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cvs.zerfleddert.de Git - proxmark3-svn/blob - armsrc/optimized_cipher.h
1 #ifndef OPTIMIZED_CIPHER_H
2 #define OPTIMIZED_CIPHER_H
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 .
23 /** The reader MAC is MAC(key, CC * NR )
25 void opt_doReaderMAC(uint8_t *cc_nr_p
, uint8_t *div_key_p
, uint8_t mac
[4]);
27 * The tag MAC is MAC(key, CC * NR * 32x0))
29 void opt_doTagMAC(uint8_t *cc_p
, const uint8_t *div_key_p
, uint8_t mac
[4]);
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.
37 * @return the cipher state
39 State
opt_doTagMAC_1(uint8_t *cc_p
, const uint8_t *div_key_p
);
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
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
49 void opt_doTagMAC_2(State _init
, uint8_t* nr
, uint8_t mac
[4], const uint8_t* div_key_p
);
51 #endif // OPTIMIZED_CIPHER_H