Rearrange the file tree.

[u/mdw/catacomb] / symm / safer.h

diff --git a/symm/safer.h b/symm/safer.h
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+/* -*-c-*-
+ *
+ * The SAFER block cipher
+ *
+ * (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.
+ */
+
+/*----- Notes on the SAFER block cipher -----------------------------------*
+ *
+ * SAFER was designed by James Massey (who also worked on IDEA) for Cylink.
+ * It's free -- patents or other silliness.  The original key schedule had
+ * some weaknesses, and a new one (the SK version) was added.  SAFER has a
+ * variable number of rounds.  The standard interface uses the recommended
+ * number for the given key schedule algorithm and key size.
+ *
+ * SAFER got a bad press in Schneier's book `Applied Cryptography'.  I think
+ * this is undeserved.  SAFER is a well-designed cipher which mostly looks
+ * pretty solid.
+ */
+
+#ifndef CATACOMB_SAFER_H
+#define CATACOMB_SAFER_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+/*----- Magical numbers ---------------------------------------------------*/
+
+#define SAFER_BLKSZ 8
+#define SAFER_KEYSZ 8
+#define SAFER_CLASS (N, B, 64)
+
+#define SAFERSK_BLKSZ SAFER_BLKSZ
+#define SAFERSK_KEYSZ 16
+#define SAFERSK_CLASS SAFER_CLASS
+
+#define SAFER_MAXROUNDS 12
+
+extern const octet safer_keysz[];
+#define safersk_keysz safer_keysz
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct safer_ctx {
+  octet k[8 * (2 * SAFER_MAXROUNDS + 1)];
+  unsigned r;
+} safer_ctx, safersk_ctx;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @safer_setup@ --- *
+ *
+ * Arguments:  @safer_ctx *k@ = pointer to context to initialize
+ *             @unsigned r@ = number of rounds wanted
+ *             @unsigned f@ = various other flags
+ *             @const void *buf@ = pointer to key material
+ *             @size_t sz@ = size of key material in bytes
+ *
+ * Returns:    ---
+ *
+ * Use:                Initializes an SAFER expanded key.  A default number of
+ *             rounds is chosen, based on the key length.
+ */
+
+#define SAFER_SK 1u
+
+extern void safer_setup(safer_ctx */*k*/, unsigned /*r*/, unsigned /*f*/,
+                       const void */*buf*/, size_t /*sz*/);
+
+/* --- @safer_init@, @safersk_init@ --- *
+ *
+ * Arguments:  @safer_ctx *k@ = pointer to context to initialize
+ *             @const void *buf@ = pointer to key material
+ *             @size_t sz@ = size of key material in bytes
+ *
+ * Returns:    ---
+ *
+ * Use:                Initializes an SAFER expanded key.  A default number of
+ *             rounds is chosen, based on the key length.
+ */
+
+extern void safer_init(safer_ctx */*k*/,
+                      const void */*buf*/, size_t /*sz*/);
+extern void safersk_init(safer_ctx */*k*/,
+                        const void */*buf*/, size_t /*sz*/);
+
+/* --- @safer_eblk@, @safer_dblk@ --- *
+ *
+ * Arguments:  @const safer_ctx *k@ = pointer to SAFER context
+ *             @const uint32 s[2]@ = pointer to source block
+ *             @const uint32 d[2]@ = pointer to destination block
+ *
+ * Returns:    ---
+ *
+ * Use:                Low-level block encryption and decryption.
+ */
+
+extern void safer_eblk(const safer_ctx */*k*/,
+                      const uint32 */*s*/, uint32 */*dst*/);
+extern void safer_dblk(const safer_ctx */*k*/,
+                      const uint32 */*s*/, uint32 */*dst*/);
+
+#define safersk_eblk safer_eblk
+#define safersk_dblk safer_dblk
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif