Ignore zero length constructed segments.
[openssl.git] / crypto / asn1 / tasn_dec.c
1 /* tasn_dec.c */
2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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);
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 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 0,      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
118 /* Decode an ASN1 item, this currently behaves just 
119  * like a standard 'd2i' function. 'in' points to 
120  * a buffer to read the data from, in future we will
121  * have more advanced versions that can input data
122  * a piece at a time and this will simply be a special
123  * case.
124  */
125
126 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
127                 const unsigned char **in, long len, const ASN1_ITEM *it)
128         {
129         ASN1_TLC c;
130         ASN1_VALUE *ptmpval = NULL;
131         if (!pval)
132                 pval = &ptmpval;
133         asn1_tlc_clear(&c);
134         if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 
135                 return *pval;
136         return NULL;
137         }
138
139 int ASN1_template_d2i(ASN1_VALUE **pval,
140                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
141         {
142         ASN1_TLC c;
143         asn1_tlc_clear(&c);
144         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
145         }
146
147
148 /* Decode an item, taking care of IMPLICIT tagging, if any.
149  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
150  */
151
152 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
153                         const ASN1_ITEM *it,
154                         int tag, int aclass, char opt, ASN1_TLC *ctx)
155         {
156         const ASN1_TEMPLATE *tt, *errtt = NULL;
157         const ASN1_COMPAT_FUNCS *cf;
158         const ASN1_EXTERN_FUNCS *ef;
159         const ASN1_AUX *aux = it->funcs;
160         ASN1_aux_cb *asn1_cb;
161         const unsigned char *p, *q;
162         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
163         unsigned char imphack = 0, oclass;
164         char seq_eoc, seq_nolen, cst, isopt;
165         long tmplen;
166         int i;
167         int otag;
168         int ret = 0;
169         ASN1_VALUE *pchval, **pchptr, *ptmpval;
170         if (!pval)
171                 return 0;
172         if (aux && aux->asn1_cb)
173                 asn1_cb = aux->asn1_cb;
174         else asn1_cb = 0;
175
176         switch(it->itype)
177                 {
178                 case ASN1_ITYPE_PRIMITIVE:
179                 if (it->templates)
180                         {
181                         /* tagging or OPTIONAL is currently illegal on an item
182                          * template because the flags can't get passed down.
183                          * In practice this isn't a problem: we include the
184                          * relevant flags from the item template in the
185                          * template itself.
186                          */
187                         if ((tag != -1) || opt)
188                                 {
189                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
190                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
191                                 goto err;
192                                 }
193                         return asn1_template_ex_d2i(pval, in, len,
194                                         it->templates, opt, ctx);
195                 }
196                 return asn1_d2i_ex_primitive(pval, in, len, it,
197                                                 tag, aclass, opt, ctx);
198                 break;
199
200                 case ASN1_ITYPE_MSTRING:
201                 p = *in;
202                 /* Just read in tag and class */
203                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
204                                                 &p, len, -1, 0, 1, ctx);
205                 if (!ret)
206                         {
207                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
208                                         ERR_R_NESTED_ASN1_ERROR);
209                         goto err;
210                         }
211
212                 /* Must be UNIVERSAL class */
213                 if (oclass != V_ASN1_UNIVERSAL)
214                         {
215                         /* If OPTIONAL, assume this is OK */
216                         if (opt) return -1;
217                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
218                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
219                         goto err;
220                         }
221                 /* Check tag matches bit map */
222                 if (!(ASN1_tag2bit(otag) & it->utype))
223                         {
224                         /* If OPTIONAL, assume this is OK */
225                         if (opt)
226                                 return -1;
227                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
228                                         ASN1_R_MSTRING_WRONG_TAG);
229                         goto err;
230                         }
231                 return asn1_d2i_ex_primitive(pval, in, len,
232                                                 it, otag, 0, 0, ctx);
233
234                 case ASN1_ITYPE_EXTERN:
235                 /* Use new style d2i */
236                 ef = it->funcs;
237                 return ef->asn1_ex_d2i(pval, in, len,
238                                                 it, tag, aclass, opt, ctx);
239
240                 case ASN1_ITYPE_COMPAT:
241                 /* we must resort to old style evil hackery */
242                 cf = it->funcs;
243
244                 /* If OPTIONAL see if it is there */
245                 if (opt)
246                         {
247                         int exptag;
248                         p = *in;
249                         if (tag == -1)
250                                 exptag = it->utype;
251                         else exptag = tag;
252                         /* Don't care about anything other than presence
253                          * of expected tag */
254
255                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
256                                         &p, len, exptag, aclass, 1, ctx);
257                         if (!ret)
258                                 {
259                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
260                                         ERR_R_NESTED_ASN1_ERROR);
261                                 goto err;
262                                 }
263                         if (ret == -1)
264                                 return -1;
265                         }
266
267                 /* This is the old style evil hack IMPLICIT handling:
268                  * since the underlying code is expecting a tag and
269                  * class other than the one present we change the
270                  * buffer temporarily then change it back afterwards.
271                  * This doesn't and never did work for tags > 30.
272                  *
273                  * Yes this is *horrible* but it is only needed for
274                  * old style d2i which will hopefully not be around
275                  * for much longer.
276                  * FIXME: should copy the buffer then modify it so
277                  * the input buffer can be const: we should *always*
278                  * copy because the old style d2i might modify the
279                  * buffer.
280                  */
281
282                 if (tag != -1)
283                         {
284                         wp = *(unsigned char **)in;
285                         imphack = *wp;
286                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
287                                                                 | it->utype);
288                         }
289
290                 ptmpval = cf->asn1_d2i(pval, in, len);
291
292                 if (tag != -1)
293                         *wp = imphack;
294
295                 if (ptmpval)
296                         return 1;
297
298                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
299                 goto err;
300
301
302                 case ASN1_ITYPE_CHOICE:
303                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
304                                 goto auxerr;
305
306                 /* Allocate structure */
307                 if (!*pval && !ASN1_item_ex_new(pval, it))
308                         {
309                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
310                                                 ERR_R_NESTED_ASN1_ERROR);
311                         goto err;
312                         }
313                 /* CHOICE type, try each possibility in turn */
314                 pchval = NULL;
315                 p = *in;
316                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
317                         {
318                         pchptr = asn1_get_field_ptr(pval, tt);
319                         /* We mark field as OPTIONAL so its absence
320                          * can be recognised.
321                          */
322                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
323                         /* If field not present, try the next one */
324                         if (ret == -1)
325                                 continue;
326                         /* If positive return, read OK, break loop */
327                         if (ret > 0)
328                                 break;
329                         /* Otherwise must be an ASN1 parsing error */
330                         errtt = tt;
331                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
332                                                 ERR_R_NESTED_ASN1_ERROR);
333                         goto err;
334                         }
335
336                 /* Did we fall off the end without reading anything? */
337                 if (i == it->tcount)
338                         {
339                         /* If OPTIONAL, this is OK */
340                         if (opt)
341                                 {
342                                 /* Free and zero it */
343                                 ASN1_item_ex_free(pval, it);
344                                 return -1;
345                                 }
346                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
347                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
348                         goto err;
349                         }
350
351                 asn1_set_choice_selector(pval, i, it);
352                 *in = p;
353                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
354                                 goto auxerr;
355                 return 1;
356
357                 case ASN1_ITYPE_NDEF_SEQUENCE:
358                 case ASN1_ITYPE_SEQUENCE:
359                 p = *in;
360                 tmplen = len;
361
362                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
363                 if (tag == -1)
364                         {
365                         tag = V_ASN1_SEQUENCE;
366                         aclass = V_ASN1_UNIVERSAL;
367                         }
368                 /* Get SEQUENCE length and update len, p */
369                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
370                                         &p, len, tag, aclass, opt, ctx);
371                 if (!ret)
372                         {
373                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
374                                         ERR_R_NESTED_ASN1_ERROR);
375                         goto err;
376                         }
377                 else if (ret == -1)
378                         return -1;
379                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
380                         {
381                         len = tmplen - (p - *in);
382                         seq_nolen = 1;
383                         }
384                 /* If indefinite we don't do a length check */
385                 else seq_nolen = seq_eoc;
386                 if (!cst)
387                         {
388                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
389                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
390                         goto err;
391                         }
392
393                 if (!*pval && !ASN1_item_ex_new(pval, it))
394                         {
395                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
396                                 ERR_R_NESTED_ASN1_ERROR);
397                         goto err;
398                         }
399
400                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
401                                 goto auxerr;
402
403                 /* Get each field entry */
404                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
405                         {
406                         const ASN1_TEMPLATE *seqtt;
407                         ASN1_VALUE **pseqval;
408                         seqtt = asn1_do_adb(pval, tt, 1);
409                         if (!seqtt)
410                                 goto err;
411                         pseqval = asn1_get_field_ptr(pval, seqtt);
412                         /* Have we ran out of data? */
413                         if (!len)
414                                 break;
415                         q = p;
416                         if (asn1_check_eoc(&p, len))
417                                 {
418                                 if (!seq_eoc)
419                                         {
420                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
421                                                         ASN1_R_UNEXPECTED_EOC);
422                                         goto err;
423                                         }
424                                 len -= p - q;
425                                 seq_eoc = 0;
426                                 q = p;
427                                 break;
428                                 }
429                         /* This determines the OPTIONAL flag value. The field
430                          * cannot be omitted if it is the last of a SEQUENCE
431                          * and there is still data to be read. This isn't
432                          * strictly necessary but it increases efficiency in
433                          * some cases.
434                          */
435                         if (i == (it->tcount - 1))
436                                 isopt = 0;
437                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
438                         /* attempt to read in field, allowing each to be
439                          * OPTIONAL */
440
441                         ret = asn1_template_ex_d2i(pseqval, &p, len,
442                                                         seqtt, isopt, ctx);
443                         if (!ret)
444                                 {
445                                 errtt = seqtt;
446                                 goto err;
447                                 }
448                         else if (ret == -1)
449                                 {
450                                 /* OPTIONAL component absent.
451                                  * Free and zero the field.
452                                  */
453                                 ASN1_template_free(pseqval, seqtt);
454                                 continue;
455                                 }
456                         /* Update length */
457                         len -= p - q;
458                         }
459
460                 /* Check for EOC if expecting one */
461                 if (seq_eoc && !asn1_check_eoc(&p, len))
462                         {
463                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
464                         goto err;
465                         }
466                 /* Check all data read */
467                 if (!seq_nolen && len)
468                         {
469                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
470                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
471                         goto err;
472                         }
473
474                 /* If we get here we've got no more data in the SEQUENCE,
475                  * however we may not have read all fields so check all
476                  * remaining are OPTIONAL and clear any that are.
477                  */
478                 for (; i < it->tcount; tt++, i++)
479                         {
480                         const ASN1_TEMPLATE *seqtt;
481                         seqtt = asn1_do_adb(pval, tt, 1);
482                         if (!seqtt)
483                                 goto err;
484                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
485                                 {
486                                 ASN1_VALUE **pseqval;
487                                 pseqval = asn1_get_field_ptr(pval, seqtt);
488                                 ASN1_template_free(pseqval, seqtt);
489                                 }
490                         else
491                                 {
492                                 errtt = seqtt;
493                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
494                                                         ASN1_R_FIELD_MISSING);
495                                 goto err;
496                                 }
497                         }
498                 /* Save encoding */
499                 if (!asn1_enc_save(pval, *in, p - *in, it))
500                         goto auxerr;
501                 *in = p;
502                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
503                                 goto auxerr;
504                 return 1;
505
506                 default:
507                 return 0;
508                 }
509         auxerr:
510         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
511         err:
512         ASN1_item_ex_free(pval, it);
513         if (errtt)
514                 ERR_add_error_data(4, "Field=", errtt->field_name,
515                                         ", Type=", it->sname);
516         else
517                 ERR_add_error_data(2, "Type=", it->sname);
518         return 0;
519         }
520
521 /* Templates are handled with two separate functions.
522  * One handles any EXPLICIT tag and the other handles the rest.
523  */
524
525 static int asn1_template_ex_d2i(ASN1_VALUE **val,
526                                 const unsigned char **in, long inlen,
527                                 const ASN1_TEMPLATE *tt, char opt,
528                                                         ASN1_TLC *ctx)
529         {
530         int flags, aclass;
531         int ret;
532         long len;
533         const unsigned char *p, *q;
534         char exp_eoc;
535         if (!val)
536                 return 0;
537         flags = tt->flags;
538         aclass = flags & ASN1_TFLG_TAG_CLASS;
539
540         p = *in;
541
542         /* Check if EXPLICIT tag expected */
543         if (flags & ASN1_TFLG_EXPTAG)
544                 {
545                 char cst;
546                 /* Need to work out amount of data available to the inner
547                  * content and where it starts: so read in EXPLICIT header to
548                  * get the info.
549                  */
550                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
551                                         &p, inlen, tt->tag, aclass, opt, ctx);
552                 q = p;
553                 if (!ret)
554                         {
555                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
556                                         ERR_R_NESTED_ASN1_ERROR);
557                         return 0;
558                         }
559                 else if (ret == -1)
560                         return -1;
561                 if (!cst)
562                         {
563                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
564                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
565                         return 0;
566                         }
567                 /* We've found the field so it can't be OPTIONAL now */
568                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
569                 if (!ret)
570                         {
571                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
572                                         ERR_R_NESTED_ASN1_ERROR);
573                         return 0;
574                         }
575                 /* We read the field in OK so update length */
576                 len -= p - q;
577                 if (exp_eoc)
578                         {
579                         /* If NDEF we must have an EOC here */
580                         if (!asn1_check_eoc(&p, len))
581                                 {
582                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
583                                                 ASN1_R_MISSING_EOC);
584                                 goto err;
585                                 }
586                         }
587                 else
588                         {
589                         /* Otherwise we must hit the EXPLICIT tag end or its
590                          * an error */
591                         if (len)
592                                 {
593                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
594                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
595                                 goto err;
596                                 }
597                         }
598                 }
599                 else 
600                         return asn1_template_noexp_d2i(val, in, inlen,
601                                                                 tt, opt, ctx);
602
603         *in = p;
604         return 1;
605
606         err:
607         ASN1_template_free(val, tt);
608         *val = NULL;
609         return 0;
610         }
611
612 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
613                                 const unsigned char **in, long len,
614                                 const ASN1_TEMPLATE *tt, char opt,
615                                 ASN1_TLC *ctx)
616         {
617         int flags, aclass;
618         int ret;
619         const unsigned char *p, *q;
620         if (!val)
621                 return 0;
622         flags = tt->flags;
623         aclass = flags & ASN1_TFLG_TAG_CLASS;
624
625         p = *in;
626         q = p;
627
628         if (flags & ASN1_TFLG_SK_MASK)
629                 {
630                 /* SET OF, SEQUENCE OF */
631                 int sktag, skaclass;
632                 char sk_eoc;
633                 /* First work out expected inner tag value */
634                 if (flags & ASN1_TFLG_IMPTAG)
635                         {
636                         sktag = tt->tag;
637                         skaclass = aclass;
638                         }
639                 else
640                         {
641                         skaclass = V_ASN1_UNIVERSAL;
642                         if (flags & ASN1_TFLG_SET_OF)
643                                 sktag = V_ASN1_SET;
644                         else
645                                 sktag = V_ASN1_SEQUENCE;
646                         }
647                 /* Get the tag */
648                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
649                                         &p, len, sktag, skaclass, opt, ctx);
650                 if (!ret)
651                         {
652                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
653                                                 ERR_R_NESTED_ASN1_ERROR);
654                         return 0;
655                         }
656                 else if (ret == -1)
657                         return -1;
658                 if (!*val)
659                         *val = (ASN1_VALUE *)sk_new_null();
660                 else
661                         {
662                         /* We've got a valid STACK: free up any items present */
663                         STACK *sktmp = (STACK *)*val;
664                         ASN1_VALUE *vtmp;
665                         while(sk_num(sktmp) > 0)
666                                 {
667                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
668                                 ASN1_item_ex_free(&vtmp,
669                                                 ASN1_ITEM_ptr(tt->item));
670                                 }
671                         }
672                                 
673                 if (!*val)
674                         {
675                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
676                                                 ERR_R_MALLOC_FAILURE);
677                         goto err;
678                         }
679
680                 /* Read as many items as we can */
681                 while(len > 0)
682                         {
683                         ASN1_VALUE *skfield;
684                         q = p;
685                         /* See if EOC found */
686                         if (asn1_check_eoc(&p, len))
687                                 {
688                                 if (!sk_eoc)
689                                         {
690                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
691                                                         ASN1_R_UNEXPECTED_EOC);
692                                         goto err;
693                                         }
694                                 len -= p - q;
695                                 sk_eoc = 0;
696                                 break;
697                                 }
698                         skfield = NULL;
699                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
700                                                 ASN1_ITEM_ptr(tt->item),
701                                                 -1, 0, 0, ctx))
702                                 {
703                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
704                                         ERR_R_NESTED_ASN1_ERROR);
705                                 goto err;
706                                 }
707                         len -= p - q;
708                         if (!sk_push((STACK *)*val, (char *)skfield))
709                                 {
710                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
711                                                 ERR_R_MALLOC_FAILURE);
712                                 goto err;
713                                 }
714                         }
715                 if (sk_eoc)
716                         {
717                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
718                         goto err;
719                         }
720                 }
721         else if (flags & ASN1_TFLG_IMPTAG)
722                 {
723                 /* IMPLICIT tagging */
724                 ret = ASN1_item_ex_d2i(val, &p, len,
725                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
726                 if (!ret)
727                         {
728                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
729                                                 ERR_R_NESTED_ASN1_ERROR);
730                         goto err;
731                         }
732                 else if (ret == -1)
733                         return -1;
734                 }
735         else
736                 {
737                 /* Nothing special */
738                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
739                                                         -1, 0, opt, ctx);
740                 if (!ret)
741                         {
742                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
743                                         ERR_R_NESTED_ASN1_ERROR);
744                         goto err;
745                         }
746                 else if (ret == -1)
747                         return -1;
748                 }
749
750         *in = p;
751         return 1;
752
753         err:
754         ASN1_template_free(val, tt);
755         *val = NULL;
756         return 0;
757         }
758
759 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
760                                 const unsigned char **in, long inlen, 
761                                 const ASN1_ITEM *it,
762                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
763         {
764         int ret = 0, utype;
765         long plen;
766         char cst, inf, free_cont = 0;
767         const unsigned char *p;
768         BUF_MEM buf;
769         const unsigned char *cont = NULL;
770         long len; 
771         if (!pval)
772                 {
773                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
774                 return 0; /* Should never happen */
775                 }
776
777         if (it->itype == ASN1_ITYPE_MSTRING)
778                 {
779                 utype = tag;
780                 tag = -1;
781                 }
782         else
783                 utype = it->utype;
784
785         if (utype == V_ASN1_ANY)
786                 {
787                 /* If type is ANY need to figure out type from tag */
788                 unsigned char oclass;
789                 if (tag >= 0)
790                         {
791                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
792                                         ASN1_R_ILLEGAL_TAGGED_ANY);
793                         return 0;
794                         }
795                 if (opt)
796                         {
797                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
798                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
799                         return 0;
800                         }
801                 p = *in;
802                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
803                                         &p, inlen, -1, 0, 0, ctx);
804                 if (!ret)
805                         {
806                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
807                                         ERR_R_NESTED_ASN1_ERROR);
808                         return 0;
809                         }
810                 if (oclass != V_ASN1_UNIVERSAL)
811                         utype = V_ASN1_OTHER;
812                 }
813         if (tag == -1)
814                 {
815                 tag = utype;
816                 aclass = V_ASN1_UNIVERSAL;
817                 }
818         p = *in;
819         /* Check header */
820         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
821                                 &p, inlen, tag, aclass, opt, ctx);
822         if (!ret)
823                 {
824                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
825                 return 0;
826                 }
827         else if (ret == -1)
828                 return -1;
829         /* SEQUENCE, SET and "OTHER" are left in encoded form */
830         if ((utype == V_ASN1_SEQUENCE)
831                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
832                 {
833                 /* Clear context cache for type OTHER because the auto clear
834                  * when we have a exact match wont work
835                  */
836                 if (utype == V_ASN1_OTHER)
837                         {
838                         asn1_tlc_clear(ctx);
839                         }
840                 /* SEQUENCE and SET must be constructed */
841                 else if (!cst)
842                         {
843                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
844                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
845                         return 0;
846                         }
847
848                 cont = *in;
849                 /* If indefinite length constructed find the real end */
850                 if (inf)
851                         {
852                         if (!asn1_find_end(&p, plen, inf))
853                                  goto err;
854                         len = p - cont;
855                         }
856                 else
857                         {
858                         len = p - cont + plen;
859                         p += plen;
860                         buf.data = NULL;
861                         }
862                 }
863         else if (cst)
864                 {
865                 buf.length = 0;
866                 buf.max = 0;
867                 buf.data = NULL;
868                 /* Should really check the internal tags are correct but
869                  * some things may get this wrong. The relevant specs
870                  * say that constructed string types should be OCTET STRINGs
871                  * internally irrespective of the type. So instead just check
872                  * for UNIVERSAL class and ignore the tag.
873                  */
874                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL))
875                         goto err;
876                 len = buf.length;
877                 /* Append a final null to string */
878                 if (!BUF_MEM_grow_clean(&buf, len + 1))
879                         {
880                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
881                                                 ERR_R_MALLOC_FAILURE);
882                         return 0;
883                         }
884                 buf.data[len] = 0;
885                 cont = (const unsigned char *)buf.data;
886                 free_cont = 1;
887                 }
888         else
889                 {
890                 cont = p;
891                 len = plen;
892                 p += plen;
893                 }
894
895         /* We now have content length and type: translate into a structure */
896         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
897                 goto err;
898
899         *in = p;
900         ret = 1;
901         err:
902         if (free_cont && buf.data) OPENSSL_free(buf.data);
903         return ret;
904         }
905
906 /* Translate ASN1 content octets into a structure */
907
908 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
909                         int utype, char *free_cont, const ASN1_ITEM *it)
910         {
911         ASN1_VALUE **opval = NULL;
912         ASN1_STRING *stmp;
913         ASN1_TYPE *typ = NULL;
914         int ret = 0;
915         const ASN1_PRIMITIVE_FUNCS *pf;
916         ASN1_INTEGER **tint;
917         pf = it->funcs;
918
919         if (pf && pf->prim_c2i)
920                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
921         /* If ANY type clear type and set pointer to internal value */
922         if (it->utype == V_ASN1_ANY)
923                 {
924                 if (!*pval)
925                         {
926                         typ = ASN1_TYPE_new();
927                         if (typ == NULL)
928                                 goto err;
929                         *pval = (ASN1_VALUE *)typ;
930                         }
931                 else
932                         typ = (ASN1_TYPE *)*pval;
933
934                 if (utype != typ->type)
935                         ASN1_TYPE_set(typ, utype, NULL);
936                 opval = pval;
937                 pval = (ASN1_VALUE **)&typ->value.ptr;
938                 }
939         switch(utype)
940                 {
941                 case V_ASN1_OBJECT:
942                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
943                         goto err;
944                 break;
945
946                 case V_ASN1_NULL:
947                 if (len)
948                         {
949                         ASN1err(ASN1_F_ASN1_EX_C2I,
950                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
951                         goto err;
952                         }
953                 *pval = (ASN1_VALUE *)1;
954                 break;
955
956                 case V_ASN1_BOOLEAN:
957                 if (len != 1)
958                         {
959                         ASN1err(ASN1_F_ASN1_EX_C2I,
960                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
961                         goto err;
962                         }
963                 else
964                         {
965                         ASN1_BOOLEAN *tbool;
966                         tbool = (ASN1_BOOLEAN *)pval;
967                         *tbool = *cont;
968                         }
969                 break;
970
971                 case V_ASN1_BIT_STRING:
972                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
973                         goto err;
974                 break;
975
976                 case V_ASN1_INTEGER:
977                 case V_ASN1_NEG_INTEGER:
978                 case V_ASN1_ENUMERATED:
979                 case V_ASN1_NEG_ENUMERATED:
980                 tint = (ASN1_INTEGER **)pval;
981                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
982                         goto err;
983                 /* Fixup type to match the expected form */
984                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
985                 break;
986
987                 case V_ASN1_OCTET_STRING:
988                 case V_ASN1_NUMERICSTRING:
989                 case V_ASN1_PRINTABLESTRING:
990                 case V_ASN1_T61STRING:
991                 case V_ASN1_VIDEOTEXSTRING:
992                 case V_ASN1_IA5STRING:
993                 case V_ASN1_UTCTIME:
994                 case V_ASN1_GENERALIZEDTIME:
995                 case V_ASN1_GRAPHICSTRING:
996                 case V_ASN1_VISIBLESTRING:
997                 case V_ASN1_GENERALSTRING:
998                 case V_ASN1_UNIVERSALSTRING:
999                 case V_ASN1_BMPSTRING:
1000                 case V_ASN1_UTF8STRING:
1001                 case V_ASN1_OTHER:
1002                 case V_ASN1_SET:
1003                 case V_ASN1_SEQUENCE:
1004                 default:
1005                 /* All based on ASN1_STRING and handled the same */
1006                 if (!*pval)
1007                         {
1008                         stmp = ASN1_STRING_type_new(utype);
1009                         if (!stmp)
1010                                 {
1011                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1012                                                         ERR_R_MALLOC_FAILURE);
1013                                 goto err;
1014                                 }
1015                         *pval = (ASN1_VALUE *)stmp;
1016                         }
1017                 else
1018                         {
1019                         stmp = (ASN1_STRING *)*pval;
1020                         stmp->type = utype;
1021                         }
1022                 /* If we've already allocated a buffer use it */
1023                 if (*free_cont)
1024                         {
1025                         if (stmp->data)
1026                                 OPENSSL_free(stmp->data);
1027                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1028                         stmp->length = len;
1029                         *free_cont = 0;
1030                         }
1031                 else
1032                         {
1033                         if (!ASN1_STRING_set(stmp, cont, len))
1034                                 {
1035                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1036                                                         ERR_R_MALLOC_FAILURE);
1037                                 ASN1_STRING_free(stmp); 
1038                                 *pval = NULL;
1039                                 goto err;
1040                                 }
1041                         }
1042                 break;
1043                 }
1044         /* If ASN1_ANY and NULL type fix up value */
1045         if (typ && (utype == V_ASN1_NULL))
1046                  typ->value.ptr = NULL;
1047
1048         ret = 1;
1049         err:
1050         if (!ret)
1051                 {
1052                 ASN1_TYPE_free(typ);
1053                 if (opval)
1054                         *opval = NULL;
1055                 }
1056         return ret;
1057         }
1058
1059
1060 /* This function finds the end of an ASN1 structure when passed its maximum
1061  * length, whether it is indefinite length and a pointer to the content.
1062  * This is more efficient than calling asn1_collect because it does not
1063  * recurse on each indefinite length header.
1064  */
1065
1066 static int asn1_find_end(const unsigned char **in, long len, char inf)
1067         {
1068         int expected_eoc;
1069         long plen;
1070         const unsigned char *p = *in, *q;
1071         /* If not indefinite length constructed just add length */
1072         if (inf == 0)
1073                 {
1074                 *in += len;
1075                 return 1;
1076                 }
1077         expected_eoc = 1;
1078         /* Indefinite length constructed form. Find the end when enough EOCs
1079          * are found. If more indefinite length constructed headers
1080          * are encountered increment the expected eoc count otherwise just
1081          * skip to the end of the data.
1082          */
1083         while (len > 0)
1084                 {
1085                 if(asn1_check_eoc(&p, len))
1086                         {
1087                         expected_eoc--;
1088                         if (expected_eoc == 0)
1089                                 break;
1090                         len -= 2;
1091                         continue;
1092                         }
1093                 q = p;
1094                 /* Just read in a header: only care about the length */
1095                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1096                                 -1, 0, 0, NULL))
1097                         {
1098                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1099                         return 0;
1100                         }
1101                 if (inf)
1102                         expected_eoc++;
1103                 else
1104                         p += plen;
1105                 len -= p - q;
1106                 }
1107         if (expected_eoc)
1108                 {
1109                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1110                 return 0;
1111                 }
1112         *in = p;
1113         return 1;
1114         }
1115 /* This function collects the asn1 data from a constructred string
1116  * type into a buffer. The values of 'in' and 'len' should refer
1117  * to the contents of the constructed type and 'inf' should be set
1118  * if it is indefinite length.
1119  */
1120
1121 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1122                                 char inf, int tag, int aclass)
1123         {
1124         const unsigned char *p, *q;
1125         long plen;
1126         char cst, ininf;
1127         p = *in;
1128         inf &= 1;
1129         /* If no buffer and not indefinite length constructed just pass over
1130          * the encoded data */
1131         if (!buf && !inf)
1132                 {
1133                 *in += len;
1134                 return 1;
1135                 }
1136         while(len > 0)
1137                 {
1138                 q = p;
1139                 /* Check for EOC */
1140                 if (asn1_check_eoc(&p, len))
1141                         {
1142                         /* EOC is illegal outside indefinite length
1143                          * constructed form */
1144                         if (!inf)
1145                                 {
1146                                 ASN1err(ASN1_F_ASN1_COLLECT,
1147                                         ASN1_R_UNEXPECTED_EOC);
1148                                 return 0;
1149                                 }
1150                         inf = 0;
1151                         break;
1152                         }
1153
1154                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1155                                         len, tag, aclass, 0, NULL))
1156                         {
1157                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1158                         return 0;
1159                         }
1160
1161                 /* If indefinite length constructed update max length */
1162                 if (cst)
1163                         {
1164 #ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS
1165                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass))
1166                                 return 0;
1167 #else
1168                         ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1169                         return 0;
1170 #endif
1171                         }
1172                 else if (plen && !collect_data(buf, &p, plen))
1173                         return 0;
1174                 len -= p - q;
1175                 }
1176         if (inf)
1177                 {
1178                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1179                 return 0;
1180                 }
1181         *in = p;
1182         return 1;
1183         }
1184
1185 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1186         {
1187         int len;
1188         if (buf)
1189                 {
1190                 len = buf->length;
1191                 if (!BUF_MEM_grow_clean(buf, len + plen))
1192                         {
1193                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1194                         return 0;
1195                         }
1196                 memcpy(buf->data + len, *p, plen);
1197                 }
1198         *p += plen;
1199         return 1;
1200         }
1201
1202 /* Check for ASN1 EOC and swallow it if found */
1203
1204 static int asn1_check_eoc(const unsigned char **in, long len)
1205         {
1206         const unsigned char *p;
1207         if (len < 2) return 0;
1208         p = *in;
1209         if (!p[0] && !p[1])
1210                 {
1211                 *in += 2;
1212                 return 1;
1213                 }
1214         return 0;
1215         }
1216
1217 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1218  * but it sets the length for indefinite length constructed
1219  * form, we don't know the exact length but we can set an
1220  * upper bound to the amount of data available minus the
1221  * header length just read.
1222  */
1223
1224 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1225                                 char *inf, char *cst,
1226                                 const unsigned char **in, long len,
1227                                 int exptag, int expclass, char opt,
1228                                 ASN1_TLC *ctx)
1229         {
1230         int i;
1231         int ptag, pclass;
1232         long plen;
1233         const unsigned char *p, *q;
1234         p = *in;
1235         q = p;
1236
1237         if (ctx && ctx->valid)
1238                 {
1239                 i = ctx->ret;
1240                 plen = ctx->plen;
1241                 pclass = ctx->pclass;
1242                 ptag = ctx->ptag;
1243                 p += ctx->hdrlen;
1244                 }
1245         else
1246                 {
1247                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1248                 if (ctx)
1249                         {
1250                         ctx->ret = i;
1251                         ctx->plen = plen;
1252                         ctx->pclass = pclass;
1253                         ctx->ptag = ptag;
1254                         ctx->hdrlen = p - q;
1255                         ctx->valid = 1;
1256                         /* If definite length, and no error, length +
1257                          * header can't exceed total amount of data available. 
1258                          */
1259                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1260                                 {
1261                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1262                                                         ASN1_R_TOO_LONG);
1263                                 asn1_tlc_clear(ctx);
1264                                 return 0;
1265                                 }
1266                         }
1267                 }
1268
1269         if (i & 0x80)
1270                 {
1271                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1272                 asn1_tlc_clear(ctx);
1273                 return 0;
1274                 }
1275         if (exptag >= 0)
1276                 {
1277                 if ((exptag != ptag) || (expclass != pclass))
1278                         {
1279                         /* If type is OPTIONAL, not an error:
1280                          * indicate missing type.
1281                          */
1282                         if (opt) return -1;
1283                         asn1_tlc_clear(ctx);
1284                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1285                         return 0;
1286                         }
1287                 /* We have a tag and class match:
1288                  * assume we are going to do something with it */
1289                 asn1_tlc_clear(ctx);
1290                 }
1291
1292         if (i & 1)
1293                 plen = len - (p - q);
1294
1295         if (inf)
1296                 *inf = i & 1;
1297
1298         if (cst)
1299                 *cst = i & V_ASN1_CONSTRUCTED;
1300
1301         if (olen)
1302                 *olen = plen;
1303
1304         if (oclass)
1305                 *oclass = pclass;
1306
1307         if (otag)
1308                 *otag = ptag;
1309
1310         *in = p;
1311         return 1;
1312         }