sal/osl/unx/random.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <oslrandom.h>
  11
  12 #include <assert.h>
  13 #include <errno.h>
  14 #include <fcntl.h>
  15 #include <unistd.h>
  16 #include <dlfcn.h>
  17
  18 bool osl_get_system_random_data(char* buffer, size_t desired_len)
  19 {
  20     int fd;
  21
  22     assert(buffer);
  23
  24     static int (*lok_open_urandom)()
  25         = reinterpret_cast<int (*)()>(dlsym(RTLD_DEFAULT, "lok_open_urandom"));
  26     if (!lok_open_urandom || (fd = lok_open_urandom()) < 0)
  27         fd = open("/dev/urandom", O_RDONLY);
  28
  29     if (fd != -1)
  30     {
  31         while (desired_len)
  32         {
  33             ssize_t nb_read;
  34             if ((nb_read = read(fd, buffer, desired_len)) < 0)
  35             {
  36                 if (errno != EINTR)
  37                 {
  38                     close(fd);
  39                     return false;
  40                 }
  41             }
  42             else
  43             {
  44                 buffer += nb_read;
  45                 desired_len -= nb_read;
  46             }
  47         }
  48         close(fd);
  49         return true;
  50     }
  51     return false;
  52 }
  53
  54 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */