src/libstrongswan/plugins/openssl/openssl_rng.c

   1 /*
   2  * Copyright (C) 2012-2018 Tobias Brunner
   3  * HSR Hochschule fuer Technik Rapperswil
   4  *
   5  * Copyright (C) 2012 Aleksandr Grinberg
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include <library.h>
  27 #include <utils/debug.h>
  28
  29 #include <openssl/rand.h>
  30
  31 #include "openssl_rng.h"
  32
  33 typedef struct private_openssl_rng_t private_openssl_rng_t;
  34
  35 /**
  36  * Private data of openssl_rng_t
  37  */
  38 struct private_openssl_rng_t {
  39
  40         /**
  41          * Public part of this class.
  42          */
  43         openssl_rng_t public;
  44
  45         /**
  46          * Quality of randomness
  47          */
  48         rng_quality_t quality;
  49 };
  50
  51 METHOD(rng_t, get_bytes, bool,
  52         private_openssl_rng_t *this, size_t bytes, uint8_t *buffer)
  53 {
  54 #if OPENSSL_VERSION_NUMBER >= 0x1010100fL
  55         if (this->quality > RNG_WEAK)
  56         {       /* use a separate DRBG for data we wan't to keep private, compared
  57                  * to e.g. nonces */
  58                 return RAND_priv_bytes((char*)buffer, bytes) == 1;
  59         }
  60 #endif
  61         return RAND_bytes((char*)buffer, bytes) == 1;
  62 }
  63
  64 METHOD(rng_t, allocate_bytes, bool,
  65         private_openssl_rng_t *this, size_t bytes, chunk_t *chunk)
  66 {
  67         *chunk = chunk_alloc(bytes);
  68         if (!get_bytes(this, chunk->len, chunk->ptr))
  69         {
  70                 chunk_free(chunk);
  71                 return FALSE;
  72         }
  73         return TRUE;
  74 }
  75
  76 METHOD(rng_t, destroy, void,
  77         private_openssl_rng_t *this)
  78 {
  79         free(this);
  80 }
  81
  82 /*
  83  * Described in header.
  84  */
  85 openssl_rng_t *openssl_rng_create(rng_quality_t quality)
  86 {
  87         private_openssl_rng_t *this;
  88
  89         INIT(this,
  90                 .public = {
  91                         .rng = {
  92                                 .get_bytes = _get_bytes,
  93                                 .allocate_bytes = _allocate_bytes,
  94                                 .destroy = _destroy,
  95                         },
  96                 },
  97                 .quality = quality,
  98         );
  99
 100         return &this->public;
 101 }