1 /* 2 * Copyright 2000-2018 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 29 static 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 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); 51 static 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); 55 static 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); 60 static 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 */ 64 static 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 85 unsigned 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 */ 104 105 ASN1_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 } 118 119 int 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 */ 134 135 static 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 p = *in; 186 /* Just read in tag and class */ 187 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 188 &p, len, -1, 0, 1, ctx); 189 if (!ret) { 190 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 191 goto err; 192 } 193 194 /* Must be UNIVERSAL class */ 195 if (oclass != V_ASN1_UNIVERSAL) { 196 /* If OPTIONAL, assume this is OK */ 197 if (opt) 198 return -1; 199 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL); 200 goto err; 201 } 202 /* Check tag matches bit map */ 203 if (!(ASN1_tag2bit(otag) & it->utype)) { 204 /* If OPTIONAL, assume this is OK */ 205 if (opt) 206 return -1; 207 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG); 208 goto err; 209 } 210 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); 211 212 case ASN1_ITYPE_EXTERN: 213 /* Use new style d2i */ 214 ef = it->funcs; 215 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); 216 217 case ASN1_ITYPE_CHOICE: 218 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 219 goto auxerr; 220 if (*pval) { 221 /* Free up and zero CHOICE value if initialised */ 222 i = asn1_get_choice_selector(pval, it); 223 if ((i >= 0) && (i < it->tcount)) { 224 tt = it->templates + i; 225 pchptr = asn1_get_field_ptr(pval, tt); 226 asn1_template_free(pchptr, tt); 227 asn1_set_choice_selector(pval, -1, it); 228 } 229 } else if (!ASN1_item_ex_new(pval, it)) { 230 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 231 goto err; 232 } 233 /* CHOICE type, try each possibility in turn */ 234 p = *in; 235 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 236 pchptr = asn1_get_field_ptr(pval, tt); 237 /* 238 * We mark field as OPTIONAL so its absence can be recognised. 239 */ 240 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth); 241 /* If field not present, try the next one */ 242 if (ret == -1) 243 continue; 244 /* If positive return, read OK, break loop */ 245 if (ret > 0) 246 break; 247 /* 248 * Must be an ASN1 parsing error. 249 * Free up any partial choice value 250 */ 251 asn1_template_free(pchptr, tt); 252 errtt = tt; 253 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 254 goto err; 255 } 256 257 /* Did we fall off the end without reading anything? */ 258 if (i == it->tcount) { 259 /* If OPTIONAL, this is OK */ 260 if (opt) { 261 /* Free and zero it */ 262 ASN1_item_ex_free(pval, it); 263 return -1; 264 } 265 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE); 266 goto err; 267 } 268 269 asn1_set_choice_selector(pval, i, it); 270 271 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 272 goto auxerr; 273 *in = p; 274 return 1; 275 276 case ASN1_ITYPE_NDEF_SEQUENCE: 277 case ASN1_ITYPE_SEQUENCE: 278 p = *in; 279 tmplen = len; 280 281 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 282 if (tag == -1) { 283 tag = V_ASN1_SEQUENCE; 284 aclass = V_ASN1_UNIVERSAL; 285 } 286 /* Get SEQUENCE length and update len, p */ 287 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 288 &p, len, tag, aclass, opt, ctx); 289 if (!ret) { 290 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 291 goto err; 292 } else if (ret == -1) 293 return -1; 294 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) { 295 len = tmplen - (p - *in); 296 seq_nolen = 1; 297 } 298 /* If indefinite we don't do a length check */ 299 else 300 seq_nolen = seq_eoc; 301 if (!cst) { 302 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 303 goto err; 304 } 305 306 if (!*pval && !ASN1_item_ex_new(pval, it)) { 307 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); 308 goto err; 309 } 310 311 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 312 goto auxerr; 313 314 /* Free up and zero any ADB found */ 315 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 316 if (tt->flags & ASN1_TFLG_ADB_MASK) { 317 const ASN1_TEMPLATE *seqtt; 318 ASN1_VALUE **pseqval; 319 seqtt = asn1_do_adb(pval, tt, 0); 320 if (seqtt == NULL) 321 continue; 322 pseqval = asn1_get_field_ptr(pval, seqtt); 323 asn1_template_free(pseqval, seqtt); 324 } 325 } 326 327 /* Get each field entry */ 328 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 329 const ASN1_TEMPLATE *seqtt; 330 ASN1_VALUE **pseqval; 331 seqtt = asn1_do_adb(pval, tt, 1); 332 if (seqtt == NULL) 333 goto err; 334 pseqval = asn1_get_field_ptr(pval, seqtt); 335 /* Have we ran out of data? */ 336 if (!len) 337 break; 338 q = p; 339 if (asn1_check_eoc(&p, len)) { 340 if (!seq_eoc) { 341 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC); 342 goto err; 343 } 344 len -= p - q; 345 seq_eoc = 0; 346 q = p; 347 break; 348 } 349 /* 350 * This determines the OPTIONAL flag value. The field cannot be 351 * omitted if it is the last of a SEQUENCE and there is still 352 * data to be read. This isn't strictly necessary but it 353 * increases efficiency in some cases. 354 */ 355 if (i == (it->tcount - 1)) 356 isopt = 0; 357 else 358 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 359 /* 360 * attempt to read in field, allowing each to be OPTIONAL 361 */ 362 363 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx, 364 depth); 365 if (!ret) { 366 errtt = seqtt; 367 goto err; 368 } else if (ret == -1) { 369 /* 370 * OPTIONAL component absent. Free and zero the field. 371 */ 372 asn1_template_free(pseqval, seqtt); 373 continue; 374 } 375 /* Update length */ 376 len -= p - q; 377 } 378 379 /* Check for EOC if expecting one */ 380 if (seq_eoc && !asn1_check_eoc(&p, len)) { 381 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC); 382 goto err; 383 } 384 /* Check all data read */ 385 if (!seq_nolen && len) { 386 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH); 387 goto err; 388 } 389 390 /* 391 * If we get here we've got no more data in the SEQUENCE, however we 392 * may not have read all fields so check all remaining are OPTIONAL 393 * and clear any that are. 394 */ 395 for (; i < it->tcount; tt++, i++) { 396 const ASN1_TEMPLATE *seqtt; 397 seqtt = asn1_do_adb(pval, tt, 1); 398 if (seqtt == NULL) 399 goto err; 400 if (seqtt->flags & ASN1_TFLG_OPTIONAL) { 401 ASN1_VALUE **pseqval; 402 pseqval = asn1_get_field_ptr(pval, seqtt); 403 asn1_template_free(pseqval, seqtt); 404 } else { 405 errtt = seqtt; 406 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING); 407 goto err; 408 } 409 } 410 /* Save encoding */ 411 if (!asn1_enc_save(pval, *in, p - *in, it)) 412 goto auxerr; 413 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 414 goto auxerr; 415 *in = p; 416 return 1; 417 418 default: 419 return 0; 420 } 421 auxerr: 422 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR); 423 err: 424 if (errtt) 425 ERR_add_error_data(4, "Field=", errtt->field_name, 426 ", Type=", it->sname); 427 else 428 ERR_add_error_data(2, "Type=", it->sname); 429 return 0; 430 } 431 432 /* 433 * Templates are handled with two separate functions. One handles any 434 * EXPLICIT tag and the other handles the rest. 435 */ 436 437 static int asn1_template_ex_d2i(ASN1_VALUE **val, 438 const unsigned char **in, long inlen, 439 const ASN1_TEMPLATE *tt, char opt, 440 ASN1_TLC *ctx, int depth) 441 { 442 int flags, aclass; 443 int ret; 444 long len; 445 const unsigned char *p, *q; 446 char exp_eoc; 447 if (!val) 448 return 0; 449 flags = tt->flags; 450 aclass = flags & ASN1_TFLG_TAG_CLASS; 451 452 p = *in; 453 454 /* Check if EXPLICIT tag expected */ 455 if (flags & ASN1_TFLG_EXPTAG) { 456 char cst; 457 /* 458 * Need to work out amount of data available to the inner content and 459 * where it starts: so read in EXPLICIT header to get the info. 460 */ 461 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 462 &p, inlen, tt->tag, aclass, opt, ctx); 463 q = p; 464 if (!ret) { 465 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 466 return 0; 467 } else if (ret == -1) 468 return -1; 469 if (!cst) { 470 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 471 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 472 return 0; 473 } 474 /* We've found the field so it can't be OPTIONAL now */ 475 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth); 476 if (!ret) { 477 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 478 return 0; 479 } 480 /* We read the field in OK so update length */ 481 len -= p - q; 482 if (exp_eoc) { 483 /* If NDEF we must have an EOC here */ 484 if (!asn1_check_eoc(&p, len)) { 485 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC); 486 goto err; 487 } 488 } else { 489 /* 490 * Otherwise we must hit the EXPLICIT tag end or its an error 491 */ 492 if (len) { 493 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 494 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 495 goto err; 496 } 497 } 498 } else 499 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth); 500 501 *in = p; 502 return 1; 503 504 err: 505 return 0; 506 } 507 508 static int asn1_template_noexp_d2i(ASN1_VALUE **val, 509 const unsigned char **in, long len, 510 const ASN1_TEMPLATE *tt, char opt, 511 ASN1_TLC *ctx, int depth) 512 { 513 int flags, aclass; 514 int ret; 515 ASN1_VALUE *tval; 516 const unsigned char *p, *q; 517 if (!val) 518 return 0; 519 flags = tt->flags; 520 aclass = flags & ASN1_TFLG_TAG_CLASS; 521 522 p = *in; 523 q = p; 524 525 /* 526 * If field is embedded then val needs fixing so it is a pointer to 527 * a pointer to a field. 528 */ 529 if (tt->flags & ASN1_TFLG_EMBED) { 530 tval = (ASN1_VALUE *)val; 531 val = &tval; 532 } 533 534 if (flags & ASN1_TFLG_SK_MASK) { 535 /* SET OF, SEQUENCE OF */ 536 int sktag, skaclass; 537 char sk_eoc; 538 /* First work out expected inner tag value */ 539 if (flags & ASN1_TFLG_IMPTAG) { 540 sktag = tt->tag; 541 skaclass = aclass; 542 } else { 543 skaclass = V_ASN1_UNIVERSAL; 544 if (flags & ASN1_TFLG_SET_OF) 545 sktag = V_ASN1_SET; 546 else 547 sktag = V_ASN1_SEQUENCE; 548 } 549 /* Get the tag */ 550 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 551 &p, len, sktag, skaclass, opt, ctx); 552 if (!ret) { 553 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 554 return 0; 555 } else if (ret == -1) 556 return -1; 557 if (!*val) 558 *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null(); 559 else { 560 /* 561 * We've got a valid STACK: free up any items present 562 */ 563 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; 564 ASN1_VALUE *vtmp; 565 while (sk_ASN1_VALUE_num(sktmp) > 0) { 566 vtmp = sk_ASN1_VALUE_pop(sktmp); 567 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); 568 } 569 } 570 571 if (!*val) { 572 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 573 goto err; 574 } 575 576 /* Read as many items as we can */ 577 while (len > 0) { 578 ASN1_VALUE *skfield; 579 q = p; 580 /* See if EOC found */ 581 if (asn1_check_eoc(&p, len)) { 582 if (!sk_eoc) { 583 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 584 ASN1_R_UNEXPECTED_EOC); 585 goto err; 586 } 587 len -= p - q; 588 sk_eoc = 0; 589 break; 590 } 591 skfield = NULL; 592 if (!asn1_item_embed_d2i(&skfield, &p, len, 593 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx, 594 depth)) { 595 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 596 ERR_R_NESTED_ASN1_ERROR); 597 /* |skfield| may be partially allocated despite failure. */ 598 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); 599 goto err; 600 } 601 len -= p - q; 602 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { 603 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 604 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); 605 goto err; 606 } 607 } 608 if (sk_eoc) { 609 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 610 goto err; 611 } 612 } else if (flags & ASN1_TFLG_IMPTAG) { 613 /* IMPLICIT tagging */ 614 ret = asn1_item_embed_d2i(val, &p, len, 615 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, 616 ctx, depth); 617 if (!ret) { 618 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 619 goto err; 620 } else if (ret == -1) 621 return -1; 622 } else { 623 /* Nothing special */ 624 ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 625 -1, 0, opt, ctx, depth); 626 if (!ret) { 627 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 628 goto err; 629 } else if (ret == -1) 630 return -1; 631 } 632 633 *in = p; 634 return 1; 635 636 err: 637 return 0; 638 } 639 640 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 641 const unsigned char **in, long inlen, 642 const ASN1_ITEM *it, 643 int tag, int aclass, char opt, ASN1_TLC *ctx) 644 { 645 int ret = 0, utype; 646 long plen; 647 char cst, inf, free_cont = 0; 648 const unsigned char *p; 649 BUF_MEM buf = { 0, NULL, 0, 0 }; 650 const unsigned char *cont = NULL; 651 long len; 652 if (!pval) { 653 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 654 return 0; /* Should never happen */ 655 } 656 657 if (it->itype == ASN1_ITYPE_MSTRING) { 658 utype = tag; 659 tag = -1; 660 } else 661 utype = it->utype; 662 663 if (utype == V_ASN1_ANY) { 664 /* If type is ANY need to figure out type from tag */ 665 unsigned char oclass; 666 if (tag >= 0) { 667 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY); 668 return 0; 669 } 670 if (opt) { 671 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 672 ASN1_R_ILLEGAL_OPTIONAL_ANY); 673 return 0; 674 } 675 p = *in; 676 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 677 &p, inlen, -1, 0, 0, ctx); 678 if (!ret) { 679 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 680 return 0; 681 } 682 if (oclass != V_ASN1_UNIVERSAL) 683 utype = V_ASN1_OTHER; 684 } 685 if (tag == -1) { 686 tag = utype; 687 aclass = V_ASN1_UNIVERSAL; 688 } 689 p = *in; 690 /* Check header */ 691 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 692 &p, inlen, tag, aclass, opt, ctx); 693 if (!ret) { 694 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 695 return 0; 696 } else if (ret == -1) 697 return -1; 698 ret = 0; 699 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 700 if ((utype == V_ASN1_SEQUENCE) 701 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) { 702 /* 703 * Clear context cache for type OTHER because the auto clear when we 704 * have a exact match won't work 705 */ 706 if (utype == V_ASN1_OTHER) { 707 asn1_tlc_clear(ctx); 708 } 709 /* SEQUENCE and SET must be constructed */ 710 else if (!cst) { 711 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 712 ASN1_R_TYPE_NOT_CONSTRUCTED); 713 return 0; 714 } 715 716 cont = *in; 717 /* If indefinite length constructed find the real end */ 718 if (inf) { 719 if (!asn1_find_end(&p, plen, inf)) 720 goto err; 721 len = p - cont; 722 } else { 723 len = p - cont + plen; 724 p += plen; 725 } 726 } else if (cst) { 727 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 728 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 729 || utype == V_ASN1_ENUMERATED) { 730 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE); 731 return 0; 732 } 733 734 /* Free any returned 'buf' content */ 735 free_cont = 1; 736 /* 737 * Should really check the internal tags are correct but some things 738 * may get this wrong. The relevant specs say that constructed string 739 * types should be OCTET STRINGs internally irrespective of the type. 740 * So instead just check for UNIVERSAL class and ignore the tag. 741 */ 742 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { 743 goto err; 744 } 745 len = buf.length; 746 /* Append a final null to string */ 747 if (!BUF_MEM_grow_clean(&buf, len + 1)) { 748 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE); 749 goto err; 750 } 751 buf.data[len] = 0; 752 cont = (const unsigned char *)buf.data; 753 } else { 754 cont = p; 755 len = plen; 756 p += plen; 757 } 758 759 /* We now have content length and type: translate into a structure */ 760 /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */ 761 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 762 goto err; 763 764 *in = p; 765 ret = 1; 766 err: 767 if (free_cont) 768 OPENSSL_free(buf.data); 769 return ret; 770 } 771 772 /* Translate ASN1 content octets into a structure */ 773 774 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 775 int utype, char *free_cont, const ASN1_ITEM *it) 776 { 777 ASN1_VALUE **opval = NULL; 778 ASN1_STRING *stmp; 779 ASN1_TYPE *typ = NULL; 780 int ret = 0; 781 const ASN1_PRIMITIVE_FUNCS *pf; 782 ASN1_INTEGER **tint; 783 pf = it->funcs; 784 785 if (pf && pf->prim_c2i) 786 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 787 /* If ANY type clear type and set pointer to internal value */ 788 if (it->utype == V_ASN1_ANY) { 789 if (!*pval) { 790 typ = ASN1_TYPE_new(); 791 if (typ == NULL) 792 goto err; 793 *pval = (ASN1_VALUE *)typ; 794 } else 795 typ = (ASN1_TYPE *)*pval; 796 797 if (utype != typ->type) 798 ASN1_TYPE_set(typ, utype, NULL); 799 opval = pval; 800 pval = &typ->value.asn1_value; 801 } 802 switch (utype) { 803 case V_ASN1_OBJECT: 804 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 805 goto err; 806 break; 807 808 case V_ASN1_NULL: 809 if (len) { 810 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH); 811 goto err; 812 } 813 *pval = (ASN1_VALUE *)1; 814 break; 815 816 case V_ASN1_BOOLEAN: 817 if (len != 1) { 818 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 819 goto err; 820 } else { 821 ASN1_BOOLEAN *tbool; 822 tbool = (ASN1_BOOLEAN *)pval; 823 *tbool = *cont; 824 } 825 break; 826 827 case V_ASN1_BIT_STRING: 828 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 829 goto err; 830 break; 831 832 case V_ASN1_INTEGER: 833 case V_ASN1_ENUMERATED: 834 tint = (ASN1_INTEGER **)pval; 835 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 836 goto err; 837 /* Fixup type to match the expected form */ 838 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 839 break; 840 841 case V_ASN1_OCTET_STRING: 842 case V_ASN1_NUMERICSTRING: 843 case V_ASN1_PRINTABLESTRING: 844 case V_ASN1_T61STRING: 845 case V_ASN1_VIDEOTEXSTRING: 846 case V_ASN1_IA5STRING: 847 case V_ASN1_UTCTIME: 848 case V_ASN1_GENERALIZEDTIME: 849 case V_ASN1_GRAPHICSTRING: 850 case V_ASN1_VISIBLESTRING: 851 case V_ASN1_GENERALSTRING: 852 case V_ASN1_UNIVERSALSTRING: 853 case V_ASN1_BMPSTRING: 854 case V_ASN1_UTF8STRING: 855 case V_ASN1_OTHER: 856 case V_ASN1_SET: 857 case V_ASN1_SEQUENCE: 858 default: 859 if (utype == V_ASN1_BMPSTRING && (len & 1)) { 860 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 861 goto err; 862 } 863 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { 864 ASN1err(ASN1_F_ASN1_EX_C2I, 865 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 866 goto err; 867 } 868 /* All based on ASN1_STRING and handled the same */ 869 if (!*pval) { 870 stmp = ASN1_STRING_type_new(utype); 871 if (stmp == NULL) { 872 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 873 goto err; 874 } 875 *pval = (ASN1_VALUE *)stmp; 876 } else { 877 stmp = (ASN1_STRING *)*pval; 878 stmp->type = utype; 879 } 880 /* If we've already allocated a buffer use it */ 881 if (*free_cont) { 882 OPENSSL_free(stmp->data); 883 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 884 stmp->length = len; 885 *free_cont = 0; 886 } else { 887 if (!ASN1_STRING_set(stmp, cont, len)) { 888 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 889 ASN1_STRING_free(stmp); 890 *pval = NULL; 891 goto err; 892 } 893 } 894 break; 895 } 896 /* If ASN1_ANY and NULL type fix up value */ 897 if (typ && (utype == V_ASN1_NULL)) 898 typ->value.ptr = NULL; 899 900 ret = 1; 901 err: 902 if (!ret) { 903 ASN1_TYPE_free(typ); 904 if (opval) 905 *opval = NULL; 906 } 907 return ret; 908 } 909 910 /* 911 * This function finds the end of an ASN1 structure when passed its maximum 912 * length, whether it is indefinite length and a pointer to the content. This 913 * is more efficient than calling asn1_collect because it does not recurse on 914 * each indefinite length header. 915 */ 916 917 static int asn1_find_end(const unsigned char **in, long len, char inf) 918 { 919 uint32_t expected_eoc; 920 long plen; 921 const unsigned char *p = *in, *q; 922 /* If not indefinite length constructed just add length */ 923 if (inf == 0) { 924 *in += len; 925 return 1; 926 } 927 expected_eoc = 1; 928 /* 929 * Indefinite length constructed form. Find the end when enough EOCs are 930 * found. If more indefinite length constructed headers are encountered 931 * increment the expected eoc count otherwise just skip to the end of the 932 * data. 933 */ 934 while (len > 0) { 935 if (asn1_check_eoc(&p, len)) { 936 expected_eoc--; 937 if (expected_eoc == 0) 938 break; 939 len -= 2; 940 continue; 941 } 942 q = p; 943 /* Just read in a header: only care about the length */ 944 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 945 -1, 0, 0, NULL)) { 946 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 947 return 0; 948 } 949 if (inf) { 950 if (expected_eoc == UINT32_MAX) { 951 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 952 return 0; 953 } 954 expected_eoc++; 955 } else { 956 p += plen; 957 } 958 len -= p - q; 959 } 960 if (expected_eoc) { 961 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 962 return 0; 963 } 964 *in = p; 965 return 1; 966 } 967 968 /* 969 * This function collects the asn1 data from a constructed string type into 970 * a buffer. The values of 'in' and 'len' should refer to the contents of the 971 * constructed type and 'inf' should be set if it is indefinite length. 972 */ 973 974 #ifndef ASN1_MAX_STRING_NEST 975 /* 976 * This determines how many levels of recursion are permitted in ASN1 string 977 * types. If it is not limited stack overflows can occur. If set to zero no 978 * recursion is allowed at all. Although zero should be adequate examples 979 * exist that require a value of 1. So 5 should be more than enough. 980 */ 981 # define ASN1_MAX_STRING_NEST 5 982 #endif 983 984 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 985 char inf, int tag, int aclass, int depth) 986 { 987 const unsigned char *p, *q; 988 long plen; 989 char cst, ininf; 990 p = *in; 991 inf &= 1; 992 /* 993 * If no buffer and not indefinite length constructed just pass over the 994 * encoded data 995 */ 996 if (!buf && !inf) { 997 *in += len; 998 return 1; 999 } 1000 while (len > 0) { 1001 q = p; 1002 /* Check for EOC */ 1003 if (asn1_check_eoc(&p, len)) { 1004 /* 1005 * EOC is illegal outside indefinite length constructed form 1006 */ 1007 if (!inf) { 1008 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC); 1009 return 0; 1010 } 1011 inf = 0; 1012 break; 1013 } 1014 1015 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1016 len, tag, aclass, 0, NULL)) { 1017 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1018 return 0; 1019 } 1020 1021 /* If indefinite length constructed update max length */ 1022 if (cst) { 1023 if (depth >= ASN1_MAX_STRING_NEST) { 1024 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); 1025 return 0; 1026 } 1027 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1028 return 0; 1029 } else if (plen && !collect_data(buf, &p, plen)) 1030 return 0; 1031 len -= p - q; 1032 } 1033 if (inf) { 1034 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1035 return 0; 1036 } 1037 *in = p; 1038 return 1; 1039 } 1040 1041 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1042 { 1043 int len; 1044 if (buf) { 1045 len = buf->length; 1046 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1047 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1048 return 0; 1049 } 1050 memcpy(buf->data + len, *p, plen); 1051 } 1052 *p += plen; 1053 return 1; 1054 } 1055 1056 /* Check for ASN1 EOC and swallow it if found */ 1057 1058 static int asn1_check_eoc(const unsigned char **in, long len) 1059 { 1060 const unsigned char *p; 1061 if (len < 2) 1062 return 0; 1063 p = *in; 1064 if (!p[0] && !p[1]) { 1065 *in += 2; 1066 return 1; 1067 } 1068 return 0; 1069 } 1070 1071 /* 1072 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1073 * length for indefinite length constructed form, we don't know the exact 1074 * length but we can set an upper bound to the amount of data available minus 1075 * the header length just read. 1076 */ 1077 1078 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1079 char *inf, char *cst, 1080 const unsigned char **in, long len, 1081 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1082 { 1083 int i; 1084 int ptag, pclass; 1085 long plen; 1086 const unsigned char *p, *q; 1087 p = *in; 1088 q = p; 1089 1090 if (ctx && ctx->valid) { 1091 i = ctx->ret; 1092 plen = ctx->plen; 1093 pclass = ctx->pclass; 1094 ptag = ctx->ptag; 1095 p += ctx->hdrlen; 1096 } else { 1097 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1098 if (ctx) { 1099 ctx->ret = i; 1100 ctx->plen = plen; 1101 ctx->pclass = pclass; 1102 ctx->ptag = ptag; 1103 ctx->hdrlen = p - q; 1104 ctx->valid = 1; 1105 /* 1106 * If definite length, and no error, length + header can't exceed 1107 * total amount of data available. 1108 */ 1109 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { 1110 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG); 1111 asn1_tlc_clear(ctx); 1112 return 0; 1113 } 1114 } 1115 } 1116 1117 if (i & 0x80) { 1118 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1119 asn1_tlc_clear(ctx); 1120 return 0; 1121 } 1122 if (exptag >= 0) { 1123 if ((exptag != ptag) || (expclass != pclass)) { 1124 /* 1125 * If type is OPTIONAL, not an error: indicate missing type. 1126 */ 1127 if (opt) 1128 return -1; 1129 asn1_tlc_clear(ctx); 1130 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1131 return 0; 1132 } 1133 /* 1134 * We have a tag and class match: assume we are going to do something 1135 * with it 1136 */ 1137 asn1_tlc_clear(ctx); 1138 } 1139 1140 if (i & 1) 1141 plen = len - (p - q); 1142 1143 if (inf) 1144 *inf = i & 1; 1145 1146 if (cst) 1147 *cst = i & V_ASN1_CONSTRUCTED; 1148 1149 if (olen) 1150 *olen = plen; 1151 1152 if (oclass) 1153 *oclass = pclass; 1154 1155 if (otag) 1156 *otag = ptag; 1157 1158 *in = p; 1159 return 1; 1160 } 1161