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33443e7c | 1 | /* crapto1.c |
2 | ||
3 | This program is free software; you can redistribute it and/or | |
4 | modify it under the terms of the GNU General Public License | |
5 | as published by the Free Software Foundation; either version 2 | |
6 | of the License, or (at your option) any later version. | |
7 | ||
8 | This program is distributed in the hope that it will be useful, | |
9 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | GNU General Public License for more details. | |
12 | ||
13 | You should have received a copy of the GNU General Public License | |
14 | along with this program; if not, write to the Free Software | |
15 | Foundation, Inc., 51 Franklin Street, Fifth Floor, | |
16 | Boston, MA 02110-1301, US$ | |
17 | ||
0ca9bc0e | 18 | Copyright (C) 2008-2014 bla <blapost@gmail.com> |
33443e7c | 19 | */ |
20 | #include "crapto1.h" | |
1f065e1d | 21 | |
33443e7c | 22 | #include <stdlib.h> |
1f065e1d | 23 | #include "parity.h" |
33443e7c | 24 | |
25 | #if !defined LOWMEM && defined __GNUC__ | |
26 | static uint8_t filterlut[1 << 20]; | |
27 | static void __attribute__((constructor)) fill_lut() | |
28 | { | |
29 | uint32_t i; | |
30 | for(i = 0; i < 1 << 20; ++i) | |
31 | filterlut[i] = filter(i); | |
32 | } | |
33 | #define filter(x) (filterlut[(x) & 0xfffff]) | |
34 | #endif | |
35 | ||
36 | ||
37 | ||
38 | typedef struct bucket { | |
39 | uint32_t *head; | |
40 | uint32_t *bp; | |
41 | } bucket_t; | |
42 | ||
43 | typedef bucket_t bucket_array_t[2][0x100]; | |
44 | ||
45 | typedef struct bucket_info { | |
46 | struct { | |
47 | uint32_t *head, *tail; | |
48 | } bucket_info[2][0x100]; | |
49 | uint32_t numbuckets; | |
50 | } bucket_info_t; | |
51 | ||
52 | ||
53 | static void bucket_sort_intersect(uint32_t* const estart, uint32_t* const estop, | |
54 | uint32_t* const ostart, uint32_t* const ostop, | |
55 | bucket_info_t *bucket_info, bucket_array_t bucket) | |
56 | { | |
57 | uint32_t *p1, *p2; | |
58 | uint32_t *start[2]; | |
59 | uint32_t *stop[2]; | |
60 | ||
61 | start[0] = estart; | |
62 | stop[0] = estop; | |
63 | start[1] = ostart; | |
64 | stop[1] = ostop; | |
65 | ||
66 | // init buckets to be empty | |
67 | for (uint32_t i = 0; i < 2; i++) { | |
68 | for (uint32_t j = 0x00; j <= 0xff; j++) { | |
69 | bucket[i][j].bp = bucket[i][j].head; | |
70 | } | |
71 | } | |
72 | ||
73 | // sort the lists into the buckets based on the MSB (contribution bits) | |
74 | for (uint32_t i = 0; i < 2; i++) { | |
75 | for (p1 = start[i]; p1 <= stop[i]; p1++) { | |
76 | uint32_t bucket_index = (*p1 & 0xff000000) >> 24; | |
77 | *(bucket[i][bucket_index].bp++) = *p1; | |
78 | } | |
79 | } | |
80 | ||
81 | ||
82 | // write back intersecting buckets as sorted list. | |
83 | // fill in bucket_info with head and tail of the bucket contents in the list and number of non-empty buckets. | |
84 | uint32_t nonempty_bucket; | |
85 | for (uint32_t i = 0; i < 2; i++) { | |
86 | p1 = start[i]; | |
87 | nonempty_bucket = 0; | |
88 | for (uint32_t j = 0x00; j <= 0xff; j++) { | |
89 | if (bucket[0][j].bp != bucket[0][j].head && bucket[1][j].bp != bucket[1][j].head) { // non-empty intersecting buckets only | |
90 | bucket_info->bucket_info[i][nonempty_bucket].head = p1; | |
91 | for (p2 = bucket[i][j].head; p2 < bucket[i][j].bp; *p1++ = *p2++); | |
92 | bucket_info->bucket_info[i][nonempty_bucket].tail = p1 - 1; | |
93 | nonempty_bucket++; | |
94 | } | |
95 | } | |
96 | bucket_info->numbuckets = nonempty_bucket; | |
97 | } | |
98 | } | |
33443e7c | 99 | /** binsearch |
100 | * Binary search for the first occurence of *stop's MSB in sorted [start,stop] | |
101 | */ | |
31a29271 | 102 | /* static inline uint32_t* binsearch(uint32_t *start, uint32_t *stop) |
33443e7c | 103 | { |
104 | uint32_t mid, val = *stop & 0xff000000; | |
105 | while(start != stop) | |
106 | if(start[mid = (stop - start) >> 1] > val) | |
107 | stop = &start[mid]; | |
108 | else | |
109 | start += mid + 1; | |
110 | ||
111 | return start; | |
112 | } | |
31a29271 | 113 | */ |
33443e7c | 114 | /** update_contribution |
115 | * helper, calculates the partial linear feedback contributions and puts in MSB | |
116 | */ | |
117 | static inline void | |
118 | update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2) | |
119 | { | |
120 | uint32_t p = *item >> 25; | |
121 | ||
1f065e1d | 122 | p = p << 1 | evenparity32(*item & mask1); |
123 | p = p << 1 | evenparity32(*item & mask2); | |
33443e7c | 124 | *item = p << 24 | (*item & 0xffffff); |
125 | } | |
126 | ||
127 | /** extend_table | |
128 | * using a bit of the keystream extend the table of possible lfsr states | |
129 | */ | |
130 | static inline void | |
131 | extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in) | |
132 | { | |
133 | in <<= 24; | |
0ca9bc0e | 134 | for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1) |
135 | if(filter(*tbl) ^ filter(*tbl | 1)) { | |
136 | *tbl |= filter(*tbl) ^ bit; | |
137 | update_contribution(tbl, m1, m2); | |
138 | *tbl ^= in; | |
139 | } else if(filter(*tbl) == bit) { | |
140 | *++*end = tbl[1]; | |
141 | tbl[1] = tbl[0] | 1; | |
142 | update_contribution(tbl, m1, m2); | |
143 | *tbl++ ^= in; | |
144 | update_contribution(tbl, m1, m2); | |
145 | *tbl ^= in; | |
146 | } else | |
147 | *tbl-- = *(*end)--; | |
33443e7c | 148 | } |
33443e7c | 149 | /** extend_table_simple |
150 | * using a bit of the keystream extend the table of possible lfsr states | |
151 | */ | |
0ca9bc0e | 152 | static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit) |
33443e7c | 153 | { |
154 | for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1) | |
0ca9bc0e | 155 | if(filter(*tbl) ^ filter(*tbl | 1)) |
33443e7c | 156 | *tbl |= filter(*tbl) ^ bit; |
0ca9bc0e | 157 | else if(filter(*tbl) == bit) { |
33443e7c | 158 | *++*end = *++tbl; |
159 | *tbl = tbl[-1] | 1; | |
0ca9bc0e | 160 | |
161 | } else | |
33443e7c | 162 | *tbl-- = *(*end)--; |
163 | } | |
164 | ||
165 | ||
166 | /** recover | |
167 | * recursively narrow down the search space, 4 bits of keystream at a time | |
168 | */ | |
169 | static struct Crypto1State* | |
170 | recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks, | |
171 | uint32_t *e_head, uint32_t *e_tail, uint32_t eks, int rem, | |
172 | struct Crypto1State *sl, uint32_t in, bucket_array_t bucket) | |
173 | { | |
0ca9bc0e | 174 | uint32_t *o, *e, i; |
33443e7c | 175 | bucket_info_t bucket_info; |
176 | ||
177 | if(rem == -1) { | |
178 | for(e = e_head; e <= e_tail; ++e) { | |
1f065e1d | 179 | *e = *e << 1 ^ evenparity32(*e & LF_POLY_EVEN) ^ !!(in & 4); |
33443e7c | 180 | for(o = o_head; o <= o_tail; ++o, ++sl) { |
181 | sl->even = *o; | |
1f065e1d | 182 | sl->odd = *e ^ evenparity32(*o & LF_POLY_ODD); |
0ca9bc0e | 183 | sl[1].odd = sl[1].even = 0; |
33443e7c | 184 | } |
185 | } | |
33443e7c | 186 | return sl; |
187 | } | |
188 | ||
0ca9bc0e | 189 | for(i = 0; i < 4 && rem--; i++) { |
190 | oks >>= 1; | |
191 | eks >>= 1; | |
192 | in >>= 2; | |
193 | extend_table(o_head, &o_tail, oks & 1, LF_POLY_EVEN << 1 | 1, | |
194 | LF_POLY_ODD << 1, 0); | |
33443e7c | 195 | if(o_head > o_tail) |
196 | return sl; | |
197 | ||
0ca9bc0e | 198 | extend_table(e_head, &e_tail, eks & 1, LF_POLY_ODD, |
199 | LF_POLY_EVEN << 1 | 1, in & 3); | |
33443e7c | 200 | if(e_head > e_tail) |
201 | return sl; | |
202 | } | |
33443e7c | 203 | bucket_sort_intersect(e_head, e_tail, o_head, o_tail, &bucket_info, bucket); |
204 | ||
205 | for (int i = bucket_info.numbuckets - 1; i >= 0; i--) { | |
206 | sl = recover(bucket_info.bucket_info[1][i].head, bucket_info.bucket_info[1][i].tail, oks, | |
207 | bucket_info.bucket_info[0][i].head, bucket_info.bucket_info[0][i].tail, eks, | |
208 | rem, sl, in, bucket); | |
209 | } | |
210 | ||
211 | return sl; | |
212 | } | |
213 | /** lfsr_recovery | |
214 | * recover the state of the lfsr given 32 bits of the keystream | |
215 | * additionally you can use the in parameter to specify the value | |
216 | * that was fed into the lfsr at the time the keystream was generated | |
217 | */ | |
218 | struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in) | |
219 | { | |
220 | struct Crypto1State *statelist; | |
221 | uint32_t *odd_head = 0, *odd_tail = 0, oks = 0; | |
222 | uint32_t *even_head = 0, *even_tail = 0, eks = 0; | |
223 | int i; | |
224 | ||
33443e7c | 225 | for(i = 31; i >= 0; i -= 2) |
226 | oks = oks << 1 | BEBIT(ks2, i); | |
227 | for(i = 30; i >= 0; i -= 2) | |
228 | eks = eks << 1 | BEBIT(ks2, i); | |
229 | ||
230 | odd_head = odd_tail = malloc(sizeof(uint32_t) << 21); | |
231 | even_head = even_tail = malloc(sizeof(uint32_t) << 21); | |
232 | statelist = malloc(sizeof(struct Crypto1State) << 18); | |
233 | if(!odd_tail-- || !even_tail-- || !statelist) { | |
0ca9bc0e | 234 | free(statelist); |
235 | statelist = 0; | |
33443e7c | 236 | goto out; |
237 | } | |
238 | statelist->odd = statelist->even = 0; | |
239 | ||
240 | // allocate memory for out of place bucket_sort | |
241 | bucket_array_t bucket; | |
242 | for (uint32_t i = 0; i < 2; i++) | |
243 | for (uint32_t j = 0; j <= 0xff; j++) { | |
244 | bucket[i][j].head = malloc(sizeof(uint32_t)<<14); | |
245 | if (!bucket[i][j].head) { | |
246 | goto out; | |
247 | } | |
248 | } | |
249 | ||
250 | ||
33443e7c | 251 | for(i = 1 << 20; i >= 0; --i) { |
252 | if(filter(i) == (oks & 1)) | |
253 | *++odd_tail = i; | |
254 | if(filter(i) == (eks & 1)) | |
255 | *++even_tail = i; | |
256 | } | |
257 | ||
33443e7c | 258 | for(i = 0; i < 4; i++) { |
259 | extend_table_simple(odd_head, &odd_tail, (oks >>= 1) & 1); | |
260 | extend_table_simple(even_head, &even_tail, (eks >>= 1) & 1); | |
261 | } | |
262 | ||
0ca9bc0e | 263 | in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00); |
33443e7c | 264 | recover(odd_head, odd_tail, oks, |
265 | even_head, even_tail, eks, 11, statelist, in << 1, bucket); | |
266 | ||
33443e7c | 267 | out: |
268 | free(odd_head); | |
269 | free(even_head); | |
270 | for (uint32_t i = 0; i < 2; i++) | |
271 | for (uint32_t j = 0; j <= 0xff; j++) | |
272 | free(bucket[i][j].head); | |
273 | ||
274 | return statelist; | |
275 | } | |
276 | ||
277 | static const uint32_t S1[] = { 0x62141, 0x310A0, 0x18850, 0x0C428, 0x06214, | |
278 | 0x0310A, 0x85E30, 0xC69AD, 0x634D6, 0xB5CDE, 0xDE8DA, 0x6F46D, 0xB3C83, | |
279 | 0x59E41, 0xA8995, 0xD027F, 0x6813F, 0x3409F, 0x9E6FA}; | |
280 | static const uint32_t S2[] = { 0x3A557B00, 0x5D2ABD80, 0x2E955EC0, 0x174AAF60, | |
281 | 0x0BA557B0, 0x05D2ABD8, 0x0449DE68, 0x048464B0, 0x42423258, 0x278192A8, | |
282 | 0x156042D0, 0x0AB02168, 0x43F89B30, 0x61FC4D98, 0x765EAD48, 0x7D8FDD20, | |
283 | 0x7EC7EE90, 0x7F63F748, 0x79117020}; | |
284 | static const uint32_t T1[] = { | |
285 | 0x4F37D, 0x279BE, 0x97A6A, 0x4BD35, 0x25E9A, 0x12F4D, 0x097A6, 0x80D66, | |
286 | 0xC4006, 0x62003, 0xB56B4, 0x5AB5A, 0xA9318, 0xD0F39, 0x6879C, 0xB057B, | |
287 | 0x582BD, 0x2C15E, 0x160AF, 0x8F6E2, 0xC3DC4, 0xE5857, 0x72C2B, 0x39615, | |
288 | 0x98DBF, 0xC806A, 0xE0680, 0x70340, 0x381A0, 0x98665, 0x4C332, 0xA272C}; | |
289 | static const uint32_t T2[] = { 0x3C88B810, 0x5E445C08, 0x2982A580, 0x14C152C0, | |
290 | 0x4A60A960, 0x253054B0, 0x52982A58, 0x2FEC9EA8, 0x1156C4D0, 0x08AB6268, | |
291 | 0x42F53AB0, 0x217A9D58, 0x161DC528, 0x0DAE6910, 0x46D73488, 0x25CB11C0, | |
292 | 0x52E588E0, 0x6972C470, 0x34B96238, 0x5CFC3A98, 0x28DE96C8, 0x12CFC0E0, | |
293 | 0x4967E070, 0x64B3F038, 0x74F97398, 0x7CDC3248, 0x38CE92A0, 0x1C674950, | |
294 | 0x0E33A4A8, 0x01B959D0, 0x40DCACE8, 0x26CEDDF0}; | |
295 | static const uint32_t C1[] = { 0x846B5, 0x4235A, 0x211AD}; | |
296 | static const uint32_t C2[] = { 0x1A822E0, 0x21A822E0, 0x21A822E0}; | |
297 | /** Reverse 64 bits of keystream into possible cipher states | |
298 | * Variation mentioned in the paper. Somewhat optimized version | |
299 | */ | |
300 | struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3) | |
301 | { | |
302 | struct Crypto1State *statelist, *sl; | |
303 | uint8_t oks[32], eks[32], hi[32]; | |
304 | uint32_t low = 0, win = 0; | |
305 | uint32_t *tail, table[1 << 16]; | |
306 | int i, j; | |
307 | ||
308 | sl = statelist = malloc(sizeof(struct Crypto1State) << 4); | |
309 | if(!sl) | |
310 | return 0; | |
311 | sl->odd = sl->even = 0; | |
312 | ||
313 | for(i = 30; i >= 0; i -= 2) { | |
0ca9bc0e | 314 | oks[i >> 1] = BEBIT(ks2, i); |
315 | oks[16 + (i >> 1)] = BEBIT(ks3, i); | |
33443e7c | 316 | } |
317 | for(i = 31; i >= 0; i -= 2) { | |
0ca9bc0e | 318 | eks[i >> 1] = BEBIT(ks2, i); |
319 | eks[16 + (i >> 1)] = BEBIT(ks3, i); | |
33443e7c | 320 | } |
321 | ||
322 | for(i = 0xfffff; i >= 0; --i) { | |
323 | if (filter(i) != oks[0]) | |
324 | continue; | |
325 | ||
326 | *(tail = table) = i; | |
327 | for(j = 1; tail >= table && j < 29; ++j) | |
328 | extend_table_simple(table, &tail, oks[j]); | |
329 | ||
330 | if(tail < table) | |
331 | continue; | |
332 | ||
333 | for(j = 0; j < 19; ++j) | |
1f065e1d | 334 | low = low << 1 | evenparity32(i & S1[j]); |
33443e7c | 335 | for(j = 0; j < 32; ++j) |
1f065e1d | 336 | hi[j] = evenparity32(i & T1[j]); |
33443e7c | 337 | |
338 | for(; tail >= table; --tail) { | |
339 | for(j = 0; j < 3; ++j) { | |
340 | *tail = *tail << 1; | |
1f065e1d | 341 | *tail |= evenparity32((i & C1[j]) ^ (*tail & C2[j])); |
33443e7c | 342 | if(filter(*tail) != oks[29 + j]) |
343 | goto continue2; | |
344 | } | |
345 | ||
346 | for(j = 0; j < 19; ++j) | |
1f065e1d | 347 | win = win << 1 | evenparity32(*tail & S2[j]); |
33443e7c | 348 | |
349 | win ^= low; | |
350 | for(j = 0; j < 32; ++j) { | |
1f065e1d | 351 | win = win << 1 ^ hi[j] ^ evenparity32(*tail & T2[j]); |
33443e7c | 352 | if(filter(win) != eks[j]) |
353 | goto continue2; | |
354 | } | |
355 | ||
1f065e1d | 356 | *tail = *tail << 1 | evenparity32(LF_POLY_EVEN & *tail); |
357 | sl->odd = *tail ^ evenparity32(LF_POLY_ODD & win); | |
33443e7c | 358 | sl->even = win; |
359 | ++sl; | |
360 | sl->odd = sl->even = 0; | |
361 | continue2:; | |
362 | } | |
363 | } | |
364 | return statelist; | |
365 | } | |
366 | ||
367 | /** lfsr_rollback_bit | |
368 | * Rollback the shift register in order to get previous states | |
369 | */ | |
0ca9bc0e | 370 | uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb) |
33443e7c | 371 | { |
372 | int out; | |
0ca9bc0e | 373 | uint8_t ret; |
374 | uint32_t t; | |
375 | ||
33443e7c | 376 | s->odd &= 0xffffff; |
0ca9bc0e | 377 | t = s->odd, s->odd = s->even, s->even = t; |
33443e7c | 378 | |
379 | out = s->even & 1; | |
380 | out ^= LF_POLY_EVEN & (s->even >>= 1); | |
381 | out ^= LF_POLY_ODD & s->odd; | |
382 | out ^= !!in; | |
0ca9bc0e | 383 | out ^= (ret = filter(s->odd)) & !!fb; |
33443e7c | 384 | |
1f065e1d | 385 | s->even |= evenparity32(out) << 23; |
0ca9bc0e | 386 | return ret; |
33443e7c | 387 | } |
388 | /** lfsr_rollback_byte | |
389 | * Rollback the shift register in order to get previous states | |
390 | */ | |
0ca9bc0e | 391 | uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb) |
33443e7c | 392 | { |
0ca9bc0e | 393 | int i, ret=0; |
33443e7c | 394 | for (i = 7; i >= 0; --i) |
0ca9bc0e | 395 | ret |= lfsr_rollback_bit(s, BIT(in, i), fb) << i; |
396 | return ret; | |
33443e7c | 397 | } |
398 | /** lfsr_rollback_word | |
399 | * Rollback the shift register in order to get previous states | |
400 | */ | |
0ca9bc0e | 401 | uint32_t lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb) |
33443e7c | 402 | { |
403 | int i; | |
0ca9bc0e | 404 | uint32_t ret = 0; |
33443e7c | 405 | for (i = 31; i >= 0; --i) |
0ca9bc0e | 406 | ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24); |
407 | return ret; | |
33443e7c | 408 | } |
409 | ||
410 | /** nonce_distance | |
411 | * x,y valid tag nonces, then prng_successor(x, nonce_distance(x, y)) = y | |
412 | */ | |
413 | static uint16_t *dist = 0; | |
414 | int nonce_distance(uint32_t from, uint32_t to) | |
415 | { | |
416 | uint16_t x, i; | |
417 | if(!dist) { | |
418 | dist = malloc(2 << 16); | |
419 | if(!dist) | |
420 | return -1; | |
421 | for (x = i = 1; i; ++i) { | |
422 | dist[(x & 0xff) << 8 | x >> 8] = i; | |
423 | x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15; | |
424 | } | |
425 | } | |
426 | return (65535 + dist[to >> 16] - dist[from >> 16]) % 65535; | |
427 | } | |
428 | ||
33443e7c | 429 | static uint32_t fastfwd[2][8] = { |
430 | { 0, 0x4BC53, 0xECB1, 0x450E2, 0x25E29, 0x6E27A, 0x2B298, 0x60ECB}, | |
431 | { 0, 0x1D962, 0x4BC53, 0x56531, 0xECB1, 0x135D3, 0x450E2, 0x58980}}; | |
33443e7c | 432 | /** lfsr_prefix_ks |
433 | * | |
434 | * Is an exported helper function from the common prefix attack | |
435 | * Described in the "dark side" paper. It returns an -1 terminated array | |
436 | * of possible partial(21 bit) secret state. | |
437 | * The required keystream(ks) needs to contain the keystream that was used to | |
0ca9bc0e | 438 | * encrypt the NACK which is observed when varying only the 3 last bits of Nr |
33443e7c | 439 | * only correct iff [NR_3] ^ NR_3 does not depend on Nr_3 |
440 | */ | |
441 | uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd) | |
442 | { | |
0ca9bc0e | 443 | uint32_t c, entry, *candidates = malloc(4 << 10); |
444 | int i, size = 0, good; | |
445 | ||
33443e7c | 446 | if(!candidates) |
447 | return 0; | |
448 | ||
0ca9bc0e | 449 | for(i = 0; i < 1 << 21; ++i) { |
450 | for(c = 0, good = 1; good && c < 8; ++c) { | |
451 | entry = i ^ fastfwd[isodd][c]; | |
452 | good &= (BIT(ks[c], isodd) == filter(entry >> 1)); | |
453 | good &= (BIT(ks[c], isodd + 2) == filter(entry)); | |
33443e7c | 454 | } |
0ca9bc0e | 455 | if(good) |
456 | candidates[size++] = i; | |
457 | } | |
458 | ||
459 | candidates[size] = -1; | |
33443e7c | 460 | |
461 | return candidates; | |
462 | } | |
463 | ||
0ca9bc0e | 464 | /** check_pfx_parity |
33443e7c | 465 | * helper function which eliminates possible secret states using parity bits |
466 | */ | |
467 | static struct Crypto1State* | |
0ca9bc0e | 468 | check_pfx_parity(uint32_t prefix, uint32_t rresp, uint8_t parities[8][8], |
de867f50 | 469 | uint32_t odd, uint32_t even, struct Crypto1State* sl, uint32_t no_par) |
33443e7c | 470 | { |
de867f50 | 471 | uint32_t ks1, nr, ks2, rr, ks3, c, good = 1; |
33443e7c | 472 | |
0ca9bc0e | 473 | for(c = 0; good && c < 8; ++c) { |
474 | sl->odd = odd ^ fastfwd[1][c]; | |
475 | sl->even = even ^ fastfwd[0][c]; | |
33443e7c | 476 | |
0ca9bc0e | 477 | lfsr_rollback_bit(sl, 0, 0); |
478 | lfsr_rollback_bit(sl, 0, 0); | |
33443e7c | 479 | |
0ca9bc0e | 480 | ks3 = lfsr_rollback_bit(sl, 0, 0); |
481 | ks2 = lfsr_rollback_word(sl, 0, 0); | |
482 | ks1 = lfsr_rollback_word(sl, prefix | c << 5, 1); | |
33443e7c | 483 | |
484 | if (no_par) | |
485 | break; | |
486 | ||
33443e7c | 487 | nr = ks1 ^ (prefix | c << 5); |
488 | rr = ks2 ^ rresp; | |
489 | ||
1f065e1d | 490 | good &= evenparity32(nr & 0x000000ff) ^ parities[c][3] ^ BIT(ks2, 24); |
491 | good &= evenparity32(rr & 0xff000000) ^ parities[c][4] ^ BIT(ks2, 16); | |
492 | good &= evenparity32(rr & 0x00ff0000) ^ parities[c][5] ^ BIT(ks2, 8); | |
493 | good &= evenparity32(rr & 0x0000ff00) ^ parities[c][6] ^ BIT(ks2, 0); | |
494 | good &= evenparity32(rr & 0x000000ff) ^ parities[c][7] ^ ks3; | |
33443e7c | 495 | } |
496 | ||
0ca9bc0e | 497 | return sl + good; |
33443e7c | 498 | } |
499 | ||
500 | ||
501 | /** lfsr_common_prefix | |
502 | * Implentation of the common prefix attack. | |
33443e7c | 503 | */ |
504 | struct Crypto1State* | |
de867f50 | 505 | lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8], uint32_t no_par) |
33443e7c | 506 | { |
507 | struct Crypto1State *statelist, *s; | |
508 | uint32_t *odd, *even, *o, *e, top; | |
509 | ||
510 | odd = lfsr_prefix_ks(ks, 1); | |
511 | even = lfsr_prefix_ks(ks, 0); | |
512 | ||
7779d73c | 513 | s = statelist = malloc((sizeof *statelist) << 22); // was << 20. Need more for no_par special attack. Enough??? |
0ca9bc0e | 514 | if(!s || !odd || !even) { |
515 | free(statelist); | |
516 | statelist = 0; | |
517 | goto out; | |
33443e7c | 518 | } |
519 | ||
0ca9bc0e | 520 | for(o = odd; *o + 1; ++o) |
521 | for(e = even; *e + 1; ++e) | |
33443e7c | 522 | for(top = 0; top < 64; ++top) { |
0ca9bc0e | 523 | *o += 1 << 21; |
524 | *e += (!(top & 7) + 1) << 21; | |
de867f50 | 525 | s = check_pfx_parity(pfx, rr, par, *o, *e, s, no_par); |
33443e7c | 526 | } |
527 | ||
0ca9bc0e | 528 | s->odd = s->even = 0; |
529 | out: | |
33443e7c | 530 | free(odd); |
531 | free(even); | |
33443e7c | 532 | return statelist; |
533 | } |