chromium/third_party/boringssl/src/crypto/mem.c

/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * 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 ([email protected]).
 *
 * 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 ([email protected])"
 *    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 ([email protected])"
 *
 * 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/mem.h>

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>

#include <openssl/err.h>

#if defined(OPENSSL_WINDOWS)
OPENSSL_MSVC_PRAGMA(warning(push, 3))
#include <windows.h>
OPENSSL_MSVC_PRAGMA(warning(pop))
#endif

#if defined(BORINGSSL_MALLOC_FAILURE_TESTING)
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#endif

#include "internal.h"


#define OPENSSL_MALLOC_PREFIX …
static_assert;

#if defined(OPENSSL_ASAN)
void __asan_poison_memory_region(const volatile void *addr, size_t size);
void __asan_unpoison_memory_region(const volatile void *addr, size_t size);
#else
static void __asan_poison_memory_region(const void *addr, size_t size) { … }
static void __asan_unpoison_memory_region(const void *addr, size_t size) { … }
#endif

// Windows doesn't really support weak symbols as of May 2019, and Clang on
// Windows will emit strong symbols instead. See
// https://bugs.llvm.org/show_bug.cgi?id=37598
//
// EDK2 targets UEFI but builds as ELF and then translates the binary to
// COFF(!). Thus it builds with __ELF__ defined but cannot actually cope with
// weak symbols.
#if !defined(__EDK2_BORINGSSL__) && defined(__ELF__) && defined(__GNUC__)
#define WEAK_SYMBOL_FUNC(rettype, name, args) …
#else
#define WEAK_SYMBOL_FUNC …
#endif

// sdallocx is a sized |free| function. By passing the size (which we happen to
// always know in BoringSSL), the malloc implementation can save work. We cannot
// depend on |sdallocx| being available, however, so it's a weak symbol.
//
// This will always be safe, but will only be overridden if the malloc
// implementation is statically linked with BoringSSL. So, if |sdallocx| is
// provided in, say, libc.so, we still won't use it because that's dynamically
// linked. This isn't an ideal result, but its helps in some cases.
WEAK_SYMBOL_FUNC(void, sdallocx, (void *ptr, size_t size, int flags));

// The following three functions can be defined to override default heap
// allocation and freeing. If defined, it is the responsibility of
// |OPENSSL_memory_free| to zero out the memory before returning it to the
// system. |OPENSSL_memory_free| will not be passed NULL pointers.
//
// WARNING: These functions are called on every allocation and free in
// BoringSSL across the entire process. They may be called by any code in the
// process which calls BoringSSL, including in process initializers and thread
// destructors. When called, BoringSSL may hold pthreads locks. Any other code
// in the process which, directly or indirectly, calls BoringSSL may be on the
// call stack and may itself be using arbitrary synchronization primitives.
//
// As a result, these functions may not have the usual programming environment
// available to most C or C++ code. In particular, they may not call into
// BoringSSL, or any library which depends on BoringSSL. Any synchronization
// primitives used must tolerate every other synchronization primitive linked
// into the process, including pthreads locks. Failing to meet these constraints
// may result in deadlocks, crashes, or memory corruption.
WEAK_SYMBOL_FUNC(void *, OPENSSL_memory_alloc, (size_t size));
WEAK_SYMBOL_FUNC(void, OPENSSL_memory_free, (void *ptr));
WEAK_SYMBOL_FUNC(size_t, OPENSSL_memory_get_size, (void *ptr));

#if defined(BORINGSSL_MALLOC_FAILURE_TESTING)
static CRYPTO_MUTEX malloc_failure_lock = CRYPTO_MUTEX_INIT;
static uint64_t current_malloc_count = 0;
static uint64_t malloc_number_to_fail = 0;
static int malloc_failure_enabled = 0, break_on_malloc_fail = 0,
           any_malloc_failed = 0, disable_malloc_failures = 0;

static void malloc_exit_handler(void) {
  CRYPTO_MUTEX_lock_read(&malloc_failure_lock);
  if (any_malloc_failed) {
    // Signal to the test driver that some allocation failed, so it knows to
    // increment the counter and continue.
    _exit(88);
  }
  CRYPTO_MUTEX_unlock_read(&malloc_failure_lock);
}

static void init_malloc_failure(void) {
  const char *env = getenv("MALLOC_NUMBER_TO_FAIL");
  if (env != NULL && env[0] != 0) {
    char *endptr;
    malloc_number_to_fail = strtoull(env, &endptr, 10);
    if (*endptr == 0) {
      malloc_failure_enabled = 1;
      atexit(malloc_exit_handler);
    }
  }
  break_on_malloc_fail = getenv("MALLOC_BREAK_ON_FAIL") != NULL;
}

// should_fail_allocation returns one if the current allocation should fail and
// zero otherwise.
static int should_fail_allocation() {
  static CRYPTO_once_t once = CRYPTO_ONCE_INIT;
  CRYPTO_once(&once, init_malloc_failure);
  if (!malloc_failure_enabled || disable_malloc_failures) {
    return 0;
  }

  // We lock just so multi-threaded tests are still correct, but we won't test
  // every malloc exhaustively.
  CRYPTO_MUTEX_lock_write(&malloc_failure_lock);
  int should_fail = current_malloc_count == malloc_number_to_fail;
  current_malloc_count++;
  any_malloc_failed = any_malloc_failed || should_fail;
  CRYPTO_MUTEX_unlock_write(&malloc_failure_lock);

  if (should_fail && break_on_malloc_fail) {
    raise(SIGTRAP);
  }
  if (should_fail) {
    errno = ENOMEM;
  }
  return should_fail;
}

void OPENSSL_reset_malloc_counter_for_testing(void) {
  CRYPTO_MUTEX_lock_write(&malloc_failure_lock);
  current_malloc_count = 0;
  CRYPTO_MUTEX_unlock_write(&malloc_failure_lock);
}

void OPENSSL_disable_malloc_failures_for_testing(void) {
  CRYPTO_MUTEX_lock_write(&malloc_failure_lock);
  BSSL_CHECK(!disable_malloc_failures);
  disable_malloc_failures = 1;
  CRYPTO_MUTEX_unlock_write(&malloc_failure_lock);
}

void OPENSSL_enable_malloc_failures_for_testing(void) {
  CRYPTO_MUTEX_lock_write(&malloc_failure_lock);
  BSSL_CHECK(disable_malloc_failures);
  disable_malloc_failures = 0;
  CRYPTO_MUTEX_unlock_write(&malloc_failure_lock);
}

#else
static int should_fail_allocation(void) { … }
#endif

void *OPENSSL_malloc(size_t size) { … }

void *OPENSSL_zalloc(size_t size) { … }

void *OPENSSL_calloc(size_t num, size_t size) { … }

void OPENSSL_free(void *orig_ptr) { … }

void *OPENSSL_realloc(void *orig_ptr, size_t new_size) { … }

void OPENSSL_cleanse(void *ptr, size_t len) { … }

void OPENSSL_clear_free(void *ptr, size_t unused) { … }

int CRYPTO_secure_malloc_init(size_t size, size_t min_size) { … }

int CRYPTO_secure_malloc_initialized(void) { … }

size_t CRYPTO_secure_used(void) { … }

void *OPENSSL_secure_malloc(size_t size) { … }

void OPENSSL_secure_clear_free(void *ptr, size_t len) { … }

int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len) { … }

uint32_t OPENSSL_hash32(const void *ptr, size_t len) { … }

uint32_t OPENSSL_strhash(const char *s) { … }

size_t OPENSSL_strnlen(const char *s, size_t len) { … }

char *OPENSSL_strdup(const char *s) { … }

int OPENSSL_isalpha(int c) { … }

int OPENSSL_isdigit(int c) { … }

int OPENSSL_isxdigit(int c) { … }

int OPENSSL_fromxdigit(uint8_t *out, int c) { … }

int OPENSSL_isalnum(int c) { … }

int OPENSSL_tolower(int c) { … }

int OPENSSL_isspace(int c) { … }

int OPENSSL_strcasecmp(const char *a, const char *b) { … }

int OPENSSL_strncasecmp(const char *a, const char *b, size_t n) { … }

int BIO_snprintf(char *buf, size_t n, const char *format, ...) { … }

int BIO_vsnprintf(char *buf, size_t n, const char *format, va_list args) { … }

int OPENSSL_vasprintf_internal(char **str, const char *format, va_list args,
                               int system_malloc) { … }

int OPENSSL_vasprintf(char **str, const char *format, va_list args) { … }

int OPENSSL_asprintf(char **str, const char *format, ...) { … }

char *OPENSSL_strndup(const char *str, size_t size) { … }

size_t OPENSSL_strlcpy(char *dst, const char *src, size_t dst_size) { … }

size_t OPENSSL_strlcat(char *dst, const char *src, size_t dst_size) { … }

void *OPENSSL_memdup(const void *data, size_t size) { … }

void *CRYPTO_malloc(size_t size, const char *file, int line) { … }

void *CRYPTO_realloc(void *ptr, size_t new_size, const char *file, int line) { … }

void CRYPTO_free(void *ptr, const char *file, int line) { … }