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-rw-r--r--src/lib/libcrypto/bytestring/bs_cbs.c616
1 files changed, 0 insertions, 616 deletions
diff --git a/src/lib/libcrypto/bytestring/bs_cbs.c b/src/lib/libcrypto/bytestring/bs_cbs.c
deleted file mode 100644
index 7852d78503..0000000000
--- a/src/lib/libcrypto/bytestring/bs_cbs.c
+++ /dev/null
@@ -1,616 +0,0 @@
1/* $OpenBSD: bs_cbs.c,v 1.3 2024/05/25 15:12:47 tb Exp $ */
2/*
3 * Copyright (c) 2014, Google Inc.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
12 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
14 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
15 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <stdint.h>
19#include <stdlib.h>
20#include <string.h>
21
22#include "bytestring.h"
23
24void
25CBS_init(CBS *cbs, const uint8_t *data, size_t len)
26{
27 cbs->data = data;
28 cbs->initial_len = len;
29 cbs->len = len;
30}
31
32void
33CBS_dup(const CBS *cbs, CBS *out)
34{
35 CBS_init(out, CBS_data(cbs), CBS_len(cbs));
36 out->initial_len = cbs->initial_len;
37}
38
39static int
40cbs_get(CBS *cbs, const uint8_t **p, size_t n)
41{
42 if (cbs->len < n)
43 return 0;
44
45 *p = cbs->data;
46 cbs->data += n;
47 cbs->len -= n;
48 return 1;
49}
50
51static int
52cbs_peek(CBS *cbs, const uint8_t **p, size_t n)
53{
54 if (cbs->len < n)
55 return 0;
56
57 *p = cbs->data;
58 return 1;
59}
60
61size_t
62CBS_offset(const CBS *cbs)
63{
64 return cbs->initial_len - cbs->len;
65}
66
67int
68CBS_skip(CBS *cbs, size_t len)
69{
70 const uint8_t *dummy;
71 return cbs_get(cbs, &dummy, len);
72}
73
74const uint8_t *
75CBS_data(const CBS *cbs)
76{
77 return cbs->data;
78}
79
80size_t
81CBS_len(const CBS *cbs)
82{
83 return cbs->len;
84}
85
86int
87CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len)
88{
89 free(*out_ptr);
90 *out_ptr = NULL;
91 *out_len = 0;
92
93 if (cbs->len == 0)
94 return 1;
95
96 if ((*out_ptr = malloc(cbs->len)) == NULL)
97 return 0;
98
99 memcpy(*out_ptr, cbs->data, cbs->len);
100
101 *out_len = cbs->len;
102 return 1;
103}
104
105int
106CBS_strdup(const CBS *cbs, char **out_ptr)
107{
108 free(*out_ptr);
109 *out_ptr = NULL;
110
111 if (CBS_contains_zero_byte(cbs))
112 return 0;
113
114 *out_ptr = strndup((const char *)cbs->data, cbs->len);
115 return (*out_ptr != NULL);
116}
117
118int
119CBS_write_bytes(const CBS *cbs, uint8_t *dst, size_t dst_len, size_t *copied)
120{
121 if (dst_len < cbs->len)
122 return 0;
123
124 memmove(dst, cbs->data, cbs->len);
125
126 if (copied != NULL)
127 *copied = cbs->len;
128
129 return 1;
130}
131
132int
133CBS_contains_zero_byte(const CBS *cbs)
134{
135 return memchr(cbs->data, 0, cbs->len) != NULL;
136}
137
138int
139CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len)
140{
141 if (len != cbs->len)
142 return 0;
143
144 return timingsafe_memcmp(cbs->data, data, len) == 0;
145}
146
147static int
148cbs_get_u(CBS *cbs, uint32_t *out, size_t len)
149{
150 uint32_t result = 0;
151 size_t i;
152 const uint8_t *data;
153
154 if (len < 1 || len > 4)
155 return 0;
156
157 if (!cbs_get(cbs, &data, len))
158 return 0;
159
160 for (i = 0; i < len; i++) {
161 result <<= 8;
162 result |= data[i];
163 }
164 *out = result;
165 return 1;
166}
167
168int
169CBS_get_u8(CBS *cbs, uint8_t *out)
170{
171 const uint8_t *v;
172
173 if (!cbs_get(cbs, &v, 1))
174 return 0;
175
176 *out = *v;
177 return 1;
178}
179
180int
181CBS_get_u16(CBS *cbs, uint16_t *out)
182{
183 uint32_t v;
184
185 if (!cbs_get_u(cbs, &v, 2))
186 return 0;
187
188 *out = v;
189 return 1;
190}
191
192int
193CBS_get_u24(CBS *cbs, uint32_t *out)
194{
195 return cbs_get_u(cbs, out, 3);
196}
197
198int
199CBS_get_u32(CBS *cbs, uint32_t *out)
200{
201 return cbs_get_u(cbs, out, 4);
202}
203
204int
205CBS_get_u64(CBS *cbs, uint64_t *out)
206{
207 uint32_t a, b;
208
209 if (cbs->len < 8)
210 return 0;
211
212 if (!CBS_get_u32(cbs, &a))
213 return 0;
214 if (!CBS_get_u32(cbs, &b))
215 return 0;
216
217 *out = (uint64_t)a << 32 | b;
218 return 1;
219}
220
221int
222CBS_get_last_u8(CBS *cbs, uint8_t *out)
223{
224 if (cbs->len == 0)
225 return 0;
226
227 *out = cbs->data[cbs->len - 1];
228 cbs->len--;
229 return 1;
230}
231
232int
233CBS_get_bytes(CBS *cbs, CBS *out, size_t len)
234{
235 const uint8_t *v;
236
237 if (!cbs_get(cbs, &v, len))
238 return 0;
239
240 CBS_init(out, v, len);
241 return 1;
242}
243
244static int
245cbs_get_length_prefixed(CBS *cbs, CBS *out, size_t len_len)
246{
247 uint32_t len;
248
249 if (!cbs_get_u(cbs, &len, len_len))
250 return 0;
251
252 return CBS_get_bytes(cbs, out, len);
253}
254
255int
256CBS_get_u8_length_prefixed(CBS *cbs, CBS *out)
257{
258 return cbs_get_length_prefixed(cbs, out, 1);
259}
260
261int
262CBS_get_u16_length_prefixed(CBS *cbs, CBS *out)
263{
264 return cbs_get_length_prefixed(cbs, out, 2);
265}
266
267int
268CBS_get_u24_length_prefixed(CBS *cbs, CBS *out)
269{
270 return cbs_get_length_prefixed(cbs, out, 3);
271}
272
273static int
274cbs_peek_u(CBS *cbs, uint32_t *out, size_t len)
275{
276 uint32_t result = 0;
277 size_t i;
278 const uint8_t *data;
279
280 if (len < 1 || len > 4)
281 return 0;
282
283 if (!cbs_peek(cbs, &data, len))
284 return 0;
285
286 for (i = 0; i < len; i++) {
287 result <<= 8;
288 result |= data[i];
289 }
290 *out = result;
291 return 1;
292}
293
294int
295CBS_peek_u8(CBS *cbs, uint8_t *out)
296{
297 const uint8_t *v;
298
299 if (!cbs_peek(cbs, &v, 1))
300 return 0;
301
302 *out = *v;
303 return 1;
304}
305
306int
307CBS_peek_u16(CBS *cbs, uint16_t *out)
308{
309 uint32_t v;
310
311 if (!cbs_peek_u(cbs, &v, 2))
312 return 0;
313
314 *out = v;
315 return 1;
316}
317
318int
319CBS_peek_u24(CBS *cbs, uint32_t *out)
320{
321 return cbs_peek_u(cbs, out, 3);
322}
323
324int
325CBS_peek_u32(CBS *cbs, uint32_t *out)
326{
327 return cbs_peek_u(cbs, out, 4);
328}
329
330int
331CBS_peek_last_u8(CBS *cbs, uint8_t *out)
332{
333 if (cbs->len == 0)
334 return 0;
335
336 *out = cbs->data[cbs->len - 1];
337 return 1;
338}
339
340int
341CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned int *out_tag,
342 size_t *out_header_len)
343{
344 return cbs_get_any_asn1_element_internal(cbs, out, out_tag,
345 out_header_len, 1);
346}
347
348/*
349 * Review X.690 for details on ASN.1 DER encoding.
350 *
351 * If non-strict mode is enabled, then DER rules are relaxed
352 * for indefinite constructs (violates DER but a little closer to BER).
353 * Non-strict mode should only be used by bs_ber.c
354 *
355 * Sections 8, 10 and 11 for DER encoding
356 */
357int
358cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned int *out_tag,
359 size_t *out_header_len, int strict)
360{
361 uint8_t tag, length_byte;
362 CBS header = *cbs;
363 CBS throwaway;
364 size_t len;
365
366 if (out == NULL)
367 out = &throwaway;
368
369 /*
370 * Get identifier octet and length octet. Only 1 octet for each
371 * is a CBS limitation.
372 */
373 if (!CBS_get_u8(&header, &tag) || !CBS_get_u8(&header, &length_byte))
374 return 0;
375
376 /* CBS limitation: long form tags are not supported. */
377 if ((tag & 0x1f) == 0x1f)
378 return 0;
379
380 if (out_tag != NULL)
381 *out_tag = tag;
382
383 if ((length_byte & 0x80) == 0) {
384 /* Short form length. */
385 len = ((size_t) length_byte) + 2;
386 if (out_header_len != NULL)
387 *out_header_len = 2;
388
389 } else {
390 /* Long form length. */
391 const size_t num_bytes = length_byte & 0x7f;
392 uint32_t len32;
393
394 /* ASN.1 reserved value for future extensions */
395 if (num_bytes == 0x7f)
396 return 0;
397
398 /* Handle indefinite form length */
399 if (num_bytes == 0) {
400 /* DER encoding doesn't allow for indefinite form. */
401 if (strict)
402 return 0;
403
404 /* Primitive cannot use indefinite in BER or DER. */
405 if ((tag & CBS_ASN1_CONSTRUCTED) == 0)
406 return 0;
407
408 /* Constructed, indefinite length allowed in BER. */
409 if (out_header_len != NULL)
410 *out_header_len = 2;
411 return CBS_get_bytes(cbs, out, 2);
412 }
413
414 /* CBS limitation. */
415 if (num_bytes > 4)
416 return 0;
417
418 if (!cbs_get_u(&header, &len32, num_bytes))
419 return 0;
420
421 /* DER has a minimum length octet requirement. */
422 if (len32 < 128)
423 /* Should have used short form instead */
424 return 0;
425
426 if ((len32 >> ((num_bytes - 1) * 8)) == 0)
427 /* Length should have been at least one byte shorter. */
428 return 0;
429
430 len = len32;
431 if (len + 2 + num_bytes < len)
432 /* Overflow. */
433 return 0;
434
435 len += 2 + num_bytes;
436 if (out_header_len != NULL)
437 *out_header_len = 2 + num_bytes;
438 }
439
440 return CBS_get_bytes(cbs, out, len);
441}
442
443static int
444cbs_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value, int skip_header)
445{
446 size_t header_len;
447 unsigned int tag;
448 CBS throwaway;
449
450 if (out == NULL)
451 out = &throwaway;
452
453 if (!CBS_get_any_asn1_element(cbs, out, &tag, &header_len) ||
454 tag != tag_value)
455 return 0;
456
457 if (skip_header && !CBS_skip(out, header_len))
458 return 0;
459
460 return 1;
461}
462
463int
464CBS_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value)
465{
466 return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */);
467}
468
469int
470CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned int tag_value)
471{
472 return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */);
473}
474
475int
476CBS_peek_asn1_tag(const CBS *cbs, unsigned int tag_value)
477{
478 if (CBS_len(cbs) < 1)
479 return 0;
480
481 /*
482 * Tag number 31 indicates the start of a long form number.
483 * This is valid in ASN.1, but CBS only supports short form.
484 */
485 if ((tag_value & 0x1f) == 0x1f)
486 return 0;
487
488 return CBS_data(cbs)[0] == tag_value;
489}
490
491/* Encoding details are in ASN.1: X.690 section 8.3 */
492int
493CBS_get_asn1_uint64(CBS *cbs, uint64_t *out)
494{
495 CBS bytes;
496 const uint8_t *data;
497 size_t i, len;
498
499 if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER))
500 return 0;
501
502 *out = 0;
503 data = CBS_data(&bytes);
504 len = CBS_len(&bytes);
505
506 if (len == 0)
507 /* An INTEGER is encoded with at least one content octet. */
508 return 0;
509
510 if ((data[0] & 0x80) != 0)
511 /* Negative number. */
512 return 0;
513
514 if (data[0] == 0 && len > 1 && (data[1] & 0x80) == 0)
515 /* Violates smallest encoding rule: excessive leading zeros. */
516 return 0;
517
518 for (i = 0; i < len; i++) {
519 if ((*out >> 56) != 0)
520 /* Too large to represent as a uint64_t. */
521 return 0;
522
523 *out <<= 8;
524 *out |= data[i];
525 }
526
527 return 1;
528}
529
530int
531CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, unsigned int tag)
532{
533 if (CBS_peek_asn1_tag(cbs, tag)) {
534 if (!CBS_get_asn1(cbs, out, tag))
535 return 0;
536
537 *out_present = 1;
538 } else {
539 *out_present = 0;
540 }
541 return 1;
542}
543
544int
545CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present,
546 unsigned int tag)
547{
548 CBS child;
549 int present;
550
551 if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
552 return 0;
553
554 if (present) {
555 if (!CBS_get_asn1(&child, out, CBS_ASN1_OCTETSTRING) ||
556 CBS_len(&child) != 0)
557 return 0;
558 } else {
559 CBS_init(out, NULL, 0);
560 }
561 if (out_present)
562 *out_present = present;
563
564 return 1;
565}
566
567int
568CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, unsigned int tag,
569 uint64_t default_value)
570{
571 CBS child;
572 int present;
573
574 if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
575 return 0;
576
577 if (present) {
578 if (!CBS_get_asn1_uint64(&child, out) ||
579 CBS_len(&child) != 0)
580 return 0;
581 } else {
582 *out = default_value;
583 }
584 return 1;
585}
586
587int
588CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned int tag,
589 int default_value)
590{
591 CBS child, child2;
592 int present;
593
594 if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
595 return 0;
596
597 if (present) {
598 uint8_t boolean;
599
600 if (!CBS_get_asn1(&child, &child2, CBS_ASN1_BOOLEAN) ||
601 CBS_len(&child2) != 1 || CBS_len(&child) != 0)
602 return 0;
603
604 boolean = CBS_data(&child2)[0];
605 if (boolean == 0)
606 *out = 0;
607 else if (boolean == 0xff)
608 *out = 1;
609 else
610 return 0;
611
612 } else {
613 *out = default_value;
614 }
615 return 1;
616}
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