+/* cast5.c */
+/*
+ This file is part of the Crypto-avr-lib/microcrypt-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: cast5.c
- * Author: Daniel Otte
- * Date: 26.07.2006
- * License: GPL
- * Description: Implementation of the CAST5 (aka CAST-128) cipher algorithm as described in RFC 2144
+ * \file cast5.c
+ * \author Daniel Otte
+ * \email daniel.otte@rub.de
+ * \date 2006-07-26
+ * \par License:
+ * GPLv3 or later
+ * \brief Implementation of the CAST5 (aka CAST-128) cipher algorithm as described in RFC 2144
*
*/
- //pgm_read_dword
#include <stdint.h>
#include <string.h>
#include "cast5.h"
#include "config.h"
- #include "uart.h"
#include "debug.h"
#undef DEBUG
+ #ifdef DEBUG
+ #include "uart.h"
+ #endif
+
#include "cast5-sbox.h"
-
+/**
+ * \brief sets up round keys (context) for cast5 en/decryption.
+ * @param s Pointer to cast5 context.
+ * @param key Pointer to binary key.
+ * @param keylength length of keydata in bits.
+ */
void cast5_init(cast5_ctx_t* s, uint8_t* key, uint8_t keylength){
/* we migth return if the key is valid and if setup was sucessfull */
uint32_t x[4], z[4];
s->shortkey = (keylength<=80);
/* littel endian only! */
memset(&(x[0]), 0 ,16); /* set x to zero */
- memcpy(&(x[0]), key, keylength/8);
+ if(keylength > 128)
+ keylength=128;
+ memcpy(&(x[0]), key, (keylength+7)/8);
/* todo: merge a and b and compress the whole stuff */
return (((ia - ib) + ic) ^ id);
#else
- return (((pgm_read_dword(&s1[((uint8_t*)&t)[IA]] ) - pgm_read_dword(&s2[((uint8_t*)&t)[IB]] ))
- + pgm_read_dword(&s3[((uint8_t*)&t)[IC]] )) ^ pgm_read_dword(&s4[((uint8_t*)&t)[ID]]));
+ return (((pgm_read_dword(&s1[((uint8_t*)&t)[IA]])
+ - pgm_read_dword(&s2[((uint8_t*)&t)[IB]]) )
+ + pgm_read_dword(&s3[((uint8_t*)&t)[IC]]) )
+ ^ pgm_read_dword(&s4[((uint8_t*)&t)[ID]]) );
#endif
}
#endif
}
+/*************************************************************************/
-
+/**
+ * \brief encrypts a datablock with cast5
+ * @param s Pointer to cast5 roundkeys (context)
+ * @param block Pointer to datablock
+ */
void cast5_enc(cast5_ctx_t *s, void* block){
uint32_t l,r, x, y;
uint8_t i;
((uint32_t*)block)[1]=l;
}
+/*************************************************************************/
+/**
+ * \brief decrypts a datablock with cast5
+ * @param s Pointer to cast5 roundkeys (context)
+ * @param block Pointer to datablock
+ */
void cast5_dec(cast5_ctx_t *s, void* block){
uint32_t l,r, x, y;
int8_t i, rounds;