]>
Commit | Line | Data |
---|---|---|
3130ba4b | 1 | // Bit-sliced Crypto-1 implementation |
2 | // The cipher states are stored with the least significant bit first, hence all bit indexes are reversed here | |
3 | /* | |
4 | Copyright (c) 2015-2016 Aram Verstegen | |
5 | ||
6 | Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | of this software and associated documentation files (the "Software"), to deal | |
8 | in the Software without restriction, including without limitation the rights | |
9 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | copies of the Software, and to permit persons to whom the Software is | |
11 | furnished to do so, subject to the following conditions: | |
12 | ||
13 | The above copyright notice and this permission notice shall be included in | |
14 | all copies or substantial portions of the Software. | |
15 | ||
16 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
19 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | THE SOFTWARE. | |
23 | */ | |
24 | ||
25 | #include "crypto1_bs.h" | |
26 | #include <inttypes.h> | |
27 | #define __STDC_FORMAT_MACROS | |
28 | #define llx PRIx64 | |
29 | #define lli PRIi64 | |
30 | #define lu PRIu32 | |
31 | ||
32 | // The following functions use this global or thread-local state | |
33 | // It is sized to fit exactly KEYSTREAM_SIZE more states next to the initial state | |
34 | __thread bitslice_t states[KEYSTREAM_SIZE+STATE_SIZE]; | |
35 | __thread bitslice_t * restrict state_p; | |
36 | ||
37 | void crypto1_bs_init(){ | |
38 | // initialize constant one and zero bit vectors | |
39 | memset(bs_ones.bytes, 0xff, VECTOR_SIZE); | |
40 | memset(bs_zeroes.bytes, 0x00, VECTOR_SIZE); | |
41 | } | |
42 | ||
43 | // The following functions have side effects on 48 bitslices at the state_p pointer | |
44 | // use the crypto1_bs_rewind_* macros to (re-)initialize them as needed | |
45 | ||
46 | inline const bitslice_value_t crypto1_bs_bit(const bitslice_value_t input, const bool is_encrypted){ | |
47 | bitslice_value_t feedback = (state_p[47- 0].value ^ state_p[47- 5].value ^ state_p[47- 9].value ^ | |
48 | state_p[47-10].value ^ state_p[47-12].value ^ state_p[47-14].value ^ | |
49 | state_p[47-15].value ^ state_p[47-17].value ^ state_p[47-19].value ^ | |
50 | state_p[47-24].value ^ state_p[47-25].value ^ state_p[47-27].value ^ | |
51 | state_p[47-29].value ^ state_p[47-35].value ^ state_p[47-39].value ^ | |
52 | state_p[47-41].value ^ state_p[47-42].value ^ state_p[47-43].value); | |
53 | const bitslice_value_t ks_bits = crypto1_bs_f20(state_p); | |
54 | if(is_encrypted){ | |
55 | feedback ^= ks_bits; | |
56 | } | |
57 | state_p--; | |
58 | state_p[0].value = feedback ^ input; | |
59 | return ks_bits; | |
60 | } | |
61 | ||
62 | inline const bitslice_value_t crypto1_bs_lfsr_rollback(const bitslice_value_t input, const bool is_encrypted){ | |
63 | bitslice_value_t feedout = state_p[0].value; | |
64 | state_p++; | |
65 | const bitslice_value_t ks_bits = crypto1_bs_f20(state_p); | |
66 | if(is_encrypted){ | |
67 | feedout ^= ks_bits; | |
68 | } | |
69 | const bitslice_value_t feedback = (feedout ^ state_p[47- 5].value ^ state_p[47- 9].value ^ | |
70 | state_p[47-10].value ^ state_p[47-12].value ^ state_p[47-14].value ^ | |
71 | state_p[47-15].value ^ state_p[47-17].value ^ state_p[47-19].value ^ | |
72 | state_p[47-24].value ^ state_p[47-25].value ^ state_p[47-27].value ^ | |
73 | state_p[47-29].value ^ state_p[47-35].value ^ state_p[47-39].value ^ | |
74 | state_p[47-41].value ^ state_p[47-42].value ^ state_p[47-43].value); | |
75 | state_p[47].value = feedback ^ input; | |
76 | return ks_bits; | |
77 | } | |
78 | ||
79 | // side-effect free from here on | |
80 | // note that bytes are sliced and unsliced with reversed endianness | |
81 | inline void crypto1_bs_convert_states(bitslice_t bitsliced_states[], state_t regular_states[]){ | |
82 | size_t bit_idx = 0, slice_idx = 0; | |
2de9622f | 83 | state_t values[MAX_BITSLICES]; |
84 | memset(values, 0x0, sizeof(values)); | |
85 | ||
3130ba4b | 86 | for(slice_idx = 0; slice_idx < MAX_BITSLICES; slice_idx++){ |
87 | for(bit_idx = 0; bit_idx < STATE_SIZE; bit_idx++){ | |
88 | bool bit = get_vector_bit(slice_idx, bitsliced_states[bit_idx]); | |
89 | values[slice_idx].value <<= 1; | |
90 | values[slice_idx].value |= bit; | |
91 | } | |
92 | // swap endianness | |
93 | values[slice_idx].value = rev_state_t(values[slice_idx].value); | |
94 | // roll off unused bits | |
2de9622f | 95 | //values[slice_idx].value >>= ((sizeof(state_t)*8)-STATE_SIZE); // - 48 |
96 | values[slice_idx].value >>= 16; | |
3130ba4b | 97 | } |
98 | memcpy(regular_states, values, sizeof(values)); | |
99 | } | |
100 | ||
101 | // bitslice a value | |
102 | void crypto1_bs_bitslice_value32(uint32_t value, bitslice_t bitsliced_value[], size_t bit_len){ | |
103 | // load nonce bytes with unswapped endianness | |
104 | size_t bit_idx; | |
105 | for(bit_idx = 0; bit_idx < bit_len; bit_idx++){ | |
106 | bool bit = get_bit(bit_len-1-bit_idx, rev32(value)); | |
107 | if(bit){ | |
108 | bitsliced_value[bit_idx].value = bs_ones.value; | |
109 | } else { | |
110 | bitsliced_value[bit_idx].value = bs_zeroes.value; | |
111 | } | |
112 | } | |
113 | } | |
114 | ||
115 | void crypto1_bs_print_states(bitslice_t bitsliced_states[]){ | |
116 | size_t slice_idx = 0; | |
cd777a05 | 117 | state_t values[MAX_BITSLICES] = {{0x00}}; |
3130ba4b | 118 | crypto1_bs_convert_states(bitsliced_states, values); |
119 | for(slice_idx = 0; slice_idx < MAX_BITSLICES; slice_idx++){ | |
120 | printf("State %03zu: %012"llx"\n", slice_idx, values[slice_idx].value); | |
121 | } | |
122 | } | |
123 |