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   1 /* -*-c-*-
   2  *
   3  * $Id: tiger.h,v 1.3 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * The Tiger hash function
   6  *
   7  * (c) 2000 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Notes on the Tiger hash function ----------------------------------*
  31  *
  32  * Tiger was designed by Eli Biham and Ross Anderson to be an efficient and
  33  * secure hash function which worked well on 64-bit processors.  This
  34  * implementation should work everywhere, but it'll be faster if real 64-bit
  35  * arithmetic is available.
  36  *
  37  * I don't know of any really good analysis of Tiger.
  38  */
  39
  40 #ifndef CATACOMB_TIGER_H
  41 #define CATACOMB_TIGER_H
  42
  43 #ifdef __cplusplus
  44   extern "C" {
  45 #endif
  46
  47 /*----- Header files ------------------------------------------------------*/
  48
  49 #include <mLib/bits.h>
  50
  51 #ifndef CATACOMB_GHASH_H
  52 #  include "ghash.h"
  53 #endif
  54
  55 /*----- Magic numbers -----------------------------------------------------*/
  56
  57 #define TIGER_BUFSZ 64
  58 #define TIGER_HASHSZ 24
  59 #define TIGER_STATESZ 24
  60
  61 /*----- Data structures ---------------------------------------------------*/
  62
  63 typedef struct tiger_ctx {
  64   kludge64 a, b, c;                     /* Chaining variables */
  65   uint32 nl, nh;                        /* Byte count so far */
  66   unsigned off;                         /* Offset into buffer */
  67   octet buf[TIGER_BUFSZ];               /* Accumulation buffer */
  68 } tiger_ctx;
  69
  70 /*----- Functions provided ------------------------------------------------*/
  71
  72 /* --- @tiger_compress@ --- *
  73  *
  74  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
  75  *              @const void *sbuf@ = pointer to buffer of appropriate size
  76  *
  77  * Returns:     ---
  78  *
  79  * Use:         Tiger compression function.
  80  */
  81
  82 extern void tiger_compress(tiger_ctx */*ctx*/, const void */*sbuf*/);
  83
  84 /* --- @tiger_init@ --- *
  85  *
  86  * Arguments:   @tiger_ctx *ctx@ = pointer to context block to initialize
  87  *
  88  * Returns:     ---
  89  *
  90  * Use:         Initializes a context block ready for hashing.
  91  */
  92
  93 extern void tiger_init(tiger_ctx */*ctx*/);
  94
  95 /* --- @tiger_set@ --- *
  96  *
  97  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
  98  *              @const void *buf@ = pointer to state buffer
  99  *              @unsigned long count@ = current count of bytes processed
 100  *
 101  * Returns:     ---
 102  *
 103  * Use:         Initializes a context block from a given state.  This is
 104  *              useful in cases where the initial hash state is meant to be
 105  *              secret, e.g., for NMAC and HMAC support.
 106  */
 107
 108 extern void tiger_set(tiger_ctx */*ctx*/, const void */*buf*/,
 109                     unsigned long /*count*/);
 110
 111 /* --- @tiger_hash@ --- *
 112  *
 113  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
 114  *              @const void *buf@ = buffer of data to hash
 115  *              @size_t sz@ = size of buffer to hash
 116  *
 117  * Returns:     ---
 118  *
 119  * Use:         Hashes a buffer of data.  The buffer may be of any size and
 120  *              alignment.
 121  */
 122
 123 extern void tiger_hash(tiger_ctx */*ctx*/, const void */*buf*/, size_t /*sz*/);
 124
 125 /* --- @tiger_done@ --- *
 126  *
 127  * Arguments:   @tiger_ctx *ctx@ = pointer to context block
 128  *              @void *hash@ = pointer to output buffer
 129  *
 130  * Returns:     ---
 131  *
 132  * Use:         Returns the hash of the data read so far.
 133  */
 134
 135 extern void tiger_done(tiger_ctx */*ctx*/, void */*hash*/);
 136
 137 /* --- @tiger_state@ --- *
 138  *
 139  * Arguments:   @tiger_ctx *ctx@ = pointer to context
 140  *              @void *state@ = pointer to buffer for current state
 141  *
 142  * Returns:     Number of bytes written to the hash function so far.
 143  *
 144  * Use:         Returns the current state of the hash function such that
 145  *              it can be passed to @tiger_set@.
 146  */
 147
 148 extern unsigned long tiger_state(tiger_ctx */*ctx*/, void */*state*/);
 149
 150 /*----- Generic hash interface --------------------------------------------*/
 151
 152 extern const gchash tiger;
 153
 154 /*----- That's all, folks -------------------------------------------------*/
 155
 156 #ifdef __cplusplus
 157   }
 158 #endif
 159
 160 #endif