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

   1 /* -*-c-*-
   2  *
   3  * The RC5-32/12 block cipher
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Notes on the RC5 block cipher -------------------------------------*
  29  *
  30  * RC5 was designed by Ron Rivest as a test vehicle for the use of data-
  31  * dependent rotations in cryptographic transformations.  The algorithm is
  32  * covered by a patent held by RSA Security Inc. (US Patent# 5,724,428).
  33  * It's vulnerable to some clever differential attacks, which can break it in
  34  * about %$2^{44}$% chosen plaintexts.  I don't recommend the use of this
  35  * cipher.
  36  */
  37
  38 #ifndef CATACOMB_RC5_H
  39 #define CATACOMB_RC5_H
  40
  41 #ifdef __cplusplus
  42   extern "C" {
  43 #endif
  44
  45 /*----- Header files ------------------------------------------------------*/
  46
  47 #include <mLib/bits.h>
  48
  49 /*----- Magic numbers -----------------------------------------------------*/
  50
  51 #define RC5_ROUNDS 12
  52 #define RC5_KEYSZ 10
  53 #define RC5_BLKSZ 8
  54 #define RC5_CLASS (N, L, 64)
  55
  56 extern const octet rc5_keysz[];
  57
  58 /*----- Data structures ---------------------------------------------------*/
  59
  60 typedef struct rc5_ctx {
  61   uint32 s[2 * (RC5_ROUNDS + 1)];
  62 } rc5_ctx;
  63
  64 /*----- Functions provided ------------------------------------------------*/
  65
  66 /* --- @rc5_init@ --- *
  67  *
  68  * Arguments:   @rc5_ctx *k@ = pointer to a key block
  69  *              @const void *sbuf@ = pointer to key material
  70  *              @size_t sz@ = size of the key material
  71  *
  72  * Returns:     ---
  73  *
  74  * Use:         Initializes an RC5 key block.
  75  */
  76
  77 extern void rc5_init(rc5_ctx */*k*/, const void */*sbuf*/, size_t /*sz*/);
  78
  79 /* --- @rc5_eblk@, @rc5_dblk@ --- *
  80  *
  81  * Arguments:   @const rc5_ctx *k@ = pointer to RC5 context block
  82  *              @const uint32 s[2]@ = pointer to source block
  83  *              @uint32 *d[2]@ = pointer to destination block
  84  *
  85  * Returns:     ---
  86  *
  87  * Use:         Low level block encryption and decryption.
  88  */
  89
  90 extern void rc5_eblk(const rc5_ctx */*k*/,
  91                      const uint32 */*s*/, uint32 */*d*/);
  92 extern void rc5_dblk(const rc5_ctx */*k*/,
  93                      const uint32 */*s*/, uint32 */*d*/);
  94
  95 /*----- That's all, folks -------------------------------------------------*/
  96
  97 #ifdef __cplusplus
  98   }
  99 #endif
 100
 101 #endif