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   1 /* -*-c-*-
   2  *
   3  * $Id: des3.h,v 1.3 2000/06/17 10:52:32 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 1.3  2000/06/17 10:52:32  mdw
  34  * Support new key size interface.
  35  *
  36  * Revision 1.2  1999/12/10 23:29:48  mdw
  37  * Change header file guard names.
  38  *
  39  * Revision 1.1  1999/09/03 08:41:11  mdw
  40  * Initial import.
  41  *
  42  */
  43
  44 #ifndef CATACOMB_DES3_H
  45 #define CATACOMB_DES3_H
  46
  47 #ifdef __cplusplus
  48   extern "C" {
  49 #endif
  50
  51 /*----- Notes on double- and triple-DES -----------------------------------*
  52  *
  53  * The normal recommendation for using DES now is `triple DES'.
  54  * Conventionally, this involves an encrypt-decrypt-encrypt sequence,
  55  * although whether the first and last operations use the same key is
  56  * unfortunately not agreed upon.  This interface handles both cases (and the
  57  * single-key one too, although the simple @des@ calls are quicker for that).
  58  */
  59
  60 /*----- Header files ------------------------------------------------------*/
  61
  62 #include <stddef.h>
  63
  64 #include <mLib/bits.h>
  65
  66 #ifndef CATACOMB_DES_H
  67 #  include "des.h"
  68 #endif
  69
  70 /*----- Magical numbers ---------------------------------------------------*/
  71
  72 #define DES3_BLKSZ 8
  73 #define DES3_KEYSZ 21
  74 #define DES3_CLASS (N, B, 64)
  75
  76 extern const octet des3_keysz[];
  77
  78 /*----- Data structures ---------------------------------------------------*/
  79
  80 typedef struct des3_ctx {
  81   des_ctx a, b, c;
  82 } des3_ctx;
  83
  84 /*----- Functions provided ------------------------------------------------*/
  85
  86 /* --- @des3_init@ --- *
  87  *
  88  * Arguments:   @des3_ctx *k@ = pointer to key block
  89  *              @const void *buf@ = pointer to key buffer
  90  *              @size_t sz@ = size of key material
  91  *
  92  * Returns:     ---
  93  *
  94  * Use:         Initializes a DES key buffer.  The key buffer may have length
  95  *              7, 8, 14, 16, 21, or 24.  These correspond to one, two or
  96  *              three DES keys, either packed or unpacked (i.e., still
  97  *              containing parity bits).
  98  */
  99
 100 extern void des3_init(des3_ctx */*k*/, const void */*buf*/, size_t /*sz*/);
 101
 102 /* --- @des3_eblk@, @des_dblk@ --- *
 103  *
 104  * Arguments:   @const des3_ctx *k@ = pointer to key block
 105  *              @const uint32 s[2]@ = pointer to source block
 106  *              @uint32 d[2]@ = pointer to destination block
 107  *
 108  * Returns:     ---
 109  *
 110  * Use:         Low-level block encryption and decryption.
 111  */
 112
 113 extern void des3_eblk(const des3_ctx */*k*/,
 114                       const uint32 */*s*/, uint32 */*d*/);
 115 extern void des3_dblk(const des3_ctx */*k*/,
 116                       const uint32 */*s*/, uint32 */*d*/);
 117
 118 /*----- That's all, folks -------------------------------------------------*/
 119
 120 #ifdef __cplusplus
 121   }
 122 #endif
 123
 124 #endif