From c6718437709108b4bcb784d774fb3df124df48e5 Mon Sep 17 00:00:00 2001
From: "Dr. Matthias St. Pierre" <Matthias.St.Pierre@ncp-e.com>
Date: Thu, 26 Apr 2018 20:36:41 +0200
Subject: [PATCH] a_strex.c: prevent out of bound read in do_buf()
which is used for ASN1_STRING_print_ex*() and X509_NAME_print_ex*().
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6105)
---
crypto/asn1/a_strex.c | 25 +++++++++++++++++++++++--
crypto/asn1/asn1_err.c | 1 +
crypto/err/openssl.txt | 1 +
include/openssl/asn1err.h | 1 +
4 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/crypto/asn1/a_strex.c b/crypto/asn1/a_strex.c
index 1d34f56b0b..6a67bc8c33 100644
--- a/crypto/asn1/a_strex.c
+++ b/crypto/asn1/a_strex.c
@@ -139,7 +139,7 @@ static int do_buf(unsigned char *buf, int buflen,
int type, unsigned short flags, char *quotes, char_io *io_ch,
void *arg)
{
- int i, outlen, len;
+ int i, outlen, len, charwidth;
unsigned short orflags;
unsigned char *p, *q;
unsigned long c;
@@ -147,12 +147,32 @@ static int do_buf(unsigned char *buf, int buflen,
p = buf;
q = buf + buflen;
outlen = 0;
+ charwidth = type & BUF_TYPE_WIDTH_MASK;
+
+ switch (charwidth) {
+ case 4:
+ if (buflen & 3) {
+ ASN1err(ASN1_F_DO_BUF, ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
+ return -1;
+ }
+ break;
+ case 2:
+ if (buflen & 1) {
+ ASN1err(ASN1_F_DO_BUF, ASN1_R_INVALID_BMPSTRING_LENGTH);
+ return -1;
+ }
+ break;
+ default:
+ break;
+ }
+
while (p != q) {
if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
orflags = CHARTYPE_FIRST_ESC_2253;
else
orflags = 0;
- switch (type & BUF_TYPE_WIDTH_MASK) {
+
+ switch (charwidth) {
case 4:
c = ((unsigned long)*p++) << 24;
c |= ((unsigned long)*p++) << 16;
@@ -173,6 +193,7 @@ static int do_buf(unsigned char *buf, int buflen,
i = UTF8_getc(p, buflen, &c);
if (i < 0)
return -1; /* Invalid UTF8String */
+ buflen -= i;
p += i;
break;
default:
diff --git a/crypto/asn1/asn1_err.c b/crypto/asn1/asn1_err.c
index 751d4414ac..22bf06f032 100644
--- a/crypto/asn1/asn1_err.c
+++ b/crypto/asn1/asn1_err.c
@@ -109,6 +109,7 @@ static const ERR_STRING_DATA ASN1_str_functs[] = {
"d2i_AutoPrivateKey"},
{ERR_PACK(ERR_LIB_ASN1, ASN1_F_D2I_PRIVATEKEY, 0), "d2i_PrivateKey"},
{ERR_PACK(ERR_LIB_ASN1, ASN1_F_D2I_PUBLICKEY, 0), "d2i_PublicKey"},
+ {ERR_PACK(ERR_LIB_ASN1, ASN1_F_DO_BUF, 0), "do_buf"},
{ERR_PACK(ERR_LIB_ASN1, ASN1_F_DO_CREATE, 0), "do_create"},
{ERR_PACK(ERR_LIB_ASN1, ASN1_F_DO_DUMP, 0), "do_dump"},
{ERR_PACK(ERR_LIB_ASN1, ASN1_F_DO_TCREATE, 0), "do_tcreate"},
diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt
index 155a8f3739..209bd0d3c3 100644
--- a/crypto/err/openssl.txt
+++ b/crypto/err/openssl.txt
@@ -82,6 +82,7 @@ ASN1_F_D2I_ASN1_UINTEGER:150:d2i_ASN1_UINTEGER
ASN1_F_D2I_AUTOPRIVATEKEY:207:d2i_AutoPrivateKey
ASN1_F_D2I_PRIVATEKEY:154:d2i_PrivateKey
ASN1_F_D2I_PUBLICKEY:155:d2i_PublicKey
+ASN1_F_DO_BUF:142:do_buf
ASN1_F_DO_CREATE:124:do_create
ASN1_F_DO_DUMP:125:do_dump
ASN1_F_DO_TCREATE:222:do_tcreate
diff --git a/include/openssl/asn1err.h b/include/openssl/asn1err.h
index 9697898f97..048a737b14 100644
--- a/include/openssl/asn1err.h
+++ b/include/openssl/asn1err.h
@@ -95,6 +95,7 @@ int ERR_load_ASN1_strings(void);
# define ASN1_F_D2I_AUTOPRIVATEKEY 207
# define ASN1_F_D2I_PRIVATEKEY 154
# define ASN1_F_D2I_PUBLICKEY 155
+# define ASN1_F_DO_BUF 142
# define ASN1_F_DO_CREATE 124
# define ASN1_F_DO_DUMP 125
# define ASN1_F_DO_TCREATE 222
--
2.25.1