cleaning up iclass.c and optimized_cipher.c
[proxmark3-svn] / armsrc / optimized_cipher.h
CommitLineData
298e1a2d 1/*****************************************************************************
2 * WARNING
3 *
4 * THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY.
5 *
6 * USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL
7 * PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL,
8 * AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES.
9 *
10 * THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS.
11 *
12 *****************************************************************************
13 *
14 * This file is part of loclass. It is a reconstructon of the cipher engine
15 * used in iClass, and RFID techology.
16 *
17 * The implementation is based on the work performed by
18 * Flavio D. Garcia, Gerhard de Koning Gans, Roel Verdult and
19 * Milosch Meriac in the paper "Dismantling IClass".
20 *
21 * Copyright (C) 2014 Martin Holst Swende
22 *
23 * This is free software: you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License version 2 as published
25 * by the Free Software Foundation, or, at your option, any later version.
26 *
27 * This file is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with loclass. If not, see <http://www.gnu.org/licenses/>.
34 *
35 *
36 ****************************************************************************/
37
17505ce2 38#ifndef OPTIMIZED_CIPHER_H__
39#define OPTIMIZED_CIPHER_H__
40
c99dc845 41#include <stdint.h>
61fe9073
MHS
42
43/**
44* Definition 1 (Cipher state). A cipher state of iClass s is an element of F 40/2
45* consisting of the following four components:
17505ce2 46* 1. the left register l = (l 0 . . . l 7 ) ∈ F 8/2 ;
47* 2. the right register r = (r 0 . . . r 7 ) ∈ F 8/2 ;
48* 3. the top register t = (t 0 . . . t 15 ) ∈ F 16/2 .
49* 4. the bottom register b = (b 0 . . . b 7 ) ∈ F 8/2 .
61fe9073
MHS
50**/
51typedef struct {
52 uint8_t l;
53 uint8_t r;
54 uint8_t b;
55 uint16_t t;
56} State;
57
58/** The reader MAC is MAC(key, CC * NR )
59 **/
60void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);
17505ce2 61
61fe9073
MHS
62/**
63 * The tag MAC is MAC(key, CC * NR * 32x0))
64 */
65void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);
66
67/**
68 * The tag MAC can be divided (both can, but no point in dividing the reader mac) into
69 * two functions, since the first 8 bytes are known, we can pre-calculate the state
70 * reached after feeding CC to the cipher.
71 * @param cc_p
72 * @param div_key_p
73 * @return the cipher state
74 */
75State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);
17505ce2 76
61fe9073
MHS
77/**
78 * The second part of the tag MAC calculation, since the CC is already calculated into the state,
79 * this function is fed only the NR, and internally feeds the remaining 32 0-bits to generate the tag
80 * MAC response.
81 * @param _init - precalculated cipher state
82 * @param nr - the reader challenge
83 * @param mac - where to store the MAC
84 * @param div_key_p - the key to use
85 */
17505ce2 86void opt_doTagMAC_2(State _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p);
61fe9073 87
17505ce2 88#endif // OPTIMIZED_CIPHER_H__
Impressum, Datenschutz