ZeroTierOne/attic/historic/anode/libanode/aes_digest.c
2017-05-04 10:42:22 -07:00

86 lines
3.4 KiB
C

/* libanode: the Anode C reference implementation
* Copyright (C) 2009-2010 Adam Ierymenko <adam.ierymenko@gmail.com>
*
* 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/>. */
#include "anode.h"
#include "impl/aes.h"
#include "impl/misc.h"
#include "impl/types.h"
void Anode_aes_digest(const void *const message,unsigned long message_len,void *const hash)
{
unsigned char previous_digest[16];
unsigned char digest[16];
unsigned char block[32];
const unsigned char *in = (const unsigned char *)message;
const unsigned char *end = in + message_len;
unsigned long block_counter;
AnodeAesExpandedKey expkey;
((uint64_t *)digest)[0] = 0ULL;
((uint64_t *)digest)[1] = 0ULL;
((uint64_t *)block)[0] = 0ULL;
((uint64_t *)block)[1] = 0ULL;
((uint64_t *)block)[2] = 0ULL;
((uint64_t *)block)[3] = 0ULL;
/* Davis-Meyer hash function built from block cipher */
block_counter = 0;
while (in != end) {
block[block_counter++] = *(in++);
if (block_counter == 32) {
block_counter = 0;
((uint64_t *)previous_digest)[0] = ((uint64_t *)digest)[0];
((uint64_t *)previous_digest)[1] = ((uint64_t *)digest)[1];
Anode_aes256_expand_key(block,&expkey);
Anode_aes256_encrypt(&expkey,digest,digest);
((uint64_t *)digest)[0] ^= ((uint64_t *)previous_digest)[0];
((uint64_t *)digest)[1] ^= ((uint64_t *)previous_digest)[1];
}
}
/* Davis-Meyer end marker */
block[block_counter++] = 0x80;
while (block_counter != 32) block[block_counter++] = 0;
((uint64_t *)previous_digest)[0] = ((uint64_t *)digest)[0];
((uint64_t *)previous_digest)[1] = ((uint64_t *)digest)[1];
Anode_aes256_expand_key(block,&expkey);
Anode_aes256_encrypt(&expkey,digest,digest);
((uint64_t *)digest)[0] ^= ((uint64_t *)previous_digest)[0];
((uint64_t *)digest)[1] ^= ((uint64_t *)previous_digest)[1];
/* Merkle-Damgård length padding */
((uint64_t *)block)[0] = 0ULL;
if (sizeof(message_len) >= 8) { /* 32/64 bit? this will get optimized out */
block[8] = (uint8_t)((uint64_t)message_len >> 56);
block[9] = (uint8_t)((uint64_t)message_len >> 48);
block[10] = (uint8_t)((uint64_t)message_len >> 40);
block[11] = (uint8_t)((uint64_t)message_len >> 32);
} else ((uint32_t *)block)[2] = 0;
block[12] = (uint8_t)(message_len >> 24);
block[13] = (uint8_t)(message_len >> 16);
block[14] = (uint8_t)(message_len >> 8);
block[15] = (uint8_t)message_len;
((uint64_t *)previous_digest)[0] = ((uint64_t *)digest)[0];
((uint64_t *)previous_digest)[1] = ((uint64_t *)digest)[1];
Anode_aes256_expand_key(block,&expkey);
Anode_aes256_encrypt(&expkey,digest,digest);
((uint64_t *)digest)[0] ^= ((uint64_t *)previous_digest)[0];
((uint64_t *)digest)[1] ^= ((uint64_t *)previous_digest)[1];
((uint64_t *)hash)[0] = ((uint64_t *)digest)[0];
((uint64_t *)hash)[1] = ((uint64_t *)digest)[1];
}