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1 | #ifndef _CRYPTO1_BS_H |
2 | #define _CRYPTO1_BS_H |
3 | #include <stdbool.h> |
4 | #include <stdint.h> |
5 | #include <stdio.h> |
6 | #include <string.h> |
7 | #include <stdlib.h> |
8 | #include <unistd.h> |
9 | |
10 | // bitslice type |
11 | // while AVX supports 256 bit vector floating point operations, we need integer operations for boolean logic |
12 | // same for AVX2 and 512 bit vectors |
13 | // using larger vectors works but seems to generate more register pressure |
14 | #if defined(__AVX2__) |
15 | #define MAX_BITSLICES 256 |
16 | #elif defined(__AVX__) |
17 | #define MAX_BITSLICES 128 |
18 | #elif defined(__SSE2__) |
19 | #define MAX_BITSLICES 128 |
20 | #else |
21 | #define MAX_BITSLICES 64 |
22 | #endif |
23 | |
24 | #define VECTOR_SIZE (MAX_BITSLICES/8) |
25 | typedef unsigned int __attribute__((aligned(VECTOR_SIZE))) __attribute__((vector_size(VECTOR_SIZE))) bitslice_value_t; |
26 | typedef union { |
27 | bitslice_value_t value; |
28 | uint64_t bytes64[MAX_BITSLICES/64]; |
29 | uint8_t bytes[MAX_BITSLICES/8]; |
30 | } bitslice_t; |
31 | |
32 | // filter function (f20) |
33 | // sourced from ``Wirelessly Pickpocketing a Mifare Classic Card'' by Flavio Garcia, Peter van Rossum, Roel Verdult and Ronny Wichers Schreur |
34 | #define f20a(a,b,c,d) (((a|b)^(a&d))^(c&((a^b)|d))) |
35 | #define f20b(a,b,c,d) (((a&b)|c)^((a^b)&(c|d))) |
36 | #define f20c(a,b,c,d,e) ((a|((b|e)&(d^e)))^((a^(b&d))&((c^d)|(b&e)))) |
37 | |
38 | #define crypto1_bs_f20(s) \ |
39 | f20c(f20a((s[47- 9].value), (s[47-11].value), (s[47-13].value), (s[47-15].value)), \ |
40 | f20b((s[47-17].value), (s[47-19].value), (s[47-21].value), (s[47-23].value)), \ |
41 | f20b((s[47-25].value), (s[47-27].value), (s[47-29].value), (s[47-31].value)), \ |
42 | f20a((s[47-33].value), (s[47-35].value), (s[47-37].value), (s[47-39].value)), \ |
43 | f20b((s[47-41].value), (s[47-43].value), (s[47-45].value), (s[47-47].value))) |
44 | |
45 | // bit indexing |
46 | #define get_bit(n, word) ((word >> (n)) & 1) |
47 | #define get_vector_bit(slice, value) get_bit(slice&0x3f, value.bytes64[slice>>6]) |
48 | |
49 | // constant ones/zeroes |
50 | bitslice_t bs_ones; |
51 | bitslice_t bs_zeroes; |
52 | |
53 | // size of crypto-1 state |
54 | #define STATE_SIZE 48 |
55 | // size of nonce to be decrypted |
56 | #define KEYSTREAM_SIZE 32 |
57 | // size of first uid^nonce byte to be rolled back to the initial key |
58 | #define ROLLBACK_SIZE 8 |
59 | // number of nonces required to test to cover entire 48-bit state |
60 | // I would have said it's 12... but bla goes with 100, so I do too |
21d359f6 |
61 | #define NONCE_TESTS 100 |
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62 | |
63 | // state pointer management |
64 | extern __thread bitslice_t states[KEYSTREAM_SIZE+STATE_SIZE]; |
65 | extern __thread bitslice_t * restrict state_p; |
66 | |
67 | // rewind to the point a0, at which KEYSTREAM_SIZE more bits can be generated |
68 | #define crypto1_bs_rewind_a0() (state_p = &states[KEYSTREAM_SIZE]) |
69 | |
70 | // bitsliced bytewise parity |
71 | #define bitsliced_byte_parity(n) (n[0].value ^ n[1].value ^ n[2].value ^ n[3].value ^ n[4].value ^ n[5].value ^ n[6].value ^ n[7].value) |
72 | |
73 | // 48-bit crypto-1 states are normally represented using 64-bit values |
74 | typedef union { |
75 | uint64_t value; |
76 | uint8_t bytes[8]; |
77 | } state_t; |
78 | |
79 | // endianness conversion |
80 | #define rev32(word) (((word & 0xff) << 24) | (((word >> 8) & 0xff) << 16) | (((word >> 16) & 0xff) << 8) | (((word >> 24) & 0xff))) |
81 | #define rev64(x) (rev32(x)<<32|(rev32((x>>32)))) |
82 | #define rev_state_t rev64 |
83 | |
84 | // crypto-1 functions |
85 | const bitslice_value_t crypto1_bs_bit(const bitslice_value_t input, const bool is_encrypted); |
86 | const bitslice_value_t crypto1_bs_lfsr_rollback(const bitslice_value_t input, const bool is_encrypted); |
87 | |
88 | // initialization functions |
89 | void crypto1_bs_init(); |
90 | |
91 | // conversion functions |
92 | void crypto1_bs_bitslice_value32(uint32_t value, bitslice_t bitsliced_value[], size_t bit_len); |
93 | void crypto1_bs_convert_states(bitslice_t bitsliced_states[], state_t regular_states[]); |
94 | |
95 | // debug print |
96 | void crypto1_bs_print_states(bitslice_t *bitsliced_states); |
97 | |
98 | #endif // _CRYPTO1_BS_H |
99 | |