+++ /dev/null
-/* -*-c-*-
- *
- * $Id: cast256.c,v 1.2 2004/04/08 01:36:15 mdw Exp $
- *
- * The CAST-256 block cipher
- *
- * (c) 2000 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * 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.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <mLib/bits.h>
-
-#include "blkc.h"
-#include "cast-base.h"
-#include "cast256.h"
-#include "gcipher.h"
-#include "paranoia.h"
-
-/*----- Global variables --------------------------------------------------*/
-
-const octet cast256_keysz[] = { KSZ_RANGE, CAST256_KEYSZ, 0, 32, 1 };
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @cast256_init@ --- *
- *
- * Arguments: @cast128_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 CAST-256 key buffer. CAST-256 accepts
- * 256-bit keys or shorter.
- */
-
-void cast256_init(cast256_ctx *k, const void *buf, size_t sz)
-{
- const octet *p = buf;
- uint32 kk[8];
- uint32 *km;
- octet *kr;
- unsigned i, j;
- uint32 a, b, c, d, e, f, g, h;
- uint32 m;
- unsigned r;
-
- /* --- Fiddle with the key size --- */
-
- KSZ_ASSERT(cast256, sz);
-
- /* --- Read the key into the array --- */
-
- i = 0;
- b = 32; a = 0;
- for (;;) {
- if (!sz)
- break;
- b -= 8;
- a |= ((uint32)*p++ << b);
- sz--;
- if (b == 0) {
- kk[i++] = a;
- if (i == 8)
- break;
- a = 0;
- b = 32;
- }
- }
-
- for (; i < 8; i++) {
- kk[i] = a;
- a = 0;
- }
-
- /* --- Read the key words out --- */
-
- a = kk[0]; b = kk[1]; c = kk[2]; d = kk[3];
- e = kk[4]; f = kk[5]; g = kk[6]; h = kk[7];
-
-#define ROOT2 0x5a827999
-#define ROOT3 0x6ed9eba1
-
- m = ROOT2;
- r = 19;
-
- km = k->km;
- kr = k->kr;
- for (i = 0; i < 12; i++) {
- for (j = 0; j < 2; j++) {
- CAST_R1(m, r, g, h); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R2(m, r, f, g); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R3(m, r, e, f); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R1(m, r, d, e); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R2(m, r, c, d); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R3(m, r, b, c); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R1(m, r, a, b); m += ROOT3; r = (r + 17) & 0x1f;
- CAST_R2(m, r, h, a); m += ROOT3; r = (r + 17) & 0x1f;
- }
- km[0] = h; km[1] = f; km[2] = d; km[3] = b;
- kr[0] = a & 0x1f; kr[1] = c & 0x1f; kr[2] = e & 0x1f; kr[3] = g & 0x1f;
- km += 4; kr += 4;
- }
-}
-
-/* --- @cast256_eblk@, @cast256_dblk@ --- *
- *
- * Arguments: @const cast256_ctx *k@ = pointer to key block
- * @const uint32 s[2]@ = pointer to source block
- * @uint32 d[2]@ = pointer to destination block
- *
- * Returns: ---
- *
- * Use: Low-level block encryption and decryption.
- */
-
-#define Q0(k, r, a, b, c, d) do { \
- CAST_R1(k[0], r[0], c, d); \
- CAST_R2(k[1], r[1], b, c); \
- CAST_R3(k[2], r[2], a, b); \
- CAST_R1(k[3], r[3], d, a); \
-} while (0)
-
-#define Q1(k, r, a, b, c, d) do { \
- CAST_R1(k[3], r[3], d, a); \
- CAST_R3(k[2], r[2], a, b); \
- CAST_R2(k[1], r[1], b, c); \
- CAST_R1(k[0], r[0], c, d); \
-} while (0)
-
-void cast256_eblk(const cast256_ctx *k, const uint32 *s, uint32 *d)
-{
- uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3];
- const uint32 *km = k->km;
- const octet *kr = k->kr;
-
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q0(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
-
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
- Q1(km, kr, aa, bb, cc, dd); km += 4; kr += 4;
-
- d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd;
-}
-
-void cast256_dblk(const cast256_ctx *k, const uint32 *s, uint32 *d)
-{
- uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3];
- const uint32 *km = k->km + 48;
- const octet *kr = k->kr + 48;
-
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q0(km, kr, aa, bb, cc, dd);
-
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
- km -= 4; kr -= 4; Q1(km, kr, aa, bb, cc, dd);
-
- d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd;
-}
-
-BLKC_TEST(CAST256, cast256)
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff