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