/* shabea.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.
+ * This file is part of AnonAccess, an access system which can be used
+ * to open door or doing other things with an anonymity featured
+ * account managment.
+ * Copyright (C) 2006, 2007, 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/>.
+ */
- 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 shabea.c
* \author Daniel Otte
#include "sha256.h"
#include "config.h"
-#include "uart.h"
-#include "debug.h"
#include "memxor.h"
* SHABEA256-n
*/
-#define BLOCKSIZE 256
-#define BLOCKSIZEB (BLOCKSIZE/8)
-#define HALFSIZEB (BLOCKSIZEB/2)
-#define HALFSIZE (BLOCKSIZE/2)
+#define SHABEA_BLOCKSIZE 256
+#define SHABEA_BLOCKSIZEB (SHABEA_BLOCKSIZE/8)
+#define SHABEA_HALFSIZEB (SHABEA_BLOCKSIZEB/2)
+#define SHABEA_HALFSIZE (SHABEA_BLOCKSIZE/2)
#define L ((uint8_t*)block+ 0)
#define R ((uint8_t*)block+16)
void shabea256(void * block, void * key, uint16_t keysize_b, uint8_t enc, uint8_t rounds){
- int8_t r; /**/
- uint8_t tb[HALFSIZEB+2+(keysize_b+7)/8]; /**/
+ uint8_t r; /**/
+ uint8_t tb[SHABEA_HALFSIZEB+2+(keysize_b+7)/8]; /**/
uint16_t kbs; /* bytes used for the key / temporary block */
sha256_hash_t hash;
-
- r = (enc?0:(rounds-1));
+ uint8_t termcond;
+ int8_t dir;
+ if(enc){
+ r = 0;
+ termcond = rounds-1;
+ dir = 1;
+ } else {
+ r = rounds-1;
+ termcond = 0;
+ dir = -1;
+ }
kbs = (keysize_b+7)/8;
- memcpy(tb+HALFSIZEB+2, key, kbs); /* copy key to temporary block */
- tb[HALFSIZEB+0] = 0; /* set round counter high value to zero */
+ memcpy(tb+SHABEA_HALFSIZEB+2, key, kbs); /* copy key to temporary block */
+ tb[SHABEA_HALFSIZEB+0] = 0; /* set round counter high value to zero */
- for(;r!=(enc?(rounds):-1);enc?r++:r--){ /* enc: 0..(rounds-1) ; !enc: (rounds-1)..0 */
- memcpy(tb, R, HALFSIZEB); /* copy right half into tb */
- tb[HALFSIZEB+1] = r;
- sha256(&hash, tb, HALFSIZE+16+keysize_b);
- if(!(r==(enc?(rounds-1):0))){
+ for(;;r+=dir){ /* enc: 0..(rounds-1) ; !enc: (rounds-1)..0 */
+ memcpy(tb, R, SHABEA_HALFSIZEB); /* copy right half into tb */
+ tb[SHABEA_HALFSIZEB+1] = r;
+ sha256(&hash, tb, SHABEA_HALFSIZE+16+keysize_b);
+ if(r!=termcond){
/* swap */
- memxor(hash, L, HALFSIZEB);
- memcpy(L, R, HALFSIZEB);
- memcpy(R, hash, HALFSIZEB);
+ memxor(hash, L, SHABEA_HALFSIZEB);
+ memcpy(L, R, SHABEA_HALFSIZEB);
+ memcpy(R, hash, SHABEA_HALFSIZEB);
} else {
+ /* last round */
/* no swap */
- memxor(L, hash, HALFSIZEB);
+ memxor(L, hash, SHABEA_HALFSIZEB);
+ return;
}
}
}
/* shabea.h */
/*
- 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 file is part of AnonAccess, an access system which can be used
+ * to open door or doing other things with an anonymity featured
+ * account managment.
+ * Copyright (C) 2006, 2007, 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/>.
+ */
- 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 shabea.h
* \author Daniel Otte
* \date 2007-06-07
* \brief SHABEA - a SHA Based Encryption Algorithm declarations
- * \license GPLv3 or later
+ * \par License
+ * GPL
*
* SHABEAn-r where n is the blocksize and r the number of round used
*
#ifndef SHABEA_H_
#define SHABEA_H_
-/** \fn void shabea256(void * block, const void * key, uint16_t keysize_b, uint8_t enc, uint8_t rounds);
- * \brief shabea256 encryption/decryption
- *
- * \param block pointer to a 256 bit (32 byte block) to en/decrypt
- * \param key pointer to the key material
- * \param keysize_b length of the key in bits
- * \param enc controls if encryption (1) or decryption (0) is done
- * \param rounds rounds to be done by the cipher (it is not recommended to use less then four rounds)
- */
-void shabea256(void * block, const void * key, uint16_t keysize_b,
- uint8_t enc, uint8_t rounds);
-
+void shabea256(void * block, void * key, uint16_t keysize_b, uint8_t enc, uint8_t rounds);
#endif /*SHABEA_H_*/
projects / avr-crypto-lib.git / commitdiff