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   1 /* -*-c-*-
   2  *
   3  * $Id: cbc.h,v 1.2 1999/12/10 23:16:39 mdw Exp $
   4  *
   5  * Ciphertext block chaining for block ciphers
   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: cbc.h,v $
  33  * Revision 1.2  1999/12/10 23:16:39  mdw
  34  * Split mode macros into interface and implementation.
  35  *
  36  * Revision 1.1  1999/09/03 08:41:11  mdw
  37  * Initial import.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_CBC_H
  42 #define CATACOMB_CBC_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Header files ------------------------------------------------------*/
  49
  50 #include <stddef.h>
  51
  52 #include <mLib/bits.h>
  53
  54 #ifndef CATACOMB_GCIPHER_H
  55 #  include "gcipher.h"
  56 #endif
  57
  58 /*----- Macros ------------------------------------------------------------*/
  59
  60 /* --- @CBC_DECL@ --- *
  61  *
  62  * Arguments:   @PRE@, @pre@ = prefixes for the underlying block cipher
  63  *
  64  * Use:         Creates declarations for CBC stealing mode.
  65  */
  66
  67 #define CBC_DECL(PRE, pre)                                              \
  68                                                                         \
  69 /* --- Cipher block chaining context --- */                             \
  70                                                                         \
  71 typedef struct pre##_cbcctx {                                           \
  72   pre##_ctx ctx;                        /* Underlying cipher context */ \
  73   uint32 iv[PRE##_BLKSZ / 4];           /* Previous ciphertext or IV */ \
  74 } pre##_cbcctx;                                                         \
  75                                                                         \
  76 /* --- @pre_cbcgetiv@ --- *                                             \
  77  *                                                                      \
  78  * Arguments:   @const pre_cbcctx *ctx@ = pointer to CBC context block  \
  79  *              @void *iv#@ = pointer to output data block              \
  80  *                                                                      \
  81  * Returns:     ---                                                     \
  82  *                                                                      \
  83  * Use:         Reads the currently set IV.  Reading and setting an IV  \
  84  *              is transparent to the CBC encryption or decryption      \
  85  *              process.                                                \
  86  */                                                                     \
  87                                                                         \
  88 extern void pre##_cbcgetiv(const pre##_cbcctx */*ctx*/,                 \
  89                            void */*iv*/);                               \
  90                                                                         \
  91 /* --- @pre_cbcsetiv@ --- *                                             \
  92  *                                                                      \
  93  * Arguments:   @pre_cbcctx *ctx@ = pointer to CBC context block        \
  94  *              @cnost void *iv@ = pointer to IV to set                 \
  95  *                                                                      \
  96  * Returns:     ---                                                     \
  97  *                                                                      \
  98  * Use:         Sets the IV to use for subsequent encryption.           \
  99  */                                                                     \
 100                                                                         \
 101 extern void pre##_cbcsetiv(pre##_cbcctx */*ctx*/,                       \
 102                            const void */*iv*/);                         \
 103                                                                         \
 104 /* --- @pre_cbcsetkey@ --- *                                            \
 105  *                                                                      \
 106  * Arguments:   @pre_cbcctx *ctx@ = pointer to CBC context block        \
 107  *              @const pre_ctx *k@ = pointer to cipher context          \
 108  *                                                                      \
 109  * Returns:     ---                                                     \
 110  *                                                                      \
 111  * Use:         Sets the CBC context to use a different cipher key.     \
 112  */                                                                     \
 113                                                                         \
 114 extern void pre##_cbcsetkey(pre##_cbcctx */*ctx*/,                      \
 115                             const pre##_ctx */*k*/);                    \
 116                                                                         \
 117 /* --- @pre_cbcinit@ --- *                                              \
 118  *                                                                      \
 119  * Arguments:   @pre_cbcctx *ctx@ = pointer to cipher context           \
 120  *              @const void *key@ = pointer to the key buffer           \
 121  *              @size_t sz@ = size of the key                           \
 122  *              @const void *iv@ = pointer to initialization vector     \
 123  *                                                                      \
 124  * Returns:     ---                                                     \
 125  *                                                                      \
 126  * Use:         Initializes a CBC context ready for use.  The @iv@      \
 127  *              argument may be passed as a null pointer to set a zero  \
 128  *              IV.  Apart from that, this call is equivalent to calls  \
 129  *              to @pre_init@, @pre_cbcsetkey@ and @pre_cbcsetiv@.      \
 130  */                                                                     \
 131                                                                         \
 132 extern void pre##_cbcinit(pre##_cbcctx */*ctx*/,                        \
 133                           const void */*key*/, size_t /*sz*/,           \
 134                           const void */*iv*/);                          \
 135                                                                         \
 136 /* --- @pre_cbcencrypt@ --- *                                           \
 137  *                                                                      \
 138  * Arguments:   @pre_cbcctx *ctx@ = pointer to CBC context block        \
 139  *              @const void *src@ = pointer to source data              \
 140  *              @void *dest@ = pointer to destination data              \
 141  *              @size_t sz@ = size of block to be encrypted             \
 142  *                                                                      \
 143  * Returns:     ---                                                     \
 144  *                                                                      \
 145  * Use:         Encrypts a block with a block cipher in CBC mode, with  \
 146  *              ciphertext stealing and other clever tricks.            \
 147  *              Essentially, data can be encrypted in arbitrary sized   \
 148  *              chunks, although decryption must use the same chunks.   \
 149  */                                                                     \
 150                                                                         \
 151 extern void pre##_cbcencrypt(pre##_cbcctx */*ctx*/,                     \
 152                              const void */*src*/, void */*dest*/,       \
 153                              size_t /*sz*/);                            \
 154                                                                         \
 155 /* --- @pre_cbcdecrypt@ --- *                                           \
 156  *                                                                      \
 157  * Arguments:   @pre_cbcctx *ctx@ = pointer to CBC context block        \
 158  *              @const void *src@ = pointer to source data              \
 159  *              @void *dest@ = pointer to destination data              \
 160  *              @size_t sz@ = size of block to be encrypted             \
 161  *                                                                      \
 162  * Returns:     ---                                                     \
 163  *                                                                      \
 164  * Use:         Decrypts a block with a block cipher in CBC mode, with  \
 165  *              ciphertext stealing and other clever tricks.            \
 166  *              Essentially, data can be encrypted in arbitrary sized   \
 167  *              chunks, although decryption must use the same chunks.   \
 168  */                                                                     \
 169                                                                         \
 170 extern void pre##_cbcdecrypt(pre##_cbcctx */*ctx*/,                     \
 171                              const void */*src*/, void */*dest*/,       \
 172                              size_t /*sz*/);                            \
 173                                                                         \
 174 /* --- Generic cipher interface --- */                                  \
 175                                                                         \
 176 extern const gccipher pre##_cbc;
 177
 178 /*----- That's all, folks -------------------------------------------------*/
 179
 180 #ifdef __cplusplus
 181   }
 182 #endif
 183
 184 #endif