mirror of
https://github.com/markqvist/OpenModem.git
synced 2024-12-18 04:14:20 -05:00
130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
/* hmac-md5.c */
|
|
/*
|
|
This file is part of the AVR-Crypto-Lib.
|
|
Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
|
|
|
|
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/>.
|
|
*/
|
|
/**
|
|
*
|
|
* implementation of HMAC as described in RFC2104
|
|
* Author: Daniel Otte
|
|
* email: bg@nerilex.org
|
|
* License: GPLv3 or later
|
|
**/
|
|
|
|
/*
|
|
* hmac = hash ( k^opad , hash( k^ipad , msg))
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include "MD5.h"
|
|
#include "HMAC_MD5.h"
|
|
|
|
#define IPAD 0x36
|
|
#define OPAD 0x5C
|
|
|
|
#ifndef HMAC_SHORTONLY
|
|
|
|
void hmac_md5_init(hmac_md5_ctx_t *s, void *key, uint16_t keylength_b){
|
|
uint8_t buffer[MD5_BLOCK_BYTES];
|
|
uint8_t i;
|
|
|
|
memset(buffer, 0, MD5_BLOCK_BYTES);
|
|
if (keylength_b > MD5_BLOCK_BITS){
|
|
md5((void*)buffer, key, keylength_b);
|
|
} else {
|
|
memcpy(buffer, key, (keylength_b+7)/8);
|
|
}
|
|
|
|
for (i=0; i<MD5_BLOCK_BYTES; ++i){
|
|
buffer[i] ^= IPAD;
|
|
}
|
|
md5_init(&(s->a));
|
|
md5_nextBlock(&(s->a), buffer);
|
|
|
|
for (i=0; i<MD5_BLOCK_BYTES; ++i){
|
|
buffer[i] ^= IPAD^OPAD;
|
|
}
|
|
md5_init(&(s->b));
|
|
md5_nextBlock(&(s->b), buffer);
|
|
|
|
#if defined SECURE_WIPE_BUFFER
|
|
memset(buffer, 0, MD5_BLOCK_BYTES);
|
|
#endif
|
|
}
|
|
|
|
void hmac_md5_nextBlock(hmac_md5_ctx_t *s, const void *block){
|
|
md5_nextBlock(&(s->a), block);
|
|
}
|
|
|
|
void hmac_md5_lastBlock(hmac_md5_ctx_t *s, const void *block, uint16_t length_b){
|
|
md5_lastBlock(&(s->a), block, length_b);
|
|
}
|
|
|
|
void hmac_md5_final(void *dest, hmac_md5_ctx_t *s){
|
|
md5_ctx2hash((md5_hash_t*)dest, &(s->a));
|
|
md5_lastBlock(&(s->b), dest, MD5_HASH_BITS);
|
|
md5_ctx2hash((md5_hash_t*)dest, &(s->b));
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
void hmac_md5_nextBlock()
|
|
void hmac_md5_lastBlock()
|
|
*/
|
|
|
|
/*
|
|
* keylength in bits!
|
|
* message length in bits!
|
|
*/
|
|
void hmac_md5(void *dest, void *key, uint16_t keylength_b, void *msg, uint32_t msglength_b){ /* a one-shot*/
|
|
md5_ctx_t s;
|
|
uint8_t i;
|
|
uint8_t buffer[MD5_BLOCK_BYTES];
|
|
|
|
memset(buffer, 0, MD5_BLOCK_BYTES);
|
|
|
|
/* if key is larger than a block we have to hash it*/
|
|
if (keylength_b > MD5_BLOCK_BITS){
|
|
md5((void*)buffer, key, keylength_b);
|
|
} else {
|
|
memcpy(buffer, key, (keylength_b+7)/8);
|
|
}
|
|
|
|
for (i=0; i<MD5_BLOCK_BYTES; ++i){
|
|
buffer[i] ^= IPAD;
|
|
}
|
|
md5_init(&s);
|
|
md5_nextBlock(&s, buffer);
|
|
while (msglength_b >= MD5_BLOCK_BITS){
|
|
md5_nextBlock(&s, msg);
|
|
msg = (uint8_t*)msg + MD5_BLOCK_BYTES;
|
|
msglength_b -= MD5_BLOCK_BITS;
|
|
}
|
|
md5_lastBlock(&s, msg, msglength_b);
|
|
/* since buffer still contains key xor ipad we can do ... */
|
|
for (i=0; i<MD5_BLOCK_BYTES; ++i){
|
|
buffer[i] ^= IPAD ^ OPAD;
|
|
}
|
|
md5_ctx2hash(dest, &s); /* save inner hash temporary to dest */
|
|
md5_init(&s);
|
|
md5_nextBlock(&s, buffer);
|
|
md5_lastBlock(&s, dest, MD5_HASH_BITS);
|
|
md5_ctx2hash(dest, &s);
|
|
}
|
|
|