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   1 /* -*-c-*-
   2  *
   3  * $Id: des3.h,v 1.2 1999/12/10 23:29:48 mdw Exp $
   4  *
   5  * Implementation of double- and triple-DES
   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: des3.h,v $
  33  * Revision 1.2  1999/12/10 23:29:48  mdw
  34  * Change header file guard names.
  35  *
  36  * Revision 1.1  1999/09/03 08:41:11  mdw
  37  * Initial import.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_DES3_H
  42 #define CATACOMB_DES3_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Notes on double- and triple-DES -----------------------------------*
  49  *
  50  * The normal recommendation for using DES now is `triple DES'.
  51  * Conventionally, this involves an encrypt-decrypt-encrypt sequence,
  52  * although whether the first and last operations use the same key is
  53  * unfortunately not agreed upon.  This interface handles both cases (and the
  54  * single-key one too, although the simple @des@ calls are quicker for that).
  55  */
  56
  57 /*----- Header files ------------------------------------------------------*/
  58
  59 #include <stddef.h>
  60
  61 #include <mLib/bits.h>
  62
  63 #ifndef CATACOMB_DES_H
  64 #  include "des.h"
  65 #endif
  66
  67 /*----- Magical numbers ---------------------------------------------------*/
  68
  69 #define DES3_BLKSZ 8
  70 #define DES3_KEYSZ 21
  71 #define DES3_CLASS (N, B, 64)
  72
  73 /*----- Data structures ---------------------------------------------------*/
  74
  75 typedef struct des3_ctx {
  76   des_ctx a, b, c;
  77 } des3_ctx;
  78
  79 /*----- Functions provided ------------------------------------------------*/
  80
  81 /* --- @des3_init@ --- *
  82  *
  83  * Arguments:   @des3_ctx *k@ = pointer to key block
  84  *              @const void *buf@ = pointer to key buffer
  85  *              @size_t sz@ = size of key material
  86  *
  87  * Returns:     ---
  88  *
  89  * Use:         Initializes a DES key buffer.  The key buffer may have length
  90  *              7, 8, 14, 16, 21, or 24.  These correspond to one, two or
  91  *              three DES keys, either packed or unpacked (i.e., still
  92  *              containing parity bits).
  93  */
  94
  95 extern void des3_init(des3_ctx */*k*/, const void */*buf*/, size_t /*sz*/);
  96
  97 /* --- @des3_eblk@, @des_dblk@ --- *
  98  *
  99  * Arguments:   @const des3_ctx *k@ = pointer to key block
 100  *              @const uint32 s[2]@ = pointer to source block
 101  *              @uint32 d[2]@ = pointer to destination block
 102  *
 103  * Returns:     ---
 104  *
 105  * Use:         Low-level block encryption and decryption.
 106  */
 107
 108 extern void des3_eblk(const des3_ctx */*k*/,
 109                       const uint32 */*s*/, uint32 */*d*/);
 110 extern void des3_dblk(const des3_ctx */*k*/,
 111                       const uint32 */*s*/, uint32 */*d*/);
 112
 113 /*----- That's all, folks -------------------------------------------------*/
 114
 115 #ifdef __cplusplus
 116   }
 117 #endif
 118
 119 #endif