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      1 /* Copyright (c) 2017, Google Inc.
      2  *
      3  * Permission to use, copy, modify, and/or distribute this software for any
      4  * purpose with or without fee is hereby granted, provided that the above
      5  * copyright notice and this permission notice appear in all copies.
      6  *
      7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
      9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
     12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
     13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
     14 
     15 #include <openssl/rand.h>
     16 
     17 #include <stdlib.h>
     18 
     19 #include "../fipsmodule/rand/internal.h"
     20 
     21 
     22 // g_buffering_enabled is true if fork-unsafe buffering has been enabled.
     23 static int g_buffering_enabled = 0;
     24 
     25 // g_lock protects |g_buffering_enabled|.
     26 static struct CRYPTO_STATIC_MUTEX g_lock = CRYPTO_STATIC_MUTEX_INIT;
     27 
     28 #if !defined(OPENSSL_WINDOWS)
     29 void RAND_enable_fork_unsafe_buffering(int fd) {
     30   // We no longer support setting the file-descriptor with this function.
     31   if (fd != -1) {
     32     abort();
     33   }
     34 
     35   CRYPTO_STATIC_MUTEX_lock_write(&g_lock);
     36   g_buffering_enabled = 1;
     37   CRYPTO_STATIC_MUTEX_unlock_write(&g_lock);
     38 }
     39 #endif
     40 
     41 int rand_fork_unsafe_buffering_enabled(void) {
     42   CRYPTO_STATIC_MUTEX_lock_read(&g_lock);
     43   const int ret = g_buffering_enabled;
     44   CRYPTO_STATIC_MUTEX_unlock_read(&g_lock);
     45   return ret;
     46 }
     47