY_NODE_new_null();
@@ -582,7 +599,7 @@ static int tree_evaluate(X509_POLICY_TREE *tree)
 
     for (i = 1; i < tree->nlevel; i++, curr++) {
         cache = 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)
From fd42c9126844f5eefa76872a1ffe5f529f8f75df Mon Sep 17 00:00:00 2001
From: Richard Levitte <levitte@openssl.org>
Date: Tue, 7 Feb 2023 14:37:22 +0100
Subject: [PATCH] Prepare for 1.1.1u-dev

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Release: yes
---
 CHANGES                    | 4 ++++
 NEWS                       | 4 ++++
 README                     | 2 +-
 include/openssl/opensslv.h | 4 ++--
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index 1e2d651b7514..f18b08cb0ee2 100644
--- CHANGES.orig
+++ CHANGES
@@ -7,6 +7,10 @@
  https://github.com/openssl/openssl/commits/ and pick the appropriate
  release branch.
 
+ Changes between 1.1.1t and 1.1.1u [xx XXX xxxx]
+
+  *)
+
  Changes between 1.1.1s and 1.1.1t [7 Feb 2023]
 
   *) Fixed X.400 address type confusion in X.509 GeneralName.
diff --git a/NEWS b/NEWS
index 2724fc4d85ba..8a18516d8609 100644
--- NEWS.orig
+++ NEWS
@@ -5,6 +5,10 @@
   This file gives a brief overview of the major changes between each OpenSSL
   release. For more details please read the CHANGES file.
 
+  Major changes between OpenSSL 1.1.1t and OpenSSL 1.1.1u [under development]
+
+      o
+
   Major changes between OpenSSL 1.1.1s and OpenSSL 1.1.1t [7 Feb 2023]
 
       o Fixed X.400 address type confusion in X.509 GeneralName (CVE-2023-0286)
diff --git a/README b/README
index b2f806be3a44..1957cf1f5515 100644
--- README.orig
+++ README
@@ -1,5 +1,5 @@
 
- OpenSSL 1.1.1t 7 Feb 2023
+ OpenSSL 1.1.1u-dev
 
  Copyright (c) 1998-2022 The OpenSSL Project
  Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
From fa425f20955c7948faed27f69ae4544f89c108ea Mon Sep 17 00:00:00 2001
From: Pauli <pauli@openssl.org>
Date: Wed, 15 Mar 2023 14:29:22 +1100
Subject: [PATCH] changes: note about policy tree size limits and circumvention

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/20569)
---
 CHANGES | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index f18b08cb0ee2..17caf6775bfe 100644
--- CHANGES.orig
+++ CHANGES
@@ -9,7 +9,13 @@
 
  Changes between 1.1.1t and 1.1.1u [xx XXX xxxx]
 
-  *)
+  *) Limited the number of nodes created in a policy tree to mitigate
+     against CVE-2023-0464.  The default limit is set to 1000 nodes, which
+     should be sufficient for most installations.  If required, the limit
+     can be adjusted by setting the OPENSSL_POLICY_TREE_NODES_MAX build
+     time define to a desired maximum number of nodes or zero to allow
+     unlimited growth.
+     [Paul Dale]
 
  Changes between 1.1.1s and 1.1.1t [7 Feb 2023]
 
