boringssl/crypto/asn1/tasn_new.c
David Benjamin 17cf2cb1d2 Work around language and compiler bug in memcpy, etc.
Most C standard library functions are undefined if passed NULL, even
when the corresponding length is zero. This gives them (and, in turn,
all functions which call them) surprising behavior on empty arrays.
Some compilers will miscompile code due to this rule. See also
https://www.imperialviolet.org/2016/06/26/nonnull.html

Add OPENSSL_memcpy, etc., wrappers which avoid this problem.

BUG=23

Change-Id: I95f42b23e92945af0e681264fffaf578e7f8465e
Reviewed-on: https://boringssl-review.googlesource.com/12928
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2016-12-21 20:34:47 +00:00

385 lines
11 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 <string.h>
#include <openssl/asn1t.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include "../internal.h"
static int asn1_item_ex_combine_new(ASN1_VALUE **pval, const ASN1_ITEM *it,
int combine);
static void asn1_item_clear(ASN1_VALUE **pval, const ASN1_ITEM *it);
static void asn1_template_clear(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt);
static void asn1_primitive_clear(ASN1_VALUE **pval, const ASN1_ITEM *it);
ASN1_VALUE *ASN1_item_new(const ASN1_ITEM *it)
{
ASN1_VALUE *ret = NULL;
if (ASN1_item_ex_new(&ret, it) > 0)
return ret;
return NULL;
}
/* Allocate an ASN1 structure */
int ASN1_item_ex_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
return asn1_item_ex_combine_new(pval, it, 0);
}
static int asn1_item_ex_combine_new(ASN1_VALUE **pval, const ASN1_ITEM *it,
int combine)
{
const ASN1_TEMPLATE *tt = NULL;
const ASN1_COMPAT_FUNCS *cf;
const ASN1_EXTERN_FUNCS *ef;
const ASN1_AUX *aux = it->funcs;
ASN1_aux_cb *asn1_cb;
ASN1_VALUE **pseqval;
int i;
if (aux && aux->asn1_cb)
asn1_cb = aux->asn1_cb;
else
asn1_cb = 0;
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_push_info(it->sname);
#endif
switch (it->itype) {
case ASN1_ITYPE_EXTERN:
ef = it->funcs;
if (ef && ef->asn1_ex_new) {
if (!ef->asn1_ex_new(pval, it))
goto memerr;
}
break;
case ASN1_ITYPE_COMPAT:
cf = it->funcs;
if (cf && cf->asn1_new) {
*pval = cf->asn1_new();
if (!*pval)
goto memerr;
}
break;
case ASN1_ITYPE_PRIMITIVE:
if (it->templates) {
if (!ASN1_template_new(pval, it->templates))
goto memerr;
} else if (!ASN1_primitive_new(pval, it))
goto memerr;
break;
case ASN1_ITYPE_MSTRING:
if (!ASN1_primitive_new(pval, it))
goto memerr;
break;
case ASN1_ITYPE_CHOICE:
if (asn1_cb) {
i = asn1_cb(ASN1_OP_NEW_PRE, pval, it, NULL);
if (!i)
goto auxerr;
if (i == 2) {
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return 1;
}
}
if (!combine) {
*pval = OPENSSL_malloc(it->size);
if (!*pval)
goto memerr;
OPENSSL_memset(*pval, 0, it->size);
}
asn1_set_choice_selector(pval, -1, it);
if (asn1_cb && !asn1_cb(ASN1_OP_NEW_POST, pval, it, NULL))
goto auxerr;
break;
case ASN1_ITYPE_NDEF_SEQUENCE:
case ASN1_ITYPE_SEQUENCE:
if (asn1_cb) {
i = asn1_cb(ASN1_OP_NEW_PRE, pval, it, NULL);
if (!i)
goto auxerr;
if (i == 2) {
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return 1;
}
}
if (!combine) {
*pval = OPENSSL_malloc(it->size);
if (!*pval)
goto memerr;
OPENSSL_memset(*pval, 0, it->size);
asn1_refcount_set_one(pval, it);
asn1_enc_init(pval, it);
}
for (i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
pseqval = asn1_get_field_ptr(pval, tt);
if (!ASN1_template_new(pseqval, tt))
goto memerr;
}
if (asn1_cb && !asn1_cb(ASN1_OP_NEW_POST, pval, it, NULL))
goto auxerr;
break;
}
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return 1;
memerr:
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
ASN1_item_ex_free(pval, it);
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return 0;
auxerr:
OPENSSL_PUT_ERROR(ASN1, ASN1_R_AUX_ERROR);
ASN1_item_ex_free(pval, it);
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return 0;
}
static void asn1_item_clear(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
const ASN1_EXTERN_FUNCS *ef;
switch (it->itype) {
case ASN1_ITYPE_EXTERN:
ef = it->funcs;
if (ef && ef->asn1_ex_clear)
ef->asn1_ex_clear(pval, it);
else
*pval = NULL;
break;
case ASN1_ITYPE_PRIMITIVE:
if (it->templates)
asn1_template_clear(pval, it->templates);
else
asn1_primitive_clear(pval, it);
break;
case ASN1_ITYPE_MSTRING:
asn1_primitive_clear(pval, it);
break;
case ASN1_ITYPE_COMPAT:
case ASN1_ITYPE_CHOICE:
case ASN1_ITYPE_SEQUENCE:
case ASN1_ITYPE_NDEF_SEQUENCE:
*pval = NULL;
break;
}
}
int ASN1_template_new(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
{
const ASN1_ITEM *it = ASN1_ITEM_ptr(tt->item);
int ret;
if (tt->flags & ASN1_TFLG_OPTIONAL) {
asn1_template_clear(pval, tt);
return 1;
}
/* If ANY DEFINED BY nothing to do */
if (tt->flags & ASN1_TFLG_ADB_MASK) {
*pval = NULL;
return 1;
}
#ifdef CRYPTO_MDEBUG
if (tt->field_name)
CRYPTO_push_info(tt->field_name);
#endif
/* If SET OF or SEQUENCE OF, its a STACK */
if (tt->flags & ASN1_TFLG_SK_MASK) {
STACK_OF(ASN1_VALUE) *skval;
skval = sk_ASN1_VALUE_new_null();
if (!skval) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
ret = 0;
goto done;
}
*pval = (ASN1_VALUE *)skval;
ret = 1;
goto done;
}
/* Otherwise pass it back to the item routine */
ret = asn1_item_ex_combine_new(pval, it, tt->flags & ASN1_TFLG_COMBINE);
done:
#ifdef CRYPTO_MDEBUG
if (it->sname)
CRYPTO_pop_info();
#endif
return ret;
}
static void asn1_template_clear(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
{
/* If ADB or STACK just NULL the field */
if (tt->flags & (ASN1_TFLG_ADB_MASK | ASN1_TFLG_SK_MASK))
*pval = NULL;
else
asn1_item_clear(pval, ASN1_ITEM_ptr(tt->item));
}
/*
* NB: could probably combine most of the real XXX_new() behaviour and junk
* all the old functions.
*/
int ASN1_primitive_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
ASN1_TYPE *typ;
ASN1_STRING *str;
int utype;
if (!it)
return 0;
if (it->funcs) {
const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;
if (pf->prim_new)
return pf->prim_new(pval, it);
}
if (it->itype == ASN1_ITYPE_MSTRING)
utype = -1;
else
utype = it->utype;
switch (utype) {
case V_ASN1_OBJECT:
*pval = (ASN1_VALUE *)OBJ_nid2obj(NID_undef);
return 1;
case V_ASN1_BOOLEAN:
*(ASN1_BOOLEAN *)pval = it->size;
return 1;
case V_ASN1_NULL:
*pval = (ASN1_VALUE *)1;
return 1;
case V_ASN1_ANY:
typ = OPENSSL_malloc(sizeof(ASN1_TYPE));
if (!typ)
return 0;
typ->value.ptr = NULL;
typ->type = -1;
*pval = (ASN1_VALUE *)typ;
break;
default:
str = ASN1_STRING_type_new(utype);
if (it->itype == ASN1_ITYPE_MSTRING && str)
str->flags |= ASN1_STRING_FLAG_MSTRING;
*pval = (ASN1_VALUE *)str;
break;
}
if (*pval)
return 1;
return 0;
}
static void asn1_primitive_clear(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
int utype;
if (it && it->funcs) {
const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;
if (pf->prim_clear)
pf->prim_clear(pval, it);
else
*pval = NULL;
return;
}
if (!it || (it->itype == ASN1_ITYPE_MSTRING))
utype = -1;
else
utype = it->utype;
if (utype == V_ASN1_BOOLEAN)
*(ASN1_BOOLEAN *)pval = it->size;
else
*pval = NULL;
}