src/libstrongswan/crypto/iv/iv_gen_rand.c

   1 /*
   2  * Copyright (C) 2013 Tobias Brunner
   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 "iv_gen_rand.h"
  17
  18 #include <library.h>
  19
  20 typedef struct private_iv_gen_t private_iv_gen_t;
  21
  22 /**
  23  * Private data of an iv_gen_t object.
  24  */
  25 struct private_iv_gen_t {
  26
  27         /**
  28          * Public iv_gen_t interface.
  29          */
  30         iv_gen_t public;
  31
  32         /**
  33          * rng_t object
  34          */
  35         rng_t *rng;
  36 };
  37
  38 METHOD(iv_gen_t, get_iv, bool,
  39         private_iv_gen_t *this, u_int64_t seq, size_t size, u_int8_t *buffer)
  40 {
  41         if (!this->rng)
  42         {
  43                 return FALSE;
  44         }
  45         return this->rng->get_bytes(this->rng, size, buffer);
  46 }
  47
  48 METHOD(iv_gen_t, allocate_iv, bool,
  49         private_iv_gen_t *this, u_int64_t seq, size_t size, chunk_t *chunk)
  50 {
  51         if (!this->rng)
  52         {
  53                 return FALSE;
  54         }
  55         return this->rng->allocate_bytes(this->rng, size, chunk);
  56 }
  57
  58 METHOD(iv_gen_t, destroy, void,
  59         private_iv_gen_t *this)
  60 {
  61         DESTROY_IF(this->rng);
  62         free(this);
  63 }
  64
  65 iv_gen_t *iv_gen_rand_create()
  66 {
  67         private_iv_gen_t *this;
  68
  69         INIT(this,
  70                 .public = {
  71                         .get_iv = _get_iv,
  72                         .allocate_iv = _allocate_iv,
  73                         .destroy = _destroy,
  74                 },
  75                 .rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK),
  76         );
  77
  78         return &this->public;
  79 }