/* 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/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 8

static_assert(OPENSSL_MALLOC_PREFIX >= sizeof(size_t), "size_t too large");

#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

#if defined(__ELF__) && defined(__GNUC__)

#define WEAK_SYMBOL_FUNC(rettype, name, args) \

  rettype name args __attribute__((weak));

#else

#define WEAK_SYMBOL_FUNC(rettype, name, args) static rettype(*name) args = NULL;

#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));

// kBoringSSLBinaryTag is a distinctive byte sequence to identify binaries that

// are linking in BoringSSL and, roughly, what version they are using.

static const uint8_t kBoringSSLBinaryTag[18] = {

    // 16 bytes of magic tag.

    0x8c,

    0x62,

    0x20,

    0x0b,

    0xd2,

    0xa0,

    0x72,

    0x58,

    0x44,

    0xa8,

    0x96,

    0x69,

    0xad,

    0x55,

    0x7e,

    0xec,

    // Current source iteration. Incremented ~monthly.

    3,

    0,

};

#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;

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) {

    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);

}

#else

static int should_fail_allocation(void) { return 0; }

#endif

void *OPENSSL_malloc(size_t size) {

  if (should_fail_allocation()) {

    goto err;

  }

  if (OPENSSL_memory_alloc != NULL) {

    assert(OPENSSL_memory_free != NULL);

    assert(OPENSSL_memory_get_size != NULL);

    void *ptr = OPENSSL_memory_alloc(size);

    if (ptr == NULL && size != 0) {

      goto err;

    }

    return ptr;

  }

  if (size + OPENSSL_MALLOC_PREFIX < size) {

    // |OPENSSL_malloc| is a central function in BoringSSL thus a reference to

    // |kBoringSSLBinaryTag| is created here so that the tag isn't discarded by

    // the linker. The following is sufficient to stop GCC, Clang, and MSVC

    // optimising away the reference at the time of writing. Since this

    // probably results in an actual memory reference, it is put in this very

    // rare code path.

    uint8_t unused = *(volatile uint8_t *)kBoringSSLBinaryTag;

    (void) unused;

    goto err;

  }

  void *ptr = malloc(size + OPENSSL_MALLOC_PREFIX);

  if (ptr == NULL) {

    goto err;

  }

  *(size_t *)ptr = size;

  __asan_poison_memory_region(ptr, OPENSSL_MALLOC_PREFIX);

  return ((uint8_t *)ptr) + OPENSSL_MALLOC_PREFIX;

 err:

  // This only works because ERR does not call OPENSSL_malloc.

  OPENSSL_PUT_ERROR(CRYPTO, ERR_R_MALLOC_FAILURE);

  return NULL;

}

void OPENSSL_free(void *orig_ptr) {

  if (orig_ptr == NULL) {

    return;

  }

  if (OPENSSL_memory_free != NULL) {

    OPENSSL_memory_free(orig_ptr);

    return;

  }

  void *ptr = ((uint8_t *)orig_ptr) - OPENSSL_MALLOC_PREFIX;

  __asan_unpoison_memory_region(ptr, OPENSSL_MALLOC_PREFIX);

  size_t size = *(size_t *)ptr;

  OPENSSL_cleanse(ptr, size + OPENSSL_MALLOC_PREFIX);

// ASan knows to intercept malloc and free, but not sdallocx.

#if defined(OPENSSL_ASAN)

  (void)sdallocx;

  free(ptr);

#else

  if (sdallocx) {

    sdallocx(ptr, size + OPENSSL_MALLOC_PREFIX, 0 /* flags */);

  } else {

    free(ptr);

  }

#endif

}

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

  if (orig_ptr == NULL) {

    return OPENSSL_malloc(new_size);

  }

  size_t old_size;

  if (OPENSSL_memory_get_size != NULL) {

    old_size = OPENSSL_memory_get_size(orig_ptr);

  } else {

    void *ptr = ((uint8_t *)orig_ptr) - OPENSSL_MALLOC_PREFIX;

    __asan_unpoison_memory_region(ptr, OPENSSL_MALLOC_PREFIX);

    old_size = *(size_t *)ptr;

    __asan_poison_memory_region(ptr, OPENSSL_MALLOC_PREFIX);

  }

  void *ret = OPENSSL_malloc(new_size);

  if (ret == NULL) {

    return NULL;

  }

  size_t to_copy = new_size;

  if (old_size < to_copy) {

    to_copy = old_size;

  }

  memcpy(ret, orig_ptr, to_copy);

  OPENSSL_free(orig_ptr);

  return ret;

}

void OPENSSL_cleanse(void *ptr, size_t len) {

#if defined(OPENSSL_WINDOWS)

  SecureZeroMemory(ptr, len);

#else

  OPENSSL_memset(ptr, 0, len);

#if !defined(OPENSSL_NO_ASM)

  /* As best as we can tell, this is sufficient to break any optimisations that

     might try to eliminate "superfluous" memsets. If there's an easy way to

     detect memset_s, it would be better to use that. */

  __asm__ __volatile__("" : : "r"(ptr) : "memory");

#endif

#endif  // !OPENSSL_NO_ASM

}

void OPENSSL_clear_free(void *ptr, size_t unused) { OPENSSL_free(ptr); }

int CRYPTO_secure_malloc_init(size_t size, size_t min_size) { return 0; }

int CRYPTO_secure_malloc_initialized(void) { return 0; }

size_t CRYPTO_secure_used(void) { return 0; }

void *OPENSSL_secure_malloc(size_t size) { return OPENSSL_malloc(size); }

void OPENSSL_secure_clear_free(void *ptr, size_t len) {

  OPENSSL_clear_free(ptr, len);

}

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

  const uint8_t *a = in_a;

  const uint8_t *b = in_b;

  uint8_t x = 0;

  for (size_t i = 0; i < len; i++) {

    x |= a[i] ^ b[i];

  }

  return x;

}

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

  // These are the FNV-1a parameters for 32 bits.

  static const uint32_t kPrime = 16777619u;

  static const uint32_t kOffsetBasis = 2166136261u;

  const uint8_t *in = ptr;

  uint32_t h = kOffsetBasis;

  for (size_t i = 0; i < len; i++) {

    h ^= in[i];

    h *= kPrime;

  }

  return h;

}

uint32_t OPENSSL_strhash(const char *s) { return OPENSSL_hash32(s, strlen(s)); }

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

  for (size_t i = 0; i < len; i++) {

    if (s[i] == 0) {

      return i;

    }

  }

  return len;

}

char *OPENSSL_strdup(const char *s) {

  if (s == NULL) {

    return NULL;

  }

  const size_t len = strlen(s) + 1;

  char *ret = OPENSSL_malloc(len);

  if (ret == NULL) {

    return NULL;

  }

  OPENSSL_memcpy(ret, s, len);

  return ret;

}

int OPENSSL_isalpha(int c) {

  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');

}

int OPENSSL_isdigit(int c) { return c >= '0' && c <= '9'; }

int OPENSSL_isxdigit(int c) {

  return OPENSSL_isdigit(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');

}

int OPENSSL_fromxdigit(uint8_t *out, int c) {

  if (OPENSSL_isdigit(c)) {

    *out = c - '0';

    return 1;

  }

  if ('a' <= c && c <= 'f') {

    *out = c - 'a' + 10;

    return 1;

  }

  if ('A' <= c && c <= 'F') {

    *out = c - 'A' + 10;

    return 1;

  }

  return 0;

}

int OPENSSL_isalnum(int c) { return OPENSSL_isalpha(c) || OPENSSL_isdigit(c); }

int OPENSSL_tolower(int c) {

  if (c >= 'A' && c <= 'Z') {

    return c + ('a' - 'A');

  }

  return c;

}

int OPENSSL_isspace(int c) {

  return c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r' ||

         c == ' ';

}

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

  for (size_t i = 0;; i++) {

    const int aa = OPENSSL_tolower(a[i]);

    const int bb = OPENSSL_tolower(b[i]);

    if (aa < bb) {

      return -1;

    } else if (aa > bb) {

      return 1;

    } else if (aa == 0) {

      return 0;

    }

  }

}

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

  for (size_t i = 0; i < n; i++) {

    const int aa = OPENSSL_tolower(a[i]);

    const int bb = OPENSSL_tolower(b[i]);

    if (aa < bb) {

      return -1;

    } else if (aa > bb) {

      return 1;

    } else if (aa == 0) {

      return 0;

    }

  }

  return 0;

}

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

  va_list args;

  va_start(args, format);

  int ret = BIO_vsnprintf(buf, n, format, args);

  va_end(args);

  return ret;

}

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

  return vsnprintf(buf, n, format, args);

}

int OPENSSL_vasprintf_internal(char **str, const char *format, va_list args,

                               int system_malloc) {

  void *(*allocate)(size_t) = system_malloc ? malloc : OPENSSL_malloc;

  void (*deallocate)(void *) = system_malloc ? free : OPENSSL_free;

  void *(*reallocate)(void *, size_t) =

      system_malloc ? realloc : OPENSSL_realloc;

  char *candidate = NULL;

  size_t candidate_len = 64;  // TODO(bbe) what's the best initial size?

  if ((candidate = allocate(candidate_len)) == NULL) {

    goto err;

  }

  va_list args_copy;

  va_copy(args_copy, args);

  int ret = vsnprintf(candidate, candidate_len, format, args_copy);

  va_end(args_copy);

  if (ret < 0) {

    goto err;

  }

  if ((size_t)ret >= candidate_len) {

    // Too big to fit in allocation.

    char *tmp;

    candidate_len = (size_t)ret + 1;

    if ((tmp = reallocate(candidate, candidate_len)) == NULL) {

      goto err;

    }

    candidate = tmp;

    ret = vsnprintf(candidate, candidate_len, format, args);

  }

  // At this point this should not happen unless vsnprintf is insane.

  if (ret < 0 || (size_t)ret >= candidate_len) {

    goto err;

  }

  *str = candidate;

  return ret;

 err:

  deallocate(candidate);

  *str = NULL;

  errno = ENOMEM;

  return -1;

}

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

  return OPENSSL_vasprintf_internal(str, format, args, /*system_malloc=*/0);

}

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

  va_list args;

  va_start(args, format);

  int ret = OPENSSL_vasprintf(str, format, args);

  va_end(args);

  return ret;

}

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

  size = OPENSSL_strnlen(str, size);

  size_t alloc_size = size + 1;

  if (alloc_size < size) {

    // overflow

    OPENSSL_PUT_ERROR(CRYPTO, ERR_R_MALLOC_FAILURE);

    return NULL;

  }

  char *ret = OPENSSL_malloc(alloc_size);

  if (ret == NULL) {

    return NULL;

  }

  OPENSSL_memcpy(ret, str, size);

  ret[size] = '\0';

  return ret;

}

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

  size_t l = 0;

  for (; dst_size > 1 && *src; dst_size--) {

    *dst++ = *src++;

    l++;

  }

  if (dst_size) {

    *dst = 0;

  }

  return l + strlen(src);

}

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

  size_t l = 0;

  for (; dst_size > 0 && *dst; dst_size--, dst++) {

    l++;

  }

  return l + OPENSSL_strlcpy(dst, src, dst_size);

}

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

  if (size == 0) {

    return NULL;

  }

  void *ret = OPENSSL_malloc(size);

  if (ret == NULL) {

    return NULL;

  }

  OPENSSL_memcpy(ret, data, size);

  return ret;

}

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

  return OPENSSL_malloc(size);

}

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

  return OPENSSL_realloc(ptr, new_size);

}

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