blob: 36e99aaa6023e4628b44e23d9ab50abed1e7af4e [file] [log] [blame]
/* Copyright (c) 2016, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/rand.h>
#if defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
#include <string.h>
#include <openssl/chacha.h>
#include "internal.h"
/* g_num_calls is the number of calls to |CRYPTO_sysrand| that have occured.
*
* TODO(davidben): This is intentionally not thread-safe. If the fuzzer mode is
* ever used in a multi-threaded program, replace this with a thread-local. (A
* mutex would not be deterministic.) */
static uint64_t g_num_calls = 0;
void RAND_reset_for_fuzzing(void) { g_num_calls = 0; }
void CRYPTO_sysrand(uint8_t *out, size_t requested) {
static const uint8_t kZeroKey[32];
uint8_t nonce[12];
OPENSSL_memset(nonce, 0, sizeof(nonce));
OPENSSL_memcpy(nonce, &g_num_calls, sizeof(g_num_calls));
OPENSSL_memset(out, 0, requested);
CRYPTO_chacha_20(out, out, requested, kZeroKey, nonce, 0);
g_num_calls++;
}
#endif /* BORINGSSL_UNSAFE_DETERMINISTIC_MODE */