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Reject invalid constructed encodings.
[thirdparty/openssl.git] / crypto / asn1 / tasn_dec.c
1 /* tasn_dec.c */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2000.
4 */
5 /* ====================================================================
6 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59
60 #include <stddef.h>
61 #include <string.h>
62 #include <openssl/asn1.h>
63 #include <openssl/asn1t.h>
64 #include <openssl/objects.h>
65 #include <openssl/buffer.h>
66 #include <openssl/err.h>
67
68 static int asn1_check_eoc(const unsigned char **in, long len);
69 static int asn1_find_end(const unsigned char **in, long len, char inf);
70
71 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
72 char inf, int tag, int aclass, int depth);
73
74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
75
76 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
77 char *inf, char *cst,
78 const unsigned char **in, long len,
79 int exptag, int expclass, char opt,
80 ASN1_TLC *ctx);
81
82 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
83 const unsigned char **in, long len,
84 const ASN1_TEMPLATE *tt, char opt,
85 ASN1_TLC *ctx);
86 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
87 const unsigned char **in, long len,
88 const ASN1_TEMPLATE *tt, char opt,
89 ASN1_TLC *ctx);
90 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
91 const unsigned char **in, long len,
92 const ASN1_ITEM *it,
93 int tag, int aclass, char opt, ASN1_TLC *ctx);
94
95 /* Table to convert tags to bit values, used for MSTRING type */
96 static const unsigned long tag2bit[32] = {
97 0, 0, 0, B_ASN1_BIT_STRING, /* tags 0 - 3 */
98 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,/* tags 4- 7 */
99 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags 8-11 */
100 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */
101 B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */
102 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING, /* tags 20-22 */
103 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, /* tags 23-24 */
104 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING, /* tags 25-27 */
105 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */
106 };
107
108 unsigned long ASN1_tag2bit(int tag)
109 {
110 if ((tag < 0) || (tag > 30)) return 0;
111 return tag2bit[tag];
112 }
113
114 /* Macro to initialize and invalidate the cache */
115
116 #define asn1_tlc_clear(c) if (c) (c)->valid = 0
117 /* Version to avoid compiler warning about 'c' always non-NULL */
118 #define asn1_tlc_clear_nc(c) (c)->valid = 0
119
120 /* Decode an ASN1 item, this currently behaves just
121 * like a standard 'd2i' function. 'in' points to
122 * a buffer to read the data from, in future we will
123 * have more advanced versions that can input data
124 * a piece at a time and this will simply be a special
125 * case.
126 */
127
128 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
129 const unsigned char **in, long len, const ASN1_ITEM *it)
130 {
131 ASN1_TLC c;
132 ASN1_VALUE *ptmpval = NULL;
133 if (!pval)
134 pval = &ptmpval;
135 asn1_tlc_clear_nc(&c);
136 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
137 return *pval;
138 return NULL;
139 }
140
141 int ASN1_template_d2i(ASN1_VALUE **pval,
142 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
143 {
144 ASN1_TLC c;
145 asn1_tlc_clear_nc(&c);
146 return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
147 }
148
149
150 /* Decode an item, taking care of IMPLICIT tagging, if any.
151 * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
152 */
153
154 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
155 const ASN1_ITEM *it,
156 int tag, int aclass, char opt, ASN1_TLC *ctx)
157 {
158 const ASN1_TEMPLATE *tt, *errtt = NULL;
159 const ASN1_COMPAT_FUNCS *cf;
160 const ASN1_EXTERN_FUNCS *ef;
161 const ASN1_AUX *aux = it->funcs;
162 ASN1_aux_cb *asn1_cb;
163 const unsigned char *p = NULL, *q;
164 unsigned char *wp=NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */
165 unsigned char imphack = 0, oclass;
166 char seq_eoc, seq_nolen, cst, isopt;
167 long tmplen;
168 int i;
169 int otag;
170 int ret = 0;
171 ASN1_VALUE **pchptr, *ptmpval;
172 if (!pval)
173 return 0;
174 if (aux && aux->asn1_cb)
175 asn1_cb = aux->asn1_cb;
176 else asn1_cb = 0;
177
178 switch(it->itype)
179 {
180 case ASN1_ITYPE_PRIMITIVE:
181 if (it->templates)
182 {
183 /* tagging or OPTIONAL is currently illegal on an item
184 * template because the flags can't get passed down.
185 * In practice this isn't a problem: we include the
186 * relevant flags from the item template in the
187 * template itself.
188 */
189 if ((tag != -1) || opt)
190 {
191 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
192 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
193 goto err;
194 }
195 return asn1_template_ex_d2i(pval, in, len,
196 it->templates, opt, ctx);
197 }
198 return asn1_d2i_ex_primitive(pval, in, len, it,
199 tag, aclass, opt, ctx);
200 break;
201
202 case ASN1_ITYPE_MSTRING:
203 p = *in;
204 /* Just read in tag and class */
205 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
206 &p, len, -1, 0, 1, ctx);
207 if (!ret)
208 {
209 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
210 ERR_R_NESTED_ASN1_ERROR);
211 goto err;
212 }
213
214 /* Must be UNIVERSAL class */
215 if (oclass != V_ASN1_UNIVERSAL)
216 {
217 /* If OPTIONAL, assume this is OK */
218 if (opt) return -1;
219 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
220 ASN1_R_MSTRING_NOT_UNIVERSAL);
221 goto err;
222 }
223 /* Check tag matches bit map */
224 if (!(ASN1_tag2bit(otag) & it->utype))
225 {
226 /* If OPTIONAL, assume this is OK */
227 if (opt)
228 return -1;
229 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
230 ASN1_R_MSTRING_WRONG_TAG);
231 goto err;
232 }
233 return asn1_d2i_ex_primitive(pval, in, len,
234 it, otag, 0, 0, ctx);
235
236 case ASN1_ITYPE_EXTERN:
237 /* Use new style d2i */
238 ef = it->funcs;
239 return ef->asn1_ex_d2i(pval, in, len,
240 it, tag, aclass, opt, ctx);
241
242 case ASN1_ITYPE_COMPAT:
243 /* we must resort to old style evil hackery */
244 cf = it->funcs;
245
246 /* If OPTIONAL see if it is there */
247 if (opt)
248 {
249 int exptag;
250 p = *in;
251 if (tag == -1)
252 exptag = it->utype;
253 else exptag = tag;
254 /* Don't care about anything other than presence
255 * of expected tag */
256
257 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
258 &p, len, exptag, aclass, 1, ctx);
259 if (!ret)
260 {
261 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
262 ERR_R_NESTED_ASN1_ERROR);
263 goto err;
264 }
265 if (ret == -1)
266 return -1;
267 }
268
269 /* This is the old style evil hack IMPLICIT handling:
270 * since the underlying code is expecting a tag and
271 * class other than the one present we change the
272 * buffer temporarily then change it back afterwards.
273 * This doesn't and never did work for tags > 30.
274 *
275 * Yes this is *horrible* but it is only needed for
276 * old style d2i which will hopefully not be around
277 * for much longer.
278 * FIXME: should copy the buffer then modify it so
279 * the input buffer can be const: we should *always*
280 * copy because the old style d2i might modify the
281 * buffer.
282 */
283
284 if (tag != -1)
285 {
286 wp = *(unsigned char **)in;
287 imphack = *wp;
288 if (p == NULL)
289 {
290 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
291 ERR_R_NESTED_ASN1_ERROR);
292 goto err;
293 }
294 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
295 | it->utype);
296 }
297
298 ptmpval = cf->asn1_d2i(pval, in, len);
299
300 if (tag != -1)
301 *wp = imphack;
302
303 if (ptmpval)
304 return 1;
305
306 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
307 goto err;
308
309
310 case ASN1_ITYPE_CHOICE:
311 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
312 goto auxerr;
313
314 /* Allocate structure */
315 if (!*pval && !ASN1_item_ex_new(pval, it))
316 {
317 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
318 ERR_R_NESTED_ASN1_ERROR);
319 goto err;
320 }
321 /* CHOICE type, try each possibility in turn */
322 p = *in;
323 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
324 {
325 pchptr = asn1_get_field_ptr(pval, tt);
326 /* We mark field as OPTIONAL so its absence
327 * can be recognised.
328 */
329 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
330 /* If field not present, try the next one */
331 if (ret == -1)
332 continue;
333 /* If positive return, read OK, break loop */
334 if (ret > 0)
335 break;
336 /* Otherwise must be an ASN1 parsing error */
337 errtt = tt;
338 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
339 ERR_R_NESTED_ASN1_ERROR);
340 goto err;
341 }
342
343 /* Did we fall off the end without reading anything? */
344 if (i == it->tcount)
345 {
346 /* If OPTIONAL, this is OK */
347 if (opt)
348 {
349 /* Free and zero it */
350 ASN1_item_ex_free(pval, it);
351 return -1;
352 }
353 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
354 ASN1_R_NO_MATCHING_CHOICE_TYPE);
355 goto err;
356 }
357
358 asn1_set_choice_selector(pval, i, it);
359 *in = p;
360 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
361 goto auxerr;
362 return 1;
363
364 case ASN1_ITYPE_NDEF_SEQUENCE:
365 case ASN1_ITYPE_SEQUENCE:
366 p = *in;
367 tmplen = len;
368
369 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
370 if (tag == -1)
371 {
372 tag = V_ASN1_SEQUENCE;
373 aclass = V_ASN1_UNIVERSAL;
374 }
375 /* Get SEQUENCE length and update len, p */
376 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
377 &p, len, tag, aclass, opt, ctx);
378 if (!ret)
379 {
380 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
381 ERR_R_NESTED_ASN1_ERROR);
382 goto err;
383 }
384 else if (ret == -1)
385 return -1;
386 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
387 {
388 len = tmplen - (p - *in);
389 seq_nolen = 1;
390 }
391 /* If indefinite we don't do a length check */
392 else seq_nolen = seq_eoc;
393 if (!cst)
394 {
395 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
396 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
397 goto err;
398 }
399
400 if (!*pval && !ASN1_item_ex_new(pval, it))
401 {
402 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
403 ERR_R_NESTED_ASN1_ERROR);
404 goto err;
405 }
406
407 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
408 goto auxerr;
409
410 /* Get each field entry */
411 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
412 {
413 const ASN1_TEMPLATE *seqtt;
414 ASN1_VALUE **pseqval;
415 seqtt = asn1_do_adb(pval, tt, 1);
416 if (!seqtt)
417 goto err;
418 pseqval = asn1_get_field_ptr(pval, seqtt);
419 /* Have we ran out of data? */
420 if (!len)
421 break;
422 q = p;
423 if (asn1_check_eoc(&p, len))
424 {
425 if (!seq_eoc)
426 {
427 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
428 ASN1_R_UNEXPECTED_EOC);
429 goto err;
430 }
431 len -= p - q;
432 seq_eoc = 0;
433 q = p;
434 break;
435 }
436 /* This determines the OPTIONAL flag value. The field
437 * cannot be omitted if it is the last of a SEQUENCE
438 * and there is still data to be read. This isn't
439 * strictly necessary but it increases efficiency in
440 * some cases.
441 */
442 if (i == (it->tcount - 1))
443 isopt = 0;
444 else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
445 /* attempt to read in field, allowing each to be
446 * OPTIONAL */
447
448 ret = asn1_template_ex_d2i(pseqval, &p, len,
449 seqtt, isopt, ctx);
450 if (!ret)
451 {
452 errtt = seqtt;
453 goto err;
454 }
455 else if (ret == -1)
456 {
457 /* OPTIONAL component absent.
458 * Free and zero the field.
459 */
460 ASN1_template_free(pseqval, seqtt);
461 continue;
462 }
463 /* Update length */
464 len -= p - q;
465 }
466
467 /* Check for EOC if expecting one */
468 if (seq_eoc && !asn1_check_eoc(&p, len))
469 {
470 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
471 goto err;
472 }
473 /* Check all data read */
474 if (!seq_nolen && len)
475 {
476 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
477 ASN1_R_SEQUENCE_LENGTH_MISMATCH);
478 goto err;
479 }
480
481 /* If we get here we've got no more data in the SEQUENCE,
482 * however we may not have read all fields so check all
483 * remaining are OPTIONAL and clear any that are.
484 */
485 for (; i < it->tcount; tt++, i++)
486 {
487 const ASN1_TEMPLATE *seqtt;
488 seqtt = asn1_do_adb(pval, tt, 1);
489 if (!seqtt)
490 goto err;
491 if (seqtt->flags & ASN1_TFLG_OPTIONAL)
492 {
493 ASN1_VALUE **pseqval;
494 pseqval = asn1_get_field_ptr(pval, seqtt);
495 ASN1_template_free(pseqval, seqtt);
496 }
497 else
498 {
499 errtt = seqtt;
500 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
501 ASN1_R_FIELD_MISSING);
502 goto err;
503 }
504 }
505 /* Save encoding */
506 if (!asn1_enc_save(pval, *in, p - *in, it))
507 goto auxerr;
508 *in = p;
509 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
510 goto auxerr;
511 return 1;
512
513 default:
514 return 0;
515 }
516 auxerr:
517 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
518 err:
519 ASN1_item_ex_free(pval, it);
520 if (errtt)
521 ERR_add_error_data(4, "Field=", errtt->field_name,
522 ", Type=", it->sname);
523 else
524 ERR_add_error_data(2, "Type=", it->sname);
525 return 0;
526 }
527
528 /* Templates are handled with two separate functions.
529 * One handles any EXPLICIT tag and the other handles the rest.
530 */
531
532 static int asn1_template_ex_d2i(ASN1_VALUE **val,
533 const unsigned char **in, long inlen,
534 const ASN1_TEMPLATE *tt, char opt,
535 ASN1_TLC *ctx)
536 {
537 int flags, aclass;
538 int ret;
539 long len;
540 const unsigned char *p, *q;
541 char exp_eoc;
542 if (!val)
543 return 0;
544 flags = tt->flags;
545 aclass = flags & ASN1_TFLG_TAG_CLASS;
546
547 p = *in;
548
549 /* Check if EXPLICIT tag expected */
550 if (flags & ASN1_TFLG_EXPTAG)
551 {
552 char cst;
553 /* Need to work out amount of data available to the inner
554 * content and where it starts: so read in EXPLICIT header to
555 * get the info.
556 */
557 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
558 &p, inlen, tt->tag, aclass, opt, ctx);
559 q = p;
560 if (!ret)
561 {
562 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
563 ERR_R_NESTED_ASN1_ERROR);
564 return 0;
565 }
566 else if (ret == -1)
567 return -1;
568 if (!cst)
569 {
570 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
571 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
572 return 0;
573 }
574 /* We've found the field so it can't be OPTIONAL now */
575 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
576 if (!ret)
577 {
578 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
579 ERR_R_NESTED_ASN1_ERROR);
580 return 0;
581 }
582 /* We read the field in OK so update length */
583 len -= p - q;
584 if (exp_eoc)
585 {
586 /* If NDEF we must have an EOC here */
587 if (!asn1_check_eoc(&p, len))
588 {
589 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
590 ASN1_R_MISSING_EOC);
591 goto err;
592 }
593 }
594 else
595 {
596 /* Otherwise we must hit the EXPLICIT tag end or its
597 * an error */
598 if (len)
599 {
600 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
601 ASN1_R_EXPLICIT_LENGTH_MISMATCH);
602 goto err;
603 }
604 }
605 }
606 else
607 return asn1_template_noexp_d2i(val, in, inlen,
608 tt, opt, ctx);
609
610 *in = p;
611 return 1;
612
613 err:
614 ASN1_template_free(val, tt);
615 return 0;
616 }
617
618 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
619 const unsigned char **in, long len,
620 const ASN1_TEMPLATE *tt, char opt,
621 ASN1_TLC *ctx)
622 {
623 int flags, aclass;
624 int ret;
625 const unsigned char *p, *q;
626 if (!val)
627 return 0;
628 flags = tt->flags;
629 aclass = flags & ASN1_TFLG_TAG_CLASS;
630
631 p = *in;
632 q = p;
633
634 if (flags & ASN1_TFLG_SK_MASK)
635 {
636 /* SET OF, SEQUENCE OF */
637 int sktag, skaclass;
638 char sk_eoc;
639 /* First work out expected inner tag value */
640 if (flags & ASN1_TFLG_IMPTAG)
641 {
642 sktag = tt->tag;
643 skaclass = aclass;
644 }
645 else
646 {
647 skaclass = V_ASN1_UNIVERSAL;
648 if (flags & ASN1_TFLG_SET_OF)
649 sktag = V_ASN1_SET;
650 else
651 sktag = V_ASN1_SEQUENCE;
652 }
653 /* Get the tag */
654 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
655 &p, len, sktag, skaclass, opt, ctx);
656 if (!ret)
657 {
658 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
659 ERR_R_NESTED_ASN1_ERROR);
660 return 0;
661 }
662 else if (ret == -1)
663 return -1;
664 if (!*val)
665 *val = (ASN1_VALUE *)sk_new_null();
666 else
667 {
668 /* We've got a valid STACK: free up any items present */
669 STACK_OF(ASN1_VALUE) *sktmp
670 = (STACK_OF(ASN1_VALUE) *)*val;
671 ASN1_VALUE *vtmp;
672 while(sk_ASN1_VALUE_num(sktmp) > 0)
673 {
674 vtmp = sk_ASN1_VALUE_pop(sktmp);
675 ASN1_item_ex_free(&vtmp,
676 ASN1_ITEM_ptr(tt->item));
677 }
678 }
679
680 if (!*val)
681 {
682 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
683 ERR_R_MALLOC_FAILURE);
684 goto err;
685 }
686
687 /* Read as many items as we can */
688 while(len > 0)
689 {
690 ASN1_VALUE *skfield;
691 q = p;
692 /* See if EOC found */
693 if (asn1_check_eoc(&p, len))
694 {
695 if (!sk_eoc)
696 {
697 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
698 ASN1_R_UNEXPECTED_EOC);
699 goto err;
700 }
701 len -= p - q;
702 sk_eoc = 0;
703 break;
704 }
705 skfield = NULL;
706 if (!ASN1_item_ex_d2i(&skfield, &p, len,
707 ASN1_ITEM_ptr(tt->item),
708 -1, 0, 0, ctx))
709 {
710 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
711 ERR_R_NESTED_ASN1_ERROR);
712 goto err;
713 }
714 len -= p - q;
715 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
716 skfield))
717 {
718 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
719 ERR_R_MALLOC_FAILURE);
720 goto err;
721 }
722 }
723 if (sk_eoc)
724 {
725 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
726 goto err;
727 }
728 }
729 else if (flags & ASN1_TFLG_IMPTAG)
730 {
731 /* IMPLICIT tagging */
732 ret = ASN1_item_ex_d2i(val, &p, len,
733 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
734 if (!ret)
735 {
736 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
737 ERR_R_NESTED_ASN1_ERROR);
738 goto err;
739 }
740 else if (ret == -1)
741 return -1;
742 }
743 else
744 {
745 /* Nothing special */
746 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
747 -1, 0, opt, ctx);
748 if (!ret)
749 {
750 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
751 ERR_R_NESTED_ASN1_ERROR);
752 goto err;
753 }
754 else if (ret == -1)
755 return -1;
756 }
757
758 *in = p;
759 return 1;
760
761 err:
762 ASN1_template_free(val, tt);
763 return 0;
764 }
765
766 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
767 const unsigned char **in, long inlen,
768 const ASN1_ITEM *it,
769 int tag, int aclass, char opt, ASN1_TLC *ctx)
770 {
771 int ret = 0, utype;
772 long plen;
773 char cst, inf, free_cont = 0;
774 const unsigned char *p;
775 BUF_MEM buf;
776 const unsigned char *cont = NULL;
777 long len;
778 if (!pval)
779 {
780 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
781 return 0; /* Should never happen */
782 }
783
784 if (it->itype == ASN1_ITYPE_MSTRING)
785 {
786 utype = tag;
787 tag = -1;
788 }
789 else
790 utype = it->utype;
791
792 if (utype == V_ASN1_ANY)
793 {
794 /* If type is ANY need to figure out type from tag */
795 unsigned char oclass;
796 if (tag >= 0)
797 {
798 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
799 ASN1_R_ILLEGAL_TAGGED_ANY);
800 return 0;
801 }
802 if (opt)
803 {
804 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
805 ASN1_R_ILLEGAL_OPTIONAL_ANY);
806 return 0;
807 }
808 p = *in;
809 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
810 &p, inlen, -1, 0, 0, ctx);
811 if (!ret)
812 {
813 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
814 ERR_R_NESTED_ASN1_ERROR);
815 return 0;
816 }
817 if (oclass != V_ASN1_UNIVERSAL)
818 utype = V_ASN1_OTHER;
819 }
820 if (tag == -1)
821 {
822 tag = utype;
823 aclass = V_ASN1_UNIVERSAL;
824 }
825 p = *in;
826 /* Check header */
827 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
828 &p, inlen, tag, aclass, opt, ctx);
829 if (!ret)
830 {
831 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
832 return 0;
833 }
834 else if (ret == -1)
835 return -1;
836 ret = 0;
837 /* SEQUENCE, SET and "OTHER" are left in encoded form */
838 if ((utype == V_ASN1_SEQUENCE)
839 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
840 {
841 /* Clear context cache for type OTHER because the auto clear
842 * when we have a exact match wont work
843 */
844 if (utype == V_ASN1_OTHER)
845 {
846 asn1_tlc_clear(ctx);
847 }
848 /* SEQUENCE and SET must be constructed */
849 else if (!cst)
850 {
851 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
852 ASN1_R_TYPE_NOT_CONSTRUCTED);
853 return 0;
854 }
855
856 cont = *in;
857 /* If indefinite length constructed find the real end */
858 if (inf)
859 {
860 if (!asn1_find_end(&p, plen, inf))
861 goto err;
862 len = p - cont;
863 }
864 else
865 {
866 len = p - cont + plen;
867 p += plen;
868 buf.data = NULL;
869 }
870 }
871 else if (cst)
872 {
873 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
874 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
875 || utype == V_ASN1_ENUMERATED)
876 {
877 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
878 ASN1_R_TYPE_NOT_PRIMITIVE);
879 return 0;
880 }
881 buf.length = 0;
882 buf.max = 0;
883 buf.data = NULL;
884 /* Should really check the internal tags are correct but
885 * some things may get this wrong. The relevant specs
886 * say that constructed string types should be OCTET STRINGs
887 * internally irrespective of the type. So instead just check
888 * for UNIVERSAL class and ignore the tag.
889 */
890 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
891 {
892 free_cont = 1;
893 goto err;
894 }
895 len = buf.length;
896 /* Append a final null to string */
897 if (!BUF_MEM_grow_clean(&buf, len + 1))
898 {
899 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
900 ERR_R_MALLOC_FAILURE);
901 return 0;
902 }
903 buf.data[len] = 0;
904 cont = (const unsigned char *)buf.data;
905 free_cont = 1;
906 }
907 else
908 {
909 cont = p;
910 len = plen;
911 p += plen;
912 }
913
914 /* We now have content length and type: translate into a structure */
915 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
916 goto err;
917
918 *in = p;
919 ret = 1;
920 err:
921 if (free_cont && buf.data) OPENSSL_free(buf.data);
922 return ret;
923 }
924
925 /* Translate ASN1 content octets into a structure */
926
927 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
928 int utype, char *free_cont, const ASN1_ITEM *it)
929 {
930 ASN1_VALUE **opval = NULL;
931 ASN1_STRING *stmp;
932 ASN1_TYPE *typ = NULL;
933 int ret = 0;
934 const ASN1_PRIMITIVE_FUNCS *pf;
935 ASN1_INTEGER **tint;
936 pf = it->funcs;
937
938 if (pf && pf->prim_c2i)
939 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
940 /* If ANY type clear type and set pointer to internal value */
941 if (it->utype == V_ASN1_ANY)
942 {
943 if (!*pval)
944 {
945 typ = ASN1_TYPE_new();
946 if (typ == NULL)
947 goto err;
948 *pval = (ASN1_VALUE *)typ;
949 }
950 else
951 typ = (ASN1_TYPE *)*pval;
952
953 if (utype != typ->type)
954 ASN1_TYPE_set(typ, utype, NULL);
955 opval = pval;
956 pval = &typ->value.asn1_value;
957 }
958 switch(utype)
959 {
960 case V_ASN1_OBJECT:
961 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
962 goto err;
963 break;
964
965 case V_ASN1_NULL:
966 if (len)
967 {
968 ASN1err(ASN1_F_ASN1_EX_C2I,
969 ASN1_R_NULL_IS_WRONG_LENGTH);
970 goto err;
971 }
972 *pval = (ASN1_VALUE *)1;
973 break;
974
975 case V_ASN1_BOOLEAN:
976 if (len != 1)
977 {
978 ASN1err(ASN1_F_ASN1_EX_C2I,
979 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
980 goto err;
981 }
982 else
983 {
984 ASN1_BOOLEAN *tbool;
985 tbool = (ASN1_BOOLEAN *)pval;
986 *tbool = *cont;
987 }
988 break;
989
990 case V_ASN1_BIT_STRING:
991 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
992 goto err;
993 break;
994
995 case V_ASN1_INTEGER:
996 case V_ASN1_NEG_INTEGER:
997 case V_ASN1_ENUMERATED:
998 case V_ASN1_NEG_ENUMERATED:
999 tint = (ASN1_INTEGER **)pval;
1000 if (!c2i_ASN1_INTEGER(tint, &cont, len))
1001 goto err;
1002 /* Fixup type to match the expected form */
1003 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
1004 break;
1005
1006 case V_ASN1_OCTET_STRING:
1007 case V_ASN1_NUMERICSTRING:
1008 case V_ASN1_PRINTABLESTRING:
1009 case V_ASN1_T61STRING:
1010 case V_ASN1_VIDEOTEXSTRING:
1011 case V_ASN1_IA5STRING:
1012 case V_ASN1_UTCTIME:
1013 case V_ASN1_GENERALIZEDTIME:
1014 case V_ASN1_GRAPHICSTRING:
1015 case V_ASN1_VISIBLESTRING:
1016 case V_ASN1_GENERALSTRING:
1017 case V_ASN1_UNIVERSALSTRING:
1018 case V_ASN1_BMPSTRING:
1019 case V_ASN1_UTF8STRING:
1020 case V_ASN1_OTHER:
1021 case V_ASN1_SET:
1022 case V_ASN1_SEQUENCE:
1023 default:
1024 if (utype == V_ASN1_BMPSTRING && (len & 1))
1025 {
1026 ASN1err(ASN1_F_ASN1_EX_C2I,
1027 ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1028 goto err;
1029 }
1030 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1031 {
1032 ASN1err(ASN1_F_ASN1_EX_C2I,
1033 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1034 goto err;
1035 }
1036 /* All based on ASN1_STRING and handled the same */
1037 if (!*pval)
1038 {
1039 stmp = ASN1_STRING_type_new(utype);
1040 if (!stmp)
1041 {
1042 ASN1err(ASN1_F_ASN1_EX_C2I,
1043 ERR_R_MALLOC_FAILURE);
1044 goto err;
1045 }
1046 *pval = (ASN1_VALUE *)stmp;
1047 }
1048 else
1049 {
1050 stmp = (ASN1_STRING *)*pval;
1051 stmp->type = utype;
1052 }
1053 /* If we've already allocated a buffer use it */
1054 if (*free_cont)
1055 {
1056 if (stmp->data)
1057 OPENSSL_free(stmp->data);
1058 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1059 stmp->length = len;
1060 *free_cont = 0;
1061 }
1062 else
1063 {
1064 if (!ASN1_STRING_set(stmp, cont, len))
1065 {
1066 ASN1err(ASN1_F_ASN1_EX_C2I,
1067 ERR_R_MALLOC_FAILURE);
1068 ASN1_STRING_free(stmp);
1069 *pval = NULL;
1070 goto err;
1071 }
1072 }
1073 break;
1074 }
1075 /* If ASN1_ANY and NULL type fix up value */
1076 if (typ && (utype == V_ASN1_NULL))
1077 typ->value.ptr = NULL;
1078
1079 ret = 1;
1080 err:
1081 if (!ret)
1082 {
1083 ASN1_TYPE_free(typ);
1084 if (opval)
1085 *opval = NULL;
1086 }
1087 return ret;
1088 }
1089
1090
1091 /* This function finds the end of an ASN1 structure when passed its maximum
1092 * length, whether it is indefinite length and a pointer to the content.
1093 * This is more efficient than calling asn1_collect because it does not
1094 * recurse on each indefinite length header.
1095 */
1096
1097 static int asn1_find_end(const unsigned char **in, long len, char inf)
1098 {
1099 int expected_eoc;
1100 long plen;
1101 const unsigned char *p = *in, *q;
1102 /* If not indefinite length constructed just add length */
1103 if (inf == 0)
1104 {
1105 *in += len;
1106 return 1;
1107 }
1108 expected_eoc = 1;
1109 /* Indefinite length constructed form. Find the end when enough EOCs
1110 * are found. If more indefinite length constructed headers
1111 * are encountered increment the expected eoc count otherwise just
1112 * skip to the end of the data.
1113 */
1114 while (len > 0)
1115 {
1116 if(asn1_check_eoc(&p, len))
1117 {
1118 expected_eoc--;
1119 if (expected_eoc == 0)
1120 break;
1121 len -= 2;
1122 continue;
1123 }
1124 q = p;
1125 /* Just read in a header: only care about the length */
1126 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1127 -1, 0, 0, NULL))
1128 {
1129 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1130 return 0;
1131 }
1132 if (inf)
1133 expected_eoc++;
1134 else
1135 p += plen;
1136 len -= p - q;
1137 }
1138 if (expected_eoc)
1139 {
1140 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1141 return 0;
1142 }
1143 *in = p;
1144 return 1;
1145 }
1146 /* This function collects the asn1 data from a constructred string
1147 * type into a buffer. The values of 'in' and 'len' should refer
1148 * to the contents of the constructed type and 'inf' should be set
1149 * if it is indefinite length.
1150 */
1151
1152 #ifndef ASN1_MAX_STRING_NEST
1153 /* This determines how many levels of recursion are permitted in ASN1
1154 * string types. If it is not limited stack overflows can occur. If set
1155 * to zero no recursion is allowed at all. Although zero should be adequate
1156 * examples exist that require a value of 1. So 5 should be more than enough.
1157 */
1158 #define ASN1_MAX_STRING_NEST 5
1159 #endif
1160
1161
1162 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1163 char inf, int tag, int aclass, int depth)
1164 {
1165 const unsigned char *p, *q;
1166 long plen;
1167 char cst, ininf;
1168 p = *in;
1169 inf &= 1;
1170 /* If no buffer and not indefinite length constructed just pass over
1171 * the encoded data */
1172 if (!buf && !inf)
1173 {
1174 *in += len;
1175 return 1;
1176 }
1177 while(len > 0)
1178 {
1179 q = p;
1180 /* Check for EOC */
1181 if (asn1_check_eoc(&p, len))
1182 {
1183 /* EOC is illegal outside indefinite length
1184 * constructed form */
1185 if (!inf)
1186 {
1187 ASN1err(ASN1_F_ASN1_COLLECT,
1188 ASN1_R_UNEXPECTED_EOC);
1189 return 0;
1190 }
1191 inf = 0;
1192 break;
1193 }
1194
1195 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1196 len, tag, aclass, 0, NULL))
1197 {
1198 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1199 return 0;
1200 }
1201
1202 /* If indefinite length constructed update max length */
1203 if (cst)
1204 {
1205 if (depth >= ASN1_MAX_STRING_NEST)
1206 {
1207 ASN1err(ASN1_F_ASN1_COLLECT,
1208 ASN1_R_NESTED_ASN1_STRING);
1209 return 0;
1210 }
1211 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1212 depth + 1))
1213 return 0;
1214 }
1215 else if (plen && !collect_data(buf, &p, plen))
1216 return 0;
1217 len -= p - q;
1218 }
1219 if (inf)
1220 {
1221 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1222 return 0;
1223 }
1224 *in = p;
1225 return 1;
1226 }
1227
1228 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1229 {
1230 int len;
1231 if (buf)
1232 {
1233 len = buf->length;
1234 if (!BUF_MEM_grow_clean(buf, len + plen))
1235 {
1236 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1237 return 0;
1238 }
1239 memcpy(buf->data + len, *p, plen);
1240 }
1241 *p += plen;
1242 return 1;
1243 }
1244
1245 /* Check for ASN1 EOC and swallow it if found */
1246
1247 static int asn1_check_eoc(const unsigned char **in, long len)
1248 {
1249 const unsigned char *p;
1250 if (len < 2) return 0;
1251 p = *in;
1252 if (!p[0] && !p[1])
1253 {
1254 *in += 2;
1255 return 1;
1256 }
1257 return 0;
1258 }
1259
1260 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1261 * but it sets the length for indefinite length constructed
1262 * form, we don't know the exact length but we can set an
1263 * upper bound to the amount of data available minus the
1264 * header length just read.
1265 */
1266
1267 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1268 char *inf, char *cst,
1269 const unsigned char **in, long len,
1270 int exptag, int expclass, char opt,
1271 ASN1_TLC *ctx)
1272 {
1273 int i;
1274 int ptag, pclass;
1275 long plen;
1276 const unsigned char *p, *q;
1277 p = *in;
1278 q = p;
1279
1280 if (ctx && ctx->valid)
1281 {
1282 i = ctx->ret;
1283 plen = ctx->plen;
1284 pclass = ctx->pclass;
1285 ptag = ctx->ptag;
1286 p += ctx->hdrlen;
1287 }
1288 else
1289 {
1290 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1291 if (ctx)
1292 {
1293 ctx->ret = i;
1294 ctx->plen = plen;
1295 ctx->pclass = pclass;
1296 ctx->ptag = ptag;
1297 ctx->hdrlen = p - q;
1298 ctx->valid = 1;
1299 /* If definite length, and no error, length +
1300 * header can't exceed total amount of data available.
1301 */
1302 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1303 {
1304 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1305 ASN1_R_TOO_LONG);
1306 asn1_tlc_clear(ctx);
1307 return 0;
1308 }
1309 }
1310 }
1311
1312 if (i & 0x80)
1313 {
1314 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1315 asn1_tlc_clear(ctx);
1316 return 0;
1317 }
1318 if (exptag >= 0)
1319 {
1320 if ((exptag != ptag) || (expclass != pclass))
1321 {
1322 /* If type is OPTIONAL, not an error:
1323 * indicate missing type.
1324 */
1325 if (opt) return -1;
1326 asn1_tlc_clear(ctx);
1327 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1328 return 0;
1329 }
1330 /* We have a tag and class match:
1331 * assume we are going to do something with it */
1332 asn1_tlc_clear(ctx);
1333 }
1334
1335 if (i & 1)
1336 plen = len - (p - q);
1337
1338 if (inf)
1339 *inf = i & 1;
1340
1341 if (cst)
1342 *cst = i & V_ASN1_CONSTRUCTED;
1343
1344 if (olen)
1345 *olen = plen;
1346
1347 if (oclass)
1348 *oclass = pclass;
1349
1350 if (otag)
1351 *otag = ptag;
1352
1353 *in = p;
1354 return 1;
1355 }
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