added arcfour/rc4

[arm-crypto-lib.git] / arcfour / arcfour.h

diff --git a/arcfour/arcfour.h b/arcfour/arcfour.h
new file mode 100644 (file)
index 0000000..bffd40b
--- /dev/null
+++ b/arcfour/arcfour.h
@@ -0,0 +1,91 @@
+/* arcfour.h */
+/*
+    This file is part of the ARM-Crypto-Lib.
+    Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * File:       arcfour.h
+ * Author:     Daniel Otte
+ * Date:       2006-06-07
+ * License: GPLv3+
+ * Description: Implementation of the ARCFOUR (RC4 compatible) stream cipher algorithm.
+ */
+
+/**
+ * \file       arcfour.h
+ * \author     Daniel Otte
+ * \date       2006-06-07
+ * \license GPLv3+
+ * \brief Implementation of the ARCFOUR (RC4 compatible) stream cipher algorithm.
+ *
+ * This header file defines the interface of the ARCFOUR cipher implementation.
+ *
+ * This implementation aims to be compatible with the ARCFOUR description
+ * available at
+ * http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt
+ */
+
+
+#ifndef ARCFOUR_H_
+#define ARCFOUR_H_
+
+#include <stdint.h>
+
+/** \typedef arcfour_ctx_t
+ * \brief type for arcfour context
+ *
+ * A variable of this type may contain a complete ARCFOUR context.
+ * The context is used to store the state of the cipher and gets
+ * created by the arcfour_init(arcfour_ctx_t *c, uint8_t *key, uint8_t length_B)
+ * function. The context is of the fixed size of 258 bytes
+ */
+
+/** \struct arcfour_ctx_st
+ * \brief base for ::arcfour_ctx_t
+ *
+ * The struct holds the two indices and the S-Box
+ */
+typedef struct arcfour_ctx_st {
+       uint8_t i,j;
+       uint8_t s[256];
+} arcfour_ctx_t;
+
+
+/** \fn void arcfour_init(const void *key, uint8_t length_B, arcfour_ctx_t *ctx)
+ * \brief setup a context with a key
+ *
+ * This function sets up a ::arcfour_ctx_t context using
+ * the supplied key of the given length.
+ * \param ctx pointer to the context
+ * \param key pointer to the key
+ * \param length_b length of the key in bits
+ */
+
+void arcfour_init(const void *key, uint16_t length_b, arcfour_ctx_t *ctx);
+
+/** \fn uint8_t arcfour_gen(arcfour_ctx_t *ctx)
+ * \brief generates a byte of keystream
+ *
+ * This function generates the next byte of keystream
+ * from the supplied ::arcfour_ctx_t context which is updated accordingly
+ *
+ * \param ctx pointer to the context
+ * \return byte of keystream
+ */
+
+uint8_t arcfour_gen(arcfour_ctx_t *ctx);
+
+#endif