--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: skipjack.c,v 1.1 2000/07/15 15:39:33 mdw Exp $
+ *
+ * The Skipjack 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: skipjack.c,v $
+ * Revision 1.1 2000/07/15 15:39:33 mdw
+ * The NSA's Skipjack block cipher.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/bits.h>
+
+#include "blkc.h"
+#include "gcipher.h"
+#include "skipjack.h"
+#include "skipjack-tab.h"
+
+/*----- Global variables --------------------------------------------------*/
+
+const octet skipjack_keysz[] = { KSZ_SET, 10, 0 };
+
+/*----- The Skipjack S-box ------------------------------------------------*/
+
+static octet f[256] = SKIPJACK_S;
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @skipjack_init@ --- *
+ *
+ * Arguments: @skipjack_ctx *k@ = pointer to key block
+ * @const void *buf@ = pointer to key buffer
+ * @size_t sz@ = size of key material
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a Skipjack key buffer. The key buffer must be
+ * exactly 10 bytes long.
+ */
+
+void skipjack_init(skipjack_ctx *k, const void *buf, size_t sz)
+{
+ KSZ_ASSERT(skipjack, sz);
+ memcpy(k->k, buf, sz);
+}
+
+/* --- @skipjack_eblk@, @skipjack_dblk@ --- *
+ *
+ * Arguments: @const skipjack_ctx *k@ = pointer to key block
+ * @const uint32 s[2]@ = pointer to source block
+ * @uint32 d[2]@ = pointer to skipjacktination block
+ *
+ * Returns: ---
+ *
+ * Use: Low-level block encryption and decryption.
+ */
+
+#define G(x, i) do { \
+ octet _x = U8(x >> 8), _y = U8(x); \
+ _x ^= f[_y ^ k->k[i++]]; if (i >= 10) i = 0; \
+ _y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0; \
+ _x ^= f[_y ^ k->k[i++]]; if (i >= 10) i = 0; \
+ _y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0; \
+ x = U16((_x << 8) | _y); \
+} while (0)
+
+#define RULE_A(w, x, y, z, n, i) do { \
+ G(w, i); z ^= w ^ n++; \
+} while (0)
+
+#define RULE_B(w, x, y, z, n, i) do { \
+ x ^= w ^ n++; G(w, i); \
+} while (0)
+
+void skipjack_eblk(const skipjack_ctx *k, const uint32 *s, uint32 *d)
+{
+ unsigned i = 0;
+ unsigned n = 1;
+ uint16 w = U16(s[0] >> 16), x = U16(s[0]);
+ uint16 y = U16(s[1] >> 16), z = U16(s[1]);
+
+ RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
+ RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
+ RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
+ RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
+ RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
+ RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
+ RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
+ RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
+ RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
+ RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
+ RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
+ RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
+ RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
+ RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
+ RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
+ RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
+
+ d[0] = ((uint32)w << 16) | (uint32)x;
+ d[1] = ((uint32)y << 16) | (uint32)z;
+}
+
+#define G_INV(x, i) do { \
+ octet _x = U8(x >> 8), _y = U8(x); \
+ _y ^= f[_x ^ k->k[--i]]; if (i == 0) i = 10; \
+ _x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10; \
+ _y ^= f[_x ^ k->k[--i]]; if (i == 0) i = 10; \
+ _x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10; \
+ x = U16((_x << 8) | _y); \
+} while (0)
+
+#define RULE_A_INV(w, x, y, z, n, i) do { \
+ w ^= x ^ --n; G_INV(x, i); \
+} while (0)
+
+#define RULE_B_INV(w, x, y, z, n, i) do { \
+ G_INV(x, i); y ^= x ^ --n; \
+} while (0)
+
+void skipjack_dblk(const skipjack_ctx *k, const uint32 *s, uint32 *d)
+{
+ unsigned i = 8;
+ unsigned n = 33;
+ uint16 w = U16(s[0] >> 16), x = U16(s[0]);
+ uint16 y = U16(s[1] >> 16), z = U16(s[1]);
+
+ RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
+ RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
+ RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
+ RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
+ RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
+ RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
+ RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
+ RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
+ RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
+ RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
+ RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
+ RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
+ RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
+ RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
+ RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
+ RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
+
+ d[0] = ((uint32)w << 16) | (uint32)x;
+ d[1] = ((uint32)y << 16) | (uint32)z;
+}
+
+BLKC_TEST(SKIPJACK, skipjack)
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff