1 /*
2 * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25 #include "inner.h"
26
27 /*
28 * Round constants.
29 */
30 static const uint64_t RC[] = {
31 0x0000000000000001, 0x0000000000008082,
32 0x800000000000808A, 0x8000000080008000,
33 0x000000000000808B, 0x0000000080000001,
34 0x8000000080008081, 0x8000000000008009,
35 0x000000000000008A, 0x0000000000000088,
36 0x0000000080008009, 0x000000008000000A,
37 0x000000008000808B, 0x800000000000008B,
38 0x8000000000008089, 0x8000000000008003,
39 0x8000000000008002, 0x8000000000000080,
40 0x000000000000800A, 0x800000008000000A,
41 0x8000000080008081, 0x8000000000008080,
42 0x0000000080000001, 0x8000000080008008
43 };
44
45 /*
46 * XOR a block of data into the provided state. This supports only
47 * blocks whose length is a multiple of 64 bits.
48 */
49 static void
xor_block(uint64_t * A,const void * data,size_t rate)50 xor_block(uint64_t *A, const void *data, size_t rate)
51 {
52 size_t u;
53
54 for (u = 0; u < rate; u += 8) {
55 A[u >> 3] ^= br_dec64le((const unsigned char *)data + u);
56 }
57 }
58
59 /*
60 * Process a block with the provided data. The data length must be a
61 * multiple of 8 (in bytes); normally, this is the "rate".
62 */
63 static void
process_block(uint64_t * A)64 process_block(uint64_t *A)
65 {
66 uint64_t t0, t1, t2, t3, t4;
67 uint64_t tt0, tt1, tt2, tt3;
68 uint64_t t, kt;
69 uint64_t c0, c1, c2, c3, c4, bnn;
70 int j;
71
72 /*
73 * Compute the 24 rounds. This loop is partially unrolled (each
74 * iteration computes two rounds).
75 */
76 for (j = 0; j < 24; j += 2) {
77
78 tt0 = A[ 1] ^ A[ 6];
79 tt1 = A[11] ^ A[16];
80 tt0 ^= A[21] ^ tt1;
81 tt0 = (tt0 << 1) | (tt0 >> 63);
82 tt2 = A[ 4] ^ A[ 9];
83 tt3 = A[14] ^ A[19];
84 tt0 ^= A[24];
85 tt2 ^= tt3;
86 t0 = tt0 ^ tt2;
87
88 tt0 = A[ 2] ^ A[ 7];
89 tt1 = A[12] ^ A[17];
90 tt0 ^= A[22] ^ tt1;
91 tt0 = (tt0 << 1) | (tt0 >> 63);
92 tt2 = A[ 0] ^ A[ 5];
93 tt3 = A[10] ^ A[15];
94 tt0 ^= A[20];
95 tt2 ^= tt3;
96 t1 = tt0 ^ tt2;
97
98 tt0 = A[ 3] ^ A[ 8];
99 tt1 = A[13] ^ A[18];
100 tt0 ^= A[23] ^ tt1;
101 tt0 = (tt0 << 1) | (tt0 >> 63);
102 tt2 = A[ 1] ^ A[ 6];
103 tt3 = A[11] ^ A[16];
104 tt0 ^= A[21];
105 tt2 ^= tt3;
106 t2 = tt0 ^ tt2;
107
108 tt0 = A[ 4] ^ A[ 9];
109 tt1 = A[14] ^ A[19];
110 tt0 ^= A[24] ^ tt1;
111 tt0 = (tt0 << 1) | (tt0 >> 63);
112 tt2 = A[ 2] ^ A[ 7];
113 tt3 = A[12] ^ A[17];
114 tt0 ^= A[22];
115 tt2 ^= tt3;
116 t3 = tt0 ^ tt2;
117
118 tt0 = A[ 0] ^ A[ 5];
119 tt1 = A[10] ^ A[15];
120 tt0 ^= A[20] ^ tt1;
121 tt0 = (tt0 << 1) | (tt0 >> 63);
122 tt2 = A[ 3] ^ A[ 8];
123 tt3 = A[13] ^ A[18];
124 tt0 ^= A[23];
125 tt2 ^= tt3;
126 t4 = tt0 ^ tt2;
127
128 A[ 0] = A[ 0] ^ t0;
129 A[ 5] = A[ 5] ^ t0;
130 A[10] = A[10] ^ t0;
131 A[15] = A[15] ^ t0;
132 A[20] = A[20] ^ t0;
133 A[ 1] = A[ 1] ^ t1;
134 A[ 6] = A[ 6] ^ t1;
135 A[11] = A[11] ^ t1;
136 A[16] = A[16] ^ t1;
137 A[21] = A[21] ^ t1;
138 A[ 2] = A[ 2] ^ t2;
139 A[ 7] = A[ 7] ^ t2;
140 A[12] = A[12] ^ t2;
141 A[17] = A[17] ^ t2;
142 A[22] = A[22] ^ t2;
143 A[ 3] = A[ 3] ^ t3;
144 A[ 8] = A[ 8] ^ t3;
145 A[13] = A[13] ^ t3;
146 A[18] = A[18] ^ t3;
147 A[23] = A[23] ^ t3;
148 A[ 4] = A[ 4] ^ t4;
149 A[ 9] = A[ 9] ^ t4;
150 A[14] = A[14] ^ t4;
151 A[19] = A[19] ^ t4;
152 A[24] = A[24] ^ t4;
153 A[ 5] = (A[ 5] << 36) | (A[ 5] >> (64 - 36));
154 A[10] = (A[10] << 3) | (A[10] >> (64 - 3));
155 A[15] = (A[15] << 41) | (A[15] >> (64 - 41));
156 A[20] = (A[20] << 18) | (A[20] >> (64 - 18));
157 A[ 1] = (A[ 1] << 1) | (A[ 1] >> (64 - 1));
158 A[ 6] = (A[ 6] << 44) | (A[ 6] >> (64 - 44));
159 A[11] = (A[11] << 10) | (A[11] >> (64 - 10));
160 A[16] = (A[16] << 45) | (A[16] >> (64 - 45));
161 A[21] = (A[21] << 2) | (A[21] >> (64 - 2));
162 A[ 2] = (A[ 2] << 62) | (A[ 2] >> (64 - 62));
163 A[ 7] = (A[ 7] << 6) | (A[ 7] >> (64 - 6));
164 A[12] = (A[12] << 43) | (A[12] >> (64 - 43));
165 A[17] = (A[17] << 15) | (A[17] >> (64 - 15));
166 A[22] = (A[22] << 61) | (A[22] >> (64 - 61));
167 A[ 3] = (A[ 3] << 28) | (A[ 3] >> (64 - 28));
168 A[ 8] = (A[ 8] << 55) | (A[ 8] >> (64 - 55));
169 A[13] = (A[13] << 25) | (A[13] >> (64 - 25));
170 A[18] = (A[18] << 21) | (A[18] >> (64 - 21));
171 A[23] = (A[23] << 56) | (A[23] >> (64 - 56));
172 A[ 4] = (A[ 4] << 27) | (A[ 4] >> (64 - 27));
173 A[ 9] = (A[ 9] << 20) | (A[ 9] >> (64 - 20));
174 A[14] = (A[14] << 39) | (A[14] >> (64 - 39));
175 A[19] = (A[19] << 8) | (A[19] >> (64 - 8));
176 A[24] = (A[24] << 14) | (A[24] >> (64 - 14));
177 bnn = ~A[12];
178 kt = A[ 6] | A[12];
179 c0 = A[ 0] ^ kt;
180 kt = bnn | A[18];
181 c1 = A[ 6] ^ kt;
182 kt = A[18] & A[24];
183 c2 = A[12] ^ kt;
184 kt = A[24] | A[ 0];
185 c3 = A[18] ^ kt;
186 kt = A[ 0] & A[ 6];
187 c4 = A[24] ^ kt;
188 A[ 0] = c0;
189 A[ 6] = c1;
190 A[12] = c2;
191 A[18] = c3;
192 A[24] = c4;
193 bnn = ~A[22];
194 kt = A[ 9] | A[10];
195 c0 = A[ 3] ^ kt;
196 kt = A[10] & A[16];
197 c1 = A[ 9] ^ kt;
198 kt = A[16] | bnn;
199 c2 = A[10] ^ kt;
200 kt = A[22] | A[ 3];
201 c3 = A[16] ^ kt;
202 kt = A[ 3] & A[ 9];
203 c4 = A[22] ^ kt;
204 A[ 3] = c0;
205 A[ 9] = c1;
206 A[10] = c2;
207 A[16] = c3;
208 A[22] = c4;
209 bnn = ~A[19];
210 kt = A[ 7] | A[13];
211 c0 = A[ 1] ^ kt;
212 kt = A[13] & A[19];
213 c1 = A[ 7] ^ kt;
214 kt = bnn & A[20];
215 c2 = A[13] ^ kt;
216 kt = A[20] | A[ 1];
217 c3 = bnn ^ kt;
218 kt = A[ 1] & A[ 7];
219 c4 = A[20] ^ kt;
220 A[ 1] = c0;
221 A[ 7] = c1;
222 A[13] = c2;
223 A[19] = c3;
224 A[20] = c4;
225 bnn = ~A[17];
226 kt = A[ 5] & A[11];
227 c0 = A[ 4] ^ kt;
228 kt = A[11] | A[17];
229 c1 = A[ 5] ^ kt;
230 kt = bnn | A[23];
231 c2 = A[11] ^ kt;
232 kt = A[23] & A[ 4];
233 c3 = bnn ^ kt;
234 kt = A[ 4] | A[ 5];
235 c4 = A[23] ^ kt;
236 A[ 4] = c0;
237 A[ 5] = c1;
238 A[11] = c2;
239 A[17] = c3;
240 A[23] = c4;
241 bnn = ~A[ 8];
242 kt = bnn & A[14];
243 c0 = A[ 2] ^ kt;
244 kt = A[14] | A[15];
245 c1 = bnn ^ kt;
246 kt = A[15] & A[21];
247 c2 = A[14] ^ kt;
248 kt = A[21] | A[ 2];
249 c3 = A[15] ^ kt;
250 kt = A[ 2] & A[ 8];
251 c4 = A[21] ^ kt;
252 A[ 2] = c0;
253 A[ 8] = c1;
254 A[14] = c2;
255 A[15] = c3;
256 A[21] = c4;
257 A[ 0] = A[ 0] ^ RC[j + 0];
258
259 tt0 = A[ 6] ^ A[ 9];
260 tt1 = A[ 7] ^ A[ 5];
261 tt0 ^= A[ 8] ^ tt1;
262 tt0 = (tt0 << 1) | (tt0 >> 63);
263 tt2 = A[24] ^ A[22];
264 tt3 = A[20] ^ A[23];
265 tt0 ^= A[21];
266 tt2 ^= tt3;
267 t0 = tt0 ^ tt2;
268
269 tt0 = A[12] ^ A[10];
270 tt1 = A[13] ^ A[11];
271 tt0 ^= A[14] ^ tt1;
272 tt0 = (tt0 << 1) | (tt0 >> 63);
273 tt2 = A[ 0] ^ A[ 3];
274 tt3 = A[ 1] ^ A[ 4];
275 tt0 ^= A[ 2];
276 tt2 ^= tt3;
277 t1 = tt0 ^ tt2;
278
279 tt0 = A[18] ^ A[16];
280 tt1 = A[19] ^ A[17];
281 tt0 ^= A[15] ^ tt1;
282 tt0 = (tt0 << 1) | (tt0 >> 63);
283 tt2 = A[ 6] ^ A[ 9];
284 tt3 = A[ 7] ^ A[ 5];
285 tt0 ^= A[ 8];
286 tt2 ^= tt3;
287 t2 = tt0 ^ tt2;
288
289 tt0 = A[24] ^ A[22];
290 tt1 = A[20] ^ A[23];
291 tt0 ^= A[21] ^ tt1;
292 tt0 = (tt0 << 1) | (tt0 >> 63);
293 tt2 = A[12] ^ A[10];
294 tt3 = A[13] ^ A[11];
295 tt0 ^= A[14];
296 tt2 ^= tt3;
297 t3 = tt0 ^ tt2;
298
299 tt0 = A[ 0] ^ A[ 3];
300 tt1 = A[ 1] ^ A[ 4];
301 tt0 ^= A[ 2] ^ tt1;
302 tt0 = (tt0 << 1) | (tt0 >> 63);
303 tt2 = A[18] ^ A[16];
304 tt3 = A[19] ^ A[17];
305 tt0 ^= A[15];
306 tt2 ^= tt3;
307 t4 = tt0 ^ tt2;
308
309 A[ 0] = A[ 0] ^ t0;
310 A[ 3] = A[ 3] ^ t0;
311 A[ 1] = A[ 1] ^ t0;
312 A[ 4] = A[ 4] ^ t0;
313 A[ 2] = A[ 2] ^ t0;
314 A[ 6] = A[ 6] ^ t1;
315 A[ 9] = A[ 9] ^ t1;
316 A[ 7] = A[ 7] ^ t1;
317 A[ 5] = A[ 5] ^ t1;
318 A[ 8] = A[ 8] ^ t1;
319 A[12] = A[12] ^ t2;
320 A[10] = A[10] ^ t2;
321 A[13] = A[13] ^ t2;
322 A[11] = A[11] ^ t2;
323 A[14] = A[14] ^ t2;
324 A[18] = A[18] ^ t3;
325 A[16] = A[16] ^ t3;
326 A[19] = A[19] ^ t3;
327 A[17] = A[17] ^ t3;
328 A[15] = A[15] ^ t3;
329 A[24] = A[24] ^ t4;
330 A[22] = A[22] ^ t4;
331 A[20] = A[20] ^ t4;
332 A[23] = A[23] ^ t4;
333 A[21] = A[21] ^ t4;
334 A[ 3] = (A[ 3] << 36) | (A[ 3] >> (64 - 36));
335 A[ 1] = (A[ 1] << 3) | (A[ 1] >> (64 - 3));
336 A[ 4] = (A[ 4] << 41) | (A[ 4] >> (64 - 41));
337 A[ 2] = (A[ 2] << 18) | (A[ 2] >> (64 - 18));
338 A[ 6] = (A[ 6] << 1) | (A[ 6] >> (64 - 1));
339 A[ 9] = (A[ 9] << 44) | (A[ 9] >> (64 - 44));
340 A[ 7] = (A[ 7] << 10) | (A[ 7] >> (64 - 10));
341 A[ 5] = (A[ 5] << 45) | (A[ 5] >> (64 - 45));
342 A[ 8] = (A[ 8] << 2) | (A[ 8] >> (64 - 2));
343 A[12] = (A[12] << 62) | (A[12] >> (64 - 62));
344 A[10] = (A[10] << 6) | (A[10] >> (64 - 6));
345 A[13] = (A[13] << 43) | (A[13] >> (64 - 43));
346 A[11] = (A[11] << 15) | (A[11] >> (64 - 15));
347 A[14] = (A[14] << 61) | (A[14] >> (64 - 61));
348 A[18] = (A[18] << 28) | (A[18] >> (64 - 28));
349 A[16] = (A[16] << 55) | (A[16] >> (64 - 55));
350 A[19] = (A[19] << 25) | (A[19] >> (64 - 25));
351 A[17] = (A[17] << 21) | (A[17] >> (64 - 21));
352 A[15] = (A[15] << 56) | (A[15] >> (64 - 56));
353 A[24] = (A[24] << 27) | (A[24] >> (64 - 27));
354 A[22] = (A[22] << 20) | (A[22] >> (64 - 20));
355 A[20] = (A[20] << 39) | (A[20] >> (64 - 39));
356 A[23] = (A[23] << 8) | (A[23] >> (64 - 8));
357 A[21] = (A[21] << 14) | (A[21] >> (64 - 14));
358 bnn = ~A[13];
359 kt = A[ 9] | A[13];
360 c0 = A[ 0] ^ kt;
361 kt = bnn | A[17];
362 c1 = A[ 9] ^ kt;
363 kt = A[17] & A[21];
364 c2 = A[13] ^ kt;
365 kt = A[21] | A[ 0];
366 c3 = A[17] ^ kt;
367 kt = A[ 0] & A[ 9];
368 c4 = A[21] ^ kt;
369 A[ 0] = c0;
370 A[ 9] = c1;
371 A[13] = c2;
372 A[17] = c3;
373 A[21] = c4;
374 bnn = ~A[14];
375 kt = A[22] | A[ 1];
376 c0 = A[18] ^ kt;
377 kt = A[ 1] & A[ 5];
378 c1 = A[22] ^ kt;
379 kt = A[ 5] | bnn;
380 c2 = A[ 1] ^ kt;
381 kt = A[14] | A[18];
382 c3 = A[ 5] ^ kt;
383 kt = A[18] & A[22];
384 c4 = A[14] ^ kt;
385 A[18] = c0;
386 A[22] = c1;
387 A[ 1] = c2;
388 A[ 5] = c3;
389 A[14] = c4;
390 bnn = ~A[23];
391 kt = A[10] | A[19];
392 c0 = A[ 6] ^ kt;
393 kt = A[19] & A[23];
394 c1 = A[10] ^ kt;
395 kt = bnn & A[ 2];
396 c2 = A[19] ^ kt;
397 kt = A[ 2] | A[ 6];
398 c3 = bnn ^ kt;
399 kt = A[ 6] & A[10];
400 c4 = A[ 2] ^ kt;
401 A[ 6] = c0;
402 A[10] = c1;
403 A[19] = c2;
404 A[23] = c3;
405 A[ 2] = c4;
406 bnn = ~A[11];
407 kt = A[ 3] & A[ 7];
408 c0 = A[24] ^ kt;
409 kt = A[ 7] | A[11];
410 c1 = A[ 3] ^ kt;
411 kt = bnn | A[15];
412 c2 = A[ 7] ^ kt;
413 kt = A[15] & A[24];
414 c3 = bnn ^ kt;
415 kt = A[24] | A[ 3];
416 c4 = A[15] ^ kt;
417 A[24] = c0;
418 A[ 3] = c1;
419 A[ 7] = c2;
420 A[11] = c3;
421 A[15] = c4;
422 bnn = ~A[16];
423 kt = bnn & A[20];
424 c0 = A[12] ^ kt;
425 kt = A[20] | A[ 4];
426 c1 = bnn ^ kt;
427 kt = A[ 4] & A[ 8];
428 c2 = A[20] ^ kt;
429 kt = A[ 8] | A[12];
430 c3 = A[ 4] ^ kt;
431 kt = A[12] & A[16];
432 c4 = A[ 8] ^ kt;
433 A[12] = c0;
434 A[16] = c1;
435 A[20] = c2;
436 A[ 4] = c3;
437 A[ 8] = c4;
438 A[ 0] = A[ 0] ^ RC[j + 1];
439 t = A[ 5];
440 A[ 5] = A[18];
441 A[18] = A[11];
442 A[11] = A[10];
443 A[10] = A[ 6];
444 A[ 6] = A[22];
445 A[22] = A[20];
446 A[20] = A[12];
447 A[12] = A[19];
448 A[19] = A[15];
449 A[15] = A[24];
450 A[24] = A[ 8];
451 A[ 8] = t;
452 t = A[ 1];
453 A[ 1] = A[ 9];
454 A[ 9] = A[14];
455 A[14] = A[ 2];
456 A[ 2] = A[13];
457 A[13] = A[23];
458 A[23] = A[ 4];
459 A[ 4] = A[21];
460 A[21] = A[16];
461 A[16] = A[ 3];
462 A[ 3] = A[17];
463 A[17] = A[ 7];
464 A[ 7] = t;
465 }
466 }
467
468 /* see bearssl_kdf.h */
469 void
br_shake_init(br_shake_context * sc,int security_level)470 br_shake_init(br_shake_context *sc, int security_level)
471 {
472 sc->rate = 200 - (size_t)(security_level >> 2);
473 sc->dptr = 0;
474 memset(sc->A, 0, sizeof sc->A);
475 sc->A[ 1] = ~(uint64_t)0;
476 sc->A[ 2] = ~(uint64_t)0;
477 sc->A[ 8] = ~(uint64_t)0;
478 sc->A[12] = ~(uint64_t)0;
479 sc->A[17] = ~(uint64_t)0;
480 sc->A[20] = ~(uint64_t)0;
481 }
482
483 /* see bearssl_kdf.h */
484 void
br_shake_inject(br_shake_context * sc,const void * data,size_t len)485 br_shake_inject(br_shake_context *sc, const void *data, size_t len)
486 {
487 const unsigned char *buf;
488 size_t rate, dptr;
489
490 buf = data;
491 rate = sc->rate;
492 dptr = sc->dptr;
493 while (len > 0) {
494 size_t clen;
495
496 clen = rate - dptr;
497 if (clen > len) {
498 clen = len;
499 }
500 memcpy(sc->dbuf + dptr, buf, clen);
501 dptr += clen;
502 buf += clen;
503 len -= clen;
504 if (dptr == rate) {
505 xor_block(sc->A, sc->dbuf, rate);
506 process_block(sc->A);
507 dptr = 0;
508 }
509 }
510 sc->dptr = dptr;
511 }
512
513 /* see bearssl_kdf.h */
514 void
br_shake_flip(br_shake_context * sc)515 br_shake_flip(br_shake_context *sc)
516 {
517 /*
518 * We apply padding and pre-XOR the value into the state. We
519 * set dptr to the end of the buffer, so that first call to
520 * shake_extract() will process the block.
521 */
522 if ((sc->dptr + 1) == sc->rate) {
523 sc->dbuf[sc->dptr ++] = 0x9F;
524 } else {
525 sc->dbuf[sc->dptr ++] = 0x1F;
526 memset(sc->dbuf + sc->dptr, 0x00, sc->rate - sc->dptr - 1);
527 sc->dbuf[sc->rate - 1] = 0x80;
528 sc->dptr = sc->rate;
529 }
530 xor_block(sc->A, sc->dbuf, sc->rate);
531 }
532
533 /* see bearssl_kdf.h */
534 void
br_shake_produce(br_shake_context * sc,void * out,size_t len)535 br_shake_produce(br_shake_context *sc, void *out, size_t len)
536 {
537 unsigned char *buf;
538 size_t dptr, rate;
539
540 buf = out;
541 dptr = sc->dptr;
542 rate = sc->rate;
543 while (len > 0) {
544 size_t clen;
545
546 if (dptr == rate) {
547 unsigned char *dbuf;
548 uint64_t *A;
549
550 A = sc->A;
551 dbuf = sc->dbuf;
552 process_block(A);
553 br_enc64le(dbuf + 0, A[ 0]);
554 br_enc64le(dbuf + 8, ~A[ 1]);
555 br_enc64le(dbuf + 16, ~A[ 2]);
556 br_enc64le(dbuf + 24, A[ 3]);
557 br_enc64le(dbuf + 32, A[ 4]);
558 br_enc64le(dbuf + 40, A[ 5]);
559 br_enc64le(dbuf + 48, A[ 6]);
560 br_enc64le(dbuf + 56, A[ 7]);
561 br_enc64le(dbuf + 64, ~A[ 8]);
562 br_enc64le(dbuf + 72, A[ 9]);
563 br_enc64le(dbuf + 80, A[10]);
564 br_enc64le(dbuf + 88, A[11]);
565 br_enc64le(dbuf + 96, ~A[12]);
566 br_enc64le(dbuf + 104, A[13]);
567 br_enc64le(dbuf + 112, A[14]);
568 br_enc64le(dbuf + 120, A[15]);
569 br_enc64le(dbuf + 128, A[16]);
570 br_enc64le(dbuf + 136, ~A[17]);
571 br_enc64le(dbuf + 144, A[18]);
572 br_enc64le(dbuf + 152, A[19]);
573 br_enc64le(dbuf + 160, ~A[20]);
574 br_enc64le(dbuf + 168, A[21]);
575 br_enc64le(dbuf + 176, A[22]);
576 br_enc64le(dbuf + 184, A[23]);
577 br_enc64le(dbuf + 192, A[24]);
578 dptr = 0;
579 }
580 clen = rate - dptr;
581 if (clen > len) {
582 clen = len;
583 }
584 memcpy(buf, sc->dbuf + dptr, clen);
585 dptr += clen;
586 buf += clen;
587 len -= clen;
588 }
589 sc->dptr = dptr;
590 }
591