Source/charon/transforms/prfs/prf_hmac_sha1.c

   1 /**
   2  * @file prf_hmac_sha1.c
   3  *
   4  * @brief Implementation of prf_t interface using the
   5  * HMAC SHA1 algorithm. This simply wraps hmac-sha1
   6  * in a prf.
   7  *
   8  */
   9
  10 /*
  11  * Copyright (C) 2005 Jan Hutter, Martin Willi
  12  * Hochschule fuer Technik Rapperswil
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the
  16  * Free Software Foundation; either version 2 of the License, or (at your
  17  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  18  *
  19  * This program is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  21  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  22  * for more details.
  23  */
  24
  25 #include "prf_hmac_sha1.h"
  26
  27 #include "../../utils/allocator.h"
  28 #include "../hmac.h"
  29
  30 typedef struct private_prf_hmac_sha1_s private_prf_hmac_sha1_t;
  31
  32 struct private_prf_hmac_sha1_s {
  33         /**
  34          * public interface for this prf
  35          */
  36         prf_hmac_sha1_t public;
  37
  38         /**
  39          * hmac to use for generation
  40          */
  41         hmac_t *hmac;
  42 };
  43
  44 /**
  45  * implementation of prf_t.get_bytes
  46  */
  47 static status_t get_bytes(private_prf_hmac_sha1_t *this, chunk_t seed, u_int8_t *buffer)
  48 {
  49         return this->hmac->get_mac(this->hmac, seed, buffer);
  50 }
  51
  52 /**
  53  * implementation of prf_t.allocate_bytes
  54  */
  55 static status_t allocate_bytes(private_prf_hmac_sha1_t *this, chunk_t seed, chunk_t *chunk)
  56 {
  57         return this->hmac->allocate_mac(this->hmac, seed, chunk);
  58 }
  59
  60 /**
  61  * implementation of prf_t.get_block_size
  62  */
  63 static size_t get_block_size(private_prf_hmac_sha1_t *this)
  64 {
  65         return this->hmac->get_block_size(this->hmac);
  66 }
  67
  68 /**
  69  * implementation of prf_t.set_key
  70  */
  71 static status_t set_key(private_prf_hmac_sha1_t *this, chunk_t key)
  72 {
  73         this->hmac->set_key(this->hmac, key);
  74         return SUCCESS;
  75 }
  76
  77 /**
  78  * implementation of prf_t.destroy
  79  */
  80 static status_t destroy(private_prf_hmac_sha1_t *this)
  81 {
  82         allocator_free(this);
  83         this->hmac->destroy(this->hmac);
  84         return SUCCESS;
  85 }
  86
  87 /*
  88  * Described in header
  89  */
  90 prf_hmac_sha1_t *prf_hmac_sha1_create()
  91 {
  92         private_prf_hmac_sha1_t *this = allocator_alloc_thing(private_prf_hmac_sha1_t);
  93
  94         if (this == NULL)
  95         {
  96                 return NULL;
  97         }
  98
  99         this->public.prf_interface.get_bytes = (status_t (*) (prf_t *,chunk_t,u_int8_t*))get_bytes;
 100         this->public.prf_interface.allocate_bytes = (status_t (*) (prf_t*,chunk_t,chunk_t*))allocate_bytes;
 101         this->public.prf_interface.get_block_size = (size_t (*) (prf_t*))get_block_size;
 102         this->public.prf_interface.set_key = (status_t (*) (prf_t *,chunk_t))set_key;
 103         this->public.prf_interface.destroy = (status_t (*) (prf_t *))destroy;
 104
 105         this->hmac = hmac_create(HASH_SHA1);
 106         if (this->hmac == NULL)
 107         {
 108                 allocator_free(this);
 109                 return NULL;
 110         }
 111
 112         return &(this->public);
 113 }