Source/charon/transforms/hashers/hasher.h

   1 /**
   2  * @file hasher.h
   3  *
   4  * @brief Generic interface for hash functions
   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 HASHER_H_
  24 #define HASHER_H_
  25
  26
  27 #include "../../types.h"
  28
  29 /**
  30  * algorithms to use for hashing
  31  */
  32 typedef enum hash_algorithm_e hash_algorithm_t;
  33
  34 enum hash_algorithm_e {
  35         SHA1,
  36         MD5
  37 };
  38
  39
  40 /**
  41  * Object representing a hasher
  42  */
  43 typedef struct hasher_s hasher_t;
  44
  45 struct hasher_s {
  46         /**
  47          * @brief hash data and write it in the buffer
  48          *
  49          * @param this                  calling hasher
  50          * @param data                  data to hash
  51          * @param [out]buffer   pointer where the hash will be written
  52          * @return
  53          *                                              - SUCCESS in any case
  54          */
  55         status_t (*get_hash) (hasher_t *this, chunk_t data, u_int8_t *buffer);
  56
  57         /**
  58          * @brief hash data and allocate space for the hash
  59          *
  60          * @param this                  calling hasher
  61          * @param seed                  a chunk containing the seed for the next bytes
  62          * @param [out]hash             chunk which will hold allocated hash
  63          * @return
  64          *                                              - SUCCESS in any case
  65          *                                              - OUT_OF_RES if space could not be allocated
  66          */
  67         status_t (*allocate_hash) (hasher_t *this, chunk_t data, chunk_t *hash);
  68
  69         /**
  70          * @brief get the block size of this hashing function
  71          *
  72          * @param this                  calling hasher
  73          * @return                              block size in bytes
  74          */
  75         size_t (*get_block_size) (hasher_t *this);
  76
  77         /**
  78          * @brief Destroys a hasher object.
  79          *
  80          * @param this  hasher_t object to destroy
  81          * @return
  82          *                              SUCCESS in any case
  83          */
  84         status_t (*destroy) (hasher_t *this);
  85 };
  86
  87 /**
  88  * Creates a new hasher_t object
  89  *
  90  * @param hash_algorithm                        Algorithm to use for hashing
  91  * @return
  92  *                                                                      - hasher_t if successfully
  93  *                                                                      - NULL if out of ressources
  94  */
  95 hasher_t *hasher_create(hash_algorithm_t hash_algorithm);
  96
  97 #endif /*HASHER_H_*/