openssl/crypto/buffer/buffer.c
Ben Laurie 5cf14ce074 memset() doesn't take NULL.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
2016-05-07 18:28:07 +01:00

213 lines
6.8 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 <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/buffer.h>
/*
* LIMIT_BEFORE_EXPANSION is the maximum n such that (n+3)/3*4 < 2**31. That
* function is applied in several functions in this file and this limit
* ensures that the result fits in an int.
*/
#define LIMIT_BEFORE_EXPANSION 0x5ffffffc
BUF_MEM *BUF_MEM_new_ex(unsigned long flags)
{
BUF_MEM *ret;
ret = BUF_MEM_new();
if (ret != NULL)
ret->flags = flags;
return (ret);
}
BUF_MEM *BUF_MEM_new(void)
{
BUF_MEM *ret;
ret = OPENSSL_zalloc(sizeof(*ret));
if (ret == NULL) {
BUFerr(BUF_F_BUF_MEM_NEW, ERR_R_MALLOC_FAILURE);
return (NULL);
}
return (ret);
}
void BUF_MEM_free(BUF_MEM *a)
{
if (a == NULL)
return;
if (a->data != NULL) {
memset(a->data, 0, (unsigned int)a->max);
if (a->flags & BUF_MEM_FLAG_SECURE)
OPENSSL_secure_free(a->data);
else
OPENSSL_clear_free(a->data, a->max);
}
OPENSSL_free(a);
}
/* Allocate a block of secure memory; copy over old data if there
* was any, and then free it. */
static char *sec_alloc_realloc(BUF_MEM *str, size_t len)
{
char *ret;
ret = OPENSSL_secure_malloc(len);
if (str->data != NULL) {
if (ret != NULL)
memcpy(ret, str->data, str->length);
OPENSSL_secure_free(str->data);
}
return (ret);
}
size_t BUF_MEM_grow(BUF_MEM *str, size_t len)
{
char *ret;
size_t n;
if (str->length >= len) {
str->length = len;
return (len);
}
if (str->max >= len) {
if (str->data != NULL)
memset(&str->data[str->length], 0, len - str->length);
str->length = len;
return (len);
}
/* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
if (len > LIMIT_BEFORE_EXPANSION) {
BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);
return 0;
}
n = (len + 3) / 3 * 4;
if ((str->flags & BUF_MEM_FLAG_SECURE))
ret = sec_alloc_realloc(str, n);
else
ret = OPENSSL_realloc(str->data, n);
if (ret == NULL) {
BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);
len = 0;
} else {
str->data = ret;
str->max = n;
memset(&str->data[str->length], 0, len - str->length);
str->length = len;
}
return (len);
}
size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len)
{
char *ret;
size_t n;
if (str->length >= len) {
if (str->data != NULL)
memset(&str->data[len], 0, str->length - len);
str->length = len;
return (len);
}
if (str->max >= len) {
memset(&str->data[str->length], 0, len - str->length);
str->length = len;
return (len);
}
/* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */
if (len > LIMIT_BEFORE_EXPANSION) {
BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);
return 0;
}
n = (len + 3) / 3 * 4;
if ((str->flags & BUF_MEM_FLAG_SECURE))
ret = sec_alloc_realloc(str, n);
else
ret = OPENSSL_clear_realloc(str->data, str->max, n);
if (ret == NULL) {
BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);
len = 0;
} else {
str->data = ret;
str->max = n;
memset(&str->data[str->length], 0, len - str->length);
str->length = len;
}
return (len);
}
void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size)
{
size_t i;
if (in) {
out += size - 1;
for (i = 0; i < size; i++)
*out-- = *in++;
} else {
unsigned char *q;
char c;
q = out + size - 1;
for (i = 0; i < size / 2; i++) {
c = *q;
*q-- = *out;
*out++ = c;
}
}
}