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
ASN1_tag2bit(int tag)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
ASN1_item_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it)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
ASN1_template_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_TEMPLATE * tt)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
ASN1_item_ex_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it,int tag,int aclass,char opt,ASN1_TLC * ctx)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))
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))
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))
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))
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
asn1_template_ex_d2i(ASN1_VALUE ** val,const unsigned char ** in,long inlen,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx)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
asn1_template_noexp_d2i(ASN1_VALUE ** val,const unsigned char ** in,long len,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx)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
asn1_d2i_ex_primitive(ASN1_VALUE ** pval,const unsigned char ** in,long inlen,const ASN1_ITEM * it,int tag,int aclass,char opt,ASN1_TLC * ctx)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 ret = 0;
830 /* SEQUENCE, SET and "OTHER" are left in encoded form */
831 if ((utype == V_ASN1_SEQUENCE)
832 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
833 {
834 /* Clear context cache for type OTHER because the auto clear
835 * when we have a exact match wont work
836 */
837 if (utype == V_ASN1_OTHER)
838 {
839 asn1_tlc_clear(ctx);
840 }
841 /* SEQUENCE and SET must be constructed */
842 else if (!cst)
843 {
844 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
845 ASN1_R_TYPE_NOT_CONSTRUCTED);
846 return 0;
847 }
848
849 cont = *in;
850 /* If indefinite length constructed find the real end */
851 if (inf)
852 {
853 if (!asn1_find_end(&p, plen, inf))
854 goto err;
855 len = p - cont;
856 }
857 else
858 {
859 len = p - cont + plen;
860 p += plen;
861 buf.data = NULL;
862 }
863 }
864 else if (cst)
865 {
866 buf.length = 0;
867 buf.max = 0;
868 buf.data = NULL;
869 /* Should really check the internal tags are correct but
870 * some things may get this wrong. The relevant specs
871 * say that constructed string types should be OCTET STRINGs
872 * internally irrespective of the type. So instead just check
873 * for UNIVERSAL class and ignore the tag.
874 */
875 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL))
876 goto err;
877 len = buf.length;
878 /* Append a final null to string */
879 if (!BUF_MEM_grow_clean(&buf, len + 1))
880 {
881 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
882 ERR_R_MALLOC_FAILURE);
883 return 0;
884 }
885 buf.data[len] = 0;
886 cont = (const unsigned char *)buf.data;
887 free_cont = 1;
888 }
889 else
890 {
891 cont = p;
892 len = plen;
893 p += plen;
894 }
895
896 /* We now have content length and type: translate into a structure */
897 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
898 goto err;
899
900 *in = p;
901 ret = 1;
902 err:
903 if (free_cont && buf.data) OPENSSL_free(buf.data);
904 return ret;
905 }
906
907 /* Translate ASN1 content octets into a structure */
908
asn1_ex_c2i(ASN1_VALUE ** pval,const unsigned char * cont,int len,int utype,char * free_cont,const ASN1_ITEM * it)909 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
910 int utype, char *free_cont, const ASN1_ITEM *it)
911 {
912 ASN1_VALUE **opval = NULL;
913 ASN1_STRING *stmp;
914 ASN1_TYPE *typ = NULL;
915 int ret = 0;
916 const ASN1_PRIMITIVE_FUNCS *pf;
917 ASN1_INTEGER **tint;
918 pf = it->funcs;
919
920 if (pf && pf->prim_c2i)
921 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
922 /* If ANY type clear type and set pointer to internal value */
923 if (it->utype == V_ASN1_ANY)
924 {
925 if (!*pval)
926 {
927 typ = ASN1_TYPE_new();
928 *pval = (ASN1_VALUE *)typ;
929 }
930 else
931 typ = (ASN1_TYPE *)*pval;
932
933 if (utype != typ->type)
934 ASN1_TYPE_set(typ, utype, NULL);
935 opval = pval;
936 pval = (ASN1_VALUE **)&typ->value.ptr;
937 }
938 switch(utype)
939 {
940 case V_ASN1_OBJECT:
941 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
942 goto err;
943 break;
944
945 case V_ASN1_NULL:
946 if (len)
947 {
948 ASN1err(ASN1_F_ASN1_EX_C2I,
949 ASN1_R_NULL_IS_WRONG_LENGTH);
950 goto err;
951 }
952 *pval = (ASN1_VALUE *)1;
953 break;
954
955 case V_ASN1_BOOLEAN:
956 if (len != 1)
957 {
958 ASN1err(ASN1_F_ASN1_EX_C2I,
959 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
960 goto err;
961 }
962 else
963 {
964 ASN1_BOOLEAN *tbool;
965 tbool = (ASN1_BOOLEAN *)pval;
966 *tbool = *cont;
967 }
968 break;
969
970 case V_ASN1_BIT_STRING:
971 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
972 goto err;
973 break;
974
975 case V_ASN1_INTEGER:
976 case V_ASN1_NEG_INTEGER:
977 case V_ASN1_ENUMERATED:
978 case V_ASN1_NEG_ENUMERATED:
979 tint = (ASN1_INTEGER **)pval;
980 if (!c2i_ASN1_INTEGER(tint, &cont, len))
981 goto err;
982 /* Fixup type to match the expected form */
983 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
984 break;
985
986 case V_ASN1_OCTET_STRING:
987 case V_ASN1_NUMERICSTRING:
988 case V_ASN1_PRINTABLESTRING:
989 case V_ASN1_T61STRING:
990 case V_ASN1_VIDEOTEXSTRING:
991 case V_ASN1_IA5STRING:
992 case V_ASN1_UTCTIME:
993 case V_ASN1_GENERALIZEDTIME:
994 case V_ASN1_GRAPHICSTRING:
995 case V_ASN1_VISIBLESTRING:
996 case V_ASN1_GENERALSTRING:
997 case V_ASN1_UNIVERSALSTRING:
998 case V_ASN1_BMPSTRING:
999 case V_ASN1_UTF8STRING:
1000 case V_ASN1_OTHER:
1001 case V_ASN1_SET:
1002 case V_ASN1_SEQUENCE:
1003 default:
1004 if (utype == V_ASN1_BMPSTRING && (len & 1))
1005 {
1006 ASN1err(ASN1_F_ASN1_EX_C2I,
1007 ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1008 goto err;
1009 }
1010 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1011 {
1012 ASN1err(ASN1_F_ASN1_EX_C2I,
1013 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1014 goto err;
1015 }
1016 /* All based on ASN1_STRING and handled the same */
1017 if (!*pval)
1018 {
1019 stmp = ASN1_STRING_type_new(utype);
1020 if (!stmp)
1021 {
1022 ASN1err(ASN1_F_ASN1_EX_C2I,
1023 ERR_R_MALLOC_FAILURE);
1024 goto err;
1025 }
1026 *pval = (ASN1_VALUE *)stmp;
1027 }
1028 else
1029 {
1030 stmp = (ASN1_STRING *)*pval;
1031 stmp->type = utype;
1032 }
1033 /* If we've already allocated a buffer use it */
1034 if (*free_cont)
1035 {
1036 if (stmp->data)
1037 OPENSSL_free(stmp->data);
1038 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1039 stmp->length = len;
1040 *free_cont = 0;
1041 }
1042 else
1043 {
1044 if (!ASN1_STRING_set(stmp, cont, len))
1045 {
1046 ASN1err(ASN1_F_ASN1_EX_C2I,
1047 ERR_R_MALLOC_FAILURE);
1048 ASN1_STRING_free(stmp);
1049 *pval = NULL;
1050 goto err;
1051 }
1052 }
1053 break;
1054 }
1055 /* If ASN1_ANY and NULL type fix up value */
1056 if (typ && (utype == V_ASN1_NULL))
1057 typ->value.ptr = NULL;
1058
1059 ret = 1;
1060 err:
1061 if (!ret)
1062 {
1063 ASN1_TYPE_free(typ);
1064 if (opval)
1065 *opval = NULL;
1066 }
1067 return ret;
1068 }
1069
1070
1071 /* This function finds the end of an ASN1 structure when passed its maximum
1072 * length, whether it is indefinite length and a pointer to the content.
1073 * This is more efficient than calling asn1_collect because it does not
1074 * recurse on each indefinite length header.
1075 */
1076
asn1_find_end(const unsigned char ** in,long len,char inf)1077 static int asn1_find_end(const unsigned char **in, long len, char inf)
1078 {
1079 int expected_eoc;
1080 long plen;
1081 const unsigned char *p = *in, *q;
1082 /* If not indefinite length constructed just add length */
1083 if (inf == 0)
1084 {
1085 *in += len;
1086 return 1;
1087 }
1088 expected_eoc = 1;
1089 /* Indefinite length constructed form. Find the end when enough EOCs
1090 * are found. If more indefinite length constructed headers
1091 * are encountered increment the expected eoc count otherwise just
1092 * skip to the end of the data.
1093 */
1094 while (len > 0)
1095 {
1096 if(asn1_check_eoc(&p, len))
1097 {
1098 expected_eoc--;
1099 if (expected_eoc == 0)
1100 break;
1101 len -= 2;
1102 continue;
1103 }
1104 q = p;
1105 /* Just read in a header: only care about the length */
1106 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1107 -1, 0, 0, NULL))
1108 {
1109 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1110 return 0;
1111 }
1112 if (inf)
1113 expected_eoc++;
1114 else
1115 p += plen;
1116 len -= p - q;
1117 }
1118 if (expected_eoc)
1119 {
1120 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1121 return 0;
1122 }
1123 *in = p;
1124 return 1;
1125 }
1126 /* This function collects the asn1 data from a constructred string
1127 * type into a buffer. The values of 'in' and 'len' should refer
1128 * to the contents of the constructed type and 'inf' should be set
1129 * if it is indefinite length.
1130 */
1131
asn1_collect(BUF_MEM * buf,const unsigned char ** in,long len,char inf,int tag,int aclass)1132 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1133 char inf, int tag, int aclass)
1134 {
1135 const unsigned char *p, *q;
1136 long plen;
1137 char cst, ininf;
1138 p = *in;
1139 inf &= 1;
1140 /* If no buffer and not indefinite length constructed just pass over
1141 * the encoded data */
1142 if (!buf && !inf)
1143 {
1144 *in += len;
1145 return 1;
1146 }
1147 while(len > 0)
1148 {
1149 q = p;
1150 /* Check for EOC */
1151 if (asn1_check_eoc(&p, len))
1152 {
1153 /* EOC is illegal outside indefinite length
1154 * constructed form */
1155 if (!inf)
1156 {
1157 ASN1err(ASN1_F_ASN1_COLLECT,
1158 ASN1_R_UNEXPECTED_EOC);
1159 return 0;
1160 }
1161 inf = 0;
1162 break;
1163 }
1164
1165 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1166 len, tag, aclass, 0, NULL))
1167 {
1168 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1169 return 0;
1170 }
1171
1172 /* If indefinite length constructed update max length */
1173 if (cst)
1174 {
1175 #ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS
1176 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass))
1177 return 0;
1178 #else
1179 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1180 return 0;
1181 #endif
1182 }
1183 else if (!collect_data(buf, &p, plen))
1184 return 0;
1185 len -= p - q;
1186 }
1187 if (inf)
1188 {
1189 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1190 return 0;
1191 }
1192 *in = p;
1193 return 1;
1194 }
1195
collect_data(BUF_MEM * buf,const unsigned char ** p,long plen)1196 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1197 {
1198 int len;
1199 if (buf)
1200 {
1201 len = buf->length;
1202 if (!BUF_MEM_grow_clean(buf, len + plen))
1203 {
1204 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1205 return 0;
1206 }
1207 memcpy(buf->data + len, *p, plen);
1208 }
1209 *p += plen;
1210 return 1;
1211 }
1212
1213 /* Check for ASN1 EOC and swallow it if found */
1214
asn1_check_eoc(const unsigned char ** in,long len)1215 static int asn1_check_eoc(const unsigned char **in, long len)
1216 {
1217 const unsigned char *p;
1218 if (len < 2) return 0;
1219 p = *in;
1220 if (!p[0] && !p[1])
1221 {
1222 *in += 2;
1223 return 1;
1224 }
1225 return 0;
1226 }
1227
1228 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1229 * but it sets the length for indefinite length constructed
1230 * form, we don't know the exact length but we can set an
1231 * upper bound to the amount of data available minus the
1232 * header length just read.
1233 */
1234
asn1_check_tlen(long * olen,int * otag,unsigned char * oclass,char * inf,char * cst,const unsigned char ** in,long len,int exptag,int expclass,char opt,ASN1_TLC * ctx)1235 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1236 char *inf, char *cst,
1237 const unsigned char **in, long len,
1238 int exptag, int expclass, char opt,
1239 ASN1_TLC *ctx)
1240 {
1241 int i;
1242 int ptag, pclass;
1243 long plen;
1244 const unsigned char *p, *q;
1245 p = *in;
1246 q = p;
1247
1248 if (ctx && ctx->valid)
1249 {
1250 i = ctx->ret;
1251 plen = ctx->plen;
1252 pclass = ctx->pclass;
1253 ptag = ctx->ptag;
1254 p += ctx->hdrlen;
1255 }
1256 else
1257 {
1258 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1259 if (ctx)
1260 {
1261 ctx->ret = i;
1262 ctx->plen = plen;
1263 ctx->pclass = pclass;
1264 ctx->ptag = ptag;
1265 ctx->hdrlen = p - q;
1266 ctx->valid = 1;
1267 /* If definite length, and no error, length +
1268 * header can't exceed total amount of data available.
1269 */
1270 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1271 {
1272 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1273 ASN1_R_TOO_LONG);
1274 asn1_tlc_clear(ctx);
1275 return 0;
1276 }
1277 }
1278 }
1279
1280 if (i & 0x80)
1281 {
1282 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1283 asn1_tlc_clear(ctx);
1284 return 0;
1285 }
1286 if (exptag >= 0)
1287 {
1288 if ((exptag != ptag) || (expclass != pclass))
1289 {
1290 /* If type is OPTIONAL, not an error:
1291 * indicate missing type.
1292 */
1293 if (opt) return -1;
1294 asn1_tlc_clear(ctx);
1295 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1296 return 0;
1297 }
1298 /* We have a tag and class match:
1299 * assume we are going to do something with it */
1300 asn1_tlc_clear(ctx);
1301 }
1302
1303 if (i & 1)
1304 plen = len - (p - q);
1305
1306 if (inf)
1307 *inf = i & 1;
1308
1309 if (cst)
1310 *cst = i & V_ASN1_CONSTRUCTED;
1311
1312 if (olen)
1313 *olen = plen;
1314
1315 if (oclass)
1316 *oclass = pclass;
1317
1318 if (otag)
1319 *otag = ptag;
1320
1321 *in = p;
1322 return 1;
1323 }
1324