--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: serpent.c,v 1.1 2000/06/17 12:08:43 mdw Exp $
+ *
+ * The Serpent 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.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: serpent.c,v $
+ * Revision 1.1 2000/06/17 12:08:43 mdw
+ * New cipher.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <assert.h>
+#include <stdio.h>
+
+#include <mLib/bits.h>
+
+#include "blkc.h"
+#include "gcipher.h"
+#include "serpent.h"
+#include "serpent-sbox.h"
+
+/*----- Global variables --------------------------------------------------*/
+
+const octet serpent_keysz[] = { KSZ_RANGE, SERPENT_KEYSZ, 0, 32, 1 };
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @serpent_init@ --- *
+ *
+ * Arguments: @serpent_ctx *k@ = pointer to context block to initialize
+ * @const void *buf@ = pointer to input buffer
+ * @size_t sz@ = size of input buffer
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a Serpent context. The key may be any length of
+ * up to 32 bytes (256 bits).
+ */
+
+void serpent_init(serpent_ctx *k, const void *buf, size_t sz)
+{
+ uint32 a;
+ unsigned b;
+ const octet *p, *q;
+ size_t i;
+ uint32 pk[8 + 132];
+
+ KSZ_ASSERT(serpent, sz);
+
+ /* --- Read the key into the buffer --- */
+
+ if (sz > 32)
+ sz = 32;
+ i = 0; p = buf; q = p + sz;
+ a = 0; b = 0;
+ while (p < q) {
+ a |= (uint32)*p++ << b;
+ b += 8;
+ if (b == 32) {
+ pk[i++] = a;
+ a = 0; b = 0;
+ }
+ }
+
+ /* --- Pad short keys --- */
+
+ if (i < 8) {
+ a |= 0x01 << b;
+ b += 8;
+ pk[i++] = a;
+ for (; i < 8; i++)
+ pk[i] = 0;
+ }
+
+ /* --- Expand the prekeys to fill the buffer --- */
+
+ for (i = 8; i < 8 + 132; i++) {
+ uint32 x = (pk[i - 8] ^ pk[i - 5] ^ pk[i - 3] ^ pk[i - 1] ^
+ (i - 8) ^ 0x9e3779b9);
+ k->k[i - 8] = pk[i] = ROL32(x, 11);
+ }
+
+ /* --- Now substitute everything --- */
+
+ i = 0;
+ goto midway;
+ while (i < 132) {
+#define KSUB(r) do { \
+ uint32 a, b, c, d; \
+ a = k->k[i]; b = k->k[i + 1]; c = k->k[i + 2]; d = k->k[i + 3]; \
+ S##r(a, b, c, d); \
+ k->k[i] = a; k->k[i + 1] = b; k->k[i + 2] = c; k->k[i + 3] = d; \
+ i += 4; \
+} while (0)
+ KSUB(2); KSUB(1); KSUB(0); KSUB(7);
+ KSUB(6); KSUB(5); KSUB(4);
+ midway:
+ KSUB(3);
+#undef KSUB
+ }
+}
+
+/* --- @serpent_eblk@, @serpent_dblk@ --- *
+ *
+ * Arguments: @const serpent_ctx *k@ = pointer to key context
+ * @const uint32 s[4]@ = pointer to source block
+ * @uint32 d[4]@ = pointer to destination block
+ *
+ * Returns: ---
+ *
+ * Use: Low-level block encryption.
+ */
+
+#define EROUND(a, b, c, d, r, k) do { \
+ a ^= *k++; b ^= *k++; c ^= *k++; d ^= *k++; \
+ S##r(a, b, c, d); \
+ a = ROL32(a, 13); c = ROL32(c, 3); b ^= a ^ c; d ^= c ^ (a << 3); \
+ b = ROL32(b, 1); d = ROL32(d, 7); a ^= b ^ d; c ^= d ^ (b << 7); \
+ a = ROL32(a, 5); c = ROL32(c, 22); \
+} while (0)
+
+#define DROUND(a, b, c, d, r, k) do { \
+ IS##r(a, b, c, d); \
+ d ^= *--k; c ^= *--k; b ^= *--k; a ^= *--k; \
+ a = ROR32(a, 5); c = ROR32(c, 22); a ^= b ^ d; c ^= d ^ (b << 7); \
+ b = ROR32(b, 1); d = ROR32(d, 7); b ^= a ^ c; d ^= c ^ (a << 3); \
+ a = ROR32(a, 13); c = ROR32(c, 3); \
+} while (0)
+
+void serpent_eblk(const serpent_ctx *k, const uint32 *s, uint32 *d)
+{
+ uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3];
+ const uint32 *kk = k->k;
+
+ EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk);
+ EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk);
+ EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk);
+ EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk);
+
+ EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk);
+ EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk);
+ EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk);
+ EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk);
+
+ EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk);
+ EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk);
+ EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk);
+ EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk);
+
+ EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk);
+ EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk);
+ EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk);
+ EROUND(aa, bb, cc, dd, 6, kk);
+
+ aa ^= *kk++; bb ^= *kk++; cc ^= *kk++; dd ^= *kk++;
+ S7(aa, bb, cc, dd);
+ aa ^= *kk++; bb ^= *kk++; cc ^= *kk++; dd ^= *kk++;
+ d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd;
+}
+
+void serpent_dblk(const serpent_ctx *k, const uint32 *s, uint32 *d)
+{
+ uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3];
+ const uint32 *kk = k->k + 132;
+
+ dd ^= *--kk; cc ^= *--kk; bb ^= *--kk; aa ^= *--kk;
+
+ DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk);
+ DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk);
+ DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk);
+ DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk);
+
+ DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk);
+ DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk);
+ DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk);
+ DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk);
+
+ DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk);
+ DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk);
+ DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk);
+ DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk);
+
+ DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk);
+ DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk);
+ DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk);
+ DROUND(aa, bb, cc, dd, 1, kk);
+
+ IS0(aa, bb, cc, dd);
+ dd ^= *--kk; cc ^= *--kk; bb ^= *--kk; aa ^= *--kk;
+ d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd;
+}
+
+BLKC_TEST(SERPENT, serpent)
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff