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[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 *pchval, **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                 pchval = NULL;
323                 p = *in;
324                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
325                         {
326                         pchptr = asn1_get_field_ptr(pval, tt);
327                         /* We mark field as OPTIONAL so its absence
328                          * can be recognised.
329                          */
330                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
331                         /* If field not present, try the next one */
332                         if (ret == -1)
333                                 continue;
334                         /* If positive return, read OK, break loop */
335                         if (ret > 0)
336                                 break;
337                         /* Otherwise must be an ASN1 parsing error */
338                         errtt = tt;
339                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
340                                                 ERR_R_NESTED_ASN1_ERROR);
341                         goto err;
342                         }
343
344                 /* Did we fall off the end without reading anything? */
345                 if (i == it->tcount)
346                         {
347                         /* If OPTIONAL, this is OK */
348                         if (opt)
349                                 {
350                                 /* Free and zero it */
351                                 ASN1_item_ex_free(pval, it);
352                                 return -1;
353                                 }
354                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
355                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
356                         goto err;
357                         }
358
359                 asn1_set_choice_selector(pval, i, it);
360                 *in = p;
361                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
362                                 goto auxerr;
363                 return 1;
364
365                 case ASN1_ITYPE_NDEF_SEQUENCE:
366                 case ASN1_ITYPE_SEQUENCE:
367                 p = *in;
368                 tmplen = len;
369
370                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
371                 if (tag == -1)
372                         {
373                         tag = V_ASN1_SEQUENCE;
374                         aclass = V_ASN1_UNIVERSAL;
375                         }
376                 /* Get SEQUENCE length and update len, p */
377                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
378                                         &p, len, tag, aclass, opt, ctx);
379                 if (!ret)
380                         {
381                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
382                                         ERR_R_NESTED_ASN1_ERROR);
383                         goto err;
384                         }
385                 else if (ret == -1)
386                         return -1;
387                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
388                         {
389                         len = tmplen - (p - *in);
390                         seq_nolen = 1;
391                         }
392                 /* If indefinite we don't do a length check */
393                 else seq_nolen = seq_eoc;
394                 if (!cst)
395                         {
396                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
397                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
398                         goto err;
399                         }
400
401                 if (!*pval && !ASN1_item_ex_new(pval, it))
402                         {
403                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
404                                 ERR_R_NESTED_ASN1_ERROR);
405                         goto err;
406                         }
407
408                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
409                                 goto auxerr;
410
411                 /* Get each field entry */
412                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
413                         {
414                         const ASN1_TEMPLATE *seqtt;
415                         ASN1_VALUE **pseqval;
416                         seqtt = asn1_do_adb(pval, tt, 1);
417                         if (!seqtt)
418                                 goto err;
419                         pseqval = asn1_get_field_ptr(pval, seqtt);
420                         /* Have we ran out of data? */
421                         if (!len)
422                                 break;
423                         q = p;
424                         if (asn1_check_eoc(&p, len))
425                                 {
426                                 if (!seq_eoc)
427                                         {
428                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
429                                                         ASN1_R_UNEXPECTED_EOC);
430                                         goto err;
431                                         }
432                                 len -= p - q;
433                                 seq_eoc = 0;
434                                 q = p;
435                                 break;
436                                 }
437                         /* This determines the OPTIONAL flag value. The field
438                          * cannot be omitted if it is the last of a SEQUENCE
439                          * and there is still data to be read. This isn't
440                          * strictly necessary but it increases efficiency in
441                          * some cases.
442                          */
443                         if (i == (it->tcount - 1))
444                                 isopt = 0;
445                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
446                         /* attempt to read in field, allowing each to be
447                          * OPTIONAL */
448
449                         ret = asn1_template_ex_d2i(pseqval, &p, len,
450                                                         seqtt, isopt, ctx);
451                         if (!ret)
452                                 {
453                                 errtt = seqtt;
454                                 goto err;
455                                 }
456                         else if (ret == -1)
457                                 {
458                                 /* OPTIONAL component absent.
459                                  * Free and zero the field.
460                                  */
461                                 ASN1_template_free(pseqval, seqtt);
462                                 continue;
463                                 }
464                         /* Update length */
465                         len -= p - q;
466                         }
467
468                 /* Check for EOC if expecting one */
469                 if (seq_eoc && !asn1_check_eoc(&p, len))
470                         {
471                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
472                         goto err;
473                         }
474                 /* Check all data read */
475                 if (!seq_nolen && len)
476                         {
477                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
478                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
479                         goto err;
480                         }
481
482                 /* If we get here we've got no more data in the SEQUENCE,
483                  * however we may not have read all fields so check all
484                  * remaining are OPTIONAL and clear any that are.
485                  */
486                 for (; i < it->tcount; tt++, i++)
487                         {
488                         const ASN1_TEMPLATE *seqtt;
489                         seqtt = asn1_do_adb(pval, tt, 1);
490                         if (!seqtt)
491                                 goto err;
492                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
493                                 {
494                                 ASN1_VALUE **pseqval;
495                                 pseqval = asn1_get_field_ptr(pval, seqtt);
496                                 ASN1_template_free(pseqval, seqtt);
497                                 }
498                         else
499                                 {
500                                 errtt = seqtt;
501                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
502                                                         ASN1_R_FIELD_MISSING);
503                                 goto err;
504                                 }
505                         }
506                 /* Save encoding */
507                 if (!asn1_enc_save(pval, *in, p - *in, it))
508                         goto auxerr;
509                 *in = p;
510                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
511                                 goto auxerr;
512                 return 1;
513
514                 default:
515                 return 0;
516                 }
517         auxerr:
518         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
519         err:
520         ASN1_item_ex_free(pval, it);
521         if (errtt)
522                 ERR_add_error_data(4, "Field=", errtt->field_name,
523                                         ", Type=", it->sname);
524         else
525                 ERR_add_error_data(2, "Type=", it->sname);
526         return 0;
527         }
528
529 /* Templates are handled with two separate functions.
530  * One handles any EXPLICIT tag and the other handles the rest.
531  */
532
533 static int asn1_template_ex_d2i(ASN1_VALUE **val,
534                                 const unsigned char **in, long inlen,
535                                 const ASN1_TEMPLATE *tt, char opt,
536                                                         ASN1_TLC *ctx)
537         {
538         int flags, aclass;
539         int ret;
540         long len;
541         const unsigned char *p, *q;
542         char exp_eoc;
543         if (!val)
544                 return 0;
545         flags = tt->flags;
546         aclass = flags & ASN1_TFLG_TAG_CLASS;
547
548         p = *in;
549
550         /* Check if EXPLICIT tag expected */
551         if (flags & ASN1_TFLG_EXPTAG)
552                 {
553                 char cst;
554                 /* Need to work out amount of data available to the inner
555                  * content and where it starts: so read in EXPLICIT header to
556                  * get the info.
557                  */
558                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
559                                         &p, inlen, tt->tag, aclass, opt, ctx);
560                 q = p;
561                 if (!ret)
562                         {
563                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
564                                         ERR_R_NESTED_ASN1_ERROR);
565                         return 0;
566                         }
567                 else if (ret == -1)
568                         return -1;
569                 if (!cst)
570                         {
571                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
572                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
573                         return 0;
574                         }
575                 /* We've found the field so it can't be OPTIONAL now */
576                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
577                 if (!ret)
578                         {
579                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
580                                         ERR_R_NESTED_ASN1_ERROR);
581                         return 0;
582                         }
583                 /* We read the field in OK so update length */
584                 len -= p - q;
585                 if (exp_eoc)
586                         {
587                         /* If NDEF we must have an EOC here */
588                         if (!asn1_check_eoc(&p, len))
589                                 {
590                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
591                                                 ASN1_R_MISSING_EOC);
592                                 goto err;
593                                 }
594                         }
595                 else
596                         {
597                         /* Otherwise we must hit the EXPLICIT tag end or its
598                          * an error */
599                         if (len)
600                                 {
601                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
602                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
603                                 goto err;
604                                 }
605                         }
606                 }
607                 else 
608                         return asn1_template_noexp_d2i(val, in, inlen,
609                                                                 tt, opt, ctx);
610
611         *in = p;
612         return 1;
613
614         err:
615         ASN1_template_free(val, tt);
616         return 0;
617         }
618
619 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
620                                 const unsigned char **in, long len,
621                                 const ASN1_TEMPLATE *tt, char opt,
622                                 ASN1_TLC *ctx)
623         {
624         int flags, aclass;
625         int ret;
626         const unsigned char *p, *q;
627         if (!val)
628                 return 0;
629         flags = tt->flags;
630         aclass = flags & ASN1_TFLG_TAG_CLASS;
631
632         p = *in;
633         q = p;
634
635         if (flags & ASN1_TFLG_SK_MASK)
636                 {
637                 /* SET OF, SEQUENCE OF */
638                 int sktag, skaclass;
639                 char sk_eoc;
640                 /* First work out expected inner tag value */
641                 if (flags & ASN1_TFLG_IMPTAG)
642                         {
643                         sktag = tt->tag;
644                         skaclass = aclass;
645                         }
646                 else
647                         {
648                         skaclass = V_ASN1_UNIVERSAL;
649                         if (flags & ASN1_TFLG_SET_OF)
650                                 sktag = V_ASN1_SET;
651                         else
652                                 sktag = V_ASN1_SEQUENCE;
653                         }
654                 /* Get the tag */
655                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
656                                         &p, len, sktag, skaclass, opt, ctx);
657                 if (!ret)
658                         {
659                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
660                                                 ERR_R_NESTED_ASN1_ERROR);
661                         return 0;
662                         }
663                 else if (ret == -1)
664                         return -1;
665                 if (!*val)
666                         *val = (ASN1_VALUE *)sk_new_null();
667                 else
668                         {
669                         /* We've got a valid STACK: free up any items present */
670                         STACK_OF(ASN1_VALUE) *sktmp
671                             = (STACK_OF(ASN1_VALUE) *)*val;
672                         ASN1_VALUE *vtmp;
673                         while(sk_ASN1_VALUE_num(sktmp) > 0)
674                                 {
675                                 vtmp = sk_ASN1_VALUE_pop(sktmp);
676                                 ASN1_item_ex_free(&vtmp,
677                                                 ASN1_ITEM_ptr(tt->item));
678                                 }
679                         }
680                                 
681                 if (!*val)
682                         {
683                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
684                                                 ERR_R_MALLOC_FAILURE);
685                         goto err;
686                         }
687
688                 /* Read as many items as we can */
689                 while(len > 0)
690                         {
691                         ASN1_VALUE *skfield;
692                         q = p;
693                         /* See if EOC found */
694                         if (asn1_check_eoc(&p, len))
695                                 {
696                                 if (!sk_eoc)
697                                         {
698                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
699                                                         ASN1_R_UNEXPECTED_EOC);
700                                         goto err;
701                                         }
702                                 len -= p - q;
703                                 sk_eoc = 0;
704                                 break;
705                                 }
706                         skfield = NULL;
707                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
708                                                 ASN1_ITEM_ptr(tt->item),
709                                                 -1, 0, 0, ctx))
710                                 {
711                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
712                                         ERR_R_NESTED_ASN1_ERROR);
713                                 goto err;
714                                 }
715                         len -= p - q;
716                         if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
717                                                 skfield))
718                                 {
719                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
720                                                 ERR_R_MALLOC_FAILURE);
721                                 goto err;
722                                 }
723                         }
724                 if (sk_eoc)
725                         {
726                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
727                         goto err;
728                         }
729                 }
730         else if (flags & ASN1_TFLG_IMPTAG)
731                 {
732                 /* IMPLICIT tagging */
733                 ret = ASN1_item_ex_d2i(val, &p, len,
734                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
735                 if (!ret)
736                         {
737                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
738                                                 ERR_R_NESTED_ASN1_ERROR);
739                         goto err;
740                         }
741                 else if (ret == -1)
742                         return -1;
743                 }
744         else
745                 {
746                 /* Nothing special */
747                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
748                                                         -1, 0, opt, ctx);
749                 if (!ret)
750                         {
751                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
752                                         ERR_R_NESTED_ASN1_ERROR);
753                         goto err;
754                         }
755                 else if (ret == -1)
756                         return -1;
757                 }
758
759         *in = p;
760         return 1;
761
762         err:
763         ASN1_template_free(val, tt);
764         return 0;
765         }
766
767 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
768                                 const unsigned char **in, long inlen, 
769                                 const ASN1_ITEM *it,
770                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
771         {
772         int ret = 0, utype;
773         long plen;
774         char cst, inf, free_cont = 0;
775         const unsigned char *p;
776         BUF_MEM buf;
777         const unsigned char *cont = NULL;
778         long len; 
779         if (!pval)
780                 {
781                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
782                 return 0; /* Should never happen */
783                 }
784
785         if (it->itype == ASN1_ITYPE_MSTRING)
786                 {
787                 utype = tag;
788                 tag = -1;
789                 }
790         else
791                 utype = it->utype;
792
793         if (utype == V_ASN1_ANY)
794                 {
795                 /* If type is ANY need to figure out type from tag */
796                 unsigned char oclass;
797                 if (tag >= 0)
798                         {
799                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
800                                         ASN1_R_ILLEGAL_TAGGED_ANY);
801                         return 0;
802                         }
803                 if (opt)
804                         {
805                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
806                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
807                         return 0;
808                         }
809                 p = *in;
810                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
811                                         &p, inlen, -1, 0, 0, ctx);
812                 if (!ret)
813                         {
814                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
815                                         ERR_R_NESTED_ASN1_ERROR);
816                         return 0;
817                         }
818                 if (oclass != V_ASN1_UNIVERSAL)
819                         utype = V_ASN1_OTHER;
820                 }
821         if (tag == -1)
822                 {
823                 tag = utype;
824                 aclass = V_ASN1_UNIVERSAL;
825                 }
826         p = *in;
827         /* Check header */
828         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
829                                 &p, inlen, tag, aclass, opt, ctx);
830         if (!ret)
831                 {
832                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
833                 return 0;
834                 }
835         else if (ret == -1)
836                 return -1;
837         ret = 0;
838         /* SEQUENCE, SET and "OTHER" are left in encoded form */
839         if ((utype == V_ASN1_SEQUENCE)
840                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
841                 {
842                 /* Clear context cache for type OTHER because the auto clear
843                  * when we have a exact match wont work
844                  */
845                 if (utype == V_ASN1_OTHER)
846                         {
847                         asn1_tlc_clear(ctx);
848                         }
849                 /* SEQUENCE and SET must be constructed */
850                 else if (!cst)
851                         {
852                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
853                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
854                         return 0;
855                         }
856
857                 cont = *in;
858                 /* If indefinite length constructed find the real end */
859                 if (inf)
860                         {
861                         if (!asn1_find_end(&p, plen, inf))
862                                  goto err;
863                         len = p - cont;
864                         }
865                 else
866                         {
867                         len = p - cont + plen;
868                         p += plen;
869                         buf.data = NULL;
870                         }
871                 }
872         else if (cst)
873                 {
874                 buf.length = 0;
875                 buf.max = 0;
876                 buf.data = NULL;
877                 /* Should really check the internal tags are correct but
878                  * some things may get this wrong. The relevant specs
879                  * say that constructed string types should be OCTET STRINGs
880                  * internally irrespective of the type. So instead just check
881                  * for UNIVERSAL class and ignore the tag.
882                  */
883                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
884                         {
885                         free_cont = 1;
886                         goto err;
887                         }
888                 len = buf.length;
889                 /* Append a final null to string */
890                 if (!BUF_MEM_grow_clean(&buf, len + 1))
891                         {
892                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
893                                                 ERR_R_MALLOC_FAILURE);
894                         return 0;
895                         }
896                 buf.data[len] = 0;
897                 cont = (const unsigned char *)buf.data;
898                 free_cont = 1;
899                 }
900         else
901                 {
902                 cont = p;
903                 len = plen;
904                 p += plen;
905                 }
906
907         /* We now have content length and type: translate into a structure */
908         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
909                 goto err;
910
911         *in = p;
912         ret = 1;
913         err:
914         if (free_cont && buf.data) OPENSSL_free(buf.data);
915         return ret;
916         }
917
918 /* Translate ASN1 content octets into a structure */
919
920 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
921                         int utype, char *free_cont, const ASN1_ITEM *it)
922         {
923         ASN1_VALUE **opval = NULL;
924         ASN1_STRING *stmp;
925         ASN1_TYPE *typ = NULL;
926         int ret = 0;
927         const ASN1_PRIMITIVE_FUNCS *pf;
928         ASN1_INTEGER **tint;
929         pf = it->funcs;
930
931         if (pf && pf->prim_c2i)
932                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
933         /* If ANY type clear type and set pointer to internal value */
934         if (it->utype == V_ASN1_ANY)
935                 {
936                 if (!*pval)
937                         {
938                         typ = ASN1_TYPE_new();
939                         if (typ == NULL)
940                                 goto err;
941                         *pval = (ASN1_VALUE *)typ;
942                         }
943                 else
944                         typ = (ASN1_TYPE *)*pval;
945
946                 if (utype != typ->type)
947                         ASN1_TYPE_set(typ, utype, NULL);
948                 opval = pval;
949                 pval = &typ->value.asn1_value;
950                 }
951         switch(utype)
952                 {
953                 case V_ASN1_OBJECT:
954                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
955                         goto err;
956                 break;
957
958                 case V_ASN1_NULL:
959                 if (len)
960                         {
961                         ASN1err(ASN1_F_ASN1_EX_C2I,
962                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
963                         goto err;
964                         }
965                 *pval = (ASN1_VALUE *)1;
966                 break;
967
968                 case V_ASN1_BOOLEAN:
969                 if (len != 1)
970                         {
971                         ASN1err(ASN1_F_ASN1_EX_C2I,
972                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
973                         goto err;
974                         }
975                 else
976                         {
977                         ASN1_BOOLEAN *tbool;
978                         tbool = (ASN1_BOOLEAN *)pval;
979                         *tbool = *cont;
980                         }
981                 break;
982
983                 case V_ASN1_BIT_STRING:
984                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
985                         goto err;
986                 break;
987
988                 case V_ASN1_INTEGER:
989                 case V_ASN1_NEG_INTEGER:
990                 case V_ASN1_ENUMERATED:
991                 case V_ASN1_NEG_ENUMERATED:
992                 tint = (ASN1_INTEGER **)pval;
993                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
994                         goto err;
995                 /* Fixup type to match the expected form */
996                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
997                 break;
998
999                 case V_ASN1_OCTET_STRING:
1000                 case V_ASN1_NUMERICSTRING:
1001                 case V_ASN1_PRINTABLESTRING:
1002                 case V_ASN1_T61STRING:
1003                 case V_ASN1_VIDEOTEXSTRING:
1004                 case V_ASN1_IA5STRING:
1005                 case V_ASN1_UTCTIME:
1006                 case V_ASN1_GENERALIZEDTIME:
1007                 case V_ASN1_GRAPHICSTRING:
1008                 case V_ASN1_VISIBLESTRING:
1009                 case V_ASN1_GENERALSTRING:
1010                 case V_ASN1_UNIVERSALSTRING:
1011                 case V_ASN1_BMPSTRING:
1012                 case V_ASN1_UTF8STRING:
1013                 case V_ASN1_OTHER:
1014                 case V_ASN1_SET:
1015                 case V_ASN1_SEQUENCE:
1016                 default:
1017                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1018                         {
1019                         ASN1err(ASN1_F_ASN1_EX_C2I,
1020                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1021                         goto err;
1022                         }
1023                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1024                         {
1025                         ASN1err(ASN1_F_ASN1_EX_C2I,
1026                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1027                         goto err;
1028                         }
1029                 /* All based on ASN1_STRING and handled the same */
1030                 if (!*pval)
1031                         {
1032                         stmp = ASN1_STRING_type_new(utype);
1033                         if (!stmp)
1034                                 {
1035                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1036                                                         ERR_R_MALLOC_FAILURE);
1037                                 goto err;
1038                                 }
1039                         *pval = (ASN1_VALUE *)stmp;
1040                         }
1041                 else
1042                         {
1043                         stmp = (ASN1_STRING *)*pval;
1044                         stmp->type = utype;
1045                         }
1046                 /* If we've already allocated a buffer use it */
1047                 if (*free_cont)
1048                         {
1049                         if (stmp->data)
1050                                 OPENSSL_free(stmp->data);
1051                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1052                         stmp->length = len;
1053                         *free_cont = 0;
1054                         }
1055                 else
1056                         {
1057                         if (!ASN1_STRING_set(stmp, cont, len))
1058                                 {
1059                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1060                                                         ERR_R_MALLOC_FAILURE);
1061                                 ASN1_STRING_free(stmp); 
1062                                 *pval = NULL;
1063                                 goto err;
1064                                 }
1065                         }
1066                 break;
1067                 }
1068         /* If ASN1_ANY and NULL type fix up value */
1069         if (typ && (utype == V_ASN1_NULL))
1070                  typ->value.ptr = NULL;
1071
1072         ret = 1;
1073         err:
1074         if (!ret)
1075                 {
1076                 ASN1_TYPE_free(typ);
1077                 if (opval)
1078                         *opval = NULL;
1079                 }
1080         return ret;
1081         }
1082
1083
1084 /* This function finds the end of an ASN1 structure when passed its maximum
1085  * length, whether it is indefinite length and a pointer to the content.
1086  * This is more efficient than calling asn1_collect because it does not
1087  * recurse on each indefinite length header.
1088  */
1089
1090 static int asn1_find_end(const unsigned char **in, long len, char inf)
1091         {
1092         int expected_eoc;
1093         long plen;
1094         const unsigned char *p = *in, *q;
1095         /* If not indefinite length constructed just add length */
1096         if (inf == 0)
1097                 {
1098                 *in += len;
1099                 return 1;
1100                 }
1101         expected_eoc = 1;
1102         /* Indefinite length constructed form. Find the end when enough EOCs
1103          * are found. If more indefinite length constructed headers
1104          * are encountered increment the expected eoc count otherwise just
1105          * skip to the end of the data.
1106          */
1107         while (len > 0)
1108                 {
1109                 if(asn1_check_eoc(&p, len))
1110                         {
1111                         expected_eoc--;
1112                         if (expected_eoc == 0)
1113                                 break;
1114                         len -= 2;
1115                         continue;
1116                         }
1117                 q = p;
1118                 /* Just read in a header: only care about the length */
1119                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1120                                 -1, 0, 0, NULL))
1121                         {
1122                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1123                         return 0;
1124                         }
1125                 if (inf)
1126                         expected_eoc++;
1127                 else
1128                         p += plen;
1129                 len -= p - q;
1130                 }
1131         if (expected_eoc)
1132                 {
1133                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1134                 return 0;
1135                 }
1136         *in = p;
1137         return 1;
1138         }
1139 /* This function collects the asn1 data from a constructred string
1140  * type into a buffer. The values of 'in' and 'len' should refer
1141  * to the contents of the constructed type and 'inf' should be set
1142  * if it is indefinite length.
1143  */
1144
1145 #ifndef ASN1_MAX_STRING_NEST
1146 /* This determines how many levels of recursion are permitted in ASN1
1147  * string types. If it is not limited stack overflows can occur. If set
1148  * to zero no recursion is allowed at all. Although zero should be adequate
1149  * examples exist that require a value of 1. So 5 should be more than enough.
1150  */
1151 #define ASN1_MAX_STRING_NEST 5
1152 #endif
1153
1154
1155 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1156                         char inf, int tag, int aclass, int depth)
1157         {
1158         const unsigned char *p, *q;
1159         long plen;
1160         char cst, ininf;
1161         p = *in;
1162         inf &= 1;
1163         /* If no buffer and not indefinite length constructed just pass over
1164          * the encoded data */
1165         if (!buf && !inf)
1166                 {
1167                 *in += len;
1168                 return 1;
1169                 }
1170         while(len > 0)
1171                 {
1172                 q = p;
1173                 /* Check for EOC */
1174                 if (asn1_check_eoc(&p, len))
1175                         {
1176                         /* EOC is illegal outside indefinite length
1177                          * constructed form */
1178                         if (!inf)
1179                                 {
1180                                 ASN1err(ASN1_F_ASN1_COLLECT,
1181                                         ASN1_R_UNEXPECTED_EOC);
1182                                 return 0;
1183                                 }
1184                         inf = 0;
1185                         break;
1186                         }
1187
1188                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1189                                         len, tag, aclass, 0, NULL))
1190                         {
1191                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1192                         return 0;
1193                         }
1194
1195                 /* If indefinite length constructed update max length */
1196                 if (cst)
1197                         {
1198                         if (depth >= ASN1_MAX_STRING_NEST)
1199                                 {
1200                                 ASN1err(ASN1_F_ASN1_COLLECT,
1201                                         ASN1_R_NESTED_ASN1_STRING);
1202                                 return 0;
1203                                 }
1204                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1205                                                 depth + 1))
1206                                 return 0;
1207                         }
1208                 else if (plen && !collect_data(buf, &p, plen))
1209                         return 0;
1210                 len -= p - q;
1211                 }
1212         if (inf)
1213                 {
1214                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1215                 return 0;
1216                 }
1217         *in = p;
1218         return 1;
1219         }
1220
1221 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1222         {
1223         int len;
1224         if (buf)
1225                 {
1226                 len = buf->length;
1227                 if (!BUF_MEM_grow_clean(buf, len + plen))
1228                         {
1229                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1230                         return 0;
1231                         }
1232                 memcpy(buf->data + len, *p, plen);
1233                 }
1234         *p += plen;
1235         return 1;
1236         }
1237
1238 /* Check for ASN1 EOC and swallow it if found */
1239
1240 static int asn1_check_eoc(const unsigned char **in, long len)
1241         {
1242         const unsigned char *p;
1243         if (len < 2) return 0;
1244         p = *in;
1245         if (!p[0] && !p[1])
1246                 {
1247                 *in += 2;
1248                 return 1;
1249                 }
1250         return 0;
1251         }
1252
1253 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1254  * but it sets the length for indefinite length constructed
1255  * form, we don't know the exact length but we can set an
1256  * upper bound to the amount of data available minus the
1257  * header length just read.
1258  */
1259
1260 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1261                                 char *inf, char *cst,
1262                                 const unsigned char **in, long len,
1263                                 int exptag, int expclass, char opt,
1264                                 ASN1_TLC *ctx)
1265         {
1266         int i;
1267         int ptag, pclass;
1268         long plen;
1269         const unsigned char *p, *q;
1270         p = *in;
1271         q = p;
1272
1273         if (ctx && ctx->valid)
1274                 {
1275                 i = ctx->ret;
1276                 plen = ctx->plen;
1277                 pclass = ctx->pclass;
1278                 ptag = ctx->ptag;
1279                 p += ctx->hdrlen;
1280                 }
1281         else
1282                 {
1283                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1284                 if (ctx)
1285                         {
1286                         ctx->ret = i;
1287                         ctx->plen = plen;
1288                         ctx->pclass = pclass;
1289                         ctx->ptag = ptag;
1290                         ctx->hdrlen = p - q;
1291                         ctx->valid = 1;
1292                         /* If definite length, and no error, length +
1293                          * header can't exceed total amount of data available. 
1294                          */
1295                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1296                                 {
1297                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1298                                                         ASN1_R_TOO_LONG);
1299                                 asn1_tlc_clear(ctx);
1300                                 return 0;
1301                                 }
1302                         }
1303                 }
1304
1305         if (i & 0x80)
1306                 {
1307                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1308                 asn1_tlc_clear(ctx);
1309                 return 0;
1310                 }
1311         if (exptag >= 0)
1312                 {
1313                 if ((exptag != ptag) || (expclass != pclass))
1314                         {
1315                         /* If type is OPTIONAL, not an error:
1316                          * indicate missing type.
1317                          */
1318                         if (opt) return -1;
1319                         asn1_tlc_clear(ctx);
1320                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1321                         return 0;
1322                         }
1323                 /* We have a tag and class match:
1324                  * assume we are going to do something with it */
1325                 asn1_tlc_clear(ctx);
1326                 }
1327
1328         if (i & 1)
1329                 plen = len - (p - q);
1330
1331         if (inf)
1332                 *inf = i & 1;
1333
1334         if (cst)
1335                 *cst = i & V_ASN1_CONSTRUCTED;
1336
1337         if (olen)
1338                 *olen = plen;
1339
1340         if (oclass)
1341                 *oclass = pclass;
1342
1343         if (otag)
1344                 *otag = ptag;
1345
1346         *in = p;
1347         return 1;
1348         }