mdw@git.distorted.org.uk Git - become/blob - src/idea.h

   1 /* -*-c-*-
   2  *
   3  * $Id: idea.h,v 1.2 1997/08/04 10:24:22 mdw Exp $
   4  *
   5  * IDEA encryption routines
   6  *  Based on Straylight ARM assembler routines
   7  *
   8  * (c) 1996, 1997 Mark Wooding
   9  */
  10
  11 /*----- Licensing notice --------------------------------------------------*
  12  *
  13  * This file is part of `become'
  14  *
  15  * `Become' is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * `Become' is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with `become'; if not, write to the Free Software Foundation,
  27  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: idea.h,v $
  33  * Revision 1.2  1997/08/04 10:24:22  mdw
  34  * Sources placed under CVS control.
  35  *
  36  * Revision 1.1  1997/07/21  13:47:48  mdw
  37  * Initial revision
  38  *
  39  */
  40
  41 #ifndef IDEA_H
  42 #define IDEA_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Required headers --------------------------------------------------*/
  49
  50 #ifndef CONFIG_H
  51 #  include "config.h"
  52 #endif
  53
  54 /*----- Useful constants --------------------------------------------------*/
  55
  56 #define IDEA_BLKSIZE (8u)               /* Number of bytes in IDEA block */
  57 #define IDEA_KEYSIZE (16u)              /* Number of bytes in IDEA key */
  58 #define IDEA_EXPKEYSIZE (52u)           /* Number of ints in expanded key */
  59
  60 /*----- Type definitions --------------------------------------------------*/
  61
  62 typedef struct idea_key {
  63   int k[IDEA_EXPKEYSIZE];               /* Subkey array */
  64 } idea_key;
  65
  66 /*----- Functions provided ------------------------------------------------*/
  67
  68 /* --- @idea_ekeys@ --- *
  69  *
  70  * Arguments:   @idea_key *k@ = the expanded key buffer
  71  *              @const unsigned char *key@ = the user's key encryption key
  72  *
  73  * Returns:     ---
  74  *
  75  * Use:         Unpacks an encryption key.
  76  */
  77
  78 extern void idea_ekeys(idea_key */*k*/, const unsigned char */*key*/);
  79
  80 /* --- @idea_invertKey@ --- *
  81  *
  82  * Arguments:   @const idea_key *in@ = pointer to input expanded key buffer
  83  *              @idea_key *out@ = pointer to output expanded key buffer
  84  *
  85  * Returns:     ---
  86  *
  87  * Use:         Computes the inverse (decryption) key given an expanded
  88  *              IDEA encryption key.
  89  */
  90
  91 extern void idea_invertKey(const idea_key */*in*/, idea_key */*out*/);
  92
  93 /* --- @idea_dkeys@ --- *
  94  *
  95  * Arguments:   @idea_key *k@ = the expanded key buffer
  96  *              @const unsigned char *key@ = the user's key encryption key
  97  *
  98  * Returns:     ---
  99  *
 100  * Use:         Unpacks a decryption key.
 101  */
 102
 103 extern void idea_dkeys(idea_key */*k*/, const unsigned char */*key*/);
 104
 105 /* --- @idea_encrypt@ --- *
 106  *
 107  * Arguments:   @const idea_key *k@ = key to use
 108  *              @const void *src@ = block to encrypt
 109  *              @void *dest@ = where to store the result
 110  *
 111  *
 112  * Returns:     ---
 113  *
 114  * Use:         Encrypts (or decrypts) a block, using the IDEA cryptosystem.
 115  *              Since the decryption operation is the same as encryption
 116  *              except that a different key buffer is used, this is all we
 117  *              need to complete the simple bits.
 118  */
 119
 120 extern void idea_encrypt(const idea_key */*k*/,
 121                          const void */*src*/, void */*dest*/);
 122
 123 /*----- That's all, folks -------------------------------------------------*/
 124
 125 #ifdef __cplusplus
 126   }
 127 #endif
 128
 129 #endif