File: camellia-set-decrypt-key.c

package info (click to toggle)
nettle 2.7.1-5%2Bdeb8u2
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 6,008 kB
  • ctags: 5,172
  • sloc: ansic: 40,330; asm: 9,790; sh: 3,517; makefile: 768; cpp: 71; awk: 7
file content (61 lines) | stat: -rw-r--r-- 1,690 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
/* camellia-set-decrypt-key.c
 *
 * Inverse key setup for the camellia block cipher.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2010 Niels Möller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02111-1301, USA.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "camellia.h"

#define SWAP(a, b) \
do { uint64_t t_swap = (a); (a) = (b); (b) = t_swap; } while(0)

void
camellia_invert_key(struct camellia_ctx *dst,
		    const struct camellia_ctx *src)
{
  unsigned nkeys = src->nkeys;
  unsigned i;
  if (dst == src)
    {
      for (i = 0; i < nkeys - 1 - i; i++)
	SWAP(dst->keys[i], dst->keys[nkeys - 1 - i]);
    }
  else
    {
      dst->nkeys = nkeys;

      for (i = 0; i < nkeys; i++)
	dst->keys[i] = src->keys[nkeys - 1 - i];
    }
}

void
camellia_set_decrypt_key(struct camellia_ctx *ctx,
			 unsigned length, const uint8_t *key)
{
  camellia_set_encrypt_key(ctx, length, key);
  camellia_invert_key(ctx, ctx);
}