+++ /dev/null
-/* -*-c-*-
- *
- * $Id: rc5.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
- *
- * The RC5-32/12 block cipher
- *
- * (c) 1999 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 <stdlib.h>
-#include <string.h>
-
-#include <mLib/alloc.h>
-#include <mLib/bits.h>
-
-#include "arena.h"
-#include "blkc.h"
-#include "gcipher.h"
-#include "rc5.h"
-
-/*----- Global variables --------------------------------------------------*/
-
-const octet rc5_keysz[] = { KSZ_RANGE, RC5_KEYSZ, 1, 255, 1 };
-
-/*----- Internal magical constants ----------------------------------------*/
-
-#define T ((RC5_ROUNDS + 1) * 2)
-#define P 0xb7e15163
-#define Q 0x9e3779b9
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @rc5_init@ --- *
- *
- * Arguments: @rc5_ctx *k@ = pointer to a key block
- * @const void *sbuf@ = pointer to key material
- * @size_t sz@ = size of the key material
- *
- * Returns: ---
- *
- * Use: Initializes an RC5 key block.
- */
-
-void rc5_init(rc5_ctx *k, const void *sbuf, size_t sz)
-{
- uint32 *l;
- size_t w;
-
- /* --- Set up the @L@ table --- *
- *
- * This is slightly unfortunately defined.
- */
-
- KSZ_ASSERT(rc5, sz);
-
- {
- int i;
- const octet *p = sbuf;
-
- /* --- Create the buffer --- */
-
- w = (sz + 3) / 4;
- l = XS_ALLOC(w * sizeof(uint32));
-
- /* --- Extract the key material --- */
-
- for (i = 0; sz > 3; i++) {
- l[i] = LOAD32_L(p);
- p += 4;
- sz -= 4;
- }
-
- /* --- Fix up the tail end --- */
-
- if (sz) {
- uint32 x = U8(*p++);
- if (sz > 1) x |= (U8(*p++) << 8);
- if (sz > 2) x |= (U8(*p++) << 16);
- l[i] = x;
- }
- }
-
- /* --- Initialize the @S@ table --- */
-
- {
- int i;
-
- k->s[0] = P;
- for (i = 1; i < T; i++)
- k->s[i] = k->s[i - 1] + Q;
- }
-
- /* --- Mix in the key --- */
-
- {
- int m = 3 * (w > T ? w : T);
- int i, j, c;
- uint32 a, b;
-
- for (c = i = j = a = b = 0; c < m; c++) {
- uint32 x;
-
- x = k->s[i] + a + b;
- k->s[i] = a = ROL32(x, 3);
- i++; if (i >= T) i = 0;
-
- x = l[j] + a + b;
- l[j] = b = ROL32(x, a + b);
- j++; if (j >= w) j = 0;
- }
- }
-
- memset(l, 0, w * sizeof(uint32));
- XS_FREE(l);
-}
-
-/* --- @EROUND@, @DROUND@ --- */
-
-#define EROUND(x, y, k) do { \
- uint32 _x; \
- _x = x ^ y; x = ROL32(_x, y) + k[0]; \
- _x = y ^ x; y = ROL32(_x, x) + k[1]; \
- k += 2; \
-} while (0)
-
-#define DROUND(x, y, k) do { \
- uint32 _x; \
- k -= 2; \
- _x = y - k[1]; y = ROR32(_x, x) ^ x; \
- _x = x - k[0]; x = ROR32(_x, y) ^ y; \
-} while (0)
-
-/* --- @EBLK@, @DBLK@ --- */
-
-#define EBLK(a, b, c, d, k) do { \
- uint32 _l, _r; \
- const uint32 *_k = (k)->s; \
- \
- _l = (a) + _k[0]; \
- _r = (b) + _k[1]; \
- _k += 2; \
- \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- EROUND(_l, _r, _k); \
- (c) = _l; \
- (d) = _r; \
-} while (0)
-
-#define DBLK(a, b, c, d, k) do { \
- uint32 _l, _r; \
- const uint32 *_k = (k)->s + T; \
- \
- _l = (a); \
- _r = (b); \
- \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- DROUND(_l, _r, _k); \
- \
- _k -= 2; \
- (d) = _r - _k[1]; \
- (c) = _l - _k[0]; \
-} while (0)
-
-/* --- @rc5_eblk@, @rc5_dblk@ --- *
- *
- * Arguments: @const rc5_ctx *k@ = pointer to RC5 context block
- * @const uint32 s[2]@ = pointer to source block
- * @uint32 *d[2]@ = pointer to destination block
- *
- * Returns: ---
- *
- * Use: Low level block encryption and decryption.
- */
-
-void rc5_eblk(const rc5_ctx *k, const uint32 *s, uint32 *d)
-{
- EBLK(s[0], s[1], d[0], d[1], k);
-}
-
-void rc5_dblk(const rc5_ctx *k, const uint32 *s, uint32 *d)
-{
- DBLK(s[0], s[1], d[0], d[1], k);
-}
-
-/* --- Test rig --- */
-
-BLKC_TEST(RC5, rc5)
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff