1/* 2 * Copyright 2000-2021 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 28static 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 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, OSSL_LIB_CTX *libctx, 51 const char *propq); 52static 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); 57static 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); 62static 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 */ 66static 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 87unsigned 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 107static 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 125int 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 133ASN1_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 150ASN1_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 162static 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 496static 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 568static 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_MALLOC_FAILURE); 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_MALLOC_FAILURE); 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 698static 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_MALLOC_FAILURE); 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 831static 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 /* All based on ASN1_STRING and handled the same */ 925 if (*pval == NULL) { 926 stmp = ASN1_STRING_type_new(utype); 927 if (stmp == NULL) { 928 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); 929 goto err; 930 } 931 *pval = (ASN1_VALUE *)stmp; 932 } else { 933 stmp = (ASN1_STRING *)*pval; 934 stmp->type = utype; 935 } 936 /* If we've already allocated a buffer use it */ 937 if (*free_cont) { 938 OPENSSL_free(stmp->data); 939 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 940 stmp->length = len; 941 *free_cont = 0; 942 } else { 943 if (!ASN1_STRING_set(stmp, cont, len)) { 944 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); 945 ASN1_STRING_free(stmp); 946 *pval = NULL; 947 goto err; 948 } 949 } 950 break; 951 } 952 /* If ASN1_ANY and NULL type fix up value */ 953 if (typ && (utype == V_ASN1_NULL)) 954 typ->value.ptr = NULL; 955 956 ret = 1; 957 err: 958 if (!ret) { 959 ASN1_TYPE_free(typ); 960 if (opval) 961 *opval = NULL; 962 } 963 return ret; 964} 965 966/* 967 * This function finds the end of an ASN1 structure when passed its maximum 968 * length, whether it is indefinite length and a pointer to the content. This 969 * is more efficient than calling asn1_collect because it does not recurse on 970 * each indefinite length header. 971 */ 972 973static int asn1_find_end(const unsigned char **in, long len, char inf) 974{ 975 uint32_t expected_eoc; 976 long plen; 977 const unsigned char *p = *in, *q; 978 /* If not indefinite length constructed just add length */ 979 if (inf == 0) { 980 *in += len; 981 return 1; 982 } 983 expected_eoc = 1; 984 /* 985 * Indefinite length constructed form. Find the end when enough EOCs are 986 * found. If more indefinite length constructed headers are encountered 987 * increment the expected eoc count otherwise just skip to the end of the 988 * data. 989 */ 990 while (len > 0) { 991 if (asn1_check_eoc(&p, len)) { 992 expected_eoc--; 993 if (expected_eoc == 0) 994 break; 995 len -= 2; 996 continue; 997 } 998 q = p; 999 /* Just read in a header: only care about the length */ 1000 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1001 -1, 0, 0, NULL)) { 1002 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR); 1003 return 0; 1004 } 1005 if (inf) { 1006 if (expected_eoc == UINT32_MAX) { 1007 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR); 1008 return 0; 1009 } 1010 expected_eoc++; 1011 } else { 1012 p += plen; 1013 } 1014 len -= p - q; 1015 } 1016 if (expected_eoc) { 1017 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC); 1018 return 0; 1019 } 1020 *in = p; 1021 return 1; 1022} 1023 1024/* 1025 * This function collects the asn1 data from a constructed string type into 1026 * a buffer. The values of 'in' and 'len' should refer to the contents of the 1027 * constructed type and 'inf' should be set if it is indefinite length. 1028 */ 1029 1030#ifndef ASN1_MAX_STRING_NEST 1031/* 1032 * This determines how many levels of recursion are permitted in ASN1 string 1033 * types. If it is not limited stack overflows can occur. If set to zero no 1034 * recursion is allowed at all. Although zero should be adequate examples 1035 * exist that require a value of 1. So 5 should be more than enough. 1036 */ 1037# define ASN1_MAX_STRING_NEST 5 1038#endif 1039 1040static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1041 char inf, int tag, int aclass, int depth) 1042{ 1043 const unsigned char *p, *q; 1044 long plen; 1045 char cst, ininf; 1046 p = *in; 1047 inf &= 1; 1048 /* 1049 * If no buffer and not indefinite length constructed just pass over the 1050 * encoded data 1051 */ 1052 if (!buf && !inf) { 1053 *in += len; 1054 return 1; 1055 } 1056 while (len > 0) { 1057 q = p; 1058 /* Check for EOC */ 1059 if (asn1_check_eoc(&p, len)) { 1060 /* 1061 * EOC is illegal outside indefinite length constructed form 1062 */ 1063 if (!inf) { 1064 ERR_raise(ERR_LIB_ASN1, ASN1_R_UNEXPECTED_EOC); 1065 return 0; 1066 } 1067 inf = 0; 1068 break; 1069 } 1070 1071 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1072 len, tag, aclass, 0, NULL)) { 1073 ERR_raise(ERR_LIB_ASN1, ERR_R_NESTED_ASN1_ERROR); 1074 return 0; 1075 } 1076 1077 /* If indefinite length constructed update max length */ 1078 if (cst) { 1079 if (depth >= ASN1_MAX_STRING_NEST) { 1080 ERR_raise(ERR_LIB_ASN1, ASN1_R_NESTED_ASN1_STRING); 1081 return 0; 1082 } 1083 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1084 return 0; 1085 } else if (plen && !collect_data(buf, &p, plen)) 1086 return 0; 1087 len -= p - q; 1088 } 1089 if (inf) { 1090 ERR_raise(ERR_LIB_ASN1, ASN1_R_MISSING_EOC); 1091 return 0; 1092 } 1093 *in = p; 1094 return 1; 1095} 1096 1097static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1098{ 1099 int len; 1100 if (buf) { 1101 len = buf->length; 1102 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1103 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); 1104 return 0; 1105 } 1106 memcpy(buf->data + len, *p, plen); 1107 } 1108 *p += plen; 1109 return 1; 1110} 1111 1112/* Check for ASN1 EOC and swallow it if found */ 1113 1114static int asn1_check_eoc(const unsigned char **in, long len) 1115{ 1116 const unsigned char *p; 1117 1118 if (len < 2) 1119 return 0; 1120 p = *in; 1121 if (p[0] == '\0' && p[1] == '\0') { 1122 *in += 2; 1123 return 1; 1124 } 1125 return 0; 1126} 1127 1128/* 1129 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1130 * length for indefinite length constructed form, we don't know the exact 1131 * length but we can set an upper bound to the amount of data available minus 1132 * the header length just read. 1133 */ 1134 1135static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1136 char *inf, char *cst, 1137 const unsigned char **in, long len, 1138 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1139{ 1140 int i; 1141 int ptag, pclass; 1142 long plen; 1143 const unsigned char *p, *q; 1144 p = *in; 1145 q = p; 1146 1147 if (len <= 0) { 1148 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL); 1149 goto err; 1150 } 1151 if (ctx != NULL && ctx->valid) { 1152 i = ctx->ret; 1153 plen = ctx->plen; 1154 pclass = ctx->pclass; 1155 ptag = ctx->ptag; 1156 p += ctx->hdrlen; 1157 } else { 1158 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1159 if (ctx != NULL) { 1160 ctx->ret = i; 1161 ctx->plen = plen; 1162 ctx->pclass = pclass; 1163 ctx->ptag = ptag; 1164 ctx->hdrlen = p - q; 1165 ctx->valid = 1; 1166 /* 1167 * If definite length, and no error, length + header can't exceed 1168 * total amount of data available. 1169 */ 1170 if ((i & 0x81) == 0 && (plen + ctx->hdrlen) > len) { 1171 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG); 1172 goto err; 1173 } 1174 } 1175 } 1176 1177 if ((i & 0x80) != 0) { 1178 ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_OBJECT_HEADER); 1179 goto err; 1180 } 1181 if (exptag >= 0) { 1182 if (exptag != ptag || expclass != pclass) { 1183 /* 1184 * If type is OPTIONAL, not an error: indicate missing type. 1185 */ 1186 if (opt != 0) 1187 return -1; 1188 ERR_raise(ERR_LIB_ASN1, ASN1_R_WRONG_TAG); 1189 goto err; 1190 } 1191 /* 1192 * We have a tag and class match: assume we are going to do something 1193 * with it 1194 */ 1195 asn1_tlc_clear(ctx); 1196 } 1197 1198 if ((i & 1) != 0) 1199 plen = len - (p - q); 1200 1201 if (inf != NULL) 1202 *inf = i & 1; 1203 1204 if (cst != NULL) 1205 *cst = i & V_ASN1_CONSTRUCTED; 1206 1207 if (olen != NULL) 1208 *olen = plen; 1209 1210 if (oclass != NULL) 1211 *oclass = pclass; 1212 1213 if (otag != NULL) 1214 *otag = ptag; 1215 1216 *in = p; 1217 return 1; 1218 1219 err: 1220 asn1_tlc_clear(ctx); 1221 return 0; 1222} 1223