src/libstrongswan/plugins/random/random_plugin.c

   1 /*
   2  * Copyright (C) 2008 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 #include "random_plugin.h"
  17
  18 #include <unistd.h>
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23
  24 #include <library.h>
  25 #include <debug.h>
  26 #include "random_rng.h"
  27
  28 #ifndef DEV_RANDOM
  29 # define DEV_RANDOM "/dev/random"
  30 #endif
  31
  32 #ifndef DEV_URANDOM
  33 # define DEV_URANDOM "/dev/urandom"
  34 #endif
  35
  36 typedef struct private_random_plugin_t private_random_plugin_t;
  37
  38 /**
  39  * private data of random_plugin
  40  */
  41 struct private_random_plugin_t {
  42
  43         /**
  44          * public functions
  45          */
  46         random_plugin_t public;
  47 };
  48
  49 /** /dev/random file descriptor */
  50 static int dev_random = -1;
  51 /** /dev/urandom file descriptor */
  52 static int dev_urandom = -1;
  53
  54 /**
  55  * See header.
  56  */
  57 int random_plugin_get_dev_random()
  58 {
  59         return dev_random;
  60 }
  61
  62 /**
  63  * See header.
  64  */
  65 int random_plugin_get_dev_urandom()
  66 {
  67         return dev_urandom;
  68 }
  69
  70 /**
  71  * Open a random device file
  72  */
  73 static bool open_dev(char *file, int *fd)
  74 {
  75         *fd = open(file, O_RDONLY);
  76         if (*fd == -1)
  77         {
  78                 DBG1(DBG_LIB, "opening \"%s\" failed: %s", file, strerror(errno));
  79                 return FALSE;
  80         }
  81         return TRUE;
  82 }
  83
  84 METHOD(plugin_t, get_name, char*,
  85         private_random_plugin_t *this)
  86 {
  87         return "random";
  88 }
  89
  90 METHOD(plugin_t, get_features, int,
  91         private_random_plugin_t *this, plugin_feature_t *features[])
  92 {
  93         static plugin_feature_t f[] = {
  94                 PLUGIN_REGISTER(RNG, random_rng_create),
  95                         PLUGIN_PROVIDE(RNG, RNG_STRONG),
  96                         PLUGIN_PROVIDE(RNG, RNG_TRUE),
  97         };
  98         *features = f;
  99         return countof(f);
 100 }
 101
 102 METHOD(plugin_t, destroy, void,
 103         private_random_plugin_t *this)
 104 {
 105         if (dev_random != -1)
 106         {
 107                 close(dev_random);
 108         }
 109         if (dev_urandom != -1)
 110         {
 111                 close(dev_urandom);
 112         }
 113         free(this);
 114 }
 115
 116 /*
 117  * see header file
 118  */
 119 plugin_t *random_plugin_create()
 120 {
 121         private_random_plugin_t *this;
 122         char *urandom_file, *random_file;
 123
 124         INIT(this,
 125                 .public = {
 126                         .plugin = {
 127                                 .get_name = _get_name,
 128                                 .get_features = _get_features,
 129                                 .destroy = _destroy,
 130                         },
 131                 },
 132         );
 133
 134         urandom_file = lib->settings->get_str(lib->settings,
 135                                                 "libstrongswan.plugins.random.urandom", DEV_URANDOM);
 136         random_file = lib->settings->get_str(lib->settings,
 137                                                 "libstrongswan.plugins.random.random", DEV_RANDOM);
 138         if (!open_dev(urandom_file, &dev_urandom) ||
 139                 !open_dev(random_file, &dev_random))
 140         {
 141                 destroy(this);
 142                 return NULL;
 143         }
 144
 145         return &this->public.plugin;
 146 }
 147