Rearrange the file tree.

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

diff --git a/symm/serpent.h b/symm/serpent.h
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+/* -*-c-*-
+ *
+ * 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.
+ */
+
+/*----- Notes on the Serpent block cipher ---------------------------------*
+ *
+ * Serpent was designed and proposed for the AES contest by Ross Anderson,
+ * Eli Biham and Lars Knudsen.  It's not particularly quick, but is
+ * stunningly secure.  The best differential and linear attacks are
+ * speculated to require %$2^{256}$% texts (it's a 128-bit block cipher).
+ * The designers originally intended to file a patent, but failed to persue
+ * it.  Use of the algorithm is completely unencumbered.
+ */
+
+#ifndef CATACOMB_SERPENT_H
+#define CATACOMB_SERPENT_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+/*----- Magic numbers -----------------------------------------------------*/
+
+#define SERPENT_BLKSZ 16
+#define SERPENT_KEYSZ 32
+#define SERPENT_CLASS (N, L, 128)
+
+extern const octet serpent_keysz[];
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct serpent_ctx {
+  uint32 k[4 * 33];
+} serpent_ctx;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @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).
+ */
+
+extern void serpent_init(serpent_ctx */*k*/,
+                        const void */*buf*/, size_t /*sz*/);
+
+/* --- @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.
+ */
+
+extern void serpent_eblk(const serpent_ctx */*k*/,
+                        const uint32 */*s*/, uint32 */*d*/);
+extern void serpent_dblk(const serpent_ctx */*k*/,
+                        const uint32 */*s*/, uint32 */*d*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif