crypto/cbc.h

   1 /* cbc.h
   2  *
   3  * Cipher block chaining mode.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2001 Niels Möller
   9  *
  10  * The nettle library is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * The nettle library is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  18  * License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  22  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  23  * MA 02111-1307, USA.
  24  */
  25
  26 #ifndef NETTLE_CBC_H_INCLUDED
  27 #define NETTLE_CBC_H_INCLUDED
  28
  29 #include <inttypes.h>
  30
  31 /* Uses a void * for cipher contexts. */
  32
  33 void
  34 cbc_encrypt(void *ctx, void (*f)(void *ctx,
  35                                  unsigned length, uint8_t *dst,
  36                                  const uint8_t *src),
  37             unsigned block_size, uint8_t *iv,
  38             unsigned length, uint8_t *dst,
  39             const uint8_t *src);
  40
  41 void
  42 cbc_decrypt(void *ctx, void (*f)(void *ctx,
  43                                  unsigned length, uint8_t *dst,
  44                                  const uint8_t *src),
  45             unsigned block_size, uint8_t *iv,
  46             unsigned length, uint8_t *dst,
  47             const uint8_t *src);
  48
  49 #define CBC_CTX(type, size) \
  50 { type ctx; uint8_t iv[size]; }
  51
  52 #define CBC_SET_IV(ctx, data) \
  53 memcpy((ctx)->iv, (data), sizeof((ctx)->iv))
  54
  55 #if 0
  56 #define CBC_ENCRYPT(self, f, length, dst, src) \
  57 do { if (0) (f)(&(self)->ctx, 0, NULL, NULL); \
  58      cbc_encrypt((void *) &(self)->ctx, \
  59                  (void (*)(void *, unsigned, uint8_t *, const uint8_t *)) (f), \
  60                  sizeof((self)->iv), (self)->iv, \
  61                  (length), (dst), (src)); \
  62 } while (0)
  63 #endif
  64
  65 #define CBC_ENCRYPT(self, f, length, dst, src) \
  66 (0 ? ((f)(&(self)->ctx, 0, NULL, NULL)) \
  67    : cbc_encrypt((void *) &(self)->ctx, \
  68                  (void (*)(void *, unsigned, uint8_t *, const uint8_t *)) (f), \
  69                  sizeof((self)->iv), (self)->iv, \
  70                  (length), (dst), (src)))
  71
  72 #define CBC_DECRYPT(self, f, length, dst, src) \
  73 (0 ? ((f)(&(self)->ctx, 0, NULL, NULL)) \
  74    : cbc_decrypt((void *) &(self)->ctx, \
  75                  (void (*)(void *, unsigned, uint8_t *, const uint8_t *)) (f), \
  76                  sizeof((self)->iv), (self)->iv, \
  77                  (length), (dst), (src)))
  78
  79 #if 0
  80 /* Type safer variants */
  81 #define CBC_ENCRYPT2(ctx, f, b, iv, l, dst, src) \
  82 (0 ? ((f)((ctx),0,NULL,NULL)) \
  83    : cbc_encrypt((void *)(ctx), \
  84                  (void (*)(void *, unsigned, uint8_t *, const uint8_t *)) (f), \
  85                  (b), (iv), (l), (dst), (src)))
  86
  87 #endif
  88
  89 #endif /* NETTLE_CBC_H_INCLUDED */