// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#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)

#include <windows.h>

#endif

#if defined(BORINGSSL_MALLOC_FAILURE_TESTING)

#include <errno.h>

#include <signal.h>

#include <unistd.h>

#endif

#include "internal.h"

using namespace bssl;

#define OPENSSL_MALLOC_PREFIX 8

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

#if defined(OPENSSL_ASAN)

extern "C" {

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) \

  extern "C" {                                \

  rettype name args __attribute__((weak));    \

  }

#else

#define WEAK_SYMBOL_FUNC(rettype, name, args) \

  static rettype(*const name) args = nullptr;

#endif

#if defined(BORINGSSL_DETECT_SDALLOCX)

// 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 mechanism is kept opt-in because it assumes that, when `sdallocx` is

// defined, it is part of the same allocator as `malloc`. This is usually true

// but may break if `malloc` does not implement `sdallocx`, but some other

// allocator with `sdallocx` is imported which does.

WEAK_SYMBOL_FUNC(void, sdallocx, (void *ptr, size_t size, int flags))

#else

static void (*const sdallocx)(void *ptr, size_t size, int flags) = nullptr;

#endif

// 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 StaticMutex malloc_failure_lock;

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() {

  MutexReadLock lock(&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);

  }

}

static void init_malloc_failure() {

  const char *env = getenv("MALLOC_NUMBER_TO_FAIL");

  if (env != nullptr && 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") != nullptr;

}

// 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.

  malloc_failure_lock.LockWrite();

  int should_fail = current_malloc_count == malloc_number_to_fail;

  current_malloc_count++;

  any_malloc_failed = any_malloc_failed || should_fail;

  malloc_failure_lock.UnlockWrite();

  if (should_fail && break_on_malloc_fail) {

    raise(SIGTRAP);

  }

  if (should_fail) {

    errno = ENOMEM;

  }

  return should_fail;

}

void bssl::OPENSSL_reset_malloc_counter_for_testing() {

  MutexWriteLock lock(&malloc_failure_lock);

  current_malloc_count = 0;

}

void bssl::OPENSSL_disable_malloc_failures_for_testing() {

  MutexWriteLock lock(&malloc_failure_lock);

  BSSL_CHECK(!disable_malloc_failures);

  disable_malloc_failures = 1;

}

void bssl::OPENSSL_enable_malloc_failures_for_testing() {

  MutexWriteLock lock(&malloc_failure_lock);

  BSSL_CHECK(disable_malloc_failures);

  disable_malloc_failures = 0;

}

#else

static int should_fail_allocation() { return 0; }

#endif

void *OPENSSL_malloc(size_t size) {

  void *ptr = nullptr;

  if (should_fail_allocation()) {

    goto err;

  }

  if (OPENSSL_memory_alloc != nullptr) {

    assert(OPENSSL_memory_free != nullptr);

    assert(OPENSSL_memory_get_size != nullptr);

    void *ptr2 = OPENSSL_memory_alloc(size);

    if (ptr2 == nullptr && size != 0) {

      goto err;

    }

    return ptr2;

  }

  if (size + OPENSSL_MALLOC_PREFIX < size) {

    goto err;

  }

  ptr = malloc(size + OPENSSL_MALLOC_PREFIX);

  if (ptr == nullptr) {

    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 nullptr;

}

void *OPENSSL_zalloc(size_t size) {

  void *ret = OPENSSL_malloc(size);

  if (ret != nullptr) {

    OPENSSL_memset(ret, 0, size);

  }

  return ret;

}

void *OPENSSL_calloc(size_t num, size_t size) {

  if (size != 0 && num > SIZE_MAX / size) {

    OPENSSL_PUT_ERROR(CRYPTO, ERR_R_OVERFLOW);

    return nullptr;

  }

  return OPENSSL_zalloc(num * size);

}

void OPENSSL_free(void *orig_ptr) {

  if (orig_ptr == nullptr) {

    return;

  }

  if (OPENSSL_memory_free != nullptr) {

    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 == nullptr) {

    return OPENSSL_malloc(new_size);

  }

  size_t old_size;

  if (OPENSSL_memory_get_size != nullptr) {

    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 == nullptr) {

    return nullptr;

  }

  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);

  // 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

}

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() { return 0; }

size_t CRYPTO_secure_used() { 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 = reinterpret_cast<const uint8_t *>(in_a);

  const uint8_t *b = reinterpret_cast<const uint8_t *>(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 = reinterpret_cast<const uint8_t *>(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 == nullptr) {

    return nullptr;

  }

  // Copy the NUL terminator.

  return reinterpret_cast<char *>(OPENSSL_memdup(s, strlen(s) + 1));

}

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 bssl::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 = nullptr;

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

  int ret;

  if ((candidate = reinterpret_cast<char *>(allocate(candidate_len))) ==

      nullptr) {

    goto err;

  }

  va_list args_copy;

  va_copy(args_copy, args);

  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 = reinterpret_cast<char *>(

             reallocate(candidate, candidate_len))) == nullptr) {

      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 = nullptr;

  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 nullptr;

  }

  char *ret = reinterpret_cast<char *>(OPENSSL_malloc(alloc_size));

  if (ret == nullptr) {

    return nullptr;

  }

  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 nullptr;

  }

  void *ret = OPENSSL_malloc(size);

  if (ret == nullptr) {

    return nullptr;

  }

  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); }