--- /dev/null
+/* -*-c-*-
+ *
+ * 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