Source/lib/crypto/prfs/prf.h

   1 /**
   2  * @file prf.h
   3  *
   4  * @brief Interface prf_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 #ifndef PRF_H_
  24 #define PRF_H_
  25
  26 #include <types.h>
  27
  28 typedef enum pseudo_random_function_t pseudo_random_function_t;
  29
  30 /**
  31  * @brief Pseudo random function, as in IKEv2 RFC 3.3.2.
  32  *
  33  * Currently only the following algorithms are implemented and therefore supported:
  34  * - PRF_HMAC_MD5
  35  * - PRF_HMAC_SHA1
  36  *
  37  * @ingroup prfs
  38  */
  39 enum pseudo_random_function_t {
  40         PRF_UNDEFINED = 1024,
  41         /**
  42          * Implemented in class hmac_prf_t.
  43          */
  44         PRF_HMAC_MD5 = 1,
  45         /**
  46          * Implemented in class hmac_prf_t.
  47          */
  48         PRF_HMAC_SHA1 = 2,
  49         PRF_HMAC_TIGER = 3,
  50         PRF_AES128_CBC = 4
  51 };
  52
  53 /**
  54  * String mappings for encryption_algorithm_t.
  55  */
  56 extern mapping_t pseudo_random_function_m[];
  57
  58
  59 typedef struct prf_t prf_t;
  60
  61 /**
  62  * @brief Generic interface for pseudo-random-functions.
  63  *
  64  * @b Constructors:
  65  *  - prf_create()
  66  *  - hmac_prf_create()
  67  *
  68  * @todo Implement more prf algorithms
  69  *
  70  * @ingroup prfs
  71  */
  72 struct prf_t {
  73         /**
  74          * @brief Generates pseudo random bytes and writes them
  75          * in the buffer.
  76          *
  77          * @param this                  calling object
  78          * @param seed                  a chunk containing the seed for the next bytes
  79          * @param[out] buffer   pointer where the generated bytes will be written
  80          */
  81         void (*get_bytes) (prf_t *this, chunk_t seed, u_int8_t *buffer);
  82
  83         /**
  84          * @brief Generates pseudo random bytes and allocate space for them.
  85          *
  86          * @param this                  calling object
  87          * @param seed                  a chunk containing the seed for the next bytes
  88          * @param[out] chunk    chunk which will hold generated bytes
  89          */
  90         void (*allocate_bytes) (prf_t *this, chunk_t seed, chunk_t *chunk);
  91
  92         /**
  93          * @brief Get the block size of this prf_t object.
  94          *
  95          * @param this                  calling object
  96          * @return                              block size in bytes
  97          */
  98         size_t (*get_block_size) (prf_t *this);
  99
 100         /**
 101          * @brief Get the key size of this prf_t object.
 102          *
 103          * @param this                  calling object
 104          * @return                              key size in bytes
 105          */
 106         size_t (*get_key_size) (prf_t *this);
 107
 108         /**
 109          * @brief Set the key for this prf_t object.
 110          *
 111          * @param this                  calling object
 112          * @param key                   key to set
 113          */
 114         void (*set_key) (prf_t *this, chunk_t key);
 115
 116         /**
 117          * @brief Destroys a prf object.
 118          *
 119          * @param this                  calling object
 120          */
 121         void (*destroy) (prf_t *this);
 122 };
 123
 124 /**
 125  * @brief Generic constructor for a prf_t oject.
 126  *
 127  * @param pseudo_random_function        Algorithm to use
 128  * @return
 129  *                                                                      - prf_t object
 130  *                                                                      - NULL if prf algorithm not supported
 131  *
 132  * @ingroup prfs
 133  */
 134 prf_t *prf_create(pseudo_random_function_t pseudo_random_function);
 135
 136 #endif /*PRF_H_*/