proxmark3/armsrc/crypto1.c
Merlokbr@gmail.com 20f9a2a1d5 1. Mifare read block command
2. Mifare read sector (via 1)
3. Mifare write block
4. fixed several bugs in iso 14443 select
added
Issue 23
Issue 26
2011-05-26 12:55:15 +00:00

95 lines
2.5 KiB
C

/* crypto1.c
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 2
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, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, US
Copyright (C) 2008-2008 bla <blapost@gmail.com>
*/
#include "crapto1.h"
#include <stdlib.h>
#define SWAPENDIAN(x)\
(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
void crypto1_create(struct Crypto1State *s, uint64_t key)
{
// struct Crypto1State *s = malloc(sizeof(*s));
int i;
for(i = 47;s && i > 0; i -= 2) {
s->odd = s->odd << 1 | BIT(key, (i - 1) ^ 7);
s->even = s->even << 1 | BIT(key, i ^ 7);
}
return;
}
void crypto1_destroy(struct Crypto1State *state)
{
// free(state);
state->odd = 0;
state->even = 0;
}
void crypto1_get_lfsr(struct Crypto1State *state, uint64_t *lfsr)
{
int i;
for(*lfsr = 0, i = 23; i >= 0; --i) {
*lfsr = *lfsr << 1 | BIT(state->odd, i ^ 3);
*lfsr = *lfsr << 1 | BIT(state->even, i ^ 3);
}
}
uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
{
uint32_t feedin;
uint8_t ret = filter(s->odd);
feedin = ret & !!is_encrypted;
feedin ^= !!in;
feedin ^= LF_POLY_ODD & s->odd;
feedin ^= LF_POLY_EVEN & s->even;
s->even = s->even << 1 | parity(feedin);
s->odd ^= (s->odd ^= s->even, s->even ^= s->odd);
return ret;
}
uint8_t crypto1_byte(struct Crypto1State *s, uint8_t in, int is_encrypted)
{
uint8_t i, ret = 0;
for (i = 0; i < 8; ++i)
ret |= crypto1_bit(s, BIT(in, i), is_encrypted) << i;
return ret;
}
uint32_t crypto1_word(struct Crypto1State *s, uint32_t in, int is_encrypted)
{
uint32_t i, ret = 0;
for (i = 0; i < 32; ++i)
ret |= crypto1_bit(s, BEBIT(in, i), is_encrypted) << (i ^ 24);
return ret;
}
/* prng_successor
* helper used to obscure the keystream during authentication
*/
uint32_t prng_successor(uint32_t x, uint32_t n)
{
SWAPENDIAN(x);
while(n--)
x = x >> 1 | (x >> 16 ^ x >> 18 ^ x >> 19 ^ x >> 21) << 31;
return SWAPENDIAN(x);
}