lib/random.c

   1 /*
   2  * Copyright (C) 2008 Free Software Foundation
   3  *
   4  * Author: Nikos Mavrogiannopoulos
   5  *
   6  * This file is part of GNUTLS.
   7  *
   8  * The GNUTLS library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 2.1 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  21  * USA
  22  *
  23  */
  24
  25 /* This file handles all the internal functions that cope with random data.
  26  */
  27
  28 #include <gnutls_int.h>
  29 #include <gnutls_errors.h>
  30 #include <random.h>
  31
  32 static gnutls_crypto_rnd_st * cc = NULL;
  33 static void * rnd_ctx;
  34
  35 int
  36 _gnutls_rnd_init ()
  37 {
  38   int result;
  39
  40   /* check if a digest has been registered
  41    */
  42   cc = _gnutls_get_crypto_rnd();
  43
  44   if (cc != NULL) {
  45     if (cc->init(& rnd_ctx) < 0) {
  46       gnutls_assert();
  47       return GNUTLS_E_RANDOM_FAILED;
  48     }
  49   } else {
  50     char c;
  51     gc_pseudo_random (&c, 1);
  52   }
  53
  54   return 0;
  55 }
  56
  57 void
  58 _gnutls_rnd_deinit ()
  59 {
  60   if (cc != NULL) {
  61     cc->deinit( rnd_ctx);
  62   }
  63
  64   return;
  65 }
  66
  67 int
  68 _gnutls_rnd (int level, void *data, int len)
  69 {
  70 int ret = GC_OK;
  71
  72   if (len > 0) {
  73
  74     if (cc != NULL) {
  75       return cc->rnd( rnd_ctx, level, data, len);
  76     }
  77
  78     if (level == RND_NONCE)
  79       ret = gc_nonce (data, len);
  80     else
  81       ret = gc_pseudo_random( data, len);
  82   }
  83
  84   if (ret == GC_OK) return 0;
  85   else return GNUTLS_E_RANDOM_FAILED;
  86 }
  87