/* -*-c-*-
*
- * $Id: xtea.c,v 1.1 2000/07/15 13:44:31 mdw Exp $
+ * $Id: xtea.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
*
* The Extended Tiny Encryption Algorithm
*
* (c) 2000 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
- *
+ *
* Catacomb 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 Library General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Library General Public
* License along with Catacomb; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: xtea.c,v $
- * Revision 1.1 2000/07/15 13:44:31 mdw
- * New ciphers.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include <mLib/bits.h>
/* --- @xtea_init@ --- *
*
- * Arguments: @xtea_ctx *k@ = pointer to key block
- * @const void *buf@ = pointer to key buffer
- * @size_t sz@ = size of key material
+ * Arguments: @xtea_ctx *k@ = pointer to key block
+ * @const void *buf@ = pointer to key buffer
+ * @size_t sz@ = size of key material
*
- * Returns: ---
+ * Returns: ---
*
- * Use: Initializes an XTEA key buffer. The key buffer must be 16
+ * Use: Initializes an XTEA key buffer. The key buffer must be 16
* bytes long.
*/
p = kb;
}
- k->k[0] = LOAD32(p + 0); k->k[1] = LOAD32(p + 4);
- k->k[2] = LOAD32(p + 8); k->k[3] = LOAD32(p + 12);
+ k->k[0] = LOAD32(p + 0); k->k[1] = LOAD32(p + 4);
+ k->k[2] = LOAD32(p + 8); k->k[3] = LOAD32(p + 12);
+ k->r = 32;
if (p == kb)
BURN(kb);
/* --- @xtea_eblk@, @xtea_dblk@ --- *
*
- * Arguments: @const xtea_ctx *k@ = pointer to key block
- * @const uint32 s[2]@ = pointer to source block
- * @uint32 d[2]@ = pointer to xteatination block
+ * Arguments: @const xtea_ctx *k@ = pointer to key block
+ * @const uint32 s[2]@ = pointer to source block
+ * @uint32 d[2]@ = pointer to xteatination block
*
- * Returns: ---
+ * Returns: ---
*
- * Use: Low-level block encryption and decryption.
+ * Use: Low-level block encryption and decryption.
*/
#define DELTA 0x9e3779b9
uint32 n = 0;
unsigned i;
- for (i = 0; i < 32; i++) {
+ for (i = 0; i < k->r; i++) {
y = U32(y + ((((z << 4) ^ (z >> 5)) + z) ^ (n + k->k[n & 3])));
n += DELTA;
z = U32(z + ((((y << 4) ^ (y >> 5)) + y) ^ (n + k->k[(n >> 11) & 3])));
void xtea_dblk(const xtea_ctx *k, const uint32 *s, uint32 *d)
{
uint32 y = s[0], z = s[1];
- uint32 n = DELTA << 5;
+ uint32 n = DELTA * k->r;
unsigned i;
- for (i = 0; i < 32; i++) {
+ for (i = 0; i < k->r; i++) {
z = U32(z - ((((y << 4) ^ (y >> 5)) + y) ^ (n + k->k[(n >> 11) & 3])));
n -= DELTA;
y = U32(y - ((((z << 4) ^ (z >> 5)) + z) ^ (n + k->k[n & 3])));