New block cipher.

[u/mdw/catacomb] / square.h

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+/* -*-c-*-
+ *
+ * $Id: square.h,v 1.1 2000/07/15 20:51:58 mdw Exp $
+ *
+ * The Square 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: square.h,v $
+ * Revision 1.1  2000/07/15 20:51:58  mdw
+ * New block cipher.
+ *
+ * Revision 1.1  2000/06/17 11:56:07  mdw
+ * New cipher.
+ *
+ */
+
+/*----- Notes on the Square block cipher ----------------------------------*
+ *
+ * Invented by Joan Daemen and Vincent Rijmen, Square is a fast and
+ * relatively simple 128-bit block cipher.  It is the predecessor to
+ * Rijndael.  I have grave doubts about the security of Square, though: a
+ * dedicated attack against Square's structure by Knudsen has been extended
+ * by the Twofish team against Rijndael, and I believe that this extended
+ * attack is also effective against Square.  This is a shame: the structure
+ * of Square (and Rijndael) is extremely elegant, and has some extremely nice
+ * properties.
+ */
+
+#ifndef CATACOMB_SQUARE_H
+#define CATACOMB_SQUARE_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+/*----- Magical numbers ---------------------------------------------------*/
+
+#define SQUARE_BLKSZ 16
+#define SQUARE_KEYSZ 16
+#define SQUARE_CLASS (N, L, 128)
+
+extern const octet square_keysz[];
+
+/*----- Data structures ---------------------------------------------------*/
+
+#define SQUARE_MAXROUNDS 8
+#define SQUARE_KWORDS ((SQUARE_MAXROUNDS + 1) * (SQUARE_BLKSZ / 4))
+
+typedef struct square_ctx {
+  uint32 w[SQUARE_KWORDS];
+  uint32 wi[SQUARE_KWORDS];
+} square_ctx;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @square_init@ --- *
+ *
+ * Arguments:  @square_ctx *k@ = pointer to context to initialize
+ *             @const void *buf@ = pointer to buffer of key material
+ *             @size_t sz@ = size of the key material
+ *
+ * Returns:    ---
+ *
+ * Use:                Initializes a Square context with a particular key.  This
+ *             implementation of Square doesn't impose any particular
+ *             limits on the key size except that it must be multiple of 4
+ *             bytes long.  256 bits seems sensible, though.
+ */
+
+extern void square_init(square_ctx */*k*/,
+                         const void */*buf*/, size_t /*sz*/);
+
+/* --- @square_eblk@, @square_dblk@ --- *
+ *
+ * Arguments:  @const square_ctx *k@ = pointer to Square context
+ *             @const uint32 s[4]@ = pointer to source block
+ *             @uint32 d[4]@ = pointer to destination block
+ *
+ * Returns:    ---
+ *
+ * Use:                Low-level block encryption and decryption.
+ */
+
+extern void square_eblk(const square_ctx */*k*/,
+                         const uint32 */*s*/, uint32 */*dst*/);
+extern void square_dblk(const square_ctx */*k*/,
+                         const uint32 */*s*/, uint32 */*dst*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif