Rearrange the file tree.

[u/mdw/catacomb] / symm / rc5.h

diff --git a/symm/rc5.h b/symm/rc5.h
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+/* -*-c-*-
+ *
+ * The RC5-32/12 block cipher
+ *
+ * (c) 1999 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 RC5 block cipher -------------------------------------*
+ *
+ * RC5 was designed by Ron Rivest as a test vehicle for the use of data-
+ * dependent rotations in cryptographic transformations.  The algorithm is
+ * covered by a patent held by RSA Security Inc. (US Patent# 5,724,428).
+ * It's vulnerable to some clever differential attacks, which can break it in
+ * about %$2^{44}$% chosen plaintexts.  I don't recommend the use of this
+ * cipher.
+ */
+
+#ifndef CATACOMB_RC5_H
+#define CATACOMB_RC5_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/bits.h>
+
+/*----- Magic numbers -----------------------------------------------------*/
+
+#define RC5_ROUNDS 12
+#define RC5_KEYSZ 10
+#define RC5_BLKSZ 8
+#define RC5_CLASS (N, L, 64)
+
+extern const octet rc5_keysz[];
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct rc5_ctx {
+  uint32 s[2 * (RC5_ROUNDS + 1)];
+} rc5_ctx;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @rc5_init@ --- *
+ *
+ * Arguments:  @rc5_ctx *k@ = pointer to a key block
+ *             @const void *sbuf@ = pointer to key material
+ *             @size_t sz@ = size of the key material
+ *
+ * Returns:    ---
+ *
+ * Use:                Initializes an RC5 key block.
+ */
+
+extern void rc5_init(rc5_ctx */*k*/, const void */*sbuf*/, size_t /*sz*/);
+
+/* --- @rc5_eblk@, @rc5_dblk@ --- *
+ *
+ * Arguments:  @const rc5_ctx *k@ = pointer to RC5 context block
+ *             @const uint32 s[2]@ = pointer to source block
+ *             @uint32 *d[2]@ = pointer to destination block
+ *
+ * Returns:    ---
+ *
+ * Use:                Low level block encryption and decryption.
+ */
+
+extern void rc5_eblk(const rc5_ctx */*k*/,
+                    const uint32 */*s*/, uint32 */*d*/);
+extern void rc5_dblk(const rc5_ctx */*k*/,
+                    const uint32 */*s*/, uint32 */*d*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif