git.zerfleddert.de Git - proxmark3-svn/blob

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 *

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 ****************************************************************************/

38 #ifndef OPTIMIZED_CIPHER_H

39 #define OPTIMIZED_CIPHER_H

40 #include <stdint.h>

42 /**

43 * Definition 1 (Cipher state). A cipher state of iClass s is an element of F 40/2

44 * consisting of the following four components:

45 * 1. the left register l = (l 0 . . . l 7 ) ∈ F 8/2 ;

46 * 2. the right register r = (r 0 . . . r 7 ) ∈ F 8/2 ;

47 * 3. the top register t = (t 0 . . . t 15 ) ∈ F 16/2 .

48 * 4. the bottom register b = (b 0 . . . b 7 ) ∈ F 8/2 .

49 **/

50 typedef struct {

51 uint8_t l;

52 uint8_t r;

53 uint8_t b;

54 uint16_t t;

55 } State;

57 /** The reader MAC is MAC(key, CC * NR )

58 **/

 void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);

60 /**

61 * The tag MAC is MAC(key, CC * NR * 32x0))

62 */

 void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);

65 /**

66 * The tag MAC can be divided (both can, but no point in dividing the reader mac) into

67 * two functions, since the first 8 bytes are known, we can pre-calculate the state

68 * reached after feeding CC to the cipher.

69 * @param cc_p

70 * @param div_key_p

71 * @return the cipher state

72 */

 State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);

74 /**

75 * The second part of the tag MAC calculation, since the CC is already calculated into the state,

76 * this function is fed only the NR, and internally feeds the remaining 32 0-bits to generate the tag

77 * MAC response.

78 * @param _init - precalculated cipher state

79 * @param nr - the reader challenge

80 * @param mac - where to store the MAC

81 * @param div_key_p - the key to use

82 */

 void opt_doTagMAC_2(State _init, uint8_t* nr, uint8_t mac[4], const uint8_t* div_key_p);

85 #endif // OPTIMIZED_CIPHER_H