/* -*-c-*-
*
- * $Id: des.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
+ * $Id$
*
* The Data Encryption Standard
*
* (c) 1999 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,
d[1] = y;
}
+/* --- @des_expand@ --- *
+ *
+ * Arguments: @const octet *k@ = pointer to key material
+ * @size_t n@ = number of octets of key material (7 or 8)
+ * @uint32 *xx, *yy@ = where to put the results
+ *
+ * Returns: ---
+ *
+ * Use: Extracts 64 bits of key material from the given buffer,
+ * possibly expanding it from 56 to 64 bits on the way.
+ * Parity is set correctly if the key is expanded.
+ */
+
+void des_expand(const octet *k, size_t n, uint32 *xx, uint32 *yy)
+{
+ uint32 x, y, z;
+
+ if (n == 8) {
+ x = LOAD32(k + 0);
+ y = LOAD32(k + 4);
+ } else {
+ x = LOAD32(k + 0);
+ x = (x & 0xfe000000) | ((x & 0x01fffff0) >> 1);
+ x = (x & 0xfffe0000) | ((x & 0x0001fff8) >> 1);
+ x = (x & 0xfffffe00) | ((x & 0x000001fc) >> 1);
+ z = x; z ^= z >> 4; z ^= z >> 2; z ^= z >> 1;
+ x |= (z & 0x01010101) ^ 0x01010101;
+ y = LOAD32(k + 3) << 1; /* Note: misaligned */
+ y = (y & 0x000000fe) | ((y & 0x1fffff00) << 1);
+ y = (y & 0x0000fefe) | ((y & 0x3fff0000) << 1);
+ y = (y & 0x00fefefe) | ((y & 0x7f000000) << 1);
+ z = y; z ^= z >> 4; z ^= z >> 2; z ^= z >> 1;
+ y |= (z & 0x01010101) ^ 0x01010101;
+ }
+ *xx = x; *yy = y;
+}
+
/* --- @des_init@ --- *
*
* Arguments: @des_ctx *k@ = pointer to key block
{
uint32 x, y;
uint32 *kp = k->k;
+ uint32 ka[2];
int i;
/* --- @pc1@ --- *
*/
static const char pc1[] = {
- 0, 0, 0, 0,
+ 0, 0, 0, 0,
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
- 10, 2, 59, 51, 43, 35, 27,
+ 10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
- 0, 0, 0, 0,
+ 0, 0, 0, 0,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
- 14, 6, 61, 53, 45, 37, 29,
+ 14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
};
*/
static const char pc2[] = {
- 0, 0, 3 + 4, 28 + 4, 15 + 4, 6 + 4, 21 + 4, 10 + 4, /* S-box 2 */
- 0, 0, 16 + 4, 7 + 4, 27 + 4, 20 + 4, 13 + 4, 2 + 4, /* S-box 4 */
- 0, 0, 30 + 8, 40 + 8, 51 + 8, 45 + 8, 33 + 8, 48 + 8, /* S-box 6 */
- 0, 0, 46 + 8, 42 + 8, 50 + 8, 36 + 8, 29 + 8, 32 + 8, /* S-box 8 */
- 0, 0, 14 + 4, 17 + 4, 11 + 4, 24 + 4, 1 + 4, 5 + 4, /* S-box 1 */
- 0, 0, 23 + 4, 19 + 4, 12 + 4, 4 + 4, 26 + 4, 8 + 4, /* S-box 3 */
- 0, 0, 41 + 8, 52 + 8, 31 + 8, 37 + 8, 47 + 8, 55 + 8, /* S-box 5 */
- 0, 0, 44 + 8, 49 + 8, 39 + 8, 56 + 8, 34 + 8, 53 + 8 /* S-box 7 */
+ 0, 0, 3 + 4, 28 + 4, 15 + 4, 6 + 4, 21 + 4, 10 + 4, /* S-box 2 */
+ 0, 0, 16 + 4, 7 + 4, 27 + 4, 20 + 4, 13 + 4, 2 + 4, /* S-box 4 */
+ 0, 0, 30 + 8, 40 + 8, 51 + 8, 45 + 8, 33 + 8, 48 + 8, /* S-box 6 */
+ 0, 0, 46 + 8, 42 + 8, 50 + 8, 36 + 8, 29 + 8, 32 + 8, /* S-box 8 */
+ 0, 0, 14 + 4, 17 + 4, 11 + 4, 24 + 4, 1 + 4, 5 + 4, /* S-box 1 */
+ 0, 0, 23 + 4, 19 + 4, 12 + 4, 4 + 4, 26 + 4, 8 + 4, /* S-box 3 */
+ 0, 0, 41 + 8, 52 + 8, 31 + 8, 37 + 8, 47 + 8, 55 + 8, /* S-box 5 */
+ 0, 0, 44 + 8, 49 + 8, 39 + 8, 56 + 8, 34 + 8, 53 + 8 /* S-box 7 */
};
/* --- @v@ --- *
*/
KSZ_ASSERT(des, sz);
-
- if (sz == 8) {
- const octet *p = buf;
- x = LOAD32(p); y = LOAD32(p + 4);
- } else {
- const octet *p = buf;
- x = LOAD32(p);
- x = (x & 0xfe000000) | ((x & 0x01fffff0) >> 1);
- x = (x & 0xfffe0000) | ((x & 0x0001fff8) >> 1);
- x = (x & 0xfffffe00) | ((x & 0x000001fc) >> 1);
- y = LOAD32(p + 3) << 1; /* Note: misaligned */
- y = (y & 0x000000fe) | ((y & 0x1fffff00) << 1);
- y = (y & 0x0000fefe) | ((y & 0x3fff0000) << 1);
- y = (y & 0x00fefefe) | ((y & 0x7f000000) << 1);
- }
+ des_expand(buf, sz, &x, &y);
/* --- Permute using the pointless PC1 --- */
- {
- uint32 ka[2];
- permute(pc1, x, y, ka);
- x = ka[0]; y = ka[1];
- }
+ permute(pc1, x, y, ka);
+ x = ka[0]; y = ka[1];
/* --- Now for the key schedule proper --- */
projects / u / mdw / catacomb / blobdiff