/* -*-c-*-
*
- * $Id: twofish.c,v 1.2 2000/06/22 18:58:00 mdw Exp $
+ * $Id: twofish.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
*
* Implementation of the Twofish cipher
*
* (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: twofish.c,v $
- * Revision 1.2 2000/06/22 18:58:00 mdw
- * Twofish can handle keys with any byte-aligned size.
- *
- * Revision 1.1 2000/06/17 12:10:17 mdw
- * New cipher.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include <assert.h>
/* --- Apply a series of @q@ tables to an integer --- */
# define Q(x, qa, qb, qc, qd) \
- ((qa[((x) >> 0) & 0xff] << 0) | \
- (qb[((x) >> 8) & 0xff] << 8) | \
+ ((qa[((x) >> 0) & 0xff] << 0) | \
+ (qb[((x) >> 8) & 0xff] << 8) | \
(qc[((x) >> 16) & 0xff] << 16) | \
(qd[((x) >> 24) & 0xff] << 24))
qmds[2][U8(x >> 16)] ^ qmds[3][U8(x >> 24)]);
}
-/* --- @twofish_init@ --- *
+/* --- @twofish_initfk@ --- *
*
* Arguments: @twofish_ctx *k@ = pointer to key block to fill in
* @const void *buf@ = pointer to buffer of key material
* @size_t sz@ = size of key material
+ * @const twofish_fk *fk@ = family-key information
*
* Returns: ---
*
- * Use: Initializes a Twofish key buffer. Twofish accepts key sizes
- * of up to 256 bits (32 bytes).
+ * Use: Does the underlying Twofish key initialization with family
+ * key. Pass in a family-key structure initialized to
+ * all-bits-zero for a standard key schedule.
*/
-void twofish_init(twofish_ctx *k, const void *buf, size_t sz)
+void twofish_initfk(twofish_ctx *k, const void *buf, size_t sz,
+ const twofish_fk *fk)
{
# define KMAX 4
/* --- Extract the easy subkeys --- */
- me[i] = LOAD32_L(q);
- mo[i] = LOAD32_L(q + 4);
+ me[i] = LOAD32_L(q) ^ fk->t0[2 * i];
+ mo[i] = LOAD32_L(q + 4) ^ fk->t0[2 * i + 1];
/* --- Now do the Reed-Solomon thing --- */
int k;
for (k = 0; k < 8; k++) {
- if (*qq)
- a ^= rsexp[rslog[*qq] + *r];
+ unsigned char x = *qq ^ fk->t1[i * 8 + k];
+ if (x) a ^= rsexp[rslog[x] + *r];
qq++;
r++;
}
-
+
s[j][sz - 1 - i] = ss[j] = a;
}
q += 8;
k->k[i + 1] = ROL32(b, 9);
ip += 2 * p;
}
+
+ for (i = 0; i < 8; i++)
+ k->k[i] ^= fk->t23[i];
+ for (i = 8; i < 40; i += 2) {
+ k->k[i] ^= fk->t4[0];
+ k->k[i + 1] ^= fk->t4[1];
+ }
}
/* --- Construct the S-box tables --- */
BURN(s);
}
+/* --- @twofish_init@ --- *
+ *
+ * Arguments: @twofish_ctx *k@ = pointer to key block to fill in
+ * @const void *buf@ = pointer to buffer of key material
+ * @size_t sz@ = size of key material
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a Twofish key buffer. Twofish accepts key sizes
+ * of up to 256 bits (32 bytes).
+ */
+
+void twofish_init(twofish_ctx *k, const void *buf, size_t sz)
+{
+ static const twofish_fk fk = { { 0 } };
+ twofish_initfk(k, buf, sz, &fk);
+}
+
+/* --- @twofish_fkinit@ --- *
+ *
+ * Arguments: @twofish_fk *fk@ = pointer to family key block
+ * @const void *buf@ = pointer to buffer of key material
+ * @size_t sz@ = size of key material
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a family-key buffer. This implementation allows
+ * family keys of any size acceptable to the Twofish algorithm.
+ */
+
+void twofish_fkinit(twofish_fk *fk, const void *buf, size_t sz)
+{
+ twofish_ctx k;
+ uint32 pt[4], ct[4];
+ const octet *kk;
+ unsigned i;
+
+ twofish_init(&k, buf, sz);
+
+ for (i = 0; i < 4; i++) pt[i] = (uint32)-1;
+ twofish_eblk(&k, pt, fk->t0 + 4);
+
+ kk = buf; sz /= 4;
+ for (i = 0; i < sz; i++) { fk->t0[i] = LOAD32_L(kk); kk += 4; }
+
+ for (i = 0; i < 4; i++) pt[i] = 0; twofish_eblk(&k, pt, ct);
+ for (i = 0; i < 4; i++) STORE32_L(fk->t1 + i * 4, ct[i]);
+ pt[0] = 1; twofish_eblk(&k, pt, ct);
+ for (i = 0; i < 4; i++) STORE32_L(fk->t1 + 4 + i * 4, ct[i]);
+
+ pt[0] = 2; twofish_eblk(&k, pt, fk->t23 + 0);
+ pt[0] = 3; twofish_eblk(&k, pt, fk->t23 + 4);
+ pt[0] = 4; twofish_eblk(&k, pt, ct);
+ fk->t4[0] = ct[0]; fk->t4[1] = ct[1];
+
+ BURN(k);
+}
+
/*----- Main encryption ---------------------------------------------------*/
/* --- Feistel function --- */
#define GG(k, t0, t1, x, y, kk) do { \
- t0 = (k->g[0][U8(x >> 0)] ^ \
- k->g[1][U8(x >> 8)] ^ \
+ t0 = (k->g[0][U8(x >> 0)] ^ \
+ k->g[1][U8(x >> 8)] ^ \
k->g[2][U8(x >> 16)] ^ \
k->g[3][U8(x >> 24)]); \
- t1 = (k->g[1][U8(y >> 0)] ^ \
- k->g[2][U8(y >> 8)] ^ \
+ t1 = (k->g[1][U8(y >> 0)] ^ \
+ k->g[2][U8(y >> 8)] ^ \
k->g[3][U8(y >> 16)] ^ \
k->g[0][U8(y >> 24)]); \
t0 += t1; \
projects / u / mdw / catacomb / blobdiff