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      1 /* Copyright (c) 2014, 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 #if defined(OPENSSL_WINDOWS) && !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
     18 
     19 #include <limits.h>
     20 #include <stdlib.h>
     21 
     22 OPENSSL_MSVC_PRAGMA(warning(push, 3))
     23 
     24 #include <windows.h>
     25 
     26 // #define needed to link in RtlGenRandom(), a.k.a. SystemFunction036.  See the
     27 // "Community Additions" comment on MSDN here:
     28 // http://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
     29 #define SystemFunction036 NTAPI SystemFunction036
     30 #include <ntsecapi.h>
     31 #undef SystemFunction036
     32 
     33 OPENSSL_MSVC_PRAGMA(warning(pop))
     34 
     35 #include "../fipsmodule/rand/internal.h"
     36 
     37 
     38 void CRYPTO_sysrand(uint8_t *out, size_t requested) {
     39   while (requested > 0) {
     40     ULONG output_bytes_this_pass = ULONG_MAX;
     41     if (requested < output_bytes_this_pass) {
     42       output_bytes_this_pass = (ULONG)requested;
     43     }
     44     if (RtlGenRandom(out, output_bytes_this_pass) == FALSE) {
     45       abort();
     46     }
     47     requested -= output_bytes_this_pass;
     48     out += output_bytes_this_pass;
     49   }
     50   return;
     51 }
     52 
     53 #endif  // OPENSSL_WINDOWS && !BORINGSSL_UNSAFE_DETERMINISTIC_MODE
     54