Source/charon/transforms/prfs/prf_hmac.c

   1 /**
   2  * @file prf_hmac.c
   3  *
   4  * @brief Implementation for prf_hmac_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #include "prf_hmac.h"
  24
  25 #include <utils/allocator.h>
  26 #include <transforms/hmac.h>
  27
  28 typedef struct private_prf_hmac_t private_prf_hmac_t;
  29
  30 struct private_prf_hmac_t {
  31         /**
  32          * public interface for this prf
  33          */
  34         prf_hmac_t public;
  35
  36         /**
  37          * hmac to use for generation
  38          */
  39         hmac_t *hmac;
  40 };
  41
  42 /**
  43  * implementation of prf_t.get_bytes
  44  */
  45 static status_t get_bytes(private_prf_hmac_t *this, chunk_t seed, u_int8_t *buffer)
  46 {
  47         return this->hmac->get_mac(this->hmac, seed, buffer);
  48 }
  49
  50 /**
  51  * implementation of prf_t.allocate_bytes
  52  */
  53 static status_t allocate_bytes(private_prf_hmac_t *this, chunk_t seed, chunk_t *chunk)
  54 {
  55         return this->hmac->allocate_mac(this->hmac, seed, chunk);
  56 }
  57
  58 /**
  59  * implementation of prf_t.get_block_size
  60  */
  61 static size_t get_block_size(private_prf_hmac_t *this)
  62 {
  63         return this->hmac->get_block_size(this->hmac);
  64 }
  65
  66 /**
  67  * implementation of prf_t.set_key
  68  */
  69 static status_t set_key(private_prf_hmac_t *this, chunk_t key)
  70 {
  71         this->hmac->set_key(this->hmac, key);
  72         return SUCCESS;
  73 }
  74
  75 /**
  76  * implementation of prf_t.destroy
  77  */
  78 static status_t destroy(private_prf_hmac_t *this)
  79 {
  80         allocator_free(this);
  81         this->hmac->destroy(this->hmac);
  82         return SUCCESS;
  83 }
  84
  85 /*
  86  * Described in header
  87  */
  88 prf_hmac_t *prf_hmac_create(hash_algorithm_t hash_algorithm)
  89 {
  90         private_prf_hmac_t *this = allocator_alloc_thing(private_prf_hmac_t);
  91
  92         if (this == NULL)
  93         {
  94                 return NULL;
  95         }
  96
  97         this->public.prf_interface.get_bytes = (status_t (*) (prf_t *,chunk_t,u_int8_t*))get_bytes;
  98         this->public.prf_interface.allocate_bytes = (status_t (*) (prf_t*,chunk_t,chunk_t*))allocate_bytes;
  99         this->public.prf_interface.get_block_size = (size_t (*) (prf_t*))get_block_size;
 100         this->public.prf_interface.set_key = (status_t (*) (prf_t *,chunk_t))set_key;
 101         this->public.prf_interface.destroy = (status_t (*) (prf_t *))destroy;
 102
 103         this->hmac = hmac_create(hash_algorithm);
 104         if (this->hmac == NULL)
 105         {
 106                 allocator_free(this);
 107                 return NULL;
 108         }
 109
 110         return &(this->public);
 111 }