/src/mbedtls/library/asn1parse.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Generic ASN.1 parsing |
3 | | * |
4 | | * Copyright The Mbed TLS Contributors |
5 | | * SPDX-License-Identifier: Apache-2.0 |
6 | | * |
7 | | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
8 | | * not use this file except in compliance with the License. |
9 | | * You may obtain a copy of the License at |
10 | | * |
11 | | * http://www.apache.org/licenses/LICENSE-2.0 |
12 | | * |
13 | | * Unless required by applicable law or agreed to in writing, software |
14 | | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
15 | | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
16 | | * See the License for the specific language governing permissions and |
17 | | * limitations under the License. |
18 | | */ |
19 | | |
20 | | #include "common.h" |
21 | | |
22 | | #if defined(MBEDTLS_ASN1_PARSE_C) |
23 | | |
24 | | #include "mbedtls/asn1.h" |
25 | | #include "mbedtls/platform_util.h" |
26 | | #include "mbedtls/error.h" |
27 | | |
28 | | #include <string.h> |
29 | | |
30 | | #if defined(MBEDTLS_BIGNUM_C) |
31 | | #include "mbedtls/bignum.h" |
32 | | #endif |
33 | | |
34 | | #include "mbedtls/platform.h" |
35 | | |
36 | | /* |
37 | | * ASN.1 DER decoding routines |
38 | | */ |
39 | | int mbedtls_asn1_get_len(unsigned char **p, |
40 | | const unsigned char *end, |
41 | | size_t *len) |
42 | 1.43M | { |
43 | 1.43M | if ((end - *p) < 1) { |
44 | 86 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
45 | 86 | } |
46 | | |
47 | 1.43M | if ((**p & 0x80) == 0) { |
48 | 1.26M | *len = *(*p)++; |
49 | 1.26M | } else { |
50 | 173k | switch (**p & 0x7F) { |
51 | 22.2k | case 1: |
52 | 22.2k | if ((end - *p) < 2) { |
53 | 42 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
54 | 42 | } |
55 | | |
56 | 22.1k | *len = (*p)[1]; |
57 | 22.1k | (*p) += 2; |
58 | 22.1k | break; |
59 | | |
60 | 150k | case 2: |
61 | 150k | if ((end - *p) < 3) { |
62 | 59 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
63 | 59 | } |
64 | | |
65 | 150k | *len = ((size_t) (*p)[1] << 8) | (*p)[2]; |
66 | 150k | (*p) += 3; |
67 | 150k | break; |
68 | | |
69 | 123 | case 3: |
70 | 123 | if ((end - *p) < 4) { |
71 | 62 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
72 | 62 | } |
73 | | |
74 | 61 | *len = ((size_t) (*p)[1] << 16) | |
75 | 61 | ((size_t) (*p)[2] << 8) | (*p)[3]; |
76 | 61 | (*p) += 4; |
77 | 61 | break; |
78 | | |
79 | 122 | case 4: |
80 | 122 | if ((end - *p) < 5) { |
81 | 63 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
82 | 63 | } |
83 | | |
84 | 59 | *len = ((size_t) (*p)[1] << 24) | ((size_t) (*p)[2] << 16) | |
85 | 59 | ((size_t) (*p)[3] << 8) | (*p)[4]; |
86 | 59 | (*p) += 5; |
87 | 59 | break; |
88 | | |
89 | 280 | default: |
90 | 280 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
91 | 173k | } |
92 | 173k | } |
93 | | |
94 | 1.43M | if (*len > (size_t) (end - *p)) { |
95 | 656 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
96 | 656 | } |
97 | | |
98 | 1.43M | return 0; |
99 | 1.43M | } |
100 | | |
101 | | int mbedtls_asn1_get_tag(unsigned char **p, |
102 | | const unsigned char *end, |
103 | | size_t *len, int tag) |
104 | 1.25M | { |
105 | 1.25M | if ((end - *p) < 1) { |
106 | 90 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
107 | 90 | } |
108 | | |
109 | 1.25M | if (**p != tag) { |
110 | 104k | return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG; |
111 | 104k | } |
112 | | |
113 | 1.14M | (*p)++; |
114 | | |
115 | 1.14M | return mbedtls_asn1_get_len(p, end, len); |
116 | 1.25M | } |
117 | | |
118 | | int mbedtls_asn1_get_bool(unsigned char **p, |
119 | | const unsigned char *end, |
120 | | int *val) |
121 | 76.0k | { |
122 | 76.0k | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
123 | 76.0k | size_t len; |
124 | | |
125 | 76.0k | if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_BOOLEAN)) != 0) { |
126 | 61.2k | return ret; |
127 | 61.2k | } |
128 | | |
129 | 14.8k | if (len != 1) { |
130 | 16 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
131 | 16 | } |
132 | | |
133 | 14.8k | *val = (**p != 0) ? 1 : 0; |
134 | 14.8k | (*p)++; |
135 | | |
136 | 14.8k | return 0; |
137 | 14.8k | } |
138 | | |
139 | | static int asn1_get_tagged_int(unsigned char **p, |
140 | | const unsigned char *end, |
141 | | int tag, int *val) |
142 | 31.1k | { |
143 | 31.1k | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
144 | 31.1k | size_t len; |
145 | | |
146 | 31.1k | if ((ret = mbedtls_asn1_get_tag(p, end, &len, tag)) != 0) { |
147 | 207 | return ret; |
148 | 207 | } |
149 | | |
150 | | /* |
151 | | * len==0 is malformed (0 must be represented as 020100 for INTEGER, |
152 | | * or 0A0100 for ENUMERATED tags |
153 | | */ |
154 | 30.9k | if (len == 0) { |
155 | 15 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
156 | 15 | } |
157 | | /* This is a cryptography library. Reject negative integers. */ |
158 | 30.8k | if ((**p & 0x80) != 0) { |
159 | 17 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
160 | 17 | } |
161 | | |
162 | | /* Skip leading zeros. */ |
163 | 34.8k | while (len > 0 && **p == 0) { |
164 | 3.93k | ++(*p); |
165 | 3.93k | --len; |
166 | 3.93k | } |
167 | | |
168 | | /* Reject integers that don't fit in an int. This code assumes that |
169 | | * the int type has no padding bit. */ |
170 | 30.8k | if (len > sizeof(int)) { |
171 | 84 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
172 | 84 | } |
173 | 30.7k | if (len == sizeof(int) && (**p & 0x80) != 0) { |
174 | 15 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
175 | 15 | } |
176 | | |
177 | 30.7k | *val = 0; |
178 | 61.5k | while (len-- > 0) { |
179 | 30.7k | *val = (*val << 8) | **p; |
180 | 30.7k | (*p)++; |
181 | 30.7k | } |
182 | | |
183 | 30.7k | return 0; |
184 | 30.7k | } |
185 | | |
186 | | int mbedtls_asn1_get_int(unsigned char **p, |
187 | | const unsigned char *end, |
188 | | int *val) |
189 | 31.1k | { |
190 | 31.1k | return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_INTEGER, val); |
191 | 31.1k | } |
192 | | |
193 | | int mbedtls_asn1_get_enum(unsigned char **p, |
194 | | const unsigned char *end, |
195 | | int *val) |
196 | 0 | { |
197 | 0 | return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_ENUMERATED, val); |
198 | 0 | } |
199 | | |
200 | | #if defined(MBEDTLS_BIGNUM_C) |
201 | | int mbedtls_asn1_get_mpi(unsigned char **p, |
202 | | const unsigned char *end, |
203 | | mbedtls_mpi *X) |
204 | 0 | { |
205 | 0 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
206 | 0 | size_t len; |
207 | |
|
208 | 0 | if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { |
209 | 0 | return ret; |
210 | 0 | } |
211 | | |
212 | 0 | ret = mbedtls_mpi_read_binary(X, *p, len); |
213 | |
|
214 | 0 | *p += len; |
215 | |
|
216 | 0 | return ret; |
217 | 0 | } |
218 | | #endif /* MBEDTLS_BIGNUM_C */ |
219 | | |
220 | | int mbedtls_asn1_get_bitstring(unsigned char **p, const unsigned char *end, |
221 | | mbedtls_asn1_bitstring *bs) |
222 | 46 | { |
223 | 46 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
224 | | |
225 | | /* Certificate type is a single byte bitstring */ |
226 | 46 | if ((ret = mbedtls_asn1_get_tag(p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING)) != 0) { |
227 | 22 | return ret; |
228 | 22 | } |
229 | | |
230 | | /* Check length, subtract one for actual bit string length */ |
231 | 24 | if (bs->len < 1) { |
232 | 0 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
233 | 0 | } |
234 | 24 | bs->len -= 1; |
235 | | |
236 | | /* Get number of unused bits, ensure unused bits <= 7 */ |
237 | 24 | bs->unused_bits = **p; |
238 | 24 | if (bs->unused_bits > 7) { |
239 | 9 | return MBEDTLS_ERR_ASN1_INVALID_LENGTH; |
240 | 9 | } |
241 | 15 | (*p)++; |
242 | | |
243 | | /* Get actual bitstring */ |
244 | 15 | bs->p = *p; |
245 | 15 | *p += bs->len; |
246 | | |
247 | 15 | if (*p != end) { |
248 | 9 | return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; |
249 | 9 | } |
250 | | |
251 | 6 | return 0; |
252 | 15 | } |
253 | | |
254 | | /* |
255 | | * Traverse an ASN.1 "SEQUENCE OF <tag>" |
256 | | * and call a callback for each entry found. |
257 | | */ |
258 | | int mbedtls_asn1_traverse_sequence_of( |
259 | | unsigned char **p, |
260 | | const unsigned char *end, |
261 | | unsigned char tag_must_mask, unsigned char tag_must_val, |
262 | | unsigned char tag_may_mask, unsigned char tag_may_val, |
263 | | int (*cb)(void *ctx, int tag, |
264 | | unsigned char *start, size_t len), |
265 | | void *ctx) |
266 | 190 | { |
267 | 190 | int ret; |
268 | 190 | size_t len; |
269 | | |
270 | | /* Get main sequence tag */ |
271 | 190 | if ((ret = mbedtls_asn1_get_tag(p, end, &len, |
272 | 190 | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { |
273 | 94 | return ret; |
274 | 94 | } |
275 | | |
276 | 96 | if (*p + len != end) { |
277 | 17 | return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; |
278 | 17 | } |
279 | | |
280 | 172 | while (*p < end) { |
281 | 151 | unsigned char const tag = *(*p)++; |
282 | | |
283 | 151 | if ((tag & tag_must_mask) != tag_must_val) { |
284 | 27 | return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG; |
285 | 27 | } |
286 | | |
287 | 124 | if ((ret = mbedtls_asn1_get_len(p, end, &len)) != 0) { |
288 | 31 | return ret; |
289 | 31 | } |
290 | | |
291 | 93 | if ((tag & tag_may_mask) == tag_may_val) { |
292 | 93 | if (cb != NULL) { |
293 | 93 | ret = cb(ctx, tag, *p, len); |
294 | 93 | if (ret != 0) { |
295 | 0 | return ret; |
296 | 0 | } |
297 | 93 | } |
298 | 93 | } |
299 | | |
300 | 93 | *p += len; |
301 | 93 | } |
302 | | |
303 | 21 | return 0; |
304 | 79 | } |
305 | | |
306 | | /* |
307 | | * Get a bit string without unused bits |
308 | | */ |
309 | | int mbedtls_asn1_get_bitstring_null(unsigned char **p, const unsigned char *end, |
310 | | size_t *len) |
311 | 42.5k | { |
312 | 42.5k | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
313 | | |
314 | 42.5k | if ((ret = mbedtls_asn1_get_tag(p, end, len, MBEDTLS_ASN1_BIT_STRING)) != 0) { |
315 | 86 | return ret; |
316 | 86 | } |
317 | | |
318 | 42.5k | if (*len == 0) { |
319 | 13 | return MBEDTLS_ERR_ASN1_INVALID_DATA; |
320 | 13 | } |
321 | 42.4k | --(*len); |
322 | | |
323 | 42.4k | if (**p != 0) { |
324 | 23 | return MBEDTLS_ERR_ASN1_INVALID_DATA; |
325 | 23 | } |
326 | 42.4k | ++(*p); |
327 | | |
328 | 42.4k | return 0; |
329 | 42.4k | } |
330 | | |
331 | | void mbedtls_asn1_sequence_free(mbedtls_asn1_sequence *seq) |
332 | 89.6k | { |
333 | 90.1k | while (seq != NULL) { |
334 | 506 | mbedtls_asn1_sequence *next = seq->next; |
335 | 506 | mbedtls_free(seq); |
336 | 506 | seq = next; |
337 | 506 | } |
338 | 89.6k | } |
339 | | |
340 | | typedef struct { |
341 | | int tag; |
342 | | mbedtls_asn1_sequence *cur; |
343 | | } asn1_get_sequence_of_cb_ctx_t; |
344 | | |
345 | | static int asn1_get_sequence_of_cb(void *ctx, |
346 | | int tag, |
347 | | unsigned char *start, |
348 | | size_t len) |
349 | 93 | { |
350 | 93 | asn1_get_sequence_of_cb_ctx_t *cb_ctx = |
351 | 93 | (asn1_get_sequence_of_cb_ctx_t *) ctx; |
352 | 93 | mbedtls_asn1_sequence *cur = |
353 | 93 | cb_ctx->cur; |
354 | | |
355 | 93 | if (cur->buf.p != NULL) { |
356 | 55 | cur->next = |
357 | 55 | mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence)); |
358 | | |
359 | 55 | if (cur->next == NULL) { |
360 | 0 | return MBEDTLS_ERR_ASN1_ALLOC_FAILED; |
361 | 0 | } |
362 | | |
363 | 55 | cur = cur->next; |
364 | 55 | } |
365 | | |
366 | 93 | cur->buf.p = start; |
367 | 93 | cur->buf.len = len; |
368 | 93 | cur->buf.tag = tag; |
369 | | |
370 | 93 | cb_ctx->cur = cur; |
371 | 93 | return 0; |
372 | 93 | } |
373 | | |
374 | | /* |
375 | | * Parses and splits an ASN.1 "SEQUENCE OF <tag>" |
376 | | */ |
377 | | int mbedtls_asn1_get_sequence_of(unsigned char **p, |
378 | | const unsigned char *end, |
379 | | mbedtls_asn1_sequence *cur, |
380 | | int tag) |
381 | 190 | { |
382 | 190 | asn1_get_sequence_of_cb_ctx_t cb_ctx = { tag, cur }; |
383 | 190 | memset(cur, 0, sizeof(mbedtls_asn1_sequence)); |
384 | 190 | return mbedtls_asn1_traverse_sequence_of( |
385 | 190 | p, end, 0xFF, tag, 0, 0, |
386 | 190 | asn1_get_sequence_of_cb, &cb_ctx); |
387 | 190 | } |
388 | | |
389 | | int mbedtls_asn1_get_alg(unsigned char **p, |
390 | | const unsigned char *end, |
391 | | mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params) |
392 | 73.7k | { |
393 | 73.7k | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
394 | 73.7k | size_t len; |
395 | | |
396 | 73.7k | if ((ret = mbedtls_asn1_get_tag(p, end, &len, |
397 | 73.7k | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { |
398 | 238 | return ret; |
399 | 238 | } |
400 | | |
401 | 73.4k | if ((end - *p) < 1) { |
402 | 0 | return MBEDTLS_ERR_ASN1_OUT_OF_DATA; |
403 | 0 | } |
404 | | |
405 | 73.4k | alg->tag = **p; |
406 | 73.4k | end = *p + len; |
407 | | |
408 | 73.4k | if ((ret = mbedtls_asn1_get_tag(p, end, &alg->len, MBEDTLS_ASN1_OID)) != 0) { |
409 | 83 | return ret; |
410 | 83 | } |
411 | | |
412 | 73.4k | alg->p = *p; |
413 | 73.4k | *p += alg->len; |
414 | | |
415 | 73.4k | if (*p == end) { |
416 | 7.41k | mbedtls_platform_zeroize(params, sizeof(mbedtls_asn1_buf)); |
417 | 7.41k | return 0; |
418 | 7.41k | } |
419 | | |
420 | 65.9k | params->tag = **p; |
421 | 65.9k | (*p)++; |
422 | | |
423 | 65.9k | if ((ret = mbedtls_asn1_get_len(p, end, ¶ms->len)) != 0) { |
424 | 107 | return ret; |
425 | 107 | } |
426 | | |
427 | 65.8k | params->p = *p; |
428 | 65.8k | *p += params->len; |
429 | | |
430 | 65.8k | if (*p != end) { |
431 | 3 | return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; |
432 | 3 | } |
433 | | |
434 | 65.8k | return 0; |
435 | 65.8k | } |
436 | | |
437 | | int mbedtls_asn1_get_alg_null(unsigned char **p, |
438 | | const unsigned char *end, |
439 | | mbedtls_asn1_buf *alg) |
440 | 0 | { |
441 | 0 | int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
442 | 0 | mbedtls_asn1_buf params; |
443 | |
|
444 | 0 | memset(¶ms, 0, sizeof(mbedtls_asn1_buf)); |
445 | |
|
446 | 0 | if ((ret = mbedtls_asn1_get_alg(p, end, alg, ¶ms)) != 0) { |
447 | 0 | return ret; |
448 | 0 | } |
449 | | |
450 | 0 | if ((params.tag != MBEDTLS_ASN1_NULL && params.tag != 0) || params.len != 0) { |
451 | 0 | return MBEDTLS_ERR_ASN1_INVALID_DATA; |
452 | 0 | } |
453 | | |
454 | 0 | return 0; |
455 | 0 | } |
456 | | |
457 | | #if !defined(MBEDTLS_DEPRECATED_REMOVED) |
458 | | void mbedtls_asn1_free_named_data(mbedtls_asn1_named_data *cur) |
459 | 0 | { |
460 | 0 | if (cur == NULL) { |
461 | 0 | return; |
462 | 0 | } |
463 | | |
464 | 0 | mbedtls_free(cur->oid.p); |
465 | 0 | mbedtls_free(cur->val.p); |
466 | |
|
467 | 0 | mbedtls_platform_zeroize(cur, sizeof(mbedtls_asn1_named_data)); |
468 | 0 | } |
469 | | #endif /* MBEDTLS_DEPRECATED_REMOVED */ |
470 | | |
471 | | void mbedtls_asn1_free_named_data_list(mbedtls_asn1_named_data **head) |
472 | 0 | { |
473 | 0 | mbedtls_asn1_named_data *cur; |
474 | |
|
475 | 0 | while ((cur = *head) != NULL) { |
476 | 0 | *head = cur->next; |
477 | 0 | mbedtls_free(cur->oid.p); |
478 | 0 | mbedtls_free(cur->val.p); |
479 | 0 | mbedtls_free(cur); |
480 | 0 | } |
481 | 0 | } |
482 | | |
483 | | void mbedtls_asn1_free_named_data_list_shallow(mbedtls_asn1_named_data *name) |
484 | 60.2k | { |
485 | 137k | for (mbedtls_asn1_named_data *next; name != NULL; name = next) { |
486 | 77.4k | next = name->next; |
487 | 77.4k | mbedtls_free(name); |
488 | 77.4k | } |
489 | 60.2k | } |
490 | | |
491 | | const mbedtls_asn1_named_data *mbedtls_asn1_find_named_data(const mbedtls_asn1_named_data *list, |
492 | | const char *oid, size_t len) |
493 | 0 | { |
494 | 0 | while (list != NULL) { |
495 | 0 | if (list->oid.len == len && |
496 | 0 | memcmp(list->oid.p, oid, len) == 0) { |
497 | 0 | break; |
498 | 0 | } |
499 | | |
500 | 0 | list = list->next; |
501 | 0 | } |
502 | |
|
503 | 0 | return list; |
504 | 0 | } |
505 | | |
506 | | #endif /* MBEDTLS_ASN1_PARSE_C */ |