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   1 /* -*-c-*-
   2  *
   3  * $Id: rc5.h,v 1.3 2000/06/17 11:55:50 mdw Exp $
   4  *
   5  * The RC5-32/12 block cipher
   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: rc5.h,v $
  33  * Revision 1.3  2000/06/17 11:55:50  mdw
  34  * New key size interface.  Add notes about the cipher.
  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 08:41:12  mdw
  40  * Initial import.
  41  *
  42  */
  43
  44 /*----- Notes on the RC5 block cipher -------------------------------------*
  45  *
  46  * RC5 was designed by Ron Rivest as a test vehicle for the use of data-
  47  * dependent rotations in cryptographic transformations.  The algorithm is
  48  * covered by a patent held by RSA Security Inc. (US Patent# 5,724,428).
  49  * It's vulnerable to some clever differential attacks, which can break it in
  50  * about %$2^{44}$% chosen plaintexts.  I don't recommend the use of this
  51  * cipher.
  52  */
  53
  54 #ifndef CATACOMB_RC5_H
  55 #define CATACOMB_RC5_H
  56
  57 #ifdef __cplusplus
  58   extern "C" {
  59 #endif
  60
  61 /*----- Header files ------------------------------------------------------*/
  62
  63 #include <mLib/bits.h>
  64
  65 /*----- Magic numbers -----------------------------------------------------*/
  66
  67 #define RC5_ROUNDS 12
  68 #define RC5_KEYSZ 10
  69 #define RC5_BLKSZ 8
  70 #define RC5_CLASS (N, L, 64)
  71
  72 extern const octet rc5_keysz[];
  73
  74 /*----- Data structures ---------------------------------------------------*/
  75
  76 typedef struct rc5_ctx {
  77   uint32 s[2 * (RC5_ROUNDS + 1)];
  78 } rc5_ctx;
  79
  80 /*----- Functions provided ------------------------------------------------*/
  81
  82 /* --- @rc5_init@ --- *
  83  *
  84  * Arguments:   @rc5_ctx *k@ = pointer to a key block
  85  *              @const void *sbuf@ = pointer to key material
  86  *              @size_t sz@ = size of the key material
  87  *
  88  * Returns:     ---
  89  *
  90  * Use:         Initializes an RC5 key block.
  91  */
  92
  93 extern void rc5_init(rc5_ctx */*k*/, const void */*sbuf*/, size_t /*sz*/);
  94
  95 /* --- @rc5_eblk@, @rc5_dblk@ --- *
  96  *
  97  * Arguments:   @const rc5_ctx *k@ = pointer to RC5 context block
  98  *              @const uint32 s[2]@ = pointer to source block
  99  *              @uint32 *d[2]@ = pointer to destination block
 100  *
 101  * Returns:     ---
 102  *
 103  * Use:         Low level block encryption and decryption.
 104  */
 105
 106 extern void rc5_eblk(const rc5_ctx */*k*/,
 107                      const uint32 */*s*/, uint32 */*d*/);
 108 extern void rc5_dblk(const rc5_ctx */*k*/,
 109                      const uint32 */*s*/, uint32 */*d*/);
 110
 111 /*----- That's all, folks -------------------------------------------------*/
 112
 113 #ifdef __cplusplus
 114   }
 115 #endif
 116
 117 #endif