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source: vbox/trunk/src/libs/openssl-1.1.1f/crypto/asn1/tasn_dec.c@ 83531

Last change on this file since 83531 was 83531, checked in by vboxsync, 5 years ago

setting svn:sync-process=export for openssl-1.1.1f, all files except tests
File size: 36.4 KB
Line 
1/*
2 * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <stddef.h>
11#include <string.h>
12#include <openssl/asn1.h>
13#include <openssl/asn1t.h>
14#include <openssl/objects.h>
15#include <openssl/buffer.h>
16#include <openssl/err.h>
17#include "internal/numbers.h"
18#include "asn1_local.h"
19
20
21/*
22 * Constructed types with a recursive definition (such as can be found in PKCS7)
23 * could eventually exceed the stack given malicious input with excessive
24 * recursion. Therefore we limit the stack depth. This is the maximum number of
25 * recursive invocations of asn1_item_embed_d2i().
26 */
27#define ASN1_MAX_CONSTRUCTED_NEST 30
28
29static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
30 long len, const ASN1_ITEM *it,
31 int tag, int aclass, char opt, ASN1_TLC *ctx,
32 int depth);
33
34static int asn1_check_eoc(const unsigned char **in, long len);
35static int asn1_find_end(const unsigned char **in, long len, char inf);
36
37static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
38 char inf, int tag, int aclass, int depth);
39
40static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
41
42static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
43 char *inf, char *cst,
44 const unsigned char **in, long len,
45 int exptag, int expclass, char opt, ASN1_TLC *ctx);
46
47static int asn1_template_ex_d2i(ASN1_VALUE **pval,
48 const unsigned char **in, long len,
49 const ASN1_TEMPLATE *tt, char opt,
50 ASN1_TLC *ctx, int depth);
51static int asn1_template_noexp_d2i(ASN1_VALUE **val,
52 const unsigned char **in, long len,
53 const ASN1_TEMPLATE *tt, char opt,
54 ASN1_TLC *ctx, int depth);
55static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
56 const unsigned char **in, long len,
57 const ASN1_ITEM *it,
58 int tag, int aclass, char opt,
59 ASN1_TLC *ctx);
60static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
61 int utype, char *free_cont, const ASN1_ITEM *it);
62
63/* Table to convert tags to bit values, used for MSTRING type */
64static const unsigned long tag2bit[32] = {
65 /* tags 0 - 3 */
66 0, 0, 0, B_ASN1_BIT_STRING,
67 /* tags 4- 7 */
68 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
69 /* tags 8-11 */
70 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
71 /* tags 12-15 */
72 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
73 /* tags 16-19 */
74 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
75 /* tags 20-22 */
76 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
77 /* tags 23-24 */
78 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
79 /* tags 25-27 */
80 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
81 /* tags 28-31 */
82 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
83};
84
85unsigned long ASN1_tag2bit(int tag)
86{
87 if ((tag < 0) || (tag > 30))
88 return 0;
89 return tag2bit[tag];
90}
91
92/* Macro to initialize and invalidate the cache */
93
94#define asn1_tlc_clear(c) if (c) (c)->valid = 0
95/* Version to avoid compiler warning about 'c' always non-NULL */
96#define asn1_tlc_clear_nc(c) (c)->valid = 0
97
98/*
99 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
100 * function. 'in' points to a buffer to read the data from, in future we
101 * will have more advanced versions that can input data a piece at a time and
102 * this will simply be a special case.
103 */
104
105ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
106 const unsigned char **in, long len,
107 const ASN1_ITEM *it)
108{
109 ASN1_TLC c;
110 ASN1_VALUE *ptmpval = NULL;
111 if (!pval)
112 pval = &ptmpval;
113 asn1_tlc_clear_nc(&c);
114 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
115 return *pval;
116 return NULL;
117}
118
119int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
120 const ASN1_ITEM *it,
121 int tag, int aclass, char opt, ASN1_TLC *ctx)
122{
123 int rv;
124 rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0);
125 if (rv <= 0)
126 ASN1_item_ex_free(pval, it);
127 return rv;
128}
129
130/*
131 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
132 * tag mismatch return -1 to handle OPTIONAL
133 */
134
135static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
136 long len, const ASN1_ITEM *it,
137 int tag, int aclass, char opt, ASN1_TLC *ctx,
138 int depth)
139{
140 const ASN1_TEMPLATE *tt, *errtt = NULL;
141 const ASN1_EXTERN_FUNCS *ef;
142 const ASN1_AUX *aux = it->funcs;
143 ASN1_aux_cb *asn1_cb;
144 const unsigned char *p = NULL, *q;
145 unsigned char oclass;
146 char seq_eoc, seq_nolen, cst, isopt;
147 long tmplen;
148 int i;
149 int otag;
150 int ret = 0;
151 ASN1_VALUE **pchptr;
152 if (!pval)
153 return 0;
154 if (aux && aux->asn1_cb)
155 asn1_cb = aux->asn1_cb;
156 else
157 asn1_cb = 0;
158
159 if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
160 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NESTED_TOO_DEEP);
161 goto err;
162 }
163
164 switch (it->itype) {
165 case ASN1_ITYPE_PRIMITIVE:
166 if (it->templates) {
167 /*
168 * tagging or OPTIONAL is currently illegal on an item template
169 * because the flags can't get passed down. In practice this
170 * isn't a problem: we include the relevant flags from the item
171 * template in the template itself.
172 */
173 if ((tag != -1) || opt) {
174 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I,
175 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
176 goto err;
177 }
178 return asn1_template_ex_d2i(pval, in, len,
179 it->templates, opt, ctx, depth);
180 }
181 return asn1_d2i_ex_primitive(pval, in, len, it,
182 tag, aclass, opt, ctx);
183
184 case ASN1_ITYPE_MSTRING:
185 p = *in;
186 /* Just read in tag and class */
187 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
188 &p, len, -1, 0, 1, ctx);
189 if (!ret) {
190 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
191 goto err;
192 }
193
194 /* Must be UNIVERSAL class */
195 if (oclass != V_ASN1_UNIVERSAL) {
196 /* If OPTIONAL, assume this is OK */
197 if (opt)
198 return -1;
199 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
200 goto err;
201 }
202 /* Check tag matches bit map */
203 if (!(ASN1_tag2bit(otag) & it->utype)) {
204 /* If OPTIONAL, assume this is OK */
205 if (opt)
206 return -1;
207 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG);
208 goto err;
209 }
210 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
211
212 case ASN1_ITYPE_EXTERN:
213 /* Use new style d2i */
214 ef = it->funcs;
215 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
216
217 case ASN1_ITYPE_CHOICE:
218 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
219 goto auxerr;
220 if (*pval) {
221 /* Free up and zero CHOICE value if initialised */
222 i = asn1_get_choice_selector(pval, it);
223 if ((i >= 0) && (i < it->tcount)) {
224 tt = it->templates + i;
225 pchptr = asn1_get_field_ptr(pval, tt);
226 asn1_template_free(pchptr, tt);
227 asn1_set_choice_selector(pval, -1, it);
228 }
229 } else if (!ASN1_item_ex_new(pval, it)) {
230 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
231 goto err;
232 }
233 /* CHOICE type, try each possibility in turn */
234 p = *in;
235 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
236 pchptr = asn1_get_field_ptr(pval, tt);
237 /*
238 * We mark field as OPTIONAL so its absence can be recognised.
239 */
240 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth);
241 /* If field not present, try the next one */
242 if (ret == -1)
243 continue;
244 /* If positive return, read OK, break loop */
245 if (ret > 0)
246 break;
247 /*
248 * Must be an ASN1 parsing error.
249 * Free up any partial choice value
250 */
251 asn1_template_free(pchptr, tt);
252 errtt = tt;
253 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
254 goto err;
255 }
256
257 /* Did we fall off the end without reading anything? */
258 if (i == it->tcount) {
259 /* If OPTIONAL, this is OK */
260 if (opt) {
261 /* Free and zero it */
262 ASN1_item_ex_free(pval, it);
263 return -1;
264 }
265 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
266 goto err;
267 }
268
269 asn1_set_choice_selector(pval, i, it);
270
271 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
272 goto auxerr;
273 *in = p;
274 return 1;
275
276 case ASN1_ITYPE_NDEF_SEQUENCE:
277 case ASN1_ITYPE_SEQUENCE:
278 p = *in;
279 tmplen = len;
280
281 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
282 if (tag == -1) {
283 tag = V_ASN1_SEQUENCE;
284 aclass = V_ASN1_UNIVERSAL;
285 }
286 /* Get SEQUENCE length and update len, p */
287 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
288 &p, len, tag, aclass, opt, ctx);
289 if (!ret) {
290 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
291 goto err;
292 } else if (ret == -1)
293 return -1;
294 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
295 len = tmplen - (p - *in);
296 seq_nolen = 1;
297 }
298 /* If indefinite we don't do a length check */
299 else
300 seq_nolen = seq_eoc;
301 if (!cst) {
302 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
303 goto err;
304 }
305
306 if (!*pval && !ASN1_item_ex_new(pval, it)) {
307 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
308 goto err;
309 }
310
311 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
312 goto auxerr;
313
314 /* Free up and zero any ADB found */
315 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
316 if (tt->flags & ASN1_TFLG_ADB_MASK) {
317 const ASN1_TEMPLATE *seqtt;
318 ASN1_VALUE **pseqval;
319 seqtt = asn1_do_adb(pval, tt, 0);
320 if (seqtt == NULL)
321 continue;
322 pseqval = asn1_get_field_ptr(pval, seqtt);
323 asn1_template_free(pseqval, seqtt);
324 }
325 }
326
327 /* Get each field entry */
328 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
329 const ASN1_TEMPLATE *seqtt;
330 ASN1_VALUE **pseqval;
331 seqtt = asn1_do_adb(pval, tt, 1);
332 if (seqtt == NULL)
333 goto err;
334 pseqval = asn1_get_field_ptr(pval, seqtt);
335 /* Have we ran out of data? */
336 if (!len)
337 break;
338 q = p;
339 if (asn1_check_eoc(&p, len)) {
340 if (!seq_eoc) {
341 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC);
342 goto err;
343 }
344 len -= p - q;
345 seq_eoc = 0;
346 q = p;
347 break;
348 }
349 /*
350 * This determines the OPTIONAL flag value. The field cannot be
351 * omitted if it is the last of a SEQUENCE and there is still
352 * data to be read. This isn't strictly necessary but it
353 * increases efficiency in some cases.
354 */
355 if (i == (it->tcount - 1))
356 isopt = 0;
357 else
358 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
359 /*
360 * attempt to read in field, allowing each to be OPTIONAL
361 */
362
363 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx,
364 depth);
365 if (!ret) {
366 errtt = seqtt;
367 goto err;
368 } else if (ret == -1) {
369 /*
370 * OPTIONAL component absent. Free and zero the field.
371 */
372 asn1_template_free(pseqval, seqtt);
373 continue;
374 }
375 /* Update length */
376 len -= p - q;
377 }
378
379 /* Check for EOC if expecting one */
380 if (seq_eoc && !asn1_check_eoc(&p, len)) {
381 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC);
382 goto err;
383 }
384 /* Check all data read */
385 if (!seq_nolen && len) {
386 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
387 goto err;
388 }
389
390 /*
391 * If we get here we've got no more data in the SEQUENCE, however we
392 * may not have read all fields so check all remaining are OPTIONAL
393 * and clear any that are.
394 */
395 for (; i < it->tcount; tt++, i++) {
396 const ASN1_TEMPLATE *seqtt;
397 seqtt = asn1_do_adb(pval, tt, 1);
398 if (seqtt == NULL)
399 goto err;
400 if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
401 ASN1_VALUE **pseqval;
402 pseqval = asn1_get_field_ptr(pval, seqtt);
403 asn1_template_free(pseqval, seqtt);
404 } else {
405 errtt = seqtt;
406 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING);
407 goto err;
408 }
409 }
410 /* Save encoding */
411 if (!asn1_enc_save(pval, *in, p - *in, it))
412 goto auxerr;
413 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
414 goto auxerr;
415 *in = p;
416 return 1;
417
418 default:
419 return 0;
420 }
421 auxerr:
422 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR);
423 err:
424 if (errtt)
425 ERR_add_error_data(4, "Field=", errtt->field_name,
426 ", Type=", it->sname);
427 else
428 ERR_add_error_data(2, "Type=", it->sname);
429 return 0;
430}
431
432/*
433 * Templates are handled with two separate functions. One handles any
434 * EXPLICIT tag and the other handles the rest.
435 */
436
437static int asn1_template_ex_d2i(ASN1_VALUE **val,
438 const unsigned char **in, long inlen,
439 const ASN1_TEMPLATE *tt, char opt,
440 ASN1_TLC *ctx, int depth)
441{
442 int flags, aclass;
443 int ret;
444 long len;
445 const unsigned char *p, *q;
446 char exp_eoc;
447 if (!val)
448 return 0;
449 flags = tt->flags;
450 aclass = flags & ASN1_TFLG_TAG_CLASS;
451
452 p = *in;
453
454 /* Check if EXPLICIT tag expected */
455 if (flags & ASN1_TFLG_EXPTAG) {
456 char cst;
457 /*
458 * Need to work out amount of data available to the inner content and
459 * where it starts: so read in EXPLICIT header to get the info.
460 */
461 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
462 &p, inlen, tt->tag, aclass, opt, ctx);
463 q = p;
464 if (!ret) {
465 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
466 return 0;
467 } else if (ret == -1)
468 return -1;
469 if (!cst) {
470 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
471 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
472 return 0;
473 }
474 /* We've found the field so it can't be OPTIONAL now */
475 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth);
476 if (!ret) {
477 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
478 return 0;
479 }
480 /* We read the field in OK so update length */
481 len -= p - q;
482 if (exp_eoc) {
483 /* If NDEF we must have an EOC here */
484 if (!asn1_check_eoc(&p, len)) {
485 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
486 goto err;
487 }
488 } else {
489 /*
490 * Otherwise we must hit the EXPLICIT tag end or its an error
491 */
492 if (len) {
493 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
494 ASN1_R_EXPLICIT_LENGTH_MISMATCH);
495 goto err;
496 }
497 }
498 } else
499 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth);
500
501 *in = p;
502 return 1;
503
504 err:
505 return 0;
506}
507
508static int asn1_template_noexp_d2i(ASN1_VALUE **val,
509 const unsigned char **in, long len,
510 const ASN1_TEMPLATE *tt, char opt,
511 ASN1_TLC *ctx, int depth)
512{
513 int flags, aclass;
514 int ret;
515 ASN1_VALUE *tval;
516 const unsigned char *p, *q;
517 if (!val)
518 return 0;
519 flags = tt->flags;
520 aclass = flags & ASN1_TFLG_TAG_CLASS;
521
522 p = *in;
523 q = p;
524
525 /*
526 * If field is embedded then val needs fixing so it is a pointer to
527 * a pointer to a field.
528 */
529 if (tt->flags & ASN1_TFLG_EMBED) {
530 tval = (ASN1_VALUE *)val;
531 val = &tval;
532 }
533
534 if (flags & ASN1_TFLG_SK_MASK) {
535 /* SET OF, SEQUENCE OF */
536 int sktag, skaclass;
537 char sk_eoc;
538 /* First work out expected inner tag value */
539 if (flags & ASN1_TFLG_IMPTAG) {
540 sktag = tt->tag;
541 skaclass = aclass;
542 } else {
543 skaclass = V_ASN1_UNIVERSAL;
544 if (flags & ASN1_TFLG_SET_OF)
545 sktag = V_ASN1_SET;
546 else
547 sktag = V_ASN1_SEQUENCE;
548 }
549 /* Get the tag */
550 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
551 &p, len, sktag, skaclass, opt, ctx);
552 if (!ret) {
553 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
554 return 0;
555 } else if (ret == -1)
556 return -1;
557 if (!*val)
558 *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null();
559 else {
560 /*
561 * We've got a valid STACK: free up any items present
562 */
563 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
564 ASN1_VALUE *vtmp;
565 while (sk_ASN1_VALUE_num(sktmp) > 0) {
566 vtmp = sk_ASN1_VALUE_pop(sktmp);
567 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
568 }
569 }
570
571 if (!*val) {
572 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
573 goto err;
574 }
575
576 /* Read as many items as we can */
577 while (len > 0) {
578 ASN1_VALUE *skfield;
579 q = p;
580 /* See if EOC found */
581 if (asn1_check_eoc(&p, len)) {
582 if (!sk_eoc) {
583 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
584 ASN1_R_UNEXPECTED_EOC);
585 goto err;
586 }
587 len -= p - q;
588 sk_eoc = 0;
589 break;
590 }
591 skfield = NULL;
592 if (!asn1_item_embed_d2i(&skfield, &p, len,
593 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx,
594 depth)) {
595 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
596 ERR_R_NESTED_ASN1_ERROR);
597 /* |skfield| may be partially allocated despite failure. */
598 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
599 goto err;
600 }
601 len -= p - q;
602 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
603 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
604 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
605 goto err;
606 }
607 }
608 if (sk_eoc) {
609 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
610 goto err;
611 }
612 } else if (flags & ASN1_TFLG_IMPTAG) {
613 /* IMPLICIT tagging */
614 ret = asn1_item_embed_d2i(val, &p, len,
615 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
616 ctx, depth);
617 if (!ret) {
618 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
619 goto err;
620 } else if (ret == -1)
621 return -1;
622 } else {
623 /* Nothing special */
624 ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
625 -1, 0, opt, ctx, depth);
626 if (!ret) {
627 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
628 goto err;
629 } else if (ret == -1)
630 return -1;
631 }
632
633 *in = p;
634 return 1;
635
636 err:
637 return 0;
638}
639
640static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
641 const unsigned char **in, long inlen,
642 const ASN1_ITEM *it,
643 int tag, int aclass, char opt, ASN1_TLC *ctx)
644{
645 int ret = 0, utype;
646 long plen;
647 char cst, inf, free_cont = 0;
648 const unsigned char *p;
649 BUF_MEM buf = { 0, NULL, 0, 0 };
650 const unsigned char *cont = NULL;
651 long len;
652 if (!pval) {
653 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
654 return 0; /* Should never happen */
655 }
656
657 if (it->itype == ASN1_ITYPE_MSTRING) {
658 utype = tag;
659 tag = -1;
660 } else
661 utype = it->utype;
662
663 if (utype == V_ASN1_ANY) {
664 /* If type is ANY need to figure out type from tag */
665 unsigned char oclass;
666 if (tag >= 0) {
667 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
668 return 0;
669 }
670 if (opt) {
671 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
672 ASN1_R_ILLEGAL_OPTIONAL_ANY);
673 return 0;
674 }
675 p = *in;
676 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
677 &p, inlen, -1, 0, 0, ctx);
678 if (!ret) {
679 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
680 return 0;
681 }
682 if (oclass != V_ASN1_UNIVERSAL)
683 utype = V_ASN1_OTHER;
684 }
685 if (tag == -1) {
686 tag = utype;
687 aclass = V_ASN1_UNIVERSAL;
688 }
689 p = *in;
690 /* Check header */
691 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
692 &p, inlen, tag, aclass, opt, ctx);
693 if (!ret) {
694 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
695 return 0;
696 } else if (ret == -1)
697 return -1;
698 ret = 0;
699 /* SEQUENCE, SET and "OTHER" are left in encoded form */
700 if ((utype == V_ASN1_SEQUENCE)
701 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
702 /*
703 * Clear context cache for type OTHER because the auto clear when we
704 * have a exact match won't work
705 */
706 if (utype == V_ASN1_OTHER) {
707 asn1_tlc_clear(ctx);
708 }
709 /* SEQUENCE and SET must be constructed */
710 else if (!cst) {
711 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
712 ASN1_R_TYPE_NOT_CONSTRUCTED);
713 return 0;
714 }
715
716 cont = *in;
717 /* If indefinite length constructed find the real end */
718 if (inf) {
719 if (!asn1_find_end(&p, plen, inf))
720 goto err;
721 len = p - cont;
722 } else {
723 len = p - cont + plen;
724 p += plen;
725 }
726 } else if (cst) {
727 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
728 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
729 || utype == V_ASN1_ENUMERATED) {
730 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
731 return 0;
732 }
733
734 /* Free any returned 'buf' content */
735 free_cont = 1;
736 /*
737 * Should really check the internal tags are correct but some things
738 * may get this wrong. The relevant specs say that constructed string
739 * types should be OCTET STRINGs internally irrespective of the type.
740 * So instead just check for UNIVERSAL class and ignore the tag.
741 */
742 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
743 goto err;
744 }
745 len = buf.length;
746 /* Append a final null to string */
747 if (!BUF_MEM_grow_clean(&buf, len + 1)) {
748 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
749 goto err;
750 }
751 buf.data[len] = 0;
752 cont = (const unsigned char *)buf.data;
753 } else {
754 cont = p;
755 len = plen;
756 p += plen;
757 }
758
759 /* We now have content length and type: translate into a structure */
760 /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */
761 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
762 goto err;
763
764 *in = p;
765 ret = 1;
766 err:
767 if (free_cont)
768 OPENSSL_free(buf.data);
769 return ret;
770}
771
772/* Translate ASN1 content octets into a structure */
773
774static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
775 int utype, char *free_cont, const ASN1_ITEM *it)
776{
777 ASN1_VALUE **opval = NULL;
778 ASN1_STRING *stmp;
779 ASN1_TYPE *typ = NULL;
780 int ret = 0;
781 const ASN1_PRIMITIVE_FUNCS *pf;
782 ASN1_INTEGER **tint;
783 pf = it->funcs;
784
785 if (pf && pf->prim_c2i)
786 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
787 /* If ANY type clear type and set pointer to internal value */
788 if (it->utype == V_ASN1_ANY) {
789 if (!*pval) {
790 typ = ASN1_TYPE_new();
791 if (typ == NULL)
792 goto err;
793 *pval = (ASN1_VALUE *)typ;
794 } else
795 typ = (ASN1_TYPE *)*pval;
796
797 if (utype != typ->type)
798 ASN1_TYPE_set(typ, utype, NULL);
799 opval = pval;
800 pval = &typ->value.asn1_value;
801 }
802 switch (utype) {
803 case V_ASN1_OBJECT:
804 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
805 goto err;
806 break;
807
808 case V_ASN1_NULL:
809 if (len) {
810 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
811 goto err;
812 }
813 *pval = (ASN1_VALUE *)1;
814 break;
815
816 case V_ASN1_BOOLEAN:
817 if (len != 1) {
818 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
819 goto err;
820 } else {
821 ASN1_BOOLEAN *tbool;
822 tbool = (ASN1_BOOLEAN *)pval;
823 *tbool = *cont;
824 }
825 break;
826
827 case V_ASN1_BIT_STRING:
828 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
829 goto err;
830 break;
831
832 case V_ASN1_INTEGER:
833 case V_ASN1_ENUMERATED:
834 tint = (ASN1_INTEGER **)pval;
835 if (!c2i_ASN1_INTEGER(tint, &cont, len))
836 goto err;
837 /* Fixup type to match the expected form */
838 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
839 break;
840
841 case V_ASN1_OCTET_STRING:
842 case V_ASN1_NUMERICSTRING:
843 case V_ASN1_PRINTABLESTRING:
844 case V_ASN1_T61STRING:
845 case V_ASN1_VIDEOTEXSTRING:
846 case V_ASN1_IA5STRING:
847 case V_ASN1_UTCTIME:
848 case V_ASN1_GENERALIZEDTIME:
849 case V_ASN1_GRAPHICSTRING:
850 case V_ASN1_VISIBLESTRING:
851 case V_ASN1_GENERALSTRING:
852 case V_ASN1_UNIVERSALSTRING:
853 case V_ASN1_BMPSTRING:
854 case V_ASN1_UTF8STRING:
855 case V_ASN1_OTHER:
856 case V_ASN1_SET:
857 case V_ASN1_SEQUENCE:
858 default:
859 if (utype == V_ASN1_BMPSTRING && (len & 1)) {
860 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
861 goto err;
862 }
863 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
864 ASN1err(ASN1_F_ASN1_EX_C2I,
865 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
866 goto err;
867 }
868 /* All based on ASN1_STRING and handled the same */
869 if (!*pval) {
870 stmp = ASN1_STRING_type_new(utype);
871 if (stmp == NULL) {
872 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
873 goto err;
874 }
875 *pval = (ASN1_VALUE *)stmp;
876 } else {
877 stmp = (ASN1_STRING *)*pval;
878 stmp->type = utype;
879 }
880 /* If we've already allocated a buffer use it */
881 if (*free_cont) {
882 OPENSSL_free(stmp->data);
883 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
884 stmp->length = len;
885 *free_cont = 0;
886 } else {
887 if (!ASN1_STRING_set(stmp, cont, len)) {
888 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
889 ASN1_STRING_free(stmp);
890 *pval = NULL;
891 goto err;
892 }
893 }
894 break;
895 }
896 /* If ASN1_ANY and NULL type fix up value */
897 if (typ && (utype == V_ASN1_NULL))
898 typ->value.ptr = NULL;
899
900 ret = 1;
901 err:
902 if (!ret) {
903 ASN1_TYPE_free(typ);
904 if (opval)
905 *opval = NULL;
906 }
907 return ret;
908}
909
910/*
911 * This function finds the end of an ASN1 structure when passed its maximum
912 * length, whether it is indefinite length and a pointer to the content. This
913 * is more efficient than calling asn1_collect because it does not recurse on
914 * each indefinite length header.
915 */
916
917static int asn1_find_end(const unsigned char **in, long len, char inf)
918{
919 uint32_t expected_eoc;
920 long plen;
921 const unsigned char *p = *in, *q;
922 /* If not indefinite length constructed just add length */
923 if (inf == 0) {
924 *in += len;
925 return 1;
926 }
927 expected_eoc = 1;
928 /*
929 * Indefinite length constructed form. Find the end when enough EOCs are
930 * found. If more indefinite length constructed headers are encountered
931 * increment the expected eoc count otherwise just skip to the end of the
932 * data.
933 */
934 while (len > 0) {
935 if (asn1_check_eoc(&p, len)) {
936 expected_eoc--;
937 if (expected_eoc == 0)
938 break;
939 len -= 2;
940 continue;
941 }
942 q = p;
943 /* Just read in a header: only care about the length */
944 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
945 -1, 0, 0, NULL)) {
946 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
947 return 0;
948 }
949 if (inf) {
950 if (expected_eoc == UINT32_MAX) {
951 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
952 return 0;
953 }
954 expected_eoc++;
955 } else {
956 p += plen;
957 }
958 len -= p - q;
959 }
960 if (expected_eoc) {
961 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
962 return 0;
963 }
964 *in = p;
965 return 1;
966}
967
968/*
969 * This function collects the asn1 data from a constructed string type into
970 * a buffer. The values of 'in' and 'len' should refer to the contents of the
971 * constructed type and 'inf' should be set if it is indefinite length.
972 */
973
974#ifndef ASN1_MAX_STRING_NEST
975/*
976 * This determines how many levels of recursion are permitted in ASN1 string
977 * types. If it is not limited stack overflows can occur. If set to zero no
978 * recursion is allowed at all. Although zero should be adequate examples
979 * exist that require a value of 1. So 5 should be more than enough.
980 */
981# define ASN1_MAX_STRING_NEST 5
982#endif
983
984static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
985 char inf, int tag, int aclass, int depth)
986{
987 const unsigned char *p, *q;
988 long plen;
989 char cst, ininf;
990 p = *in;
991 inf &= 1;
992 /*
993 * If no buffer and not indefinite length constructed just pass over the
994 * encoded data
995 */
996 if (!buf && !inf) {
997 *in += len;
998 return 1;
999 }
1000 while (len > 0) {
1001 q = p;
1002 /* Check for EOC */
1003 if (asn1_check_eoc(&p, len)) {
1004 /*
1005 * EOC is illegal outside indefinite length constructed form
1006 */
1007 if (!inf) {
1008 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
1009 return 0;
1010 }
1011 inf = 0;
1012 break;
1013 }
1014
1015 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1016 len, tag, aclass, 0, NULL)) {
1017 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1018 return 0;
1019 }
1020
1021 /* If indefinite length constructed update max length */
1022 if (cst) {
1023 if (depth >= ASN1_MAX_STRING_NEST) {
1024 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1025 return 0;
1026 }
1027 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1028 return 0;
1029 } else if (plen && !collect_data(buf, &p, plen))
1030 return 0;
1031 len -= p - q;
1032 }
1033 if (inf) {
1034 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1035 return 0;
1036 }
1037 *in = p;
1038 return 1;
1039}
1040
1041static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1042{
1043 int len;
1044 if (buf) {
1045 len = buf->length;
1046 if (!BUF_MEM_grow_clean(buf, len + plen)) {
1047 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1048 return 0;
1049 }
1050 memcpy(buf->data + len, *p, plen);
1051 }
1052 *p += plen;
1053 return 1;
1054}
1055
1056/* Check for ASN1 EOC and swallow it if found */
1057
1058static int asn1_check_eoc(const unsigned char **in, long len)
1059{
1060 const unsigned char *p;
1061 if (len < 2)
1062 return 0;
1063 p = *in;
1064 if (!p[0] && !p[1]) {
1065 *in += 2;
1066 return 1;
1067 }
1068 return 0;
1069}
1070
1071/*
1072 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1073 * length for indefinite length constructed form, we don't know the exact
1074 * length but we can set an upper bound to the amount of data available minus
1075 * the header length just read.
1076 */
1077
1078static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1079 char *inf, char *cst,
1080 const unsigned char **in, long len,
1081 int exptag, int expclass, char opt, ASN1_TLC *ctx)
1082{
1083 int i;
1084 int ptag, pclass;
1085 long plen;
1086 const unsigned char *p, *q;
1087 p = *in;
1088 q = p;
1089
1090 if (ctx && ctx->valid) {
1091 i = ctx->ret;
1092 plen = ctx->plen;
1093 pclass = ctx->pclass;
1094 ptag = ctx->ptag;
1095 p += ctx->hdrlen;
1096 } else {
1097 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1098 if (ctx) {
1099 ctx->ret = i;
1100 ctx->plen = plen;
1101 ctx->pclass = pclass;
1102 ctx->ptag = ptag;
1103 ctx->hdrlen = p - q;
1104 ctx->valid = 1;
1105 /*
1106 * If definite length, and no error, length + header can't exceed
1107 * total amount of data available.
1108 */
1109 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
1110 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
1111 asn1_tlc_clear(ctx);
1112 return 0;
1113 }
1114 }
1115 }
1116
1117 if (i & 0x80) {
1118 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1119 asn1_tlc_clear(ctx);
1120 return 0;
1121 }
1122 if (exptag >= 0) {
1123 if ((exptag != ptag) || (expclass != pclass)) {
1124 /*
1125 * If type is OPTIONAL, not an error: indicate missing type.
1126 */
1127 if (opt)
1128 return -1;
1129 asn1_tlc_clear(ctx);
1130 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1131 return 0;
1132 }
1133 /*
1134 * We have a tag and class match: assume we are going to do something
1135 * with it
1136 */
1137 asn1_tlc_clear(ctx);
1138 }
1139
1140 if (i & 1)
1141 plen = len - (p - q);
1142
1143 if (inf)
1144 *inf = i & 1;
1145
1146 if (cst)
1147 *cst = i & V_ASN1_CONSTRUCTED;
1148
1149 if (olen)
1150 *olen = plen;
1151
1152 if (oclass)
1153 *oclass = pclass;
1154
1155 if (otag)
1156 *otag = ptag;
1157
1158 *in = p;
1159 return 1;
1160}
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