]> git.zerfleddert.de Git - proxmark3-svn/blame - armsrc/optimized_cipher.h
chg: unused .. but not for long
[proxmark3-svn] / armsrc / optimized_cipher.h
CommitLineData
c99dc845
MHS
1#ifndef OPTIMIZED_CIPHER_H
2#define OPTIMIZED_CIPHER_H
5e1de05a 3
c99dc845 4#include <stdint.h>
57778a46 5#include <stddef.h>
5e1de05a 6#include <stdbool.h>
61fe9073
MHS
7
8/**
9* Definition 1 (Cipher state). A cipher state of iClass s is an element of F 40/2
10* consisting of the following four components:
11* 1. the left register l = (l 0 . . . l 7 ) ∈ F 8/2 ;
12* 2. the right register r = (r 0 . . . r 7 ) ∈ F 8/2 ;
13* 3. the top register t = (t 0 . . . t 15 ) ∈ F 16/2 .
14* 4. the bottom register b = (b 0 . . . b 7 ) ∈ F 8/2 .
15**/
16typedef struct {
17 uint8_t l;
18 uint8_t r;
19 uint8_t b;
20 uint16_t t;
21} State;
22
23/** The reader MAC is MAC(key, CC * NR )
24 **/
25void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);
26/**
27 * The tag MAC is MAC(key, CC * NR * 32x0))
28 */
29void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);
30
31/**
32 * The tag MAC can be divided (both can, but no point in dividing the reader mac) into
33 * two functions, since the first 8 bytes are known, we can pre-calculate the state
34 * reached after feeding CC to the cipher.
35 * @param cc_p
36 * @param div_key_p
37 * @return the cipher state
38 */
39State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);
40/**
41 * The second part of the tag MAC calculation, since the CC is already calculated into the state,
42 * this function is fed only the NR, and internally feeds the remaining 32 0-bits to generate the tag
43 * MAC response.
44 * @param _init - precalculated cipher state
45 * @param nr - the reader challenge
46 * @param mac - where to store the MAC
47 * @param div_key_p - the key to use
48 */
49void opt_doTagMAC_2(State _init, uint8_t* nr, uint8_t mac[4], const uint8_t* div_key_p);
50
c99dc845 51#endif // OPTIMIZED_CIPHER_H
Impressum, Datenschutz