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

73 lines
2.2 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 "aes.h"
void Anode_cmac_aes256(
const AnodeAesExpandedKey *expkey,
const unsigned char *restrict data,
unsigned long data_len,
unsigned char *restrict mac)
{
unsigned char cbc[16];
unsigned char pad[16];
const unsigned char *restrict pos = data;
unsigned long i;
unsigned long remaining = data_len;
unsigned char c;
((uint64_t *)((void *)cbc))[0] = 0ULL;
((uint64_t *)((void *)cbc))[1] = 0ULL;
while (remaining >= 16) {
((uint64_t *)((void *)cbc))[0] ^= ((uint64_t *)((void *)pos))[0];
((uint64_t *)((void *)cbc))[1] ^= ((uint64_t *)((void *)pos))[1];
pos += 16;
if (remaining > 16)
Anode_aes256_encrypt(expkey,cbc,cbc);
remaining -= 16;
}
((uint64_t *)((void *)pad))[0] = 0ULL;
((uint64_t *)((void *)pad))[1] = 0ULL;
Anode_aes256_encrypt(expkey,pad,pad);
c = pad[0] & 0x80;
for(i=0;i<15;++i)
pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
pad[15] <<= 1;
if (c)
pad[15] ^= 0x87;
if (remaining||(!data_len)) {
for(i=0;i<remaining;++i)
cbc[i] ^= *(pos++);
cbc[remaining] ^= 0x80;
c = pad[0] & 0x80;
for(i=0;i<15;++i)
pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
pad[15] <<= 1;
if (c)
pad[15] ^= 0x87;
}
((uint64_t *)((void *)mac))[0] = ((uint64_t *)((void *)pad))[0] ^ ((uint64_t *)((void *)cbc))[0];
((uint64_t *)((void *)mac))[1] = ((uint64_t *)((void *)pad))[1] ^ ((uint64_t *)((void *)cbc))[1];
Anode_aes256_encrypt(expkey,mac,mac);
}