lib/gnutls_random.c

   1 /*
   2  *      Copyright (C) 2001 Nikos Mavroyanopoulos
   3  *
   4  * This file is part of GNUTLS.
   5  *
   6  *  The GNUTLS library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation; either
   9  *  version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
  19  *
  20  */
  21
  22 #include <gnutls_int.h>
  23 #include <gnutls_random.h>
  24 #include <gnutls_errors.h>
  25 #ifndef USE_GCRYPT
  26 # ifdef HAVE_UNISTD_H
  27 #  include <unistd.h>
  28 # endif
  29 # include <sys/types.h>
  30 # include <sys/stat.h>
  31 # include <fcntl.h>
  32 #endif
  33
  34 /* fills the buffer 'res' with random bytes of 'bytes' long.
  35  * level is WEAK, STRONG, or VERY_STRONG (libgcrypt)
  36  */
  37 int _gnutls_get_random(opaque * res, int bytes, int level)
  38 {
  39 #ifndef USE_GCRYPT
  40     int fd;
  41     char *device;
  42
  43     device = "dev/urandom";
  44
  45     fd = open(device, O_RDONLY);
  46     if (device == NULL || fd < 0) {
  47         _gnutls_log( "Could not open random device\n");
  48         return GNUTLS_E_FILE_ERROR;
  49     } else {
  50         read(fd, res, bytes);
  51         close(fd);
  52     }
  53     return 0;
  54 #else                           /* using gcrypt */
  55     gcry_randomize( res, bytes, level);
  56
  57     return 0;
  58 #endif
  59
  60 }
  61