X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=arcfour.h;h=d332d7f8ed1f384f6368b4bfe2f1ae6caded66ad;hb=8f855d283a31a468ea014774c4723a8b77b81644;hp=030c014f69860455ea4ee2fac527e06100319543;hpb=96ebafd201c9e8441c7677577b24aa402c1defc6;p=avr-crypto-lib.git

diff --git a/arcfour.h b/arcfour.h
index 030c014..d332d7f 100644
--- a/arcfour.h
+++ b/arcfour.h
@@ -1,6 +1,6 @@
 /* arcfour.h */
 /*
-    This file is part of the Crypto-avr-lib/microcrypt-lib.
+    This file is part of the AVR-Crypto-Lib.
     Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
 
     This program is free software: you can redistribute it and/or modify
@@ -16,26 +16,76 @@
     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: GPL
+ * 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 struct {
+/** \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;
- 
 
-void arcfour_init(arcfour_ctx_t *c, uint8_t *key, uint8_t length);
-uint8_t arcfour_gen(arcfour_ctx_t *c);
+
+/** \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 bytes (between 1 and 255)
+ */
+
+void arcfour_init(const void *key, uint8_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