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   1 /* -*-c-*-
   2  *
   3  * $Id: sha.h,v 1.5 2000/10/15 19:09:20 mdw Exp $
   4  *
   5  * Implementation of the SHA-1 hash function
   6  *
   7  * (c) 1999 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: sha.h,v $
  33  * Revision 1.5  2000/10/15 19:09:20  mdw
  34  * Support HMAC mode for hash functions which need to store more state than
  35  * the hash output size.
  36  *
  37  * Revision 1.4  2000/06/17 11:32:52  mdw
  38  * Change buffer offset to be unsigned.
  39  *
  40  * Revision 1.3  1999/12/10 23:20:03  mdw
  41  * New hash interface requirements.
  42  *
  43  * Revision 1.2  1999/11/19 13:20:08  mdw
  44  * Modify notes section slightly.
  45  *
  46  * Revision 1.1  1999/09/03 08:41:12  mdw
  47  * Initial import.
  48  *
  49  */
  50
  51 /*----- Notes on the SHA-1 hash function ----------------------------------*
  52  *
  53  * SHA (Secure Hash Algorithm) was designed by the NSA, for use with the
  54  * Digital Signature Algorithm.  It is defined by FIPS 180-1.  It has gained
  55  * wide acceptance since its initial publication, and is probably now most
  56  * people's collision-resistant function of choice.  The author prefers
  57  * RIPEMD-160, for no particularly good reasons.
  58  */
  59
  60 #ifndef CATACOMB_SHA_H
  61 #define CATACOMB_SHA_H
  62
  63 #ifdef __cplusplus
  64   extern "C" {
  65 #endif
  66
  67 /*----- Header files ------------------------------------------------------*/
  68
  69 #include <mLib/bits.h>
  70
  71 #ifndef CATACOMB_GHASH_H
  72 #  include "ghash.h"
  73 #endif
  74
  75 /*----- Magic numbers -----------------------------------------------------*/
  76
  77 #define SHA_BUFSZ 64
  78 #define SHA_HASHSZ 20
  79 #define SHA_STATESZ 20
  80
  81 /*----- Data structures ---------------------------------------------------*/
  82
  83 typedef struct sha_ctx {
  84   uint32 a, b, c, d, e;                 /* Chaining variables */
  85   uint32 nl, nh;                        /* Byte count so far */
  86   unsigned off;                         /* Offset into buffer */
  87   octet buf[SHA_BUFSZ];                 /* Accumulation buffer */
  88 } sha_ctx;
  89
  90 /*----- Functions provided ------------------------------------------------*/
  91
  92 /* --- @sha_compress@ --- *
  93  *
  94  * Arguments:   @sha_ctx *ctx@ = pointer to context block
  95  *              @const void *sbuf@ = pointer to buffer of appropriate size
  96  *
  97  * Returns:     ---
  98  *
  99  * Use:         SHA compression function.
 100  */
 101
 102 extern void sha_compress(sha_ctx */*ctx*/, const void */*sbuf*/);
 103
 104 /* --- @sha_init@ --- *
 105  *
 106  * Arguments:   @sha_ctx *ctx@ = pointer to context block to initialize
 107  *
 108  * Returns:     ---
 109  *
 110  * Use:         Initializes a context block ready for hashing.
 111  */
 112
 113 extern void sha_init(sha_ctx */*ctx*/);
 114
 115 /* --- @sha_set@ --- *
 116  *
 117  * Arguments:   @sha_ctx *ctx@ = pointer to context block
 118  *              @const void *buf@ = pointer to state buffer
 119  *              @unsigned long count@ = current count of bytes processed
 120  *
 121  * Returns:     ---
 122  *
 123  * Use:         Initializes a context block from a given state.  This is
 124  *              useful in cases where the initial hash state is meant to be
 125  *              secret, e.g., for NMAC and HMAC support.
 126  */
 127
 128 extern void sha_set(sha_ctx */*ctx*/, const void */*buf*/,
 129                     unsigned long /*count*/);
 130
 131 /* --- @sha_hash@ --- *
 132  *
 133  * Arguments:   @sha_ctx *ctx@ = pointer to context block
 134  *              @const void *buf@ = buffer of data to hash
 135  *              @size_t sz@ = size of buffer to hash
 136  *
 137  * Returns:     ---
 138  *
 139  * Use:         Hashes a buffer of data.  The buffer may be of any size and
 140  *              alignment.
 141  */
 142
 143 extern void sha_hash(sha_ctx */*ctx*/, const void */*buf*/, size_t /*sz*/);
 144
 145 /* --- @sha_done@ --- *
 146  *
 147  * Arguments:   @sha_ctx *ctx@ = pointer to context block
 148  *              @void *hash@ = pointer to output buffer
 149  *
 150  * Returns:     ---
 151  *
 152  * Use:         Returns the hash of the data read so far.
 153  */
 154
 155 extern void sha_done(sha_ctx */*ctx*/, void */*hash*/);
 156
 157 /* --- @sha_state@ --- *
 158  *
 159  * Arguments:   @sha_ctx *ctx@ = pointer to context
 160  *              @void *state@ = pointer to buffer for current state
 161  *
 162  * Returns:     Number of bytes written to the hash function so far.
 163  *
 164  * Use:         Returns the current state of the hash function such that
 165  *              it can be passed to @sha_set@.
 166  */
 167
 168 extern unsigned long sha_state(sha_ctx */*ctx*/, void */*state*/);
 169
 170 /*----- Generic hash interface --------------------------------------------*/
 171
 172 extern const gchash sha;
 173
 174 /*----- That's all, folks -------------------------------------------------*/
 175
 176 #ifdef __cplusplus
 177   }
 178 #endif
 179
 180 #endif