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