boringssl/crypto/asn1/a_enum.c
Adam Langley 2a768d04c6 Fix overflow checks when converting ASN.1 integers to long.
(Credit to libFuzzer for finding this.)

Change-Id: I0353d686d883703d39145c5bdd1e56368a587a35
Reviewed-on: https://boringssl-review.googlesource.com/22324
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-10-27 19:08:08 +00:00

196 lines
6.1 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/asn1.h>
#include <limits.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "../internal.h"
/*
* Code for ENUMERATED type: identical to INTEGER apart from a different tag.
* for comments on encoding see a_int.c
*/
int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v)
{
int j, k;
unsigned int i;
unsigned char buf[sizeof(long) + 1];
long d;
a->type = V_ASN1_ENUMERATED;
if (a->length < (int)(sizeof(long) + 1)) {
if (a->data != NULL)
OPENSSL_free(a->data);
if ((a->data =
(unsigned char *)OPENSSL_malloc(sizeof(long) + 1)) != NULL)
OPENSSL_memset((char *)a->data, 0, sizeof(long) + 1);
}
if (a->data == NULL) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
return (0);
}
d = v;
if (d < 0) {
d = -d;
a->type = V_ASN1_NEG_ENUMERATED;
}
for (i = 0; i < sizeof(long); i++) {
if (d == 0)
break;
buf[i] = (int)d & 0xff;
d >>= 8;
}
j = 0;
for (k = i - 1; k >= 0; k--)
a->data[j++] = buf[k];
a->length = j;
return (1);
}
long ASN1_ENUMERATED_get(ASN1_ENUMERATED *a)
{
int neg = 0, i;
if (a == NULL)
return (0L);
i = a->type;
if (i == V_ASN1_NEG_ENUMERATED)
neg = 1;
else if (i != V_ASN1_ENUMERATED)
return -1;
OPENSSL_COMPILE_ASSERT(sizeof(uint64_t) >= sizeof(long),
long_larger_than_uint64_t);
if (a->length > (int)sizeof(uint64_t)) {
/* hmm... a bit ugly */
return -1;
}
uint64_t r64 = 0;
if (a->data != NULL) {
for (i = 0; i < a->length; i++) {
r64 <<= 8;
r64 |= (unsigned char)a->data[i];
}
if (r64 > LONG_MAX) {
return -1;
}
}
long r = (long) r64;
if (neg)
r = -r;
return r;
}
ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(BIGNUM *bn, ASN1_ENUMERATED *ai)
{
ASN1_ENUMERATED *ret;
int len, j;
if (ai == NULL)
ret = M_ASN1_ENUMERATED_new();
else
ret = ai;
if (ret == NULL) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
goto err;
}
if (BN_is_negative(bn))
ret->type = V_ASN1_NEG_ENUMERATED;
else
ret->type = V_ASN1_ENUMERATED;
j = BN_num_bits(bn);
len = ((j == 0) ? 0 : ((j / 8) + 1));
if (ret->length < len + 4) {
unsigned char *new_data = OPENSSL_realloc(ret->data, len + 4);
if (!new_data) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
goto err;
}
ret->data = new_data;
}
ret->length = BN_bn2bin(bn, ret->data);
return (ret);
err:
if (ret != ai)
M_ASN1_ENUMERATED_free(ret);
return (NULL);
}
BIGNUM *ASN1_ENUMERATED_to_BN(ASN1_ENUMERATED *ai, BIGNUM *bn)
{
BIGNUM *ret;
if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == NULL)
OPENSSL_PUT_ERROR(ASN1, ASN1_R_BN_LIB);
else if (ai->type == V_ASN1_NEG_ENUMERATED)
BN_set_negative(ret, 1);
return (ret);
}