1 /*
2 * Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stddef.h>
11 #include <string.h>
12 #include <openssl/asn1.h>
13 #include <openssl/asn1t.h>
14 #include <openssl/objects.h>
15 #include <openssl/buffer.h>
16 #include <openssl/err.h>
17 #include "internal/numbers.h"
18 #include "asn1_local.h"
19
20 /*
21 * Constructed types with a recursive definition (such as can be found in PKCS7)
22 * could eventually exceed the stack given malicious input with excessive
23 * recursion. Therefore we limit the stack depth. This is the maximum number of
24 * recursive invocations of asn1_item_embed_d2i().
25 */
26 #define ASN1_MAX_CONSTRUCTED_NEST 30
27
28 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
29 long len, const ASN1_ITEM *it,
30 int tag, int aclass, char opt, ASN1_TLC *ctx,
31 int depth, OSSL_LIB_CTX *libctx,
32 const char *propq);
33
34 static int asn1_check_eoc(const unsigned char **in, long len);
35 static int asn1_find_end(const unsigned char **in, long len, char inf);
36
37 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
38 char inf, int tag, int aclass, int depth);
39
40 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
41
42 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
43 char *inf, char *cst,
44 const unsigned char **in, long len,
45 int exptag, int expclass, char opt, ASN1_TLC *ctx);
46
47 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
48 const unsigned char **in, long len,
49 const ASN1_TEMPLATE *tt, char opt,
50 ASN1_TLC *ctx, int depth, OSSL_LIB_CTX *libctx,
51 const char *propq);
52 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
53 const unsigned char **in, long len,
54 const ASN1_TEMPLATE *tt, char opt,
55 ASN1_TLC *ctx, int depth,
56 OSSL_LIB_CTX *libctx, const char *propq);
57 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
58 const unsigned char **in, long len,
59 const ASN1_ITEM *it,
60 int tag, int aclass, char opt,
61 ASN1_TLC *ctx);
62 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
63 int utype, char *free_cont, const ASN1_ITEM *it);
64
65 /* Table to convert tags to bit values, used for MSTRING type */
66 static const unsigned long tag2bit[32] = {
67 /* tags 0 - 3 */
68 0, 0, 0, B_ASN1_BIT_STRING,
69 /* tags 4- 7 */
70 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
71 /* tags 8-11 */
72 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, 0, B_ASN1_UNKNOWN,
73 /* tags 12-15 */
74 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
75 /* tags 16-19 */
76 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
77 /* tags 20-22 */
78 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
79 /* tags 23-24 */
80 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
81 /* tags 25-27 */
82 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
83 /* tags 28-31 */
84 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
85 };
86
ASN1_tag2bit(int tag)87 unsigned long ASN1_tag2bit(int tag)
88 {
89 if ((tag < 0) || (tag > 30))
90 return 0;
91 return tag2bit[tag];
92 }
93
94 /* Macro to initialize and invalidate the cache */
95
96 #define asn1_tlc_clear(c) do { if ((c) != NULL) (c)->valid = 0; } while (0)
97 /* Version to avoid compiler warning about 'c' always non-NULL */
98 #define asn1_tlc_clear_nc(c) do {(c)->valid = 0; } while (0)
99
100 /*
101 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
102 * function. 'in' points to a buffer to read the data from, in future we
103 * will have more advanced versions that can input data a piece at a time and
104 * this will simply be a special case.
105 */
106
asn1_item_ex_d2i_intern(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it,int tag,int aclass,char opt,ASN1_TLC * ctx,OSSL_LIB_CTX * libctx,const char * propq)107 static int asn1_item_ex_d2i_intern(ASN1_VALUE **pval, const unsigned char **in,
108 long len, const ASN1_ITEM *it, int tag,
109 int aclass, char opt, ASN1_TLC *ctx,
110 OSSL_LIB_CTX *libctx, const char *propq)
111 {
112 int rv;
113
114 if (pval == NULL || it == NULL) {
115 ERR_raise(ERR_LIB_ASN1, ERR_R_PASSED_NULL_PARAMETER);
116 return 0;
117 }
118 rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0,
119 libctx, propq);
120 if (rv <= 0)
121 ASN1_item_ex_free(pval, it);
122 return rv;
123 }
124
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)125 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
126 const ASN1_ITEM *it,
127 int tag, int aclass, char opt, ASN1_TLC *ctx)
128 {
129 return asn1_item_ex_d2i_intern(pval, in, len, it, tag, aclass, opt, ctx,
130 NULL, NULL);
131 }
132
ASN1_item_d2i_ex(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it,OSSL_LIB_CTX * libctx,const char * propq)133 ASN1_VALUE *ASN1_item_d2i_ex(ASN1_VALUE **pval,
134 const unsigned char **in, long len,
135 const ASN1_ITEM *it, OSSL_LIB_CTX *libctx,
136 const char *propq)
137 {
138 ASN1_TLC c;
139 ASN1_VALUE *ptmpval = NULL;
140
141 if (pval == NULL)
142 pval = &ptmpval;
143 asn1_tlc_clear_nc(&c);
144 if (asn1_item_ex_d2i_intern(pval, in, len, it, -1, 0, 0, &c, libctx,
145 propq) > 0)
146 return *pval;
147 return NULL;
148 }
149
ASN1_item_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it)150 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
151 const unsigned char **in, long len,
152 const ASN1_ITEM *it)
153 {
154 return ASN1_item_d2i_ex(pval, in, len, it, NULL, NULL);
155 }
156
157 /*
158 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
159 * tag mismatch return -1 to handle OPTIONAL
160 */
161
asn1_item_embed_d2i(ASN1_VALUE ** pval,const unsigned char ** in,long len,const ASN1_ITEM * it,int tag,int aclass,char opt,ASN1_TLC * ctx,int depth,OSSL_LIB_CTX * libctx,const char * propq)162 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
163 long len, const ASN1_ITEM *it,
164 int tag, int aclass, char opt, ASN1_TLC *ctx,
165 int depth, OSSL_LIB_CTX *libctx,
166 const char *propq)
167 {
168 const ASN1_TEMPLATE *tt, *errtt = NULL;
169 const ASN1_EXTERN_FUNCS *ef;
170 const ASN1_AUX *aux;
171 ASN1_aux_cb *asn1_cb;
172 const unsigned char *p = NULL, *q;
173 unsigned char oclass;
174 char seq_eoc, seq_nolen, cst, isopt;
175 long tmplen;
176 int i;
177 int otag;
178 int ret = 0;
179 ASN1_VALUE **pchptr;
180
181 if (pval == NULL || it == NULL) {
182 ERR_raise(ERR_LIB_ASN1, ERR_R_PASSED_NULL_PARAMETER);
183 return 0;
184 }
185 if (len <= 0) {
186 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL);
187 return 0;
188 }
189 aux = it->funcs;
190 if (aux && aux->asn1_cb)
191 asn1_cb = aux->asn1_cb;
192 else
193 asn1_cb = 0;
194
195 if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
196 ERR_raise(ERR_LIB_ASN1, ASN1_R_NESTED_TOO_DEEP);
197 goto err;
198 }
199
200 switch (it->itype) {
201 case ASN1_ITYPE_PRIMITIVE:
202 if (it->templates) {
203 /*
204 * tagging or OPTIONAL is currently illegal on an item template
205 * because the flags can't get passed down. In practice this
206 * isn't a problem: we include the relevant flags from the item
207 * template in the template itself.
208 */
209 if ((tag != -1) || opt) {
210 ERR_raise(ERR_LIB_ASN1,
211 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
212 goto err;
213 }
214 return asn1_template_ex_d2i(pval, in, len, it->templates, opt, ctx,
215 depth, libctx, propq);
216 }
217 return asn1_d2i_ex_primitive(pval, in, len, it,
218 tag, aclass, opt, ctx);
219
220 case ASN1_ITYPE_MSTRING:
221 /*
222 * It never makes sense for multi-strings to have implicit tagging, so
223 * if tag != -1, then this looks like an error in the template.
224 */
225 if (tag != -1) {
226 ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_TEMPLATE);
227 goto err;
228 }
229
230 p = *in;
231 /* Just read in tag and class */
232 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
233 &p, len, -1, 0, 1, ctx);
234 if (!ret) {
235 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
236 goto err;
237 }
238
239 /* Must be UNIVERSAL class */
240 if (oclass != V_ASN1_UNIVERSAL) {
241 /* If OPTIONAL, assume this is OK */
242 if (opt)
243 return -1;
244 ERR_raise(ERR_LIB_ASN1, ASN1_R_MSTRING_NOT_UNIVERSAL);
245 goto err;
246 }
247
248 /* Check tag matches bit map */
249 if (!(ASN1_tag2bit(otag) & it->utype)) {
250 /* If OPTIONAL, assume this is OK */
251 if (opt)
252 return -1;
253 ERR_raise(ERR_LIB_ASN1, ASN1_R_MSTRING_WRONG_TAG);
254 goto err;
255 }
256 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
257
258 case ASN1_ITYPE_EXTERN:
259 /* Use new style d2i */
260 ef = it->funcs;
261 if (ef->asn1_ex_d2i_ex != NULL)
262 return ef->asn1_ex_d2i_ex(pval, in, len, it, tag, aclass, opt, ctx,
263 libctx, propq);
264 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
265
266 case ASN1_ITYPE_CHOICE:
267 /*
268 * It never makes sense for CHOICE types to have implicit tagging, so
269 * if tag != -1, then this looks like an error in the template.
270 */
271 if (tag != -1) {
272 ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_TEMPLATE);
273 goto err;
274 }
275
276 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
277 goto auxerr;
278 if (*pval) {
279 /* Free up and zero CHOICE value if initialised */
280 i = ossl_asn1_get_choice_selector(pval, it);
281 if ((i >= 0) && (i < it->tcount)) {
282 tt = it->templates + i;
283 pchptr = ossl_asn1_get_field_ptr(pval, tt);
284 ossl_asn1_template_free(pchptr, tt);
285 ossl_asn1_set_choice_selector(pval, -1, it);
286 }
287 } else if (!ossl_asn1_item_ex_new_intern(pval, it, libctx, propq)) {
288 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
289 goto err;
290 }
291 /* CHOICE type, try each possibility in turn */
292 p = *in;
293 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
294 pchptr = ossl_asn1_get_field_ptr(pval, tt);
295 /*
296 * We mark field as OPTIONAL so its absence can be recognised.
297 */
298 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth,
299 libctx, propq);
300 /* If field not present, try the next one */
301 if (ret == -1)
302 continue;
303 /* If positive return, read OK, break loop */
304 if (ret > 0)
305 break;
306 /*
307 * Must be an ASN1 parsing error.
308 * Free up any partial choice value
309 */
310 ossl_asn1_template_free(pchptr, tt);
311 errtt = tt;
312 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
313 goto err;
314 }
315
316 /* Did we fall off the end without reading anything? */
317 if (i == it->tcount) {
318 /* If OPTIONAL, this is OK */
319 if (opt) {
320 /* Free and zero it */
321 ASN1_item_ex_free(pval, it);
322 return -1;
323 }
324 ERR_raise(ERR_LIB_ASN1, ASN1_R_NO_MATCHING_CHOICE_TYPE);
325 goto err;
326 }
327
328 ossl_asn1_set_choice_selector(pval, i, it);
329
330 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
331 goto auxerr;
332 *in = p;
333 return 1;
334
335 case ASN1_ITYPE_NDEF_SEQUENCE:
336 case ASN1_ITYPE_SEQUENCE:
337 p = *in;
338 tmplen = len;
339
340 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
341 if (tag == -1) {
342 tag = V_ASN1_SEQUENCE;
343 aclass = V_ASN1_UNIVERSAL;
344 }
345 /* Get SEQUENCE length and update len, p */
346 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
347 &p, len, tag, aclass, opt, ctx);
348 if (!ret) {
349 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
350 goto err;
351 } else if (ret == -1)
352 return -1;
353 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
354 len = tmplen - (p - *in);
355 seq_nolen = 1;
356 }
357 /* If indefinite we don't do a length check */
358 else
359 seq_nolen = seq_eoc;
360 if (!cst) {
361 ERR_raise(ERR_LIB_ASN1, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
362 goto err;
363 }
364
365 if (*pval == NULL
366 && !ossl_asn1_item_ex_new_intern(pval, it, libctx, propq)) {
367 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
368 goto err;
369 }
370
371 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
372 goto auxerr;
373
374 /* Free up and zero any ADB found */
375 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
376 if (tt->flags & ASN1_TFLG_ADB_MASK) {
377 const ASN1_TEMPLATE *seqtt;
378 ASN1_VALUE **pseqval;
379 seqtt = ossl_asn1_do_adb(*pval, tt, 0);
380 if (seqtt == NULL)
381 continue;
382 pseqval = ossl_asn1_get_field_ptr(pval, seqtt);
383 ossl_asn1_template_free(pseqval, seqtt);
384 }
385 }
386
387 /* Get each field entry */
388 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
389 const ASN1_TEMPLATE *seqtt;
390 ASN1_VALUE **pseqval;
391 seqtt = ossl_asn1_do_adb(*pval, tt, 1);
392 if (seqtt == NULL)
393 goto err;
394 pseqval = ossl_asn1_get_field_ptr(pval, seqtt);
395 /* Have we ran out of data? */
396 if (!len)
397 break;
398 q = p;
399 if (asn1_check_eoc(&p, len)) {
400 if (!seq_eoc) {
401 ERR_raise(ERR_LIB_ASN1, ASN1_R_UNEXPECTED_EOC);
402 goto err;
403 }
404 len -= p - q;
405 seq_eoc = 0;
406 break;
407 }
408 /*
409 * This determines the OPTIONAL flag value. The field cannot be
410 * omitted if it is the last of a SEQUENCE and there is still
411 * data to be read. This isn't strictly necessary but it
412 * increases efficiency in some cases.
413 */
414 if (i == (it->tcount - 1))
415 isopt = 0;
416 else
417 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
418 /*
419 * attempt to read in field, allowing each to be OPTIONAL
420 */
421
422 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx,
423 depth, libctx, propq);
424 if (!ret) {
425 errtt = seqtt;
426 goto err;
427 } else if (ret == -1) {
428 /*
429 * OPTIONAL component absent. Free and zero the field.
430 */
431 ossl_asn1_template_free(pseqval, seqtt);
432 continue;
433 }
434 /* Update length */
435 len -= p - q;
436 }
437
438 /* Check for EOC if expecting one */
439 if (seq_eoc && !asn1_check_eoc(&p, len)) {
440 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC);
441 goto err;
442 }
443 /* Check all data read */
444 if (!seq_nolen && len) {
445 ERR_raise(ERR_LIB_ASN1, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
446 goto err;
447 }
448
449 /*
450 * If we get here we've got no more data in the SEQUENCE, however we
451 * may not have read all fields so check all remaining are OPTIONAL
452 * and clear any that are.
453 */
454 for (; i < it->tcount; tt++, i++) {
455 const ASN1_TEMPLATE *seqtt;
456 seqtt = ossl_asn1_do_adb(*pval, tt, 1);
457 if (seqtt == NULL)
458 goto err;
459 if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
460 ASN1_VALUE **pseqval;
461 pseqval = ossl_asn1_get_field_ptr(pval, seqtt);
462 ossl_asn1_template_free(pseqval, seqtt);
463 } else {
464 errtt = seqtt;
465 ERR_raise(ERR_LIB_ASN1, ASN1_R_FIELD_MISSING);
466 goto err;
467 }
468 }
469 /* Save encoding */
470 if (!ossl_asn1_enc_save(pval, *in, p - *in, it))
471 goto auxerr;
472 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
473 goto auxerr;
474 *in = p;
475 return 1;
476
477 default:
478 return 0;
479 }
480 auxerr:
481 ERR_raise(ERR_LIB_ASN1, ASN1_R_AUX_ERROR);
482 err:
483 if (errtt)
484 ERR_add_error_data(4, "Field=", errtt->field_name,
485 ", Type=", it->sname);
486 else
487 ERR_add_error_data(2, "Type=", it->sname);
488 return 0;
489 }
490
491 /*
492 * Templates are handled with two separate functions. One handles any
493 * EXPLICIT tag and the other handles the rest.
494 */
495
asn1_template_ex_d2i(ASN1_VALUE ** val,const unsigned char ** in,long inlen,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx,int depth,OSSL_LIB_CTX * libctx,const char * propq)496 static int asn1_template_ex_d2i(ASN1_VALUE **val,
497 const unsigned char **in, long inlen,
498 const ASN1_TEMPLATE *tt, char opt,
499 ASN1_TLC *ctx, int depth,
500 OSSL_LIB_CTX *libctx, const char *propq)
501 {
502 int flags, aclass;
503 int ret;
504 long len;
505 const unsigned char *p, *q;
506 char exp_eoc;
507 if (!val)
508 return 0;
509 flags = tt->flags;
510 aclass = flags & ASN1_TFLG_TAG_CLASS;
511
512 p = *in;
513
514 /* Check if EXPLICIT tag expected */
515 if (flags & ASN1_TFLG_EXPTAG) {
516 char cst;
517 /*
518 * Need to work out amount of data available to the inner content and
519 * where it starts: so read in EXPLICIT header to get the info.
520 */
521 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
522 &p, inlen, tt->tag, aclass, opt, ctx);
523 q = p;
524 if (!ret) {
525 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
526 return 0;
527 } else if (ret == -1)
528 return -1;
529 if (!cst) {
530 ERR_raise(ERR_LIB_ASN1, ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
531 return 0;
532 }
533 /* We've found the field so it can't be OPTIONAL now */
534 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth, libctx,
535 propq);
536 if (!ret) {
537 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
538 return 0;
539 }
540 /* We read the field in OK so update length */
541 len -= p - q;
542 if (exp_eoc) {
543 /* If NDEF we must have an EOC here */
544 if (!asn1_check_eoc(&p, len)) {
545 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC);
546 goto err;
547 }
548 } else {
549 /*
550 * Otherwise we must hit the EXPLICIT tag end or its an error
551 */
552 if (len) {
553 ERR_raise(ERR_LIB_ASN1, ASN1_R_EXPLICIT_LENGTH_MISMATCH);
554 goto err;
555 }
556 }
557 } else
558 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth,
559 libctx, propq);
560
561 *in = p;
562 return 1;
563
564 err:
565 return 0;
566 }
567
asn1_template_noexp_d2i(ASN1_VALUE ** val,const unsigned char ** in,long len,const ASN1_TEMPLATE * tt,char opt,ASN1_TLC * ctx,int depth,OSSL_LIB_CTX * libctx,const char * propq)568 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
569 const unsigned char **in, long len,
570 const ASN1_TEMPLATE *tt, char opt,
571 ASN1_TLC *ctx, int depth,
572 OSSL_LIB_CTX *libctx, const char *propq)
573 {
574 int flags, aclass;
575 int ret;
576 ASN1_VALUE *tval;
577 const unsigned char *p, *q;
578 if (!val)
579 return 0;
580 flags = tt->flags;
581 aclass = flags & ASN1_TFLG_TAG_CLASS;
582
583 p = *in;
584
585 /*
586 * If field is embedded then val needs fixing so it is a pointer to
587 * a pointer to a field.
588 */
589 if (tt->flags & ASN1_TFLG_EMBED) {
590 tval = (ASN1_VALUE *)val;
591 val = &tval;
592 }
593
594 if (flags & ASN1_TFLG_SK_MASK) {
595 /* SET OF, SEQUENCE OF */
596 int sktag, skaclass;
597 char sk_eoc;
598 /* First work out expected inner tag value */
599 if (flags & ASN1_TFLG_IMPTAG) {
600 sktag = tt->tag;
601 skaclass = aclass;
602 } else {
603 skaclass = V_ASN1_UNIVERSAL;
604 if (flags & ASN1_TFLG_SET_OF)
605 sktag = V_ASN1_SET;
606 else
607 sktag = V_ASN1_SEQUENCE;
608 }
609 /* Get the tag */
610 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
611 &p, len, sktag, skaclass, opt, ctx);
612 if (!ret) {
613 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
614 return 0;
615 } else if (ret == -1)
616 return -1;
617 if (*val == NULL)
618 *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null();
619 else {
620 /*
621 * We've got a valid STACK: free up any items present
622 */
623 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
624 ASN1_VALUE *vtmp;
625 while (sk_ASN1_VALUE_num(sktmp) > 0) {
626 vtmp = sk_ASN1_VALUE_pop(sktmp);
627 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
628 }
629 }
630
631 if (*val == NULL) {
632 ERR_raise(ERR_LIB_ASN1, ERR_R_CRYPTO_LIB);
633 goto err;
634 }
635
636 /* Read as many items as we can */
637 while (len > 0) {
638 ASN1_VALUE *skfield;
639 q = p;
640 /* See if EOC found */
641 if (asn1_check_eoc(&p, len)) {
642 if (!sk_eoc) {
643 ERR_raise(ERR_LIB_ASN1, ASN1_R_UNEXPECTED_EOC);
644 goto err;
645 }
646 len -= p - q;
647 sk_eoc = 0;
648 break;
649 }
650 skfield = NULL;
651 if (asn1_item_embed_d2i(&skfield, &p, len,
652 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx,
653 depth, libctx, propq) <= 0) {
654 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
655 /* |skfield| may be partially allocated despite failure. */
656 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
657 goto err;
658 }
659 len -= p - q;
660 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
661 ERR_raise(ERR_LIB_ASN1, ERR_R_CRYPTO_LIB);
662 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
663 goto err;
664 }
665 }
666 if (sk_eoc) {
667 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC);
668 goto err;
669 }
670 } else if (flags & ASN1_TFLG_IMPTAG) {
671 /* IMPLICIT tagging */
672 ret = asn1_item_embed_d2i(val, &p, len,
673 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
674 ctx, depth, libctx, propq);
675 if (!ret) {
676 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
677 goto err;
678 } else if (ret == -1)
679 return -1;
680 } else {
681 /* Nothing special */
682 ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
683 -1, 0, opt, ctx, depth, libctx, propq);
684 if (!ret) {
685 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
686 goto err;
687 } else if (ret == -1)
688 return -1;
689 }
690
691 *in = p;
692 return 1;
693
694 err:
695 return 0;
696 }
697
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)698 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
699 const unsigned char **in, long inlen,
700 const ASN1_ITEM *it,
701 int tag, int aclass, char opt, ASN1_TLC *ctx)
702 {
703 int ret = 0, utype;
704 long plen;
705 char cst, inf, free_cont = 0;
706 const unsigned char *p;
707 BUF_MEM buf = { 0, NULL, 0, 0 };
708 const unsigned char *cont = NULL;
709 long len;
710
711 if (pval == NULL) {
712 ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_NULL);
713 return 0; /* Should never happen */
714 }
715
716 if (it->itype == ASN1_ITYPE_MSTRING) {
717 utype = tag;
718 tag = -1;
719 } else
720 utype = it->utype;
721
722 if (utype == V_ASN1_ANY) {
723 /* If type is ANY need to figure out type from tag */
724 unsigned char oclass;
725 if (tag >= 0) {
726 ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_TAGGED_ANY);
727 return 0;
728 }
729 if (opt) {
730 ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_OPTIONAL_ANY);
731 return 0;
732 }
733 p = *in;
734 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
735 &p, inlen, -1, 0, 0, ctx);
736 if (!ret) {
737 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
738 return 0;
739 }
740 if (oclass != V_ASN1_UNIVERSAL)
741 utype = V_ASN1_OTHER;
742 }
743 if (tag == -1) {
744 tag = utype;
745 aclass = V_ASN1_UNIVERSAL;
746 }
747 p = *in;
748 /* Check header */
749 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
750 &p, inlen, tag, aclass, opt, ctx);
751 if (!ret) {
752 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
753 return 0;
754 } else if (ret == -1)
755 return -1;
756 ret = 0;
757 /* SEQUENCE, SET and "OTHER" are left in encoded form */
758 if ((utype == V_ASN1_SEQUENCE)
759 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
760 /*
761 * Clear context cache for type OTHER because the auto clear when we
762 * have a exact match won't work
763 */
764 if (utype == V_ASN1_OTHER) {
765 asn1_tlc_clear(ctx);
766 }
767 /* SEQUENCE and SET must be constructed */
768 else if (!cst) {
769 ERR_raise(ERR_LIB_ASN1, ASN1_R_TYPE_NOT_CONSTRUCTED);
770 return 0;
771 }
772
773 cont = *in;
774 /* If indefinite length constructed find the real end */
775 if (inf) {
776 if (!asn1_find_end(&p, plen, inf))
777 goto err;
778 len = p - cont;
779 } else {
780 len = p - cont + plen;
781 p += plen;
782 }
783 } else if (cst) {
784 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
785 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
786 || utype == V_ASN1_ENUMERATED) {
787 ERR_raise(ERR_LIB_ASN1, ASN1_R_TYPE_NOT_PRIMITIVE);
788 return 0;
789 }
790
791 /* Free any returned 'buf' content */
792 free_cont = 1;
793 /*
794 * Should really check the internal tags are correct but some things
795 * may get this wrong. The relevant specs say that constructed string
796 * types should be OCTET STRINGs internally irrespective of the type.
797 * So instead just check for UNIVERSAL class and ignore the tag.
798 */
799 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
800 goto err;
801 }
802 len = buf.length;
803 /* Append a final null to string */
804 if (!BUF_MEM_grow_clean(&buf, len + 1)) {
805 ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);
806 goto err;
807 }
808 buf.data[len] = 0;
809 cont = (const unsigned char *)buf.data;
810 } else {
811 cont = p;
812 len = plen;
813 p += plen;
814 }
815
816 /* We now have content length and type: translate into a structure */
817 /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */
818 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
819 goto err;
820
821 *in = p;
822 ret = 1;
823 err:
824 if (free_cont)
825 OPENSSL_free(buf.data);
826 return ret;
827 }
828
829 /* Translate ASN1 content octets into a structure */
830
asn1_ex_c2i(ASN1_VALUE ** pval,const unsigned char * cont,int len,int utype,char * free_cont,const ASN1_ITEM * it)831 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
832 int utype, char *free_cont, const ASN1_ITEM *it)
833 {
834 ASN1_VALUE **opval = NULL;
835 ASN1_STRING *stmp;
836 ASN1_TYPE *typ = NULL;
837 int ret = 0;
838 const ASN1_PRIMITIVE_FUNCS *pf;
839 ASN1_INTEGER **tint;
840 pf = it->funcs;
841
842 if (pf && pf->prim_c2i)
843 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
844 /* If ANY type clear type and set pointer to internal value */
845 if (it->utype == V_ASN1_ANY) {
846 if (*pval == NULL) {
847 typ = ASN1_TYPE_new();
848 if (typ == NULL)
849 goto err;
850 *pval = (ASN1_VALUE *)typ;
851 } else
852 typ = (ASN1_TYPE *)*pval;
853
854 if (utype != typ->type)
855 ASN1_TYPE_set(typ, utype, NULL);
856 opval = pval;
857 pval = &typ->value.asn1_value;
858 }
859 switch (utype) {
860 case V_ASN1_OBJECT:
861 if (!ossl_c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
862 goto err;
863 break;
864
865 case V_ASN1_NULL:
866 if (len) {
867 ERR_raise(ERR_LIB_ASN1, ASN1_R_NULL_IS_WRONG_LENGTH);
868 goto err;
869 }
870 *pval = (ASN1_VALUE *)1;
871 break;
872
873 case V_ASN1_BOOLEAN:
874 if (len != 1) {
875 ERR_raise(ERR_LIB_ASN1, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
876 goto err;
877 } else {
878 ASN1_BOOLEAN *tbool;
879 tbool = (ASN1_BOOLEAN *)pval;
880 *tbool = *cont;
881 }
882 break;
883
884 case V_ASN1_BIT_STRING:
885 if (!ossl_c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
886 goto err;
887 break;
888
889 case V_ASN1_INTEGER:
890 case V_ASN1_ENUMERATED:
891 tint = (ASN1_INTEGER **)pval;
892 if (!ossl_c2i_ASN1_INTEGER(tint, &cont, len))
893 goto err;
894 /* Fixup type to match the expected form */
895 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
896 break;
897
898 case V_ASN1_OCTET_STRING:
899 case V_ASN1_NUMERICSTRING:
900 case V_ASN1_PRINTABLESTRING:
901 case V_ASN1_T61STRING:
902 case V_ASN1_VIDEOTEXSTRING:
903 case V_ASN1_IA5STRING:
904 case V_ASN1_UTCTIME:
905 case V_ASN1_GENERALIZEDTIME:
906 case V_ASN1_GRAPHICSTRING:
907 case V_ASN1_VISIBLESTRING:
908 case V_ASN1_GENERALSTRING:
909 case V_ASN1_UNIVERSALSTRING:
910 case V_ASN1_BMPSTRING:
911 case V_ASN1_UTF8STRING:
912 case V_ASN1_OTHER:
913 case V_ASN1_SET:
914 case V_ASN1_SEQUENCE:
915 default:
916 if (utype == V_ASN1_BMPSTRING && (len & 1)) {
917 ERR_raise(ERR_LIB_ASN1, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
918 goto err;
919 }
920 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
921 ERR_raise(ERR_LIB_ASN1, ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
922 goto err;
923 }
924 if (utype == V_ASN1_GENERALIZEDTIME && (len < 15)) {
925 ERR_raise(ERR_LIB_ASN1, ASN1_R_GENERALIZEDTIME_IS_TOO_SHORT);
926 goto err;
927 }
928 if (utype == V_ASN1_UTCTIME && (len < 13)) {
929 ERR_raise(ERR_LIB_ASN1, ASN1_R_UTCTIME_IS_TOO_SHORT);
930 goto err;
931 }
932 /* All based on ASN1_STRING and handled the same */
933 if (*pval == NULL) {
934 stmp = ASN1_STRING_type_new(utype);
935 if (stmp == NULL) {
936 ERR_raise(ERR_LIB_ASN1, ERR_R_ASN1_LIB);
937 goto err;
938 }
939 *pval = (ASN1_VALUE *)stmp;
940 } else {
941 stmp = (ASN1_STRING *)*pval;
942 stmp->type = utype;
943 }
944 /* If we've already allocated a buffer use it */
945 if (*free_cont) {
946 ASN1_STRING_set0(stmp, (unsigned char *)cont /* UGLY CAST! */, len);
947 *free_cont = 0;
948 } else {
949 if (!ASN1_STRING_set(stmp, cont, len)) {
950 ERR_raise(ERR_LIB_ASN1, ERR_R_ASN1_LIB);
951 ASN1_STRING_free(stmp);
952 *pval = NULL;
953 goto err;
954 }
955 }
956 break;
957 }
958 /* If ASN1_ANY and NULL type fix up value */
959 if (typ && (utype == V_ASN1_NULL))
960 typ->value.ptr = NULL;
961
962 ret = 1;
963 err:
964 if (!ret) {
965 ASN1_TYPE_free(typ);
966 if (opval)
967 *opval = NULL;
968 }
969 return ret;
970 }
971
972 /*
973 * This function finds the end of an ASN1 structure when passed its maximum
974 * length, whether it is indefinite length and a pointer to the content. This
975 * is more efficient than calling asn1_collect because it does not recurse on
976 * each indefinite length header.
977 */
978
asn1_find_end(const unsigned char ** in,long len,char inf)979 static int asn1_find_end(const unsigned char **in, long len, char inf)
980 {
981 uint32_t expected_eoc;
982 long plen;
983 const unsigned char *p = *in, *q;
984 /* If not indefinite length constructed just add length */
985 if (inf == 0) {
986 *in += len;
987 return 1;
988 }
989 expected_eoc = 1;
990 /*
991 * Indefinite length constructed form. Find the end when enough EOCs are
992 * found. If more indefinite length constructed headers are encountered
993 * increment the expected eoc count otherwise just skip to the end of the
994 * data.
995 */
996 while (len > 0) {
997 if (asn1_check_eoc(&p, len)) {
998 expected_eoc--;
999 if (expected_eoc == 0)
1000 break;
1001 len -= 2;
1002 continue;
1003 }
1004 q = p;
1005 /* Just read in a header: only care about the length */
1006 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1007 -1, 0, 0, NULL)) {
1008 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
1009 return 0;
1010 }
1011 if (inf) {
1012 if (expected_eoc == UINT32_MAX) {
1013 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
1014 return 0;
1015 }
1016 expected_eoc++;
1017 } else {
1018 p += plen;
1019 }
1020 len -= p - q;
1021 }
1022 if (expected_eoc) {
1023 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC);
1024 return 0;
1025 }
1026 *in = p;
1027 return 1;
1028 }
1029
1030 /*
1031 * This function collects the asn1 data from a constructed string type into
1032 * a buffer. The values of 'in' and 'len' should refer to the contents of the
1033 * constructed type and 'inf' should be set if it is indefinite length.
1034 */
1035
1036 #ifndef ASN1_MAX_STRING_NEST
1037 /*
1038 * This determines how many levels of recursion are permitted in ASN1 string
1039 * types. If it is not limited stack overflows can occur. If set to zero no
1040 * recursion is allowed at all. Although zero should be adequate examples
1041 * exist that require a value of 1. So 5 should be more than enough.
1042 */
1043 # define ASN1_MAX_STRING_NEST 5
1044 #endif
1045
asn1_collect(BUF_MEM * buf,const unsigned char ** in,long len,char inf,int tag,int aclass,int depth)1046 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1047 char inf, int tag, int aclass, int depth)
1048 {
1049 const unsigned char *p, *q;
1050 long plen;
1051 char cst, ininf;
1052 p = *in;
1053 inf &= 1;
1054 /*
1055 * If no buffer and not indefinite length constructed just pass over the
1056 * encoded data
1057 */
1058 if (!buf && !inf) {
1059 *in += len;
1060 return 1;
1061 }
1062 while (len > 0) {
1063 q = p;
1064 /* Check for EOC */
1065 if (asn1_check_eoc(&p, len)) {
1066 /*
1067 * EOC is illegal outside indefinite length constructed form
1068 */
1069 if (!inf) {
1070 ERR_raise(ERR_LIB_ASN1, ASN1_R_UNEXPECTED_EOC);
1071 return 0;
1072 }
1073 inf = 0;
1074 break;
1075 }
1076
1077 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1078 len, tag, aclass, 0, NULL)) {
1079 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR);
1080 return 0;
1081 }
1082
1083 /* If indefinite length constructed update max length */
1084 if (cst) {
1085 if (depth >= ASN1_MAX_STRING_NEST) {
1086 ERR_raise(ERR_LIB_ASN1, ASN1_R_NESTED_ASN1_STRING);
1087 return 0;
1088 }
1089 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1090 return 0;
1091 } else if (plen && !collect_data(buf, &p, plen))
1092 return 0;
1093 len -= p - q;
1094 }
1095 if (inf) {
1096 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC);
1097 return 0;
1098 }
1099 *in = p;
1100 return 1;
1101 }
1102
collect_data(BUF_MEM * buf,const unsigned char ** p,long plen)1103 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1104 {
1105 int len;
1106 if (buf) {
1107 len = buf->length;
1108 if (!BUF_MEM_grow_clean(buf, len + plen)) {
1109 ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);
1110 return 0;
1111 }
1112 memcpy(buf->data + len, *p, plen);
1113 }
1114 *p += plen;
1115 return 1;
1116 }
1117
1118 /* Check for ASN1 EOC and swallow it if found */
1119
asn1_check_eoc(const unsigned char ** in,long len)1120 static int asn1_check_eoc(const unsigned char **in, long len)
1121 {
1122 const unsigned char *p;
1123
1124 if (len < 2)
1125 return 0;
1126 p = *in;
1127 if (p[0] == '\0' && p[1] == '\0') {
1128 *in += 2;
1129 return 1;
1130 }
1131 return 0;
1132 }
1133
1134 /*
1135 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1136 * length for indefinite length constructed form, we don't know the exact
1137 * length but we can set an upper bound to the amount of data available minus
1138 * the header length just read.
1139 */
1140
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)1141 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1142 char *inf, char *cst,
1143 const unsigned char **in, long len,
1144 int exptag, int expclass, char opt, ASN1_TLC *ctx)
1145 {
1146 int i;
1147 int ptag, pclass;
1148 long plen;
1149 const unsigned char *p, *q;
1150 p = *in;
1151 q = p;
1152
1153 if (len <= 0) {
1154 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL);
1155 goto err;
1156 }
1157 if (ctx != NULL && ctx->valid) {
1158 i = ctx->ret;
1159 plen = ctx->plen;
1160 pclass = ctx->pclass;
1161 ptag = ctx->ptag;
1162 p += ctx->hdrlen;
1163 } else {
1164 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1165 if (ctx != NULL) {
1166 ctx->ret = i;
1167 ctx->plen = plen;
1168 ctx->pclass = pclass;
1169 ctx->ptag = ptag;
1170 ctx->hdrlen = p - q;
1171 ctx->valid = 1;
1172 /*
1173 * If definite length, and no error, length + header can't exceed
1174 * total amount of data available.
1175 */
1176 if ((i & 0x81) == 0 && (plen + ctx->hdrlen) > len) {
1177 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);
1178 goto err;
1179 }
1180 }
1181 }
1182
1183 if ((i & 0x80) != 0) {
1184 ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_OBJECT_HEADER);
1185 goto err;
1186 }
1187 if (exptag >= 0) {
1188 if (exptag != ptag || expclass != pclass) {
1189 /*
1190 * If type is OPTIONAL, not an error: indicate missing type.
1191 */
1192 if (opt != 0)
1193 return -1;
1194 ERR_raise(ERR_LIB_ASN1, ASN1_R_WRONG_TAG);
1195 goto err;
1196 }
1197 /*
1198 * We have a tag and class match: assume we are going to do something
1199 * with it
1200 */
1201 asn1_tlc_clear(ctx);
1202 }
1203
1204 if ((i & 1) != 0)
1205 plen = len - (p - q);
1206
1207 if (inf != NULL)
1208 *inf = i & 1;
1209
1210 if (cst != NULL)
1211 *cst = i & V_ASN1_CONSTRUCTED;
1212
1213 if (olen != NULL)
1214 *olen = plen;
1215
1216 if (oclass != NULL)
1217 *oclass = pclass;
1218
1219 if (otag != NULL)
1220 *otag = ptag;
1221
1222 *in = p;
1223 return 1;
1224
1225 err:
1226 asn1_tlc_clear(ctx);
1227 return 0;
1228 }
1229
