openssl/crypto/asn1/a_d2i_fp.c
Dr. Stephen Henson 564a503b1b Check for potentially exploitable overflows in asn1_d2i_read_bio
BUF_mem_grow and BUF_mem_grow_clean. Refuse attempts to shrink buffer
in CRYPTO_realloc_clean.

Thanks to Tavis Ormandy, Google Security Team, for discovering this
issue and to Adam Langley <agl@chromium.org> for fixing it. (CVE-2012-2110)
2012-04-19 16:19:07 +00:00

286 lines
7.4 KiB
C

/* crypto/asn1/a_d2i_fp.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 <stdio.h>
#include <limits.h>
#include "cryptlib.h"
#include <openssl/buffer.h>
#include <openssl/asn1_mac.h>
static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb);
#ifndef NO_OLD_ASN1
#ifndef OPENSSL_NO_FP_API
void *ASN1_d2i_fp(void *(*xnew)(void), d2i_of_void *d2i, FILE *in, void **x)
{
BIO *b;
void *ret;
if ((b=BIO_new(BIO_s_file())) == NULL)
{
ASN1err(ASN1_F_ASN1_D2I_FP,ERR_R_BUF_LIB);
return(NULL);
}
BIO_set_fp(b,in,BIO_NOCLOSE);
ret=ASN1_d2i_bio(xnew,d2i,b,x);
BIO_free(b);
return(ret);
}
#endif
void *ASN1_d2i_bio(void *(*xnew)(void), d2i_of_void *d2i, BIO *in, void **x)
{
BUF_MEM *b = NULL;
const unsigned char *p;
void *ret=NULL;
int len;
len = asn1_d2i_read_bio(in, &b);
if(len < 0) goto err;
p=(unsigned char *)b->data;
ret=d2i(x,&p,len);
err:
if (b != NULL) BUF_MEM_free(b);
return(ret);
}
#endif
void *ASN1_item_d2i_bio(const ASN1_ITEM *it, BIO *in, void *x)
{
BUF_MEM *b = NULL;
const unsigned char *p;
void *ret=NULL;
int len;
len = asn1_d2i_read_bio(in, &b);
if(len < 0) goto err;
p=(const unsigned char *)b->data;
ret=ASN1_item_d2i(x,&p,len, it);
err:
if (b != NULL) BUF_MEM_free(b);
return(ret);
}
#ifndef OPENSSL_NO_FP_API
void *ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *x)
{
BIO *b;
char *ret;
if ((b=BIO_new(BIO_s_file())) == NULL)
{
ASN1err(ASN1_F_ASN1_ITEM_D2I_FP,ERR_R_BUF_LIB);
return(NULL);
}
BIO_set_fp(b,in,BIO_NOCLOSE);
ret=ASN1_item_d2i_bio(it,b,x);
BIO_free(b);
return(ret);
}
#endif
#define HEADER_SIZE 8
static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)
{
BUF_MEM *b;
unsigned char *p;
int i;
ASN1_const_CTX c;
size_t want=HEADER_SIZE;
int eos=0;
size_t off=0;
size_t len=0;
b=BUF_MEM_new();
if (b == NULL)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ERR_R_MALLOC_FAILURE);
return -1;
}
ERR_clear_error();
for (;;)
{
if (want >= (len-off))
{
want-=(len-off);
if (len + want < len || !BUF_MEM_grow_clean(b,len+want))
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ERR_R_MALLOC_FAILURE);
goto err;
}
i=BIO_read(in,&(b->data[len]),want);
if ((i < 0) && ((len-off) == 0))
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_NOT_ENOUGH_DATA);
goto err;
}
if (i > 0)
{
if (len+i < len)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_TOO_LONG);
goto err;
}
len+=i;
}
}
/* else data already loaded */
p=(unsigned char *)&(b->data[off]);
c.p=p;
c.inf=ASN1_get_object(&(c.p),&(c.slen),&(c.tag),&(c.xclass),
len-off);
if (c.inf & 0x80)
{
unsigned long e;
e=ERR_GET_REASON(ERR_peek_error());
if (e != ASN1_R_TOO_LONG)
goto err;
else
ERR_clear_error(); /* clear error */
}
i=c.p-p;/* header length */
off+=i; /* end of data */
if (c.inf & 1)
{
/* no data body so go round again */
eos++;
if (eos < 0)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_HEADER_TOO_LONG);
goto err;
}
want=HEADER_SIZE;
}
else if (eos && (c.slen == 0) && (c.tag == V_ASN1_EOC))
{
/* eos value, so go back and read another header */
eos--;
if (eos <= 0)
break;
else
want=HEADER_SIZE;
}
else
{
/* suck in c.slen bytes of data */
want=c.slen;
if (want > (len-off))
{
want-=(len-off);
if (want > INT_MAX /* BIO_read takes an int length */ ||
len+want < len)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_TOO_LONG);
goto err;
}
if (!BUF_MEM_grow_clean(b,len+want))
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ERR_R_MALLOC_FAILURE);
goto err;
}
while (want > 0)
{
i=BIO_read(in,&(b->data[len]),want);
if (i <= 0)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,
ASN1_R_NOT_ENOUGH_DATA);
goto err;
}
/* This can't overflow because
* |len+want| didn't overflow. */
len+=i;
want-=i;
}
}
if (off + c.slen < off)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_TOO_LONG);
goto err;
}
off+=c.slen;
if (eos <= 0)
{
break;
}
else
want=HEADER_SIZE;
}
}
if (off > INT_MAX)
{
ASN1err(ASN1_F_ASN1_D2I_READ_BIO,ASN1_R_TOO_LONG);
goto err;
}
*pb = b;
return off;
err:
if (b != NULL) BUF_MEM_free(b);
return -1;
}