Coverage Report

Created: 2023-12-13 08:18

/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
2.48M
{
43
2.48M
    if ((end - *p) < 1) {
44
135
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
45
135
    }
46
47
2.48M
    if ((**p & 0x80) == 0) {
48
2.17M
        *len = *(*p)++;
49
2.17M
    } else {
50
306k
        switch (**p & 0x7F) {
51
40.9k
            case 1:
52
40.9k
                if ((end - *p) < 2) {
53
72
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
54
72
                }
55
56
40.8k
                *len = (*p)[1];
57
40.8k
                (*p) += 2;
58
40.8k
                break;
59
60
264k
            case 2:
61
264k
                if ((end - *p) < 3) {
62
97
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
63
97
                }
64
65
264k
                *len = ((size_t) (*p)[1] << 8) | (*p)[2];
66
264k
                (*p) += 3;
67
264k
                break;
68
69
215
            case 3:
70
215
                if ((end - *p) < 4) {
71
98
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
72
98
                }
73
74
117
                *len = ((size_t) (*p)[1] << 16) |
75
117
                       ((size_t) (*p)[2] << 8) | (*p)[3];
76
117
                (*p) += 4;
77
117
                break;
78
79
211
            case 4:
80
211
                if ((end - *p) < 5) {
81
99
                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
82
99
                }
83
84
112
                *len = ((size_t) (*p)[1] << 24) | ((size_t) (*p)[2] << 16) |
85
112
                       ((size_t) (*p)[3] << 8) |           (*p)[4];
86
112
                (*p) += 5;
87
112
                break;
88
89
390
            default:
90
390
                return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
91
306k
        }
92
306k
    }
93
94
2.48M
    if (*len > (size_t) (end - *p)) {
95
1.00k
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
96
1.00k
    }
97
98
2.48M
    return 0;
99
2.48M
}
100
101
int mbedtls_asn1_get_tag(unsigned char **p,
102
                         const unsigned char *end,
103
                         size_t *len, int tag)
104
2.17M
{
105
2.17M
    if ((end - *p) < 1) {
106
150
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
107
150
    }
108
109
2.17M
    if (**p != tag) {
110
184k
        return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
111
184k
    }
112
113
1.99M
    (*p)++;
114
115
1.99M
    return mbedtls_asn1_get_len(p, end, len);
116
2.17M
}
117
118
int mbedtls_asn1_get_bool(unsigned char **p,
119
                          const unsigned char *end,
120
                          int *val)
121
133k
{
122
133k
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
123
133k
    size_t len;
124
125
133k
    if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_BOOLEAN)) != 0) {
126
108k
        return ret;
127
108k
    }
128
129
25.0k
    if (len != 1) {
130
36
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
131
36
    }
132
133
25.0k
    *val = (**p != 0) ? 1 : 0;
134
25.0k
    (*p)++;
135
136
25.0k
    return 0;
137
25.0k
}
138
139
static int asn1_get_tagged_int(unsigned char **p,
140
                               const unsigned char *end,
141
                               int tag, int *val)
142
50.0k
{
143
50.0k
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
144
50.0k
    size_t len;
145
146
50.0k
    if ((ret = mbedtls_asn1_get_tag(p, end, &len, tag)) != 0) {
147
332
        return ret;
148
332
    }
149
150
    /*
151
     * len==0 is malformed (0 must be represented as 020100 for INTEGER,
152
     * or 0A0100 for ENUMERATED tags
153
     */
154
49.7k
    if (len == 0) {
155
24
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
156
24
    }
157
    /* This is a cryptography library. Reject negative integers. */
158
49.7k
    if ((**p & 0x80) != 0) {
159
21
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
160
21
    }
161
162
    /* Skip leading zeros. */
163
55.2k
    while (len > 0 && **p == 0) {
164
5.52k
        ++(*p);
165
5.52k
        --len;
166
5.52k
    }
167
168
    /* Reject integers that don't fit in an int. This code assumes that
169
     * the int type has no padding bit. */
170
49.6k
    if (len > sizeof(int)) {
171
134
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
172
134
    }
173
49.5k
    if (len == sizeof(int) && (**p & 0x80) != 0) {
174
18
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
175
18
    }
176
177
49.5k
    *val = 0;
178
99.0k
    while (len-- > 0) {
179
49.4k
        *val = (*val << 8) | **p;
180
49.4k
        (*p)++;
181
49.4k
    }
182
183
49.5k
    return 0;
184
49.5k
}
185
186
int mbedtls_asn1_get_int(unsigned char **p,
187
                         const unsigned char *end,
188
                         int *val)
189
50.0k
{
190
50.0k
    return asn1_get_tagged_int(p, end, MBEDTLS_ASN1_INTEGER, val);
191
50.0k
}
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
138
{
223
138
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
224
225
    /* Certificate type is a single byte bitstring */
226
138
    if ((ret = mbedtls_asn1_get_tag(p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
227
47
        return ret;
228
47
    }
229
230
    /* Check length, subtract one for actual bit string length */
231
91
    if (bs->len < 1) {
232
20
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
233
20
    }
234
71
    bs->len -= 1;
235
236
    /* Get number of unused bits, ensure unused bits <= 7 */
237
71
    bs->unused_bits = **p;
238
71
    if (bs->unused_bits > 7) {
239
20
        return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
240
20
    }
241
51
    (*p)++;
242
243
    /* Get actual bitstring */
244
51
    bs->p = *p;
245
51
    *p += bs->len;
246
247
51
    if (*p != end) {
248
19
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
249
19
    }
250
251
32
    return 0;
252
51
}
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
447
{
267
447
    int ret;
268
447
    size_t len;
269
270
    /* Get main sequence tag */
271
447
    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
272
447
                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
273
212
        return ret;
274
212
    }
275
276
235
    if (*p + len != end) {
277
26
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
278
26
    }
279
280
924
    while (*p < end) {
281
893
        unsigned char const tag = *(*p)++;
282
283
893
        if ((tag & tag_must_mask) != tag_must_val) {
284
82
            return MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
285
82
        }
286
287
811
        if ((ret = mbedtls_asn1_get_len(p, end, &len)) != 0) {
288
96
            return ret;
289
96
        }
290
291
715
        if ((tag & tag_may_mask) == tag_may_val) {
292
715
            if (cb != NULL) {
293
715
                ret = cb(ctx, tag, *p, len);
294
715
                if (ret != 0) {
295
0
                    return ret;
296
0
                }
297
715
            }
298
715
        }
299
300
715
        *p += len;
301
715
    }
302
303
31
    return 0;
304
209
}
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
74.7k
{
312
74.7k
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
313
314
74.7k
    if ((ret = mbedtls_asn1_get_tag(p, end, len, MBEDTLS_ASN1_BIT_STRING)) != 0) {
315
116
        return ret;
316
116
    }
317
318
74.5k
    if (*len == 0) {
319
20
        return MBEDTLS_ERR_ASN1_INVALID_DATA;
320
20
    }
321
74.5k
    --(*len);
322
323
74.5k
    if (**p != 0) {
324
34
        return MBEDTLS_ERR_ASN1_INVALID_DATA;
325
34
    }
326
74.5k
    ++(*p);
327
328
74.5k
    return 0;
329
74.5k
}
330
331
void mbedtls_asn1_sequence_free(mbedtls_asn1_sequence *seq)
332
145k
{
333
146k
    while (seq != NULL) {
334
1.01k
        mbedtls_asn1_sequence *next = seq->next;
335
1.01k
        mbedtls_free(seq);
336
1.01k
        seq = next;
337
1.01k
    }
338
145k
}
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
715
{
350
715
    asn1_get_sequence_of_cb_ctx_t *cb_ctx =
351
715
        (asn1_get_sequence_of_cb_ctx_t *) ctx;
352
715
    mbedtls_asn1_sequence *cur =
353
715
        cb_ctx->cur;
354
355
715
    if (cur->buf.p != NULL) {
356
581
        cur->next =
357
581
            mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));
358
359
581
        if (cur->next == NULL) {
360
0
            return MBEDTLS_ERR_ASN1_ALLOC_FAILED;
361
0
        }
362
363
581
        cur = cur->next;
364
581
    }
365
366
715
    cur->buf.p = start;
367
715
    cur->buf.len = len;
368
715
    cur->buf.tag = tag;
369
370
715
    cb_ctx->cur = cur;
371
715
    return 0;
372
715
}
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
447
{
382
447
    asn1_get_sequence_of_cb_ctx_t cb_ctx = { tag, cur };
383
447
    memset(cur, 0, sizeof(mbedtls_asn1_sequence));
384
447
    return mbedtls_asn1_traverse_sequence_of(
385
447
        p, end, 0xFF, tag, 0, 0,
386
447
        asn1_get_sequence_of_cb, &cb_ctx);
387
447
}
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
124k
{
393
124k
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
394
124k
    size_t len;
395
396
124k
    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
397
124k
                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
398
382
        return ret;
399
382
    }
400
401
124k
    if ((end - *p) < 1) {
402
0
        return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
403
0
    }
404
405
124k
    alg->tag = **p;
406
124k
    end = *p + len;
407
408
124k
    if ((ret = mbedtls_asn1_get_tag(p, end, &alg->len, MBEDTLS_ASN1_OID)) != 0) {
409
119
        return ret;
410
119
    }
411
412
124k
    alg->p = *p;
413
124k
    *p += alg->len;
414
415
124k
    if (*p == end) {
416
11.2k
        mbedtls_platform_zeroize(params, sizeof(mbedtls_asn1_buf));
417
11.2k
        return 0;
418
11.2k
    }
419
420
112k
    params->tag = **p;
421
112k
    (*p)++;
422
423
112k
    if ((ret = mbedtls_asn1_get_len(p, end, &params->len)) != 0) {
424
159
        return ret;
425
159
    }
426
427
112k
    params->p = *p;
428
112k
    *p += params->len;
429
430
112k
    if (*p != end) {
431
40
        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
432
40
    }
433
434
112k
    return 0;
435
112k
}
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(&params, 0, sizeof(mbedtls_asn1_buf));
445
446
0
    if ((ret = mbedtls_asn1_get_alg(p, end, alg, &params)) != 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
98.0k
{
485
240k
    for (mbedtls_asn1_named_data *next; name != NULL; name = next) {
486
142k
        next = name->next;
487
142k
        mbedtls_free(name);
488
142k
    }
489
98.0k
}
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 */