1/* 2 * Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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/* 22 * Constructed types with a recursive definition (such as can be found in PKCS7) 23 * could eventually exceed the stack given malicious input with excessive 24 * recursion. Therefore we limit the stack depth. This is the maximum number of 25 * recursive invocations of asn1_item_embed_d2i(). 26 */ 27#define ASN1_MAX_CONSTRUCTED_NEST 30 28 29static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in, 30 long len, const ASN1_ITEM *it, 31 int tag, int aclass, char opt, ASN1_TLC *ctx, 32 int depth); 33 34static int asn1_check_eoc(const unsigned char **in, long len); 35static int asn1_find_end(const unsigned char **in, long len, char inf); 36 37static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 38 char inf, int tag, int aclass, int depth); 39 40static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen); 41 42static 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 47static 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); 51static int asn1_template_noexp_d2i(ASN1_VALUE **val, 52 const unsigned char **in, long len, 53 const ASN1_TEMPLATE *tt, char opt, 54 ASN1_TLC *ctx, int depth); 55static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 56 const unsigned char **in, long len, 57 const ASN1_ITEM *it, 58 int tag, int aclass, char opt, 59 ASN1_TLC *ctx); 60static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 61 int utype, char *free_cont, const ASN1_ITEM *it); 62 63/* Table to convert tags to bit values, used for MSTRING type */ 64static const unsigned long tag2bit[32] = { 65 /* tags 0 - 3 */ 66 0, 0, 0, B_ASN1_BIT_STRING, 67 /* tags 4- 7 */ 68 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN, 69 /* tags 8-11 */ 70 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, 71 /* tags 12-15 */ 72 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, 73 /* tags 16-19 */ 74 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING, 75 /* tags 20-22 */ 76 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING, 77 /* tags 23-24 */ 78 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, 79 /* tags 25-27 */ 80 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING, 81 /* tags 28-31 */ 82 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN, 83}; 84 85unsigned long ASN1_tag2bit(int tag) 86{ 87 if ((tag < 0) || (tag > 30)) 88 return 0; 89 return tag2bit[tag]; 90} 91 92/* Macro to initialize and invalidate the cache */ 93 94#define asn1_tlc_clear(c) if (c) (c)->valid = 0 95/* Version to avoid compiler warning about 'c' always non-NULL */ 96#define asn1_tlc_clear_nc(c) (c)->valid = 0 97 98/* 99 * Decode an ASN1 item, this currently behaves just like a standard 'd2i' 100 * function. 'in' points to a buffer to read the data from, in future we 101 * will have more advanced versions that can input data a piece at a time and 102 * this will simply be a special case. 103 */ 104 105ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, 106 const unsigned char **in, long len, 107 const ASN1_ITEM *it) 108{ 109 ASN1_TLC c; 110 ASN1_VALUE *ptmpval = NULL; 111 if (!pval) 112 pval = &ptmpval; 113 asn1_tlc_clear_nc(&c); 114 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 115 return *pval; 116 return NULL; 117} 118 119int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, 120 const ASN1_ITEM *it, 121 int tag, int aclass, char opt, ASN1_TLC *ctx) 122{ 123 int rv; 124 rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0); 125 if (rv <= 0) 126 ASN1_item_ex_free(pval, it); 127 return rv; 128} 129 130/* 131 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and 132 * tag mismatch return -1 to handle OPTIONAL 133 */ 134 135static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in, 136 long len, const ASN1_ITEM *it, 137 int tag, int aclass, char opt, ASN1_TLC *ctx, 138 int depth) 139{ 140 const ASN1_TEMPLATE *tt, *errtt = NULL; 141 const ASN1_EXTERN_FUNCS *ef; 142 const ASN1_AUX *aux = it->funcs; 143 ASN1_aux_cb *asn1_cb; 144 const unsigned char *p = NULL, *q; 145 unsigned char oclass; 146 char seq_eoc, seq_nolen, cst, isopt; 147 long tmplen; 148 int i; 149 int otag; 150 int ret = 0; 151 ASN1_VALUE **pchptr; 152 if (!pval) 153 return 0; 154 if (aux && aux->asn1_cb) 155 asn1_cb = aux->asn1_cb; 156 else 157 asn1_cb = 0; 158 159 if (++depth > ASN1_MAX_CONSTRUCTED_NEST) { 160 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NESTED_TOO_DEEP); 161 goto err; 162 } 163 164 switch (it->itype) { 165 case ASN1_ITYPE_PRIMITIVE: 166 if (it->templates) { 167 /* 168 * tagging or OPTIONAL is currently illegal on an item template 169 * because the flags can't get passed down. In practice this 170 * isn't a problem: we include the relevant flags from the item 171 * template in the template itself. 172 */ 173 if ((tag != -1) || opt) { 174 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, 175 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 176 goto err; 177 } 178 return asn1_template_ex_d2i(pval, in, len, 179 it->templates, opt, ctx, depth); 180 } 181 return asn1_d2i_ex_primitive(pval, in, len, it, 182 tag, aclass, opt, ctx); 183 184 case ASN1_ITYPE_MSTRING: 185 /* 186 * It never makes sense for multi-strings to have implicit tagging, so 187 * if tag != -1, then this looks like an error in the template. 188 */ 189 if (tag != -1) { 190 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_BAD_TEMPLATE); 191 goto err; 192 } 193 194 p = *in; 195 /* Just read in tag and class */ 196 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 197 &p, len, -1, 0, 1, ctx); 198 if (!ret) { 199 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 200 goto err; 201 } 202 203 /* Must be UNIVERSAL class */ 204 if (oclass != V_ASN1_UNIVERSAL) { 205 /* If OPTIONAL, assume this is OK */ 206 if (opt) 207 return -1; 208 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL); 209 goto err; 210 } 211 212 /* Check tag matches bit map */ 213 if (!(ASN1_tag2bit(otag) & it->utype)) { 214 /* If OPTIONAL, assume this is OK */ 215 if (opt) 216 return -1; 217 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG); 218 goto err; 219 } 220 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); 221 222 case ASN1_ITYPE_EXTERN: 223 /* Use new style d2i */ 224 ef = it->funcs; 225 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); 226 227 case ASN1_ITYPE_CHOICE: 228 /* 229 * It never makes sense for CHOICE types to have implicit tagging, so 230 * if tag != -1, then this looks like an error in the template. 231 */ 232 if (tag != -1) { 233 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_BAD_TEMPLATE); 234 goto err; 235 } 236 237 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 238 goto auxerr; 239 if (*pval) { 240 /* Free up and zero CHOICE value if initialised */ 241 i = asn1_get_choice_selector(pval, it); 242 if ((i >= 0) && (i < it->tcount)) { 243 tt = it->templates + i; 244 pchptr = asn1_get_field_ptr(pval, tt); 245 asn1_template_free(pchptr, tt); 246 asn1_set_choice_selector(pval, -1, it); 247 } 248 } else if (!ASN1_item_ex_new(pval, it)) { 249 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 250 goto err; 251 } 252 /* CHOICE type, try each possibility in turn */ 253 p = *in; 254 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 255 pchptr = asn1_get_field_ptr(pval, tt); 256 /* 257 * We mark field as OPTIONAL so its absence can be recognised. 258 */ 259 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth); 260 /* If field not present, try the next one */ 261 if (ret == -1) 262 continue; 263 /* If positive return, read OK, break loop */ 264 if (ret > 0) 265 break; 266 /* 267 * Must be an ASN1 parsing error. 268 * Free up any partial choice value 269 */ 270 asn1_template_free(pchptr, tt); 271 errtt = tt; 272 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 273 goto err; 274 } 275 276 /* Did we fall off the end without reading anything? */ 277 if (i == it->tcount) { 278 /* If OPTIONAL, this is OK */ 279 if (opt) { 280 /* Free and zero it */ 281 ASN1_item_ex_free(pval, it); 282 return -1; 283 } 284 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE); 285 goto err; 286 } 287 288 asn1_set_choice_selector(pval, i, it); 289 290 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 291 goto auxerr; 292 *in = p; 293 return 1; 294 295 case ASN1_ITYPE_NDEF_SEQUENCE: 296 case ASN1_ITYPE_SEQUENCE: 297 p = *in; 298 tmplen = len; 299 300 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 301 if (tag == -1) { 302 tag = V_ASN1_SEQUENCE; 303 aclass = V_ASN1_UNIVERSAL; 304 } 305 /* Get SEQUENCE length and update len, p */ 306 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 307 &p, len, tag, aclass, opt, ctx); 308 if (!ret) { 309 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 310 goto err; 311 } else if (ret == -1) 312 return -1; 313 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) { 314 len = tmplen - (p - *in); 315 seq_nolen = 1; 316 } 317 /* If indefinite we don't do a length check */ 318 else 319 seq_nolen = seq_eoc; 320 if (!cst) { 321 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 322 goto err; 323 } 324 325 if (!*pval && !ASN1_item_ex_new(pval, it)) { 326 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 327 goto err; 328 } 329 330 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 331 goto auxerr; 332 333 /* Free up and zero any ADB found */ 334 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 335 if (tt->flags & ASN1_TFLG_ADB_MASK) { 336 const ASN1_TEMPLATE *seqtt; 337 ASN1_VALUE **pseqval; 338 seqtt = asn1_do_adb(pval, tt, 0); 339 if (seqtt == NULL) 340 continue; 341 pseqval = asn1_get_field_ptr(pval, seqtt); 342 asn1_template_free(pseqval, seqtt); 343 } 344 } 345 346 /* Get each field entry */ 347 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 348 const ASN1_TEMPLATE *seqtt; 349 ASN1_VALUE **pseqval; 350 seqtt = asn1_do_adb(pval, tt, 1); 351 if (seqtt == NULL) 352 goto err; 353 pseqval = asn1_get_field_ptr(pval, seqtt); 354 /* Have we ran out of data? */ 355 if (!len) 356 break; 357 q = p; 358 if (asn1_check_eoc(&p, len)) { 359 if (!seq_eoc) { 360 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC); 361 goto err; 362 } 363 len -= p - q; 364 seq_eoc = 0; 365 q = p; 366 break; 367 } 368 /* 369 * This determines the OPTIONAL flag value. The field cannot be 370 * omitted if it is the last of a SEQUENCE and there is still 371 * data to be read. This isn't strictly necessary but it 372 * increases efficiency in some cases. 373 */ 374 if (i == (it->tcount - 1)) 375 isopt = 0; 376 else 377 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 378 /* 379 * attempt to read in field, allowing each to be OPTIONAL 380 */ 381 382 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx, 383 depth); 384 if (!ret) { 385 errtt = seqtt; 386 goto err; 387 } else if (ret == -1) { 388 /* 389 * OPTIONAL component absent. Free and zero the field. 390 */ 391 asn1_template_free(pseqval, seqtt); 392 continue; 393 } 394 /* Update length */ 395 len -= p - q; 396 } 397 398 /* Check for EOC if expecting one */ 399 if (seq_eoc && !asn1_check_eoc(&p, len)) { 400 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC); 401 goto err; 402 } 403 /* Check all data read */ 404 if (!seq_nolen && len) { 405 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH); 406 goto err; 407 } 408 409 /* 410 * If we get here we've got no more data in the SEQUENCE, however we 411 * may not have read all fields so check all remaining are OPTIONAL 412 * and clear any that are. 413 */ 414 for (; i < it->tcount; tt++, i++) { 415 const ASN1_TEMPLATE *seqtt; 416 seqtt = asn1_do_adb(pval, tt, 1); 417 if (seqtt == NULL) 418 goto err; 419 if (seqtt->flags & ASN1_TFLG_OPTIONAL) { 420 ASN1_VALUE **pseqval; 421 pseqval = asn1_get_field_ptr(pval, seqtt); 422 asn1_template_free(pseqval, seqtt); 423 } else { 424 errtt = seqtt; 425 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING); 426 goto err; 427 } 428 } 429 /* Save encoding */ 430 if (!asn1_enc_save(pval, *in, p - *in, it)) 431 goto auxerr; 432 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 433 goto auxerr; 434 *in = p; 435 return 1; 436 437 default: 438 return 0; 439 } 440 auxerr: 441 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR); 442 err: 443 if (errtt) 444 ERR_add_error_data(4, "Field=", errtt->field_name, 445 ", Type=", it->sname); 446 else 447 ERR_add_error_data(2, "Type=", it->sname); 448 return 0; 449} 450 451/* 452 * Templates are handled with two separate functions. One handles any 453 * EXPLICIT tag and the other handles the rest. 454 */ 455 456static int asn1_template_ex_d2i(ASN1_VALUE **val, 457 const unsigned char **in, long inlen, 458 const ASN1_TEMPLATE *tt, char opt, 459 ASN1_TLC *ctx, int depth) 460{ 461 int flags, aclass; 462 int ret; 463 long len; 464 const unsigned char *p, *q; 465 char exp_eoc; 466 if (!val) 467 return 0; 468 flags = tt->flags; 469 aclass = flags & ASN1_TFLG_TAG_CLASS; 470 471 p = *in; 472 473 /* Check if EXPLICIT tag expected */ 474 if (flags & ASN1_TFLG_EXPTAG) { 475 char cst; 476 /* 477 * Need to work out amount of data available to the inner content and 478 * where it starts: so read in EXPLICIT header to get the info. 479 */ 480 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 481 &p, inlen, tt->tag, aclass, opt, ctx); 482 q = p; 483 if (!ret) { 484 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 485 return 0; 486 } else if (ret == -1) 487 return -1; 488 if (!cst) { 489 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 490 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 491 return 0; 492 } 493 /* We've found the field so it can't be OPTIONAL now */ 494 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth); 495 if (!ret) { 496 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 497 return 0; 498 } 499 /* We read the field in OK so update length */ 500 len -= p - q; 501 if (exp_eoc) { 502 /* If NDEF we must have an EOC here */ 503 if (!asn1_check_eoc(&p, len)) { 504 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC); 505 goto err; 506 } 507 } else { 508 /* 509 * Otherwise we must hit the EXPLICIT tag end or its an error 510 */ 511 if (len) { 512 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 513 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 514 goto err; 515 } 516 } 517 } else 518 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth); 519 520 *in = p; 521 return 1; 522 523 err: 524 return 0; 525} 526 527static int asn1_template_noexp_d2i(ASN1_VALUE **val, 528 const unsigned char **in, long len, 529 const ASN1_TEMPLATE *tt, char opt, 530 ASN1_TLC *ctx, int depth) 531{ 532 int flags, aclass; 533 int ret; 534 ASN1_VALUE *tval; 535 const unsigned char *p, *q; 536 if (!val) 537 return 0; 538 flags = tt->flags; 539 aclass = flags & ASN1_TFLG_TAG_CLASS; 540 541 p = *in; 542 q = p; 543 544 /* 545 * If field is embedded then val needs fixing so it is a pointer to 546 * a pointer to a field. 547 */ 548 if (tt->flags & ASN1_TFLG_EMBED) { 549 tval = (ASN1_VALUE *)val; 550 val = &tval; 551 } 552 553 if (flags & ASN1_TFLG_SK_MASK) { 554 /* SET OF, SEQUENCE OF */ 555 int sktag, skaclass; 556 char sk_eoc; 557 /* First work out expected inner tag value */ 558 if (flags & ASN1_TFLG_IMPTAG) { 559 sktag = tt->tag; 560 skaclass = aclass; 561 } else { 562 skaclass = V_ASN1_UNIVERSAL; 563 if (flags & ASN1_TFLG_SET_OF) 564 sktag = V_ASN1_SET; 565 else 566 sktag = V_ASN1_SEQUENCE; 567 } 568 /* Get the tag */ 569 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 570 &p, len, sktag, skaclass, opt, ctx); 571 if (!ret) { 572 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 573 return 0; 574 } else if (ret == -1) 575 return -1; 576 if (!*val) 577 *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null(); 578 else { 579 /* 580 * We've got a valid STACK: free up any items present 581 */ 582 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; 583 ASN1_VALUE *vtmp; 584 while (sk_ASN1_VALUE_num(sktmp) > 0) { 585 vtmp = sk_ASN1_VALUE_pop(sktmp); 586 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); 587 } 588 } 589 590 if (!*val) { 591 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 592 goto err; 593 } 594 595 /* Read as many items as we can */ 596 while (len > 0) { 597 ASN1_VALUE *skfield; 598 q = p; 599 /* See if EOC found */ 600 if (asn1_check_eoc(&p, len)) { 601 if (!sk_eoc) { 602 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 603 ASN1_R_UNEXPECTED_EOC); 604 goto err; 605 } 606 len -= p - q; 607 sk_eoc = 0; 608 break; 609 } 610 skfield = NULL; 611 if (!asn1_item_embed_d2i(&skfield, &p, len, 612 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx, 613 depth)) { 614 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 615 ERR_R_NESTED_ASN1_ERROR); 616 /* |skfield| may be partially allocated despite failure. */ 617 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); 618 goto err; 619 } 620 len -= p - q; 621 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { 622 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 623 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); 624 goto err; 625 } 626 } 627 if (sk_eoc) { 628 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 629 goto err; 630 } 631 } else if (flags & ASN1_TFLG_IMPTAG) { 632 /* IMPLICIT tagging */ 633 ret = asn1_item_embed_d2i(val, &p, len, 634 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, 635 ctx, depth); 636 if (!ret) { 637 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 638 goto err; 639 } else if (ret == -1) 640 return -1; 641 } else { 642 /* Nothing special */ 643 ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 644 -1, 0, opt, ctx, depth); 645 if (!ret) { 646 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 647 goto err; 648 } else if (ret == -1) 649 return -1; 650 } 651 652 *in = p; 653 return 1; 654 655 err: 656 return 0; 657} 658 659static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 660 const unsigned char **in, long inlen, 661 const ASN1_ITEM *it, 662 int tag, int aclass, char opt, ASN1_TLC *ctx) 663{ 664 int ret = 0, utype; 665 long plen; 666 char cst, inf, free_cont = 0; 667 const unsigned char *p; 668 BUF_MEM buf = { 0, NULL, 0, 0 }; 669 const unsigned char *cont = NULL; 670 long len; 671 if (!pval) { 672 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 673 return 0; /* Should never happen */ 674 } 675 676 if (it->itype == ASN1_ITYPE_MSTRING) { 677 utype = tag; 678 tag = -1; 679 } else 680 utype = it->utype; 681 682 if (utype == V_ASN1_ANY) { 683 /* If type is ANY need to figure out type from tag */ 684 unsigned char oclass; 685 if (tag >= 0) { 686 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY); 687 return 0; 688 } 689 if (opt) { 690 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 691 ASN1_R_ILLEGAL_OPTIONAL_ANY); 692 return 0; 693 } 694 p = *in; 695 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 696 &p, inlen, -1, 0, 0, ctx); 697 if (!ret) { 698 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 699 return 0; 700 } 701 if (oclass != V_ASN1_UNIVERSAL) 702 utype = V_ASN1_OTHER; 703 } 704 if (tag == -1) { 705 tag = utype; 706 aclass = V_ASN1_UNIVERSAL; 707 } 708 p = *in; 709 /* Check header */ 710 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 711 &p, inlen, tag, aclass, opt, ctx); 712 if (!ret) { 713 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 714 return 0; 715 } else if (ret == -1) 716 return -1; 717 ret = 0; 718 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 719 if ((utype == V_ASN1_SEQUENCE) 720 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) { 721 /* 722 * Clear context cache for type OTHER because the auto clear when we 723 * have a exact match won't work 724 */ 725 if (utype == V_ASN1_OTHER) { 726 asn1_tlc_clear(ctx); 727 } 728 /* SEQUENCE and SET must be constructed */ 729 else if (!cst) { 730 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 731 ASN1_R_TYPE_NOT_CONSTRUCTED); 732 return 0; 733 } 734 735 cont = *in; 736 /* If indefinite length constructed find the real end */ 737 if (inf) { 738 if (!asn1_find_end(&p, plen, inf)) 739 goto err; 740 len = p - cont; 741 } else { 742 len = p - cont + plen; 743 p += plen; 744 } 745 } else if (cst) { 746 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 747 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 748 || utype == V_ASN1_ENUMERATED) { 749 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE); 750 return 0; 751 } 752 753 /* Free any returned 'buf' content */ 754 free_cont = 1; 755 /* 756 * Should really check the internal tags are correct but some things 757 * may get this wrong. The relevant specs say that constructed string 758 * types should be OCTET STRINGs internally irrespective of the type. 759 * So instead just check for UNIVERSAL class and ignore the tag. 760 */ 761 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { 762 goto err; 763 } 764 len = buf.length; 765 /* Append a final null to string */ 766 if (!BUF_MEM_grow_clean(&buf, len + 1)) { 767 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE); 768 goto err; 769 } 770 buf.data[len] = 0; 771 cont = (const unsigned char *)buf.data; 772 } else { 773 cont = p; 774 len = plen; 775 p += plen; 776 } 777 778 /* We now have content length and type: translate into a structure */ 779 /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */ 780 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 781 goto err; 782 783 *in = p; 784 ret = 1; 785 err: 786 if (free_cont) 787 OPENSSL_free(buf.data); 788 return ret; 789} 790 791/* Translate ASN1 content octets into a structure */ 792 793static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 794 int utype, char *free_cont, const ASN1_ITEM *it) 795{ 796 ASN1_VALUE **opval = NULL; 797 ASN1_STRING *stmp; 798 ASN1_TYPE *typ = NULL; 799 int ret = 0; 800 const ASN1_PRIMITIVE_FUNCS *pf; 801 ASN1_INTEGER **tint; 802 pf = it->funcs; 803 804 if (pf && pf->prim_c2i) 805 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 806 /* If ANY type clear type and set pointer to internal value */ 807 if (it->utype == V_ASN1_ANY) { 808 if (!*pval) { 809 typ = ASN1_TYPE_new(); 810 if (typ == NULL) 811 goto err; 812 *pval = (ASN1_VALUE *)typ; 813 } else 814 typ = (ASN1_TYPE *)*pval; 815 816 if (utype != typ->type) 817 ASN1_TYPE_set(typ, utype, NULL); 818 opval = pval; 819 pval = &typ->value.asn1_value; 820 } 821 switch (utype) { 822 case V_ASN1_OBJECT: 823 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 824 goto err; 825 break; 826 827 case V_ASN1_NULL: 828 if (len) { 829 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH); 830 goto err; 831 } 832 *pval = (ASN1_VALUE *)1; 833 break; 834 835 case V_ASN1_BOOLEAN: 836 if (len != 1) { 837 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 838 goto err; 839 } else { 840 ASN1_BOOLEAN *tbool; 841 tbool = (ASN1_BOOLEAN *)pval; 842 *tbool = *cont; 843 } 844 break; 845 846 case V_ASN1_BIT_STRING: 847 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 848 goto err; 849 break; 850 851 case V_ASN1_INTEGER: 852 case V_ASN1_ENUMERATED: 853 tint = (ASN1_INTEGER **)pval; 854 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 855 goto err; 856 /* Fixup type to match the expected form */ 857 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 858 break; 859 860 case V_ASN1_OCTET_STRING: 861 case V_ASN1_NUMERICSTRING: 862 case V_ASN1_PRINTABLESTRING: 863 case V_ASN1_T61STRING: 864 case V_ASN1_VIDEOTEXSTRING: 865 case V_ASN1_IA5STRING: 866 case V_ASN1_UTCTIME: 867 case V_ASN1_GENERALIZEDTIME: 868 case V_ASN1_GRAPHICSTRING: 869 case V_ASN1_VISIBLESTRING: 870 case V_ASN1_GENERALSTRING: 871 case V_ASN1_UNIVERSALSTRING: 872 case V_ASN1_BMPSTRING: 873 case V_ASN1_UTF8STRING: 874 case V_ASN1_OTHER: 875 case V_ASN1_SET: 876 case V_ASN1_SEQUENCE: 877 default: 878 if (utype == V_ASN1_BMPSTRING && (len & 1)) { 879 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 880 goto err; 881 } 882 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { 883 ASN1err(ASN1_F_ASN1_EX_C2I, 884 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 885 goto err; 886 } 887 /* All based on ASN1_STRING and handled the same */ 888 if (!*pval) { 889 stmp = ASN1_STRING_type_new(utype); 890 if (stmp == NULL) { 891 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 892 goto err; 893 } 894 *pval = (ASN1_VALUE *)stmp; 895 } else { 896 stmp = (ASN1_STRING *)*pval; 897 stmp->type = utype; 898 } 899 /* If we've already allocated a buffer use it */ 900 if (*free_cont) { 901 OPENSSL_free(stmp->data); 902 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 903 stmp->length = len; 904 *free_cont = 0; 905 } else { 906 if (!ASN1_STRING_set(stmp, cont, len)) { 907 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 908 ASN1_STRING_free(stmp); 909 *pval = NULL; 910 goto err; 911 } 912 } 913 break; 914 } 915 /* If ASN1_ANY and NULL type fix up value */ 916 if (typ && (utype == V_ASN1_NULL)) 917 typ->value.ptr = NULL; 918 919 ret = 1; 920 err: 921 if (!ret) { 922 ASN1_TYPE_free(typ); 923 if (opval) 924 *opval = NULL; 925 } 926 return ret; 927} 928 929/* 930 * This function finds the end of an ASN1 structure when passed its maximum 931 * length, whether it is indefinite length and a pointer to the content. This 932 * is more efficient than calling asn1_collect because it does not recurse on 933 * each indefinite length header. 934 */ 935 936static int asn1_find_end(const unsigned char **in, long len, char inf) 937{ 938 uint32_t expected_eoc; 939 long plen; 940 const unsigned char *p = *in, *q; 941 /* If not indefinite length constructed just add length */ 942 if (inf == 0) { 943 *in += len; 944 return 1; 945 } 946 expected_eoc = 1; 947 /* 948 * Indefinite length constructed form. Find the end when enough EOCs are 949 * found. If more indefinite length constructed headers are encountered 950 * increment the expected eoc count otherwise just skip to the end of the 951 * data. 952 */ 953 while (len > 0) { 954 if (asn1_check_eoc(&p, len)) { 955 expected_eoc--; 956 if (expected_eoc == 0) 957 break; 958 len -= 2; 959 continue; 960 } 961 q = p; 962 /* Just read in a header: only care about the length */ 963 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 964 -1, 0, 0, NULL)) { 965 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 966 return 0; 967 } 968 if (inf) { 969 if (expected_eoc == UINT32_MAX) { 970 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 971 return 0; 972 } 973 expected_eoc++; 974 } else { 975 p += plen; 976 } 977 len -= p - q; 978 } 979 if (expected_eoc) { 980 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 981 return 0; 982 } 983 *in = p; 984 return 1; 985} 986 987/* 988 * This function collects the asn1 data from a constructed string type into 989 * a buffer. The values of 'in' and 'len' should refer to the contents of the 990 * constructed type and 'inf' should be set if it is indefinite length. 991 */ 992 993#ifndef ASN1_MAX_STRING_NEST 994/* 995 * This determines how many levels of recursion are permitted in ASN1 string 996 * types. If it is not limited stack overflows can occur. If set to zero no 997 * recursion is allowed at all. Although zero should be adequate examples 998 * exist that require a value of 1. So 5 should be more than enough. 999 */ 1000# define ASN1_MAX_STRING_NEST 5 1001#endif 1002 1003static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1004 char inf, int tag, int aclass, int depth) 1005{ 1006 const unsigned char *p, *q; 1007 long plen; 1008 char cst, ininf; 1009 p = *in; 1010 inf &= 1; 1011 /* 1012 * If no buffer and not indefinite length constructed just pass over the 1013 * encoded data 1014 */ 1015 if (!buf && !inf) { 1016 *in += len; 1017 return 1; 1018 } 1019 while (len > 0) { 1020 q = p; 1021 /* Check for EOC */ 1022 if (asn1_check_eoc(&p, len)) { 1023 /* 1024 * EOC is illegal outside indefinite length constructed form 1025 */ 1026 if (!inf) { 1027 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC); 1028 return 0; 1029 } 1030 inf = 0; 1031 break; 1032 } 1033 1034 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1035 len, tag, aclass, 0, NULL)) { 1036 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1037 return 0; 1038 } 1039 1040 /* If indefinite length constructed update max length */ 1041 if (cst) { 1042 if (depth >= ASN1_MAX_STRING_NEST) { 1043 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); 1044 return 0; 1045 } 1046 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1047 return 0; 1048 } else if (plen && !collect_data(buf, &p, plen)) 1049 return 0; 1050 len -= p - q; 1051 } 1052 if (inf) { 1053 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1054 return 0; 1055 } 1056 *in = p; 1057 return 1; 1058} 1059 1060static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1061{ 1062 int len; 1063 if (buf) { 1064 len = buf->length; 1065 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1066 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1067 return 0; 1068 } 1069 memcpy(buf->data + len, *p, plen); 1070 } 1071 *p += plen; 1072 return 1; 1073} 1074 1075/* Check for ASN1 EOC and swallow it if found */ 1076 1077static int asn1_check_eoc(const unsigned char **in, long len) 1078{ 1079 const unsigned char *p; 1080 if (len < 2) 1081 return 0; 1082 p = *in; 1083 if (!p[0] && !p[1]) { 1084 *in += 2; 1085 return 1; 1086 } 1087 return 0; 1088} 1089 1090/* 1091 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1092 * length for indefinite length constructed form, we don't know the exact 1093 * length but we can set an upper bound to the amount of data available minus 1094 * the header length just read. 1095 */ 1096 1097static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1098 char *inf, char *cst, 1099 const unsigned char **in, long len, 1100 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1101{ 1102 int i; 1103 int ptag, pclass; 1104 long plen; 1105 const unsigned char *p, *q; 1106 p = *in; 1107 q = p; 1108 1109 if (ctx && ctx->valid) { 1110 i = ctx->ret; 1111 plen = ctx->plen; 1112 pclass = ctx->pclass; 1113 ptag = ctx->ptag; 1114 p += ctx->hdrlen; 1115 } else { 1116 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1117 if (ctx) { 1118 ctx->ret = i; 1119 ctx->plen = plen; 1120 ctx->pclass = pclass; 1121 ctx->ptag = ptag; 1122 ctx->hdrlen = p - q; 1123 ctx->valid = 1; 1124 /* 1125 * If definite length, and no error, length + header can't exceed 1126 * total amount of data available. 1127 */ 1128 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { 1129 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG); 1130 asn1_tlc_clear(ctx); 1131 return 0; 1132 } 1133 } 1134 } 1135 1136 if (i & 0x80) { 1137 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1138 asn1_tlc_clear(ctx); 1139 return 0; 1140 } 1141 if (exptag >= 0) { 1142 if ((exptag != ptag) || (expclass != pclass)) { 1143 /* 1144 * If type is OPTIONAL, not an error: indicate missing type. 1145 */ 1146 if (opt) 1147 return -1; 1148 asn1_tlc_clear(ctx); 1149 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1150 return 0; 1151 } 1152 /* 1153 * We have a tag and class match: assume we are going to do something 1154 * with it 1155 */ 1156 asn1_tlc_clear(ctx); 1157 } 1158 1159 if (i & 1) 1160 plen = len - (p - q); 1161 1162 if (inf) 1163 *inf = i & 1; 1164 1165 if (cst) 1166 *cst = i & V_ASN1_CONSTRUCTED; 1167 1168 if (olen) 1169 *olen = plen; 1170 1171 if (oclass) 1172 *oclass = pclass; 1173 1174 if (otag) 1175 *otag = ptag; 1176 1177 *in = p; 1178 return 1; 1179} 1180