git.distorted.org.uk Git - u/mdw/catacomb/blob - rc5.h

   1 /* -*-c-*-
   2  *
   3  * $Id: rc5.h,v 1.4 2004/04/08 01:36:15 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 /*----- Notes on the RC5 block cipher -------------------------------------*
  31  *
  32  * RC5 was designed by Ron Rivest as a test vehicle for the use of data-
  33  * dependent rotations in cryptographic transformations.  The algorithm is
  34  * covered by a patent held by RSA Security Inc. (US Patent# 5,724,428).
  35  * It's vulnerable to some clever differential attacks, which can break it in
  36  * about %$2^{44}$% chosen plaintexts.  I don't recommend the use of this
  37  * cipher.
  38  */
  39
  40 #ifndef CATACOMB_RC5_H
  41 #define CATACOMB_RC5_H
  42
  43 #ifdef __cplusplus
  44   extern "C" {
  45 #endif
  46
  47 /*----- Header files ------------------------------------------------------*/
  48
  49 #include <mLib/bits.h>
  50
  51 /*----- Magic numbers -----------------------------------------------------*/
  52
  53 #define RC5_ROUNDS 12
  54 #define RC5_KEYSZ 10
  55 #define RC5_BLKSZ 8
  56 #define RC5_CLASS (N, L, 64)
  57
  58 extern const octet rc5_keysz[];
  59
  60 /*----- Data structures ---------------------------------------------------*/
  61
  62 typedef struct rc5_ctx {
  63   uint32 s[2 * (RC5_ROUNDS + 1)];
  64 } rc5_ctx;
  65
  66 /*----- Functions provided ------------------------------------------------*/
  67
  68 /* --- @rc5_init@ --- *
  69  *
  70  * Arguments:   @rc5_ctx *k@ = pointer to a key block
  71  *              @const void *sbuf@ = pointer to key material
  72  *              @size_t sz@ = size of the key material
  73  *
  74  * Returns:     ---
  75  *
  76  * Use:         Initializes an RC5 key block.
  77  */
  78
  79 extern void rc5_init(rc5_ctx */*k*/, const void */*sbuf*/, size_t /*sz*/);
  80
  81 /* --- @rc5_eblk@, @rc5_dblk@ --- *
  82  *
  83  * Arguments:   @const rc5_ctx *k@ = pointer to RC5 context block
  84  *              @const uint32 s[2]@ = pointer to source block
  85  *              @uint32 *d[2]@ = pointer to destination block
  86  *
  87  * Returns:     ---
  88  *
  89  * Use:         Low level block encryption and decryption.
  90  */
  91
  92 extern void rc5_eblk(const rc5_ctx */*k*/,
  93                      const uint32 */*s*/, uint32 */*d*/);
  94 extern void rc5_dblk(const rc5_ctx */*k*/,
  95                      const uint32 */*s*/, uint32 */*d*/);
  96
  97 /*----- That's all, folks -------------------------------------------------*/
  98
  99 #ifdef __cplusplus
 100   }
 101 #endif
 102
 103 #endif