openssl/crypto/mem.c

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2023-05-09 22:08:48 +00:00
/*
* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "e_os.h"
#include "internal/cryptlib.h"
#include "crypto/cryptlib.h"
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <openssl/crypto.h>
#ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
# include <execinfo.h>
#endif
/*
* the following pointers may be changed as long as 'allow_customize' is set
*/
static int allow_customize = 1;
static void *(*malloc_impl)(size_t, const char *, int)
= CRYPTO_malloc;
static void *(*realloc_impl)(void *, size_t, const char *, int)
= CRYPTO_realloc;
static void (*free_impl)(void *, const char *, int)
= CRYPTO_free;
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
# include "internal/tsan_assist.h"
static TSAN_QUALIFIER int malloc_count;
static TSAN_QUALIFIER int realloc_count;
static TSAN_QUALIFIER int free_count;
# define INCREMENT(x) tsan_counter(&(x))
static char *md_failstring;
static long md_count;
static int md_fail_percent = 0;
static int md_tracefd = -1;
static int call_malloc_debug = 1;
static void parseit(void);
static int shouldfail(void);
# define FAILTEST() if (shouldfail()) return NULL
#else
static int call_malloc_debug = 0;
# define INCREMENT(x) /* empty */
# define FAILTEST() /* empty */
#endif
int CRYPTO_set_mem_functions(
void *(*m)(size_t, const char *, int),
void *(*r)(void *, size_t, const char *, int),
void (*f)(void *, const char *, int))
{
if (!allow_customize)
return 0;
if (m)
malloc_impl = m;
if (r)
realloc_impl = r;
if (f)
free_impl = f;
return 1;
}
int CRYPTO_set_mem_debug(int flag)
{
if (!allow_customize)
return 0;
call_malloc_debug = flag;
return 1;
}
void CRYPTO_get_mem_functions(
void *(**m)(size_t, const char *, int),
void *(**r)(void *, size_t, const char *, int),
void (**f)(void *, const char *, int))
{
if (m != NULL)
*m = malloc_impl;
if (r != NULL)
*r = realloc_impl;
if (f != NULL)
*f = free_impl;
}
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount)
{
if (mcount != NULL)
*mcount = tsan_load(&malloc_count);
if (rcount != NULL)
*rcount = tsan_load(&realloc_count);
if (fcount != NULL)
*fcount = tsan_load(&free_count);
}
/*
* Parse a "malloc failure spec" string. This likes like a set of fields
* separated by semicolons. Each field has a count and an optional failure
* percentage. For example:
* 100@0;100@25;0@0
* or 100;100@25;0
* This means 100 mallocs succeed, then next 100 fail 25% of the time, and
* all remaining (count is zero) succeed.
*/
static void parseit(void)
{
char *semi = strchr(md_failstring, ';');
char *atsign;
if (semi != NULL)
*semi++ = '\0';
/* Get the count (atol will stop at the @ if there), and percentage */
md_count = atol(md_failstring);
atsign = strchr(md_failstring, '@');
md_fail_percent = atsign == NULL ? 0 : atoi(atsign + 1);
if (semi != NULL)
md_failstring = semi;
}
/*
* Windows doesn't have random(), but it has rand()
* Some rand() implementations aren't good, but we're not
* dealing with secure randomness here.
*/
# ifdef _WIN32
# define random() rand()
# endif
/*
* See if the current malloc should fail.
*/
static int shouldfail(void)
{
int roll = (int)(random() % 100);
int shoulditfail = roll < md_fail_percent;
# ifndef _WIN32
/* suppressed on Windows as POSIX-like file descriptors are non-inheritable */
int len;
char buff[80];
if (md_tracefd > 0) {
BIO_snprintf(buff, sizeof(buff),
"%c C%ld %%%d R%d\n",
shoulditfail ? '-' : '+', md_count, md_fail_percent, roll);
len = strlen(buff);
if (write(md_tracefd, buff, len) != len)
perror("shouldfail write failed");
# ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
if (shoulditfail) {
void *addrs[30];
int num = backtrace(addrs, OSSL_NELEM(addrs));
backtrace_symbols_fd(addrs, num, md_tracefd);
}
# endif
}
# endif
if (md_count) {
/* If we used up this one, go to the next. */
if (--md_count == 0)
parseit();
}
return shoulditfail;
}
void ossl_malloc_setup_failures(void)
{
const char *cp = getenv("OPENSSL_MALLOC_FAILURES");
if (cp != NULL && (md_failstring = strdup(cp)) != NULL)
parseit();
if ((cp = getenv("OPENSSL_MALLOC_FD")) != NULL)
md_tracefd = atoi(cp);
}
#endif
void *CRYPTO_malloc(size_t num, const char *file, int line)
{
void *ret = NULL;
INCREMENT(malloc_count);
if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)
return malloc_impl(num, file, line);
if (num == 0)
return NULL;
FAILTEST();
if (allow_customize) {
/*
* Disallow customization after the first allocation. We only set this
* if necessary to avoid a store to the same cache line on every
* allocation.
*/
allow_customize = 0;
}
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
if (call_malloc_debug) {
CRYPTO_mem_debug_malloc(NULL, num, 0, file, line);
ret = malloc(num);
CRYPTO_mem_debug_malloc(ret, num, 1, file, line);
} else {
ret = malloc(num);
}
#else
(void)(file); (void)(line);
ret = malloc(num);
#endif
return ret;
}
void *CRYPTO_zalloc(size_t num, const char *file, int line)
{
void *ret = CRYPTO_malloc(num, file, line);
FAILTEST();
if (ret != NULL)
memset(ret, 0, num);
return ret;
}
void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)
{
INCREMENT(realloc_count);
if (realloc_impl != NULL && realloc_impl != &CRYPTO_realloc)
return realloc_impl(str, num, file, line);
FAILTEST();
if (str == NULL)
return CRYPTO_malloc(num, file, line);
if (num == 0) {
CRYPTO_free(str, file, line);
return NULL;
}
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
if (call_malloc_debug) {
void *ret;
CRYPTO_mem_debug_realloc(str, NULL, num, 0, file, line);
ret = realloc(str, num);
CRYPTO_mem_debug_realloc(str, ret, num, 1, file, line);
return ret;
}
#else
(void)(file); (void)(line);
#endif
return realloc(str, num);
}
void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,
const char *file, int line)
{
void *ret = NULL;
if (str == NULL)
return CRYPTO_malloc(num, file, line);
if (num == 0) {
CRYPTO_clear_free(str, old_len, file, line);
return NULL;
}
/* Can't shrink the buffer since memcpy below copies |old_len| bytes. */
if (num < old_len) {
OPENSSL_cleanse((char*)str + num, old_len - num);
return str;
}
ret = CRYPTO_malloc(num, file, line);
if (ret != NULL) {
memcpy(ret, str, old_len);
CRYPTO_clear_free(str, old_len, file, line);
}
return ret;
}
void CRYPTO_free(void *str, const char *file, int line)
{
INCREMENT(free_count);
if (free_impl != NULL && free_impl != &CRYPTO_free) {
free_impl(str, file, line);
return;
}
#ifndef OPENSSL_NO_CRYPTO_MDEBUG
if (call_malloc_debug) {
CRYPTO_mem_debug_free(str, 0, file, line);
free(str);
CRYPTO_mem_debug_free(str, 1, file, line);
} else {
free(str);
}
#else
free(str);
#endif
}
void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)
{
if (str == NULL)
return;
if (num)
OPENSSL_cleanse(str, num);
CRYPTO_free(str, file, line);
}