1 /* tasn_dec.c */
2 /*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2000.
5 */
6 /* ====================================================================
7 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
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, ASN1_TLC *ctx);
80
81 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
82 const unsigned char **in, long len,
83 const ASN1_TEMPLATE *tt, char opt,
84 ASN1_TLC *ctx);
85 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
86 const unsigned char **in, long len,
87 const ASN1_TEMPLATE *tt, char opt,
88 ASN1_TLC *ctx);
89 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
90 const unsigned char **in, long len,
91 const ASN1_ITEM *it,
92 int tag, int aclass, char opt,
93 ASN1_TLC *ctx);
94
95 /* Table to convert tags to bit values, used for MSTRING type */
96 static const unsigned long tag2bit[32] = {
97 /* tags 0 - 3 */
98 0, 0, 0, B_ASN1_BIT_STRING,
99 /* tags 4- 7 */
100 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
101 /* tags 8-11 */
102 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
103 /* tags 12-15 */
104 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
105 /* tags 16-19 */
106 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
107 /* tags 20-22 */
108 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
109 /* tags 23-24 */
110 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
111 /* tags 25-27 */
112 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
113 /* tags 28-31 */
114 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
115 };
116
ASN1_tag2bit(int tag)117 unsigned long ASN1_tag2bit(int tag)
118 {
119 if ((tag < 0) || (tag > 30))
120 return 0;
121 return tag2bit[tag];
122 }
123
124 /* Macro to initialize and invalidate the cache */
125
126 #define asn1_tlc_clear(c) if (c) (c)->valid = 0
127 /* Version to avoid compiler warning about 'c' always non-NULL */
128 #define asn1_tlc_clear_nc(c) (c)->valid = 0
129
130 /*
131 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
132 * function. 'in' points to a buffer to read the data from, in future we
133 * will have more advanced versions that can input data a piece at a time and
134 * this will simply be a special case.
135 */
136
ASN1_item_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it)137 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
138 const unsigned char **in, long len,
139 const ASN1_ITEM *it)
140 {
141 ASN1_TLC c;
142 ASN1_VALUE *ptmpval = NULL;
143 if (!pval)
144 pval = &ptmpval;
145 asn1_tlc_clear_nc(&c);
146 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
147 return *pval;
148 return NULL;
149 }
150
ASN1_template_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_TEMPLATE * tt)151 int ASN1_template_d2i(ASN1_VALUE **pval,
152 const unsigned char **in, long len,
153 const ASN1_TEMPLATE *tt)
154 {
155 ASN1_TLC c;
156 asn1_tlc_clear_nc(&c);
157 return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
158 }
159
160 /*
161 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
162 * tag mismatch return -1 to handle OPTIONAL
163 */
164
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)165 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
166 const ASN1_ITEM *it,
167 int tag, int aclass, char opt, ASN1_TLC *ctx)
168 {
169 const ASN1_TEMPLATE *tt, *errtt = NULL;
170 const ASN1_COMPAT_FUNCS *cf;
171 const ASN1_EXTERN_FUNCS *ef;
172 const ASN1_AUX *aux = it->funcs;
173 ASN1_aux_cb *asn1_cb;
174 const unsigned char *p = NULL, *q;
175 unsigned char *wp = NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */
176 unsigned char imphack = 0, oclass;
177 char seq_eoc, seq_nolen, cst, isopt;
178 long tmplen;
179 int i;
180 int otag;
181 int ret = 0;
182 ASN1_VALUE **pchptr, *ptmpval;
183 if (!pval)
184 return 0;
185 if (aux && aux->asn1_cb)
186 asn1_cb = aux->asn1_cb;
187 else
188 asn1_cb = 0;
189
190 switch (it->itype) {
191 case ASN1_ITYPE_PRIMITIVE:
192 if (it->templates) {
193 /*
194 * tagging or OPTIONAL is currently illegal on an item template
195 * because the flags can't get passed down. In practice this
196 * isn't a problem: we include the relevant flags from the item
197 * template in the template itself.
198 */
199 if ((tag != -1) || opt) {
200 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
201 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
202 goto err;
203 }
204 return asn1_template_ex_d2i(pval, in, len,
205 it->templates, opt, ctx);
206 }
207 return asn1_d2i_ex_primitive(pval, in, len, it,
208 tag, aclass, opt, ctx);
209 break;
210
211 case ASN1_ITYPE_MSTRING:
212 p = *in;
213 /* Just read in tag and class */
214 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
215 &p, len, -1, 0, 1, ctx);
216 if (!ret) {
217 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
218 goto err;
219 }
220
221 /* Must be UNIVERSAL class */
222 if (oclass != V_ASN1_UNIVERSAL) {
223 /* If OPTIONAL, assume this is OK */
224 if (opt)
225 return -1;
226 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
227 goto err;
228 }
229 /* Check tag matches bit map */
230 if (!(ASN1_tag2bit(otag) & it->utype)) {
231 /* If OPTIONAL, assume this is OK */
232 if (opt)
233 return -1;
234 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_WRONG_TAG);
235 goto err;
236 }
237 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
238
239 case ASN1_ITYPE_EXTERN:
240 /* Use new style d2i */
241 ef = it->funcs;
242 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
243
244 case ASN1_ITYPE_COMPAT:
245 /* we must resort to old style evil hackery */
246 cf = it->funcs;
247
248 /* If OPTIONAL see if it is there */
249 if (opt) {
250 int exptag;
251 p = *in;
252 if (tag == -1)
253 exptag = it->utype;
254 else
255 exptag = tag;
256 /*
257 * Don't care about anything other than presence of expected tag
258 */
259
260 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
261 &p, len, exptag, aclass, 1, ctx);
262 if (!ret) {
263 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
264 goto err;
265 }
266 if (ret == -1)
267 return -1;
268 }
269
270 /*
271 * This is the old style evil hack IMPLICIT handling: since the
272 * underlying code is expecting a tag and class other than the one
273 * present we change the buffer temporarily then change it back
274 * afterwards. This doesn't and never did work for tags > 30. Yes
275 * this is *horrible* but it is only needed for old style d2i which
276 * will hopefully not be around for much longer. FIXME: should copy
277 * the buffer then modify it so the input buffer can be const: we
278 * should *always* copy because the old style d2i might modify the
279 * buffer.
280 */
281
282 if (tag != -1) {
283 wp = *(unsigned char **)in;
284 imphack = *wp;
285 if (p == NULL) {
286 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
287 goto err;
288 }
289 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
290 | it->utype);
291 }
292
293 ptmpval = cf->asn1_d2i(pval, in, len);
294
295 if (tag != -1)
296 *wp = imphack;
297
298 if (ptmpval)
299 return 1;
300
301 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
302 goto err;
303
304 case ASN1_ITYPE_CHOICE:
305 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
306 goto auxerr;
307 if (*pval) {
308 /* Free up and zero CHOICE value if initialised */
309 i = asn1_get_choice_selector(pval, it);
310 if ((i >= 0) && (i < it->tcount)) {
311 tt = it->templates + i;
312 pchptr = asn1_get_field_ptr(pval, tt);
313 ASN1_template_free(pchptr, tt);
314 asn1_set_choice_selector(pval, -1, it);
315 }
316 } else if (!ASN1_item_ex_new(pval, it)) {
317 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
318 goto err;
319 }
320 /* CHOICE type, try each possibility in turn */
321 p = *in;
322 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
323 pchptr = asn1_get_field_ptr(pval, tt);
324 /*
325 * We mark field as OPTIONAL so its absence can be recognised.
326 */
327 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
328 /* If field not present, try the next one */
329 if (ret == -1)
330 continue;
331 /* If positive return, read OK, break loop */
332 if (ret > 0)
333 break;
334 /* Otherwise must be an ASN1 parsing error */
335 errtt = tt;
336 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
337 goto err;
338 }
339
340 /* Did we fall off the end without reading anything? */
341 if (i == it->tcount) {
342 /* If OPTIONAL, this is OK */
343 if (opt) {
344 /* Free and zero it */
345 ASN1_item_ex_free(pval, it);
346 return -1;
347 }
348 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
349 goto err;
350 }
351
352 asn1_set_choice_selector(pval, i, it);
353 *in = p;
354 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
355 goto auxerr;
356 return 1;
357
358 case ASN1_ITYPE_NDEF_SEQUENCE:
359 case ASN1_ITYPE_SEQUENCE:
360 p = *in;
361 tmplen = len;
362
363 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
364 if (tag == -1) {
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 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
373 goto err;
374 } else if (ret == -1)
375 return -1;
376 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
377 len = tmplen - (p - *in);
378 seq_nolen = 1;
379 }
380 /* If indefinite we don't do a length check */
381 else
382 seq_nolen = seq_eoc;
383 if (!cst) {
384 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
385 goto err;
386 }
387
388 if (!*pval && !ASN1_item_ex_new(pval, it)) {
389 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
390 goto err;
391 }
392
393 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
394 goto auxerr;
395
396 /* Free up and zero any ADB found */
397 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
398 if (tt->flags & ASN1_TFLG_ADB_MASK) {
399 const ASN1_TEMPLATE *seqtt;
400 ASN1_VALUE **pseqval;
401 seqtt = asn1_do_adb(pval, tt, 1);
402 pseqval = asn1_get_field_ptr(pval, seqtt);
403 ASN1_template_free(pseqval, seqtt);
404 }
405 }
406
407 /* Get each field entry */
408 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
409 const ASN1_TEMPLATE *seqtt;
410 ASN1_VALUE **pseqval;
411 seqtt = asn1_do_adb(pval, tt, 1);
412 if (!seqtt)
413 goto err;
414 pseqval = asn1_get_field_ptr(pval, seqtt);
415 /* Have we ran out of data? */
416 if (!len)
417 break;
418 q = p;
419 if (asn1_check_eoc(&p, len)) {
420 if (!seq_eoc) {
421 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_UNEXPECTED_EOC);
422 goto err;
423 }
424 len -= p - q;
425 seq_eoc = 0;
426 q = p;
427 break;
428 }
429 /*
430 * This determines the OPTIONAL flag value. The field cannot be
431 * omitted if it is the last of a SEQUENCE and there is still
432 * data to be read. This isn't strictly necessary but it
433 * increases efficiency in some cases.
434 */
435 if (i == (it->tcount - 1))
436 isopt = 0;
437 else
438 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
439 /*
440 * attempt to read in field, allowing each to be OPTIONAL
441 */
442
443 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx);
444 if (!ret) {
445 errtt = seqtt;
446 goto err;
447 } else if (ret == -1) {
448 /*
449 * OPTIONAL component absent. Free and zero the field.
450 */
451 ASN1_template_free(pseqval, seqtt);
452 continue;
453 }
454 /* Update length */
455 len -= p - q;
456 }
457
458 /* Check for EOC if expecting one */
459 if (seq_eoc && !asn1_check_eoc(&p, len)) {
460 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
461 goto err;
462 }
463 /* Check all data read */
464 if (!seq_nolen && len) {
465 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
466 goto err;
467 }
468
469 /*
470 * If we get here we've got no more data in the SEQUENCE, however we
471 * may not have read all fields so check all remaining are OPTIONAL
472 * and clear any that are.
473 */
474 for (; i < it->tcount; tt++, i++) {
475 const ASN1_TEMPLATE *seqtt;
476 seqtt = asn1_do_adb(pval, tt, 1);
477 if (!seqtt)
478 goto err;
479 if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
480 ASN1_VALUE **pseqval;
481 pseqval = asn1_get_field_ptr(pval, seqtt);
482 ASN1_template_free(pseqval, seqtt);
483 } else {
484 errtt = seqtt;
485 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_FIELD_MISSING);
486 goto err;
487 }
488 }
489 /* Save encoding */
490 if (!asn1_enc_save(pval, *in, p - *in, it))
491 goto auxerr;
492 *in = p;
493 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
494 goto auxerr;
495 return 1;
496
497 default:
498 return 0;
499 }
500 auxerr:
501 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
502 err:
503 ASN1_item_ex_free(pval, it);
504 if (errtt)
505 ERR_add_error_data(4, "Field=", errtt->field_name,
506 ", Type=", it->sname);
507 else
508 ERR_add_error_data(2, "Type=", it->sname);
509 return 0;
510 }
511
512 /*
513 * Templates are handled with two separate functions. One handles any
514 * EXPLICIT tag and the other handles the rest.
515 */
516
asn1_template_ex_d2i(ASN1_VALUE ** val,const unsigned char ** in,long inlen,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx)517 static int asn1_template_ex_d2i(ASN1_VALUE **val,
518 const unsigned char **in, long inlen,
519 const ASN1_TEMPLATE *tt, char opt,
520 ASN1_TLC *ctx)
521 {
522 int flags, aclass;
523 int ret;
524 long len;
525 const unsigned char *p, *q;
526 char exp_eoc;
527 if (!val)
528 return 0;
529 flags = tt->flags;
530 aclass = flags & ASN1_TFLG_TAG_CLASS;
531
532 p = *in;
533
534 /* Check if EXPLICIT tag expected */
535 if (flags & ASN1_TFLG_EXPTAG) {
536 char cst;
537 /*
538 * Need to work out amount of data available to the inner content and
539 * where it starts: so read in EXPLICIT header to get the info.
540 */
541 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
542 &p, inlen, tt->tag, aclass, opt, ctx);
543 q = p;
544 if (!ret) {
545 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
546 return 0;
547 } else if (ret == -1)
548 return -1;
549 if (!cst) {
550 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
551 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
552 return 0;
553 }
554 /* We've found the field so it can't be OPTIONAL now */
555 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
556 if (!ret) {
557 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
558 return 0;
559 }
560 /* We read the field in OK so update length */
561 len -= p - q;
562 if (exp_eoc) {
563 /* If NDEF we must have an EOC here */
564 if (!asn1_check_eoc(&p, len)) {
565 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
566 goto err;
567 }
568 } else {
569 /*
570 * Otherwise we must hit the EXPLICIT tag end or its an error
571 */
572 if (len) {
573 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
574 ASN1_R_EXPLICIT_LENGTH_MISMATCH);
575 goto err;
576 }
577 }
578 } else
579 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx);
580
581 *in = p;
582 return 1;
583
584 err:
585 ASN1_template_free(val, tt);
586 return 0;
587 }
588
asn1_template_noexp_d2i(ASN1_VALUE ** val,const unsigned char ** in,long len,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx)589 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
590 const unsigned char **in, long len,
591 const ASN1_TEMPLATE *tt, char opt,
592 ASN1_TLC *ctx)
593 {
594 int flags, aclass;
595 int ret;
596 const unsigned char *p, *q;
597 if (!val)
598 return 0;
599 flags = tt->flags;
600 aclass = flags & ASN1_TFLG_TAG_CLASS;
601
602 p = *in;
603 q = p;
604
605 if (flags & ASN1_TFLG_SK_MASK) {
606 /* SET OF, SEQUENCE OF */
607 int sktag, skaclass;
608 char sk_eoc;
609 /* First work out expected inner tag value */
610 if (flags & ASN1_TFLG_IMPTAG) {
611 sktag = tt->tag;
612 skaclass = aclass;
613 } else {
614 skaclass = V_ASN1_UNIVERSAL;
615 if (flags & ASN1_TFLG_SET_OF)
616 sktag = V_ASN1_SET;
617 else
618 sktag = V_ASN1_SEQUENCE;
619 }
620 /* Get the tag */
621 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
622 &p, len, sktag, skaclass, opt, ctx);
623 if (!ret) {
624 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
625 return 0;
626 } else if (ret == -1)
627 return -1;
628 if (!*val)
629 *val = (ASN1_VALUE *)sk_new_null();
630 else {
631 /*
632 * We've got a valid STACK: free up any items present
633 */
634 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
635 ASN1_VALUE *vtmp;
636 while (sk_ASN1_VALUE_num(sktmp) > 0) {
637 vtmp = sk_ASN1_VALUE_pop(sktmp);
638 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
639 }
640 }
641
642 if (!*val) {
643 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
644 goto err;
645 }
646
647 /* Read as many items as we can */
648 while (len > 0) {
649 ASN1_VALUE *skfield;
650 q = p;
651 /* See if EOC found */
652 if (asn1_check_eoc(&p, len)) {
653 if (!sk_eoc) {
654 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
655 ASN1_R_UNEXPECTED_EOC);
656 goto err;
657 }
658 len -= p - q;
659 sk_eoc = 0;
660 break;
661 }
662 skfield = NULL;
663 if (!ASN1_item_ex_d2i(&skfield, &p, len,
664 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) {
665 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
666 ERR_R_NESTED_ASN1_ERROR);
667 goto err;
668 }
669 len -= p - q;
670 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
671 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
672 goto err;
673 }
674 }
675 if (sk_eoc) {
676 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
677 goto err;
678 }
679 } else if (flags & ASN1_TFLG_IMPTAG) {
680 /* IMPLICIT tagging */
681 ret = ASN1_item_ex_d2i(val, &p, len,
682 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
683 ctx);
684 if (!ret) {
685 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
686 goto err;
687 } else if (ret == -1)
688 return -1;
689 } else {
690 /* Nothing special */
691 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
692 -1, 0, opt, ctx);
693 if (!ret) {
694 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
695 goto err;
696 } else if (ret == -1)
697 return -1;
698 }
699
700 *in = p;
701 return 1;
702
703 err:
704 ASN1_template_free(val, tt);
705 return 0;
706 }
707
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)708 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
709 const unsigned char **in, long inlen,
710 const ASN1_ITEM *it,
711 int tag, int aclass, char opt, ASN1_TLC *ctx)
712 {
713 int ret = 0, utype;
714 long plen;
715 char cst, inf, free_cont = 0;
716 const unsigned char *p;
717 BUF_MEM buf;
718 const unsigned char *cont = NULL;
719 long len;
720 if (!pval) {
721 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
722 return 0; /* Should never happen */
723 }
724
725 if (it->itype == ASN1_ITYPE_MSTRING) {
726 utype = tag;
727 tag = -1;
728 } else
729 utype = it->utype;
730
731 if (utype == V_ASN1_ANY) {
732 /* If type is ANY need to figure out type from tag */
733 unsigned char oclass;
734 if (tag >= 0) {
735 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
736 return 0;
737 }
738 if (opt) {
739 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
740 ASN1_R_ILLEGAL_OPTIONAL_ANY);
741 return 0;
742 }
743 p = *in;
744 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
745 &p, inlen, -1, 0, 0, ctx);
746 if (!ret) {
747 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
748 return 0;
749 }
750 if (oclass != V_ASN1_UNIVERSAL)
751 utype = V_ASN1_OTHER;
752 }
753 if (tag == -1) {
754 tag = utype;
755 aclass = V_ASN1_UNIVERSAL;
756 }
757 p = *in;
758 /* Check header */
759 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
760 &p, inlen, tag, aclass, opt, ctx);
761 if (!ret) {
762 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
763 return 0;
764 } else if (ret == -1)
765 return -1;
766 ret = 0;
767 /* SEQUENCE, SET and "OTHER" are left in encoded form */
768 if ((utype == V_ASN1_SEQUENCE)
769 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
770 /*
771 * Clear context cache for type OTHER because the auto clear when we
772 * have a exact match wont work
773 */
774 if (utype == V_ASN1_OTHER) {
775 asn1_tlc_clear(ctx);
776 }
777 /* SEQUENCE and SET must be constructed */
778 else if (!cst) {
779 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
780 ASN1_R_TYPE_NOT_CONSTRUCTED);
781 return 0;
782 }
783
784 cont = *in;
785 /* If indefinite length constructed find the real end */
786 if (inf) {
787 if (!asn1_find_end(&p, plen, inf))
788 goto err;
789 len = p - cont;
790 } else {
791 len = p - cont + plen;
792 p += plen;
793 buf.data = NULL;
794 }
795 } else if (cst) {
796 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
797 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
798 || utype == V_ASN1_ENUMERATED) {
799 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
800 return 0;
801 }
802 buf.length = 0;
803 buf.max = 0;
804 buf.data = NULL;
805 /*
806 * Should really check the internal tags are correct but some things
807 * may get this wrong. The relevant specs say that constructed string
808 * types should be OCTET STRINGs internally irrespective of the type.
809 * So instead just check for UNIVERSAL class and ignore the tag.
810 */
811 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
812 free_cont = 1;
813 goto err;
814 }
815 len = buf.length;
816 /* Append a final null to string */
817 if (!BUF_MEM_grow_clean(&buf, len + 1)) {
818 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
819 return 0;
820 }
821 buf.data[len] = 0;
822 cont = (const unsigned char *)buf.data;
823 free_cont = 1;
824 } else {
825 cont = p;
826 len = plen;
827 p += plen;
828 }
829
830 /* We now have content length and type: translate into a structure */
831 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
832 goto err;
833
834 *in = p;
835 ret = 1;
836 err:
837 if (free_cont && buf.data)
838 OPENSSL_free(buf.data);
839 return ret;
840 }
841
842 /* Translate ASN1 content octets into a structure */
843
asn1_ex_c2i(ASN1_VALUE ** pval,const unsigned char * cont,int len,int utype,char * free_cont,const ASN1_ITEM * it)844 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
845 int utype, char *free_cont, const ASN1_ITEM *it)
846 {
847 ASN1_VALUE **opval = NULL;
848 ASN1_STRING *stmp;
849 ASN1_TYPE *typ = NULL;
850 int ret = 0;
851 const ASN1_PRIMITIVE_FUNCS *pf;
852 ASN1_INTEGER **tint;
853 pf = it->funcs;
854
855 if (pf && pf->prim_c2i)
856 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
857 /* If ANY type clear type and set pointer to internal value */
858 if (it->utype == V_ASN1_ANY) {
859 if (!*pval) {
860 typ = ASN1_TYPE_new();
861 if (typ == NULL)
862 goto err;
863 *pval = (ASN1_VALUE *)typ;
864 } else
865 typ = (ASN1_TYPE *)*pval;
866
867 if (utype != typ->type)
868 ASN1_TYPE_set(typ, utype, NULL);
869 opval = pval;
870 pval = &typ->value.asn1_value;
871 }
872 switch (utype) {
873 case V_ASN1_OBJECT:
874 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
875 goto err;
876 break;
877
878 case V_ASN1_NULL:
879 if (len) {
880 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
881 goto err;
882 }
883 *pval = (ASN1_VALUE *)1;
884 break;
885
886 case V_ASN1_BOOLEAN:
887 if (len != 1) {
888 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
889 goto err;
890 } else {
891 ASN1_BOOLEAN *tbool;
892 tbool = (ASN1_BOOLEAN *)pval;
893 *tbool = *cont;
894 }
895 break;
896
897 case V_ASN1_BIT_STRING:
898 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
899 goto err;
900 break;
901
902 case V_ASN1_INTEGER:
903 case V_ASN1_NEG_INTEGER:
904 case V_ASN1_ENUMERATED:
905 case V_ASN1_NEG_ENUMERATED:
906 tint = (ASN1_INTEGER **)pval;
907 if (!c2i_ASN1_INTEGER(tint, &cont, len))
908 goto err;
909 /* Fixup type to match the expected form */
910 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
911 break;
912
913 case V_ASN1_OCTET_STRING:
914 case V_ASN1_NUMERICSTRING:
915 case V_ASN1_PRINTABLESTRING:
916 case V_ASN1_T61STRING:
917 case V_ASN1_VIDEOTEXSTRING:
918 case V_ASN1_IA5STRING:
919 case V_ASN1_UTCTIME:
920 case V_ASN1_GENERALIZEDTIME:
921 case V_ASN1_GRAPHICSTRING:
922 case V_ASN1_VISIBLESTRING:
923 case V_ASN1_GENERALSTRING:
924 case V_ASN1_UNIVERSALSTRING:
925 case V_ASN1_BMPSTRING:
926 case V_ASN1_UTF8STRING:
927 case V_ASN1_OTHER:
928 case V_ASN1_SET:
929 case V_ASN1_SEQUENCE:
930 default:
931 if (utype == V_ASN1_BMPSTRING && (len & 1)) {
932 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
933 goto err;
934 }
935 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
936 ASN1err(ASN1_F_ASN1_EX_C2I,
937 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
938 goto err;
939 }
940 /* All based on ASN1_STRING and handled the same */
941 if (!*pval) {
942 stmp = ASN1_STRING_type_new(utype);
943 if (!stmp) {
944 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
945 goto err;
946 }
947 *pval = (ASN1_VALUE *)stmp;
948 } else {
949 stmp = (ASN1_STRING *)*pval;
950 stmp->type = utype;
951 }
952 /* If we've already allocated a buffer use it */
953 if (*free_cont) {
954 if (stmp->data)
955 OPENSSL_free(stmp->data);
956 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
957 stmp->length = len;
958 *free_cont = 0;
959 } else {
960 if (!ASN1_STRING_set(stmp, cont, len)) {
961 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
962 ASN1_STRING_free(stmp);
963 *pval = NULL;
964 goto err;
965 }
966 }
967 break;
968 }
969 /* If ASN1_ANY and NULL type fix up value */
970 if (typ && (utype == V_ASN1_NULL))
971 typ->value.ptr = NULL;
972
973 ret = 1;
974 err:
975 if (!ret) {
976 ASN1_TYPE_free(typ);
977 if (opval)
978 *opval = NULL;
979 }
980 return ret;
981 }
982
983 /*
984 * This function finds the end of an ASN1 structure when passed its maximum
985 * length, whether it is indefinite length and a pointer to the content. This
986 * is more efficient than calling asn1_collect because it does not recurse on
987 * each indefinite length header.
988 */
989
asn1_find_end(const unsigned char ** in,long len,char inf)990 static int asn1_find_end(const unsigned char **in, long len, char inf)
991 {
992 int expected_eoc;
993 long plen;
994 const unsigned char *p = *in, *q;
995 /* If not indefinite length constructed just add length */
996 if (inf == 0) {
997 *in += len;
998 return 1;
999 }
1000 expected_eoc = 1;
1001 /*
1002 * Indefinite length constructed form. Find the end when enough EOCs are
1003 * found. If more indefinite length constructed headers are encountered
1004 * increment the expected eoc count otherwise just skip to the end of the
1005 * data.
1006 */
1007 while (len > 0) {
1008 if (asn1_check_eoc(&p, len)) {
1009 expected_eoc--;
1010 if (expected_eoc == 0)
1011 break;
1012 len -= 2;
1013 continue;
1014 }
1015 q = p;
1016 /* Just read in a header: only care about the length */
1017 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1018 -1, 0, 0, NULL)) {
1019 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1020 return 0;
1021 }
1022 if (inf)
1023 expected_eoc++;
1024 else
1025 p += plen;
1026 len -= p - q;
1027 }
1028 if (expected_eoc) {
1029 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1030 return 0;
1031 }
1032 *in = p;
1033 return 1;
1034 }
1035
1036 /*
1037 * This function collects the asn1 data from a constructred string type into
1038 * a buffer. The values of 'in' and 'len' should refer to the contents of the
1039 * constructed type and 'inf' should be set if it is indefinite length.
1040 */
1041
1042 #ifndef ASN1_MAX_STRING_NEST
1043 /*
1044 * This determines how many levels of recursion are permitted in ASN1 string
1045 * types. If it is not limited stack overflows can occur. If set to zero no
1046 * recursion is allowed at all. Although zero should be adequate examples
1047 * exist that require a value of 1. So 5 should be more than enough.
1048 */
1049 # define ASN1_MAX_STRING_NEST 5
1050 #endif
1051
asn1_collect(BUF_MEM * buf,const unsigned char ** in,long len,char inf,int tag,int aclass,int depth)1052 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1053 char inf, int tag, int aclass, int depth)
1054 {
1055 const unsigned char *p, *q;
1056 long plen;
1057 char cst, ininf;
1058 p = *in;
1059 inf &= 1;
1060 /*
1061 * If no buffer and not indefinite length constructed just pass over the
1062 * encoded data
1063 */
1064 if (!buf && !inf) {
1065 *in += len;
1066 return 1;
1067 }
1068 while (len > 0) {
1069 q = p;
1070 /* Check for EOC */
1071 if (asn1_check_eoc(&p, len)) {
1072 /*
1073 * EOC is illegal outside indefinite length constructed form
1074 */
1075 if (!inf) {
1076 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
1077 return 0;
1078 }
1079 inf = 0;
1080 break;
1081 }
1082
1083 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1084 len, tag, aclass, 0, NULL)) {
1085 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1086 return 0;
1087 }
1088
1089 /* If indefinite length constructed update max length */
1090 if (cst) {
1091 if (depth >= ASN1_MAX_STRING_NEST) {
1092 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1093 return 0;
1094 }
1095 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1096 return 0;
1097 } else if (plen && !collect_data(buf, &p, plen))
1098 return 0;
1099 len -= p - q;
1100 }
1101 if (inf) {
1102 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1103 return 0;
1104 }
1105 *in = p;
1106 return 1;
1107 }
1108
collect_data(BUF_MEM * buf,const unsigned char ** p,long plen)1109 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1110 {
1111 int len;
1112 if (buf) {
1113 len = buf->length;
1114 if (!BUF_MEM_grow_clean(buf, len + plen)) {
1115 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1116 return 0;
1117 }
1118 memcpy(buf->data + len, *p, plen);
1119 }
1120 *p += plen;
1121 return 1;
1122 }
1123
1124 /* Check for ASN1 EOC and swallow it if found */
1125
asn1_check_eoc(const unsigned char ** in,long len)1126 static int asn1_check_eoc(const unsigned char **in, long len)
1127 {
1128 const unsigned char *p;
1129 if (len < 2)
1130 return 0;
1131 p = *in;
1132 if (!p[0] && !p[1]) {
1133 *in += 2;
1134 return 1;
1135 }
1136 return 0;
1137 }
1138
1139 /*
1140 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1141 * length for indefinite length constructed form, we don't know the exact
1142 * length but we can set an upper bound to the amount of data available minus
1143 * the header length just read.
1144 */
1145
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)1146 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1147 char *inf, char *cst,
1148 const unsigned char **in, long len,
1149 int exptag, int expclass, char opt, ASN1_TLC *ctx)
1150 {
1151 int i;
1152 int ptag, pclass;
1153 long plen;
1154 const unsigned char *p, *q;
1155 p = *in;
1156 q = p;
1157
1158 if (ctx && ctx->valid) {
1159 i = ctx->ret;
1160 plen = ctx->plen;
1161 pclass = ctx->pclass;
1162 ptag = ctx->ptag;
1163 p += ctx->hdrlen;
1164 } else {
1165 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1166 if (ctx) {
1167 ctx->ret = i;
1168 ctx->plen = plen;
1169 ctx->pclass = pclass;
1170 ctx->ptag = ptag;
1171 ctx->hdrlen = p - q;
1172 ctx->valid = 1;
1173 /*
1174 * If definite length, and no error, length + header can't exceed
1175 * total amount of data available.
1176 */
1177 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
1178 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
1179 asn1_tlc_clear(ctx);
1180 return 0;
1181 }
1182 }
1183 }
1184
1185 if (i & 0x80) {
1186 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1187 asn1_tlc_clear(ctx);
1188 return 0;
1189 }
1190 if (exptag >= 0) {
1191 if ((exptag != ptag) || (expclass != pclass)) {
1192 /*
1193 * If type is OPTIONAL, not an error: indicate missing type.
1194 */
1195 if (opt)
1196 return -1;
1197 asn1_tlc_clear(ctx);
1198 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1199 return 0;
1200 }
1201 /*
1202 * We have a tag and class match: assume we are going to do something
1203 * with it
1204 */
1205 asn1_tlc_clear(ctx);
1206 }
1207
1208 if (i & 1)
1209 plen = len - (p - q);
1210
1211 if (inf)
1212 *inf = i & 1;
1213
1214 if (cst)
1215 *cst = i & V_ASN1_CONSTRUCTED;
1216
1217 if (olen)
1218 *olen = plen;
1219
1220 if (oclass)
1221 *oclass = pclass;
1222
1223 if (otag)
1224 *otag = ptag;
1225
1226 *in = p;
1227 return 1;
1228 }
1229