--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: desx.c,v 1.1 2001/04/03 19:36:50 mdw Exp $
+ *
+ * Implementation of DESX
+ *
+ * (c) 2001 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: desx.c,v $
+ * Revision 1.1 2001/04/03 19:36:50 mdw
+ * New block cipher DESX added.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mLib/bits.h>
+
+#include "blkc.h"
+#include "des-base.h"
+#include "des.h"
+#include "desx.h"
+#include "desx-tab.h"
+#include "gcipher.h"
+
+/*----- Tables ------------------------------------------------------------*/
+
+static octet s[256] = DESX_S;
+
+/*----- Global variables --------------------------------------------------*/
+
+const octet desx_keysz[] = { KSZ_SET, 7, 8, 15, 16, 23, 24, 0 };
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @desx_init@ --- *
+ *
+ * Arguments: @desx_ctx *k@ = pointer to key block
+ * @const void *buf@ = pointer to key buffer
+ * @size_t sz@ = size of key material
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a DESX key buffer. The key buffer contains, in
+ * order, a single-DES key (either 7 or 8 bytes), an optional
+ * 8-byte pre-whitening key, and an optional 8-byte
+ * port-whitening key. If no whitening keys are specified, the
+ * algorithm becomes the same as single-DES.
+ */
+
+static void mangle(octet *b, const octet *p)
+{
+ unsigned i;
+
+ for (i = 0; i < 8; i++)
+ b[i] = *p++ ^ s[b[i] ^ b[(i + 1) & 7u]];
+}
+
+void desx_init(desx_ctx *k, const void *buf, size_t sz)
+{
+ const octet *p = buf, *kk = buf;
+ size_t n;
+
+ KSZ_ASSERT(desx, sz);
+
+ n = sz % 8 == 7 ? 7 : 8;
+ des_init(&k->k, p, n);
+ p += n;
+ sz -= n;
+ if (!sz)
+ k->prea = k->preb = k->posta = k->postb = 0;
+ else {
+ const octet *q = p;
+ k->prea = LOAD32(q + 0);
+ k->preb = LOAD32(q + 4);
+ p += 8;
+ sz -= 8;
+ if (sz) {
+ k->posta = LOAD32(p + 0);
+ k->postb = LOAD32(p + 4);
+ } else {
+ octet b[16];
+
+ if (n == 7) {
+
+ /* --- Expand 7 bits to 8 bits --- *
+ *
+ * Cloned and hacked from @des_init@ to set parity.
+ */
+
+ uint32 x, y, z;
+ x = LOAD32(kk + 0);
+ x = (x & 0xfe000000) | ((x & 0x01fffff0) >> 1);
+ x = (x & 0xfffe0000) | ((x & 0x0001fff8) >> 1);
+ x = (x & 0xfffffe00) | ((x & 0x000001fc) >> 1);
+ z = x; z ^= z >> 4; z ^= z >> 2; z ^= z >> 1;
+ x |= (z & 0x01010101) ^ 0x01010101;
+
+ y = LOAD32(kk + 3) << 1;
+ y = (y & 0x000000fe) | ((y & 0x1fffff00) << 1);
+ y = (y & 0x0000fefe) | ((y & 0x3fff0000) << 1);
+ y = (y & 0x00fefefe) | ((y & 0x7f000000) << 1);
+ z = y; z ^= z >> 4; z ^= z >> 2; z ^= z >> 1;
+ y |= (z & 0x01010101) ^ 0x01010101;
+
+ kk = b + 8;
+ STORE32(kk + 0, x); STORE32(kk + 4, y);
+ }
+
+ memset(b, 0, 8);
+ mangle(b, kk);
+ mangle(b, q);
+ k->posta = LOAD32(b + 0);
+ k->postb = LOAD32(b + 4);
+ }
+ }
+}
+
+/* --- @desx_eblk@, @desx_dblk@ --- *
+ *
+ * Arguments: @const desx_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.
+ */
+
+void desx_eblk(const desx_ctx *k, const uint32 *s, uint32 *d)
+{
+ uint32 x = s[0], y = s[1];
+ x ^= k->prea; y ^= k->preb;
+ DES_IP(x, y);
+ DES_EBLK(k->k.k, x, y, x, y);
+ DES_IPINV(x, y);
+ x ^= k->posta; y ^= k->postb;
+ d[0] = x, d[1] = y;
+}
+
+void desx_dblk(const desx_ctx *k, const uint32 *s, uint32 *d)
+{
+ uint32 x = s[0], y = s[1];
+ x ^= k->posta; y ^= k->postb;
+ DES_IP(x, y);
+ DES_DBLK(k->k.k, x, y, x, y);
+ DES_IPINV(x, y);
+ x ^= k->prea; y ^= k->preb;
+ d[0] = x, d[1] = y;
+}
+
+BLKC_TEST(DESX, desx)
+
+/*----- That's all, folks -------------------------------------------------*/