avr-crypto-lib/a51/A5_1.h

66 lines
1.6 KiB
C

/* A5_1.h */
/*
This file is part of the AVR-Crypto-Lib.
Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
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/>.
*/
/*
* File: A5_1.h
* Author: Daniel Otte
* Date: 24.06.2006
* License: GPL
* Description: Implementation of the A5/1 stream cipher algorithm, as used in GSM.
* ! Warning, this is weak crypto !
*
*/
#ifndef A5_1_H_
#define A5_1_H_
#include <stdint.h>
#define R1_LENGTH 19
#define R2_LENGTH 22
#define R3_LENGTH 23
#define R1_CLK 11
#define R2_CLK 12
#define R3_CLK 13
/* 3-Bit word parity lookup table (Byte)
* 0: 0
* 1: 1
* 2: 1
* 3: 0
* 4: 1
* 5: 0
* 6: 0
* 7: 1
* => 1001.0110 = 0x96
*
*/
#define PARITY_LOOKUP 0x96
typedef struct {
/* we are wasting one byte here but this allows a much faster implementation */
uint8_t r1[3], r2[3], r3[3]; /* the three regs, 19,22,23 bit in length */
} a5_1_ctx_t;
void a5_1_init(a5_1_ctx_t *c, void *key, uint8_t keylength_b, void *iv, uint8_t ivlength_b);
uint8_t a5_1_clock(a5_1_ctx_t *c);
uint8_t a5_1_gen(a5_1_ctx_t *c);
#endif