git.distorted.org.uk Git - u/mdw/catacomb/blob - symm/tiger.h

   1 /* -*-c-*-
   2  *
   3  * The Tiger hash function
   4  *
   5  * (c) 2000 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Notes on the Tiger hash function ----------------------------------*
  29  *
  30  * Tiger was designed by Eli Biham and Ross Anderson to be an efficient and
  31  * secure hash function which worked well on 64-bit processors.  This
  32  * implementation should work everywhere, but it'll be faster if real 64-bit
  33  * arithmetic is available.
  34  *
  35  * I don't know of any really good analysis of Tiger.
  36  */
  37
  38 #ifndef CATACOMB_TIGER_H
  39 #define CATACOMB_TIGER_H
  40
  41 #ifdef __cplusplus
  42   extern "C" {
  43 #endif
  44
  45 /*----- Header files ------------------------------------------------------*/
  46
  47 #include <mLib/bits.h>
  48
  49 #ifndef CATACOMB_GHASH_H
  50 #  include "ghash.h"
  51 #endif
  52
  53 /*----- Magic numbers -----------------------------------------------------*/
  54
  55 #define TIGER_BUFSZ 64
  56 #define TIGER_HASHSZ 24
  57 #define TIGER_STATESZ 24
  58
  59 /*----- Data structures ---------------------------------------------------*/
  60
  61 typedef struct tiger_ctx {
  62   kludge64 a, b, c;                     /* Chaining variables */
  63   uint32 nl, nh;                        /* Byte count so far */
  64   unsigned off;                         /* Offset into buffer */
  65   octet buf[TIGER_BUFSZ];               /* Accumulation buffer */
  66 } tiger_ctx;
  67
  68 /*----- Functions provided ------------------------------------------------*/
  69
  70 /* --- @tiger_compress@ --- *
  71  *
  72  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
  73  *              @const void *sbuf@ = pointer to buffer of appropriate size
  74  *
  75  * Returns:     ---
  76  *
  77  * Use:         Tiger compression function.
  78  */
  79
  80 extern void tiger_compress(tiger_ctx */*ctx*/, const void */*sbuf*/);
  81
  82 /* --- @tiger_init@ --- *
  83  *
  84  * Arguments:   @tiger_ctx *ctx@ = pointer to context block to initialize
  85  *
  86  * Returns:     ---
  87  *
  88  * Use:         Initializes a context block ready for hashing.
  89  */
  90
  91 extern void tiger_init(tiger_ctx */*ctx*/);
  92
  93 /* --- @tiger_set@ --- *
  94  *
  95  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
  96  *              @const void *buf@ = pointer to state buffer
  97  *              @unsigned long count@ = current count of bytes processed
  98  *
  99  * Returns:     ---
 100  *
 101  * Use:         Initializes a context block from a given state.  This is
 102  *              useful in cases where the initial hash state is meant to be
 103  *              secret, e.g., for NMAC and HMAC support.
 104  */
 105
 106 extern void tiger_set(tiger_ctx */*ctx*/, const void */*buf*/,
 107                     unsigned long /*count*/);
 108
 109 /* --- @tiger_hash@ --- *
 110  *
 111  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
 112  *              @const void *buf@ = buffer of data to hash
 113  *              @size_t sz@ = size of buffer to hash
 114  *
 115  * Returns:     ---
 116  *
 117  * Use:         Hashes a buffer of data.  The buffer may be of any size and
 118  *              alignment.
 119  */
 120
 121 extern void tiger_hash(tiger_ctx */*ctx*/, const void */*buf*/, size_t /*sz*/);
 122
 123 /* --- @tiger_done@ --- *
 124  *
 125  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
 126  *              @void *hash@ = pointer to output buffer
 127  *
 128  * Returns:     ---
 129  *
 130  * Use:         Returns the hash of the data read so far.
 131  */
 132
 133 extern void tiger_done(tiger_ctx */*ctx*/, void */*hash*/);
 134
 135 /* --- @tiger_state@ --- *
 136  *
 137  * Arguments:   @tiger_ctx *ctx@ = pointer to context
 138  *              @void *state@ = pointer to buffer for current state
 139  *
 140  * Returns:     Number of bytes written to the hash function so far.
 141  *
 142  * Use:         Returns the current state of the hash function such that
 143  *              it can be passed to @tiger_set@.
 144  */
 145
 146 extern unsigned long tiger_state(tiger_ctx */*ctx*/, void */*state*/);
 147
 148 /*----- Generic hash interface --------------------------------------------*/
 149
 150 extern const gchash tiger;
 151
 152 /*----- That's all, folks -------------------------------------------------*/
 153
 154 #ifdef __cplusplus
 155   }
 156 #endif
 157
 158 #endif