+/* sha256.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: sha256.c
- * Author: Daniel Otte
- * Date: 16.05.2006
- * License: GPL
+ * \file sha256.c
+ * \author Daniel Otte
+ * \date 16.05.2006
+ *
+ * \par License:
+ * GPL
+ *
+ * \brief SHA-256 implementation.
+ *
*
*/
#endif
+/*************************************************************************/
+
uint32_t sha256_init_vector[]={
0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19 };
+
+/*************************************************************************/
+
+/**
+ * \brief \c sh256_init initialises a sha256 context for hashing.
+ * \c sh256_init c initialises the given sha256 context for hashing
+ * @param state pointer to a sha256 context
+ * @return none
+ */
void sha256_init(sha256_ctx_t *state){
state->length=0;
memcpy(state->h, sha256_init_vector, 8*4);
}
-/*
+/*************************************************************************/
+
+/**
* rotate x right by n positions
*/
-
uint32_t rotr32( uint32_t x, uint8_t n){
return ((x>>n) | (x<<(32-n)));
}
+
+/*************************************************************************/
+
// #define CHANGE_ENDIAN32(x) (((x)<<24) | ((x)>>24) | (((x)& 0x0000ff00)<<8) | (((x)& 0x00ff0000)>>8))
uint32_t change_endian32(uint32_t x){
}
+/*************************************************************************/
+
/* sha256 functions as macros for speed and size, cause they are called only once */
#define CH(x,y,z) (((x)&(y)) ^ ((~(x))&(z)))
};
+/*************************************************************************/
+
/**
* block must be, 512, Bit = 64, Byte, long !!!
*/
-void sha256_nextBlock (sha256_ctx_t *state, void* block){
+void sha256_nextBlock (sha256_ctx_t *state, const void* block){
uint32_t w[64]; /* this is 256, byte, large, */
uint8_t i;
uint32_t a[8],t1,t2;
state->length += 512;
}
-/*
- * length is the length of only THIS block in BITS not in bytes!
+
+/*************************************************************************/
+
+/**
+ * \brief function to process the last block being hashed
+ * @param state Pointer to the context in which this block should be processed.
+ * @param block Pointer to the message wich should be hashed.
+ * @param length is the length of only THIS block in BITS not in bytes!
* bits are big endian, meaning high bits come first.
* if you have a message with bits at the end, the byte must be padded with zeros
- * */
-void sha256_lastBlock(sha256_ctx_t *state, void* block, uint16_t length){
+ */
+void sha256_lastBlock(sha256_ctx_t *state, const void* block, uint16_t length){
uint8_t lb[SHA256_BLOCK_BITS/8]; /* local block */
state->length += length;
memcpy (&(lb[0]), block, length/8);
}
+/*************************************************************************/
+
/*
* length in bits!
*/
-
-void sha256(sha256_hash_t *dest, void* msg, uint32_t length){ /* length could be choosen longer but this is for ?C */
+void sha256(sha256_hash_t *dest, const void* msg, uint32_t length){ /* length could be choosen longer but this is for µC */
sha256_ctx_t s;
sha256_init(&s);
while(length >= SHA256_BLOCK_BITS){
sha256_nextBlock(&s, msg);
- msg += SHA256_BLOCK_BITS/8;
+ msg = (uint8_t*)msg + SHA256_BLOCK_BITS/8;
length -= SHA256_BLOCK_BITS;
}
sha256_lastBlock(&s, msg, length);
+/*************************************************************************/
-void sha256_ctx2hash(sha256_hash_t *dest, sha256_ctx_t *state){
+void sha256_ctx2hash(sha256_hash_t *dest, const sha256_ctx_t *state){
#if defined LITTLE_ENDIAN
uint8_t i;
for(i=0; i<8; ++i){