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