+++ /dev/null
-/* 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)
-
-struct Crypto1State * crypto1_create(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 s;
-}
-void crypto1_destroy(struct Crypto1State *state)
-{
- free(state);
-}
-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;
- uint32_t tmp;
- 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);
-
- tmp = s->odd;
- s->odd = s->even;
- s->even = tmp;
-
- 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 < 4; ++i, in <<= 8)
- ret = ret << 8 | crypto1_byte(s, in >> 24, is_encrypted);
-
- 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);
-}