Harden asn1 oid loader to invalid inputs

In the event that a config file contains this sequence:
=======
openssl_conf = openssl_init

config_diagnostics = 1

[openssl_init]
oid_section = oids

[oids]
testoid1 = 1.2.3.4.1
testoid2 = A Very Long OID Name, 1.2.3.4.2
testoid3 = ,1.2.3.4.3
======

The leading comma in testoid3 can cause a heap buffer overflow, as the
parsing code will move the string pointer back 1 character, thereby
pointing to an invalid memory space

correct the parser to detect this condition and handle it by treating it
as if the comma doesn't exist (i.e. an empty long oid name)

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22957)

diff --git a/apps/asn1parse.c b/apps/asn1parse.c
index 6597a6180b0a2945d2604fb8b47c208e712e24ff..bf62f8594790759a5db9e8837b4c9a4a6d9c00f5 100644 (file)
--- a/apps/asn1parse.c
+++ b/apps/asn1parse.c
@@ -178,7 +178,7 @@ int asn1parse_main(int argc, char **argv)
 
     if ((buf = BUF_MEM_new()) == NULL)
         goto end;
-    if (genstr == NULL && informat == FORMAT_PEM) {
+    if (genconf == NULL && genstr == NULL && informat == FORMAT_PEM) {
         if (PEM_read_bio(in, &name, &header, &str, &num) != 1) {
             BIO_printf(bio_err, "Error reading PEM file\n");
             ERR_print_errors(bio_err);

diff --git a/crypto/asn1/asn_moid.c b/crypto/asn1/asn_moid.c
index 6f816307afd4d69f937a9fd07477bd4bf9cf9dfc..1e183f4f18aa5cd51534daa20db97e2ee7323e34 100644 (file)
--- a/crypto/asn1/asn_moid.c
+++ b/crypto/asn1/asn_moid.c
@@ -67,6 +67,10 @@ static int do_create(const char *value, const char *name)
     if (p == NULL) {
         ln = name;
         ostr = value;
+    } else if (p == value) {
+        /* we started with a leading comma */
+        ln = name;
+        ostr = p + 1;
     } else {
         ln = value;
         ostr = p + 1;

diff --git a/test/recipes/04-test_asn1_parse.t b/test/recipes/04-test_asn1_parse.t
new file mode 100644 (file)
index 0000000..f3af436
--- /dev/null
+++ b/test/recipes/04-test_asn1_parse.t
@@ -0,0 +1,26 @@
+#! /usr/bin/env perl
+# Copyright 2023 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
+
+use strict;
+use OpenSSL::Test qw(:DEFAULT srctop_file);
+use OpenSSL::Test::Utils;
+
+setup("test_asn1_parse");
+
+plan tests => 3;
+
+$ENV{OPENSSL_CONF} = srctop_file("test", "test_asn1_parse.cnf");
+
+ok(run(app(([ 'openssl', 'asn1parse',
+              '-genstr', 'OID:1.2.3.4.1']))));
+
+ok(run(app(([ 'openssl', 'asn1parse',
+              '-genstr', 'OID:1.2.3.4.2']))));
+
+ok(run(app(([ 'openssl', 'asn1parse',
+              '-genstr', 'OID:1.2.3.4.3']))));

diff --git a/test/test_asn1_parse.cnf b/test/test_asn1_parse.cnf
new file mode 100644 (file)
index 0000000..5f03056
--- /dev/null
+++ b/test/test_asn1_parse.cnf
@@ -0,0 +1,12 @@
+openssl_conf = openssl_init
+
+# Comment out the next line to ignore configuration errors
+config_diagnostics = 1
+
+[openssl_init]
+oid_section = oids
+
+[oids]
+testoid1 = 1.2.3.4.1
+testoid2 = A Very Long OID Name, 1.2.3.4.2
+testoid3 = ,1.2.3.4.3