tasn_dec.c revision 280275
1/* tasn_dec.c */ 2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2000. 4 */ 5/* ==================================================================== 6 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 60#include <stddef.h> 61#include <string.h> 62#include <openssl/asn1.h> 63#include <openssl/asn1t.h> 64#include <openssl/objects.h> 65#include <openssl/buffer.h> 66#include <openssl/err.h> 67 68static int asn1_check_eoc(const unsigned char **in, long len); 69static int asn1_find_end(const unsigned char **in, long len, char inf); 70 71static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 72 char inf, int tag, int aclass, int depth); 73 74static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen); 75 76static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 77 char *inf, char *cst, 78 const unsigned char **in, long len, 79 int exptag, int expclass, char opt, 80 ASN1_TLC *ctx); 81 82static int asn1_template_ex_d2i(ASN1_VALUE **pval, 83 const unsigned char **in, long len, 84 const ASN1_TEMPLATE *tt, char opt, 85 ASN1_TLC *ctx); 86static int asn1_template_noexp_d2i(ASN1_VALUE **val, 87 const unsigned char **in, long len, 88 const ASN1_TEMPLATE *tt, char opt, 89 ASN1_TLC *ctx); 90static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 91 const unsigned char **in, long len, 92 const ASN1_ITEM *it, 93 int tag, int aclass, char opt, ASN1_TLC *ctx); 94 95/* Table to convert tags to bit values, used for MSTRING type */ 96static const unsigned long tag2bit[32] = { 970, 0, 0, B_ASN1_BIT_STRING, /* tags 0 - 3 */ 98B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,/* tags 4- 7 */ 99B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags 8-11 */ 100B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */ 101B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */ 102B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING, /* tags 20-22 */ 103B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, /* tags 23-24 */ 104B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING, /* tags 25-27 */ 105B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */ 106 }; 107 108unsigned long ASN1_tag2bit(int tag) 109 { 110 if ((tag < 0) || (tag > 30)) return 0; 111 return tag2bit[tag]; 112 } 113 114/* Macro to initialize and invalidate the cache */ 115 116#define asn1_tlc_clear(c) if (c) (c)->valid = 0 117 118/* Decode an ASN1 item, this currently behaves just 119 * like a standard 'd2i' function. 'in' points to 120 * a buffer to read the data from, in future we will 121 * have more advanced versions that can input data 122 * a piece at a time and this will simply be a special 123 * case. 124 */ 125 126ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, 127 const unsigned char **in, long len, const ASN1_ITEM *it) 128 { 129 ASN1_TLC c; 130 ASN1_VALUE *ptmpval = NULL; 131 if (!pval) 132 pval = &ptmpval; 133 c.valid = 0; 134 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 135 return *pval; 136 return NULL; 137 } 138 139int ASN1_template_d2i(ASN1_VALUE **pval, 140 const unsigned char **in, long len, const ASN1_TEMPLATE *tt) 141 { 142 ASN1_TLC c; 143 c.valid = 0; 144 return asn1_template_ex_d2i(pval, in, len, tt, 0, &c); 145 } 146 147 148/* Decode an item, taking care of IMPLICIT tagging, if any. 149 * If 'opt' set and tag mismatch return -1 to handle OPTIONAL 150 */ 151 152int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, 153 const ASN1_ITEM *it, 154 int tag, int aclass, char opt, ASN1_TLC *ctx) 155 { 156 const ASN1_TEMPLATE *tt, *errtt = NULL; 157 const ASN1_COMPAT_FUNCS *cf; 158 const ASN1_EXTERN_FUNCS *ef; 159 const ASN1_AUX *aux = it->funcs; 160 ASN1_aux_cb *asn1_cb; 161 const unsigned char *p = NULL, *q; 162 unsigned char *wp=NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */ 163 unsigned char imphack = 0, oclass; 164 char seq_eoc, seq_nolen, cst, isopt; 165 long tmplen; 166 int i; 167 int otag; 168 int ret = 0; 169 ASN1_VALUE **pchptr, *ptmpval; 170 if (!pval) 171 return 0; 172 if (aux && aux->asn1_cb) 173 asn1_cb = aux->asn1_cb; 174 else asn1_cb = 0; 175 176 switch(it->itype) 177 { 178 case ASN1_ITYPE_PRIMITIVE: 179 if (it->templates) 180 { 181 /* tagging or OPTIONAL is currently illegal on an item 182 * template because the flags can't get passed down. 183 * In practice this isn't a problem: we include the 184 * relevant flags from the item template in the 185 * template itself. 186 */ 187 if ((tag != -1) || opt) 188 { 189 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 190 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 191 goto err; 192 } 193 return asn1_template_ex_d2i(pval, in, len, 194 it->templates, opt, ctx); 195 } 196 return asn1_d2i_ex_primitive(pval, in, len, it, 197 tag, aclass, opt, ctx); 198 break; 199 200 case ASN1_ITYPE_MSTRING: 201 p = *in; 202 /* Just read in tag and class */ 203 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 204 &p, len, -1, 0, 1, ctx); 205 if (!ret) 206 { 207 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 208 ERR_R_NESTED_ASN1_ERROR); 209 goto err; 210 } 211 212 /* Must be UNIVERSAL class */ 213 if (oclass != V_ASN1_UNIVERSAL) 214 { 215 /* If OPTIONAL, assume this is OK */ 216 if (opt) return -1; 217 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 218 ASN1_R_MSTRING_NOT_UNIVERSAL); 219 goto err; 220 } 221 /* Check tag matches bit map */ 222 if (!(ASN1_tag2bit(otag) & it->utype)) 223 { 224 /* If OPTIONAL, assume this is OK */ 225 if (opt) 226 return -1; 227 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 228 ASN1_R_MSTRING_WRONG_TAG); 229 goto err; 230 } 231 return asn1_d2i_ex_primitive(pval, in, len, 232 it, otag, 0, 0, ctx); 233 234 case ASN1_ITYPE_EXTERN: 235 /* Use new style d2i */ 236 ef = it->funcs; 237 return ef->asn1_ex_d2i(pval, in, len, 238 it, tag, aclass, opt, ctx); 239 240 case ASN1_ITYPE_COMPAT: 241 /* we must resort to old style evil hackery */ 242 cf = it->funcs; 243 244 /* If OPTIONAL see if it is there */ 245 if (opt) 246 { 247 int exptag; 248 p = *in; 249 if (tag == -1) 250 exptag = it->utype; 251 else exptag = tag; 252 /* Don't care about anything other than presence 253 * of expected tag */ 254 255 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL, 256 &p, len, exptag, aclass, 1, ctx); 257 if (!ret) 258 { 259 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 260 ERR_R_NESTED_ASN1_ERROR); 261 goto err; 262 } 263 if (ret == -1) 264 return -1; 265 } 266 267 /* This is the old style evil hack IMPLICIT handling: 268 * since the underlying code is expecting a tag and 269 * class other than the one present we change the 270 * buffer temporarily then change it back afterwards. 271 * This doesn't and never did work for tags > 30. 272 * 273 * Yes this is *horrible* but it is only needed for 274 * old style d2i which will hopefully not be around 275 * for much longer. 276 * FIXME: should copy the buffer then modify it so 277 * the input buffer can be const: we should *always* 278 * copy because the old style d2i might modify the 279 * buffer. 280 */ 281 282 if (tag != -1) 283 { 284 wp = *(unsigned char **)in; 285 imphack = *wp; 286 if (p == NULL) 287 { 288 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 289 ERR_R_NESTED_ASN1_ERROR); 290 goto err; 291 } 292 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED) 293 | it->utype); 294 } 295 296 ptmpval = cf->asn1_d2i(pval, in, len); 297 298 if (tag != -1) 299 *wp = imphack; 300 301 if (ptmpval) 302 return 1; 303 304 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 305 goto err; 306 307 308 case ASN1_ITYPE_CHOICE: 309 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it)) 310 goto auxerr; 311 312 if (*pval) { 313 /* Free up and zero CHOICE value if initialised */ 314 i = asn1_get_choice_selector(pval, it); 315 if ((i >= 0) && (i < it->tcount)) { 316 tt = it->templates + i; 317 pchptr = asn1_get_field_ptr(pval, tt); 318 ASN1_template_free(pchptr, tt); 319 asn1_set_choice_selector(pval, -1, it); 320 } 321 } else if (!ASN1_item_ex_new(pval, it)) { 322 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 323 ERR_R_NESTED_ASN1_ERROR); 324 goto err; 325 } 326 /* CHOICE type, try each possibility in turn */ 327 p = *in; 328 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++) 329 { 330 pchptr = asn1_get_field_ptr(pval, tt); 331 /* We mark field as OPTIONAL so its absence 332 * can be recognised. 333 */ 334 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx); 335 /* If field not present, try the next one */ 336 if (ret == -1) 337 continue; 338 /* If positive return, read OK, break loop */ 339 if (ret > 0) 340 break; 341 /* Otherwise must be an ASN1 parsing error */ 342 errtt = tt; 343 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 344 ERR_R_NESTED_ASN1_ERROR); 345 goto err; 346 } 347 348 /* Did we fall off the end without reading anything? */ 349 if (i == it->tcount) 350 { 351 /* If OPTIONAL, this is OK */ 352 if (opt) 353 { 354 /* Free and zero it */ 355 ASN1_item_ex_free(pval, it); 356 return -1; 357 } 358 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 359 ASN1_R_NO_MATCHING_CHOICE_TYPE); 360 goto err; 361 } 362 363 asn1_set_choice_selector(pval, i, it); 364 *in = p; 365 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it)) 366 goto auxerr; 367 return 1; 368 369 case ASN1_ITYPE_NDEF_SEQUENCE: 370 case ASN1_ITYPE_SEQUENCE: 371 p = *in; 372 tmplen = len; 373 374 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 375 if (tag == -1) 376 { 377 tag = V_ASN1_SEQUENCE; 378 aclass = V_ASN1_UNIVERSAL; 379 } 380 /* Get SEQUENCE length and update len, p */ 381 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 382 &p, len, tag, aclass, opt, ctx); 383 if (!ret) 384 { 385 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 386 ERR_R_NESTED_ASN1_ERROR); 387 goto err; 388 } 389 else if (ret == -1) 390 return -1; 391 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) 392 { 393 len = tmplen - (p - *in); 394 seq_nolen = 1; 395 } 396 /* If indefinite we don't do a length check */ 397 else seq_nolen = seq_eoc; 398 if (!cst) 399 { 400 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 401 ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 402 goto err; 403 } 404 405 if (!*pval && !ASN1_item_ex_new(pval, it)) 406 { 407 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 408 ERR_R_NESTED_ASN1_ERROR); 409 goto err; 410 } 411 412 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it)) 413 goto auxerr; 414 415 /* Free up and zero any ADB found */ 416 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 417 if (tt->flags & ASN1_TFLG_ADB_MASK) { 418 const ASN1_TEMPLATE *seqtt; 419 ASN1_VALUE **pseqval; 420 seqtt = asn1_do_adb(pval, tt, 1); 421 pseqval = asn1_get_field_ptr(pval, seqtt); 422 ASN1_template_free(pseqval, seqtt); 423 } 424 } 425 426 /* Get each field entry */ 427 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) 428 { 429 const ASN1_TEMPLATE *seqtt; 430 ASN1_VALUE **pseqval; 431 seqtt = asn1_do_adb(pval, tt, 1); 432 if (!seqtt) 433 goto err; 434 pseqval = asn1_get_field_ptr(pval, seqtt); 435 /* Have we ran out of data? */ 436 if (!len) 437 break; 438 q = p; 439 if (asn1_check_eoc(&p, len)) 440 { 441 if (!seq_eoc) 442 { 443 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 444 ASN1_R_UNEXPECTED_EOC); 445 goto err; 446 } 447 len -= p - q; 448 seq_eoc = 0; 449 q = p; 450 break; 451 } 452 /* This determines the OPTIONAL flag value. The field 453 * cannot be omitted if it is the last of a SEQUENCE 454 * and there is still data to be read. This isn't 455 * strictly necessary but it increases efficiency in 456 * some cases. 457 */ 458 if (i == (it->tcount - 1)) 459 isopt = 0; 460 else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 461 /* attempt to read in field, allowing each to be 462 * OPTIONAL */ 463 464 ret = asn1_template_ex_d2i(pseqval, &p, len, 465 seqtt, isopt, ctx); 466 if (!ret) 467 { 468 errtt = seqtt; 469 goto err; 470 } 471 else if (ret == -1) 472 { 473 /* OPTIONAL component absent. 474 * Free and zero the field. 475 */ 476 ASN1_template_free(pseqval, seqtt); 477 continue; 478 } 479 /* Update length */ 480 len -= p - q; 481 } 482 483 /* Check for EOC if expecting one */ 484 if (seq_eoc && !asn1_check_eoc(&p, len)) 485 { 486 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC); 487 goto err; 488 } 489 /* Check all data read */ 490 if (!seq_nolen && len) 491 { 492 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 493 ASN1_R_SEQUENCE_LENGTH_MISMATCH); 494 goto err; 495 } 496 497 /* If we get here we've got no more data in the SEQUENCE, 498 * however we may not have read all fields so check all 499 * remaining are OPTIONAL and clear any that are. 500 */ 501 for (; i < it->tcount; tt++, i++) 502 { 503 const ASN1_TEMPLATE *seqtt; 504 seqtt = asn1_do_adb(pval, tt, 1); 505 if (!seqtt) 506 goto err; 507 if (seqtt->flags & ASN1_TFLG_OPTIONAL) 508 { 509 ASN1_VALUE **pseqval; 510 pseqval = asn1_get_field_ptr(pval, seqtt); 511 ASN1_template_free(pseqval, seqtt); 512 } 513 else 514 { 515 errtt = seqtt; 516 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 517 ASN1_R_FIELD_MISSING); 518 goto err; 519 } 520 } 521 /* Save encoding */ 522 if (!asn1_enc_save(pval, *in, p - *in, it)) 523 goto auxerr; 524 *in = p; 525 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it)) 526 goto auxerr; 527 return 1; 528 529 default: 530 return 0; 531 } 532 auxerr: 533 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR); 534 err: 535 ASN1_item_ex_free(pval, it); 536 if (errtt) 537 ERR_add_error_data(4, "Field=", errtt->field_name, 538 ", Type=", it->sname); 539 else 540 ERR_add_error_data(2, "Type=", it->sname); 541 return 0; 542 } 543 544/* Templates are handled with two separate functions. 545 * One handles any EXPLICIT tag and the other handles the rest. 546 */ 547 548static int asn1_template_ex_d2i(ASN1_VALUE **val, 549 const unsigned char **in, long inlen, 550 const ASN1_TEMPLATE *tt, char opt, 551 ASN1_TLC *ctx) 552 { 553 int flags, aclass; 554 int ret; 555 long len; 556 const unsigned char *p, *q; 557 char exp_eoc; 558 if (!val) 559 return 0; 560 flags = tt->flags; 561 aclass = flags & ASN1_TFLG_TAG_CLASS; 562 563 p = *in; 564 565 /* Check if EXPLICIT tag expected */ 566 if (flags & ASN1_TFLG_EXPTAG) 567 { 568 char cst; 569 /* Need to work out amount of data available to the inner 570 * content and where it starts: so read in EXPLICIT header to 571 * get the info. 572 */ 573 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 574 &p, inlen, tt->tag, aclass, opt, ctx); 575 q = p; 576 if (!ret) 577 { 578 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 579 ERR_R_NESTED_ASN1_ERROR); 580 return 0; 581 } 582 else if (ret == -1) 583 return -1; 584 if (!cst) 585 { 586 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 587 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 588 return 0; 589 } 590 /* We've found the field so it can't be OPTIONAL now */ 591 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 592 if (!ret) 593 { 594 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 595 ERR_R_NESTED_ASN1_ERROR); 596 return 0; 597 } 598 /* We read the field in OK so update length */ 599 len -= p - q; 600 if (exp_eoc) 601 { 602 /* If NDEF we must have an EOC here */ 603 if (!asn1_check_eoc(&p, len)) 604 { 605 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 606 ASN1_R_MISSING_EOC); 607 goto err; 608 } 609 } 610 else 611 { 612 /* Otherwise we must hit the EXPLICIT tag end or its 613 * an error */ 614 if (len) 615 { 616 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 617 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 618 goto err; 619 } 620 } 621 } 622 else 623 return asn1_template_noexp_d2i(val, in, inlen, 624 tt, opt, ctx); 625 626 *in = p; 627 return 1; 628 629 err: 630 ASN1_template_free(val, tt); 631 return 0; 632 } 633 634static int asn1_template_noexp_d2i(ASN1_VALUE **val, 635 const unsigned char **in, long len, 636 const ASN1_TEMPLATE *tt, char opt, 637 ASN1_TLC *ctx) 638 { 639 int flags, aclass; 640 int ret; 641 const unsigned char *p, *q; 642 if (!val) 643 return 0; 644 flags = tt->flags; 645 aclass = flags & ASN1_TFLG_TAG_CLASS; 646 647 p = *in; 648 q = p; 649 650 if (flags & ASN1_TFLG_SK_MASK) 651 { 652 /* SET OF, SEQUENCE OF */ 653 int sktag, skaclass; 654 char sk_eoc; 655 /* First work out expected inner tag value */ 656 if (flags & ASN1_TFLG_IMPTAG) 657 { 658 sktag = tt->tag; 659 skaclass = aclass; 660 } 661 else 662 { 663 skaclass = V_ASN1_UNIVERSAL; 664 if (flags & ASN1_TFLG_SET_OF) 665 sktag = V_ASN1_SET; 666 else 667 sktag = V_ASN1_SEQUENCE; 668 } 669 /* Get the tag */ 670 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 671 &p, len, sktag, skaclass, opt, ctx); 672 if (!ret) 673 { 674 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 675 ERR_R_NESTED_ASN1_ERROR); 676 return 0; 677 } 678 else if (ret == -1) 679 return -1; 680 if (!*val) 681 *val = (ASN1_VALUE *)sk_new_null(); 682 else 683 { 684 /* We've got a valid STACK: free up any items present */ 685 STACK *sktmp = (STACK *)*val; 686 ASN1_VALUE *vtmp; 687 while(sk_num(sktmp) > 0) 688 { 689 vtmp = (ASN1_VALUE *)sk_pop(sktmp); 690 ASN1_item_ex_free(&vtmp, 691 ASN1_ITEM_ptr(tt->item)); 692 } 693 } 694 695 if (!*val) 696 { 697 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 698 ERR_R_MALLOC_FAILURE); 699 goto err; 700 } 701 702 /* Read as many items as we can */ 703 while(len > 0) 704 { 705 ASN1_VALUE *skfield; 706 q = p; 707 /* See if EOC found */ 708 if (asn1_check_eoc(&p, len)) 709 { 710 if (!sk_eoc) 711 { 712 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 713 ASN1_R_UNEXPECTED_EOC); 714 goto err; 715 } 716 len -= p - q; 717 sk_eoc = 0; 718 break; 719 } 720 skfield = NULL; 721 if (!ASN1_item_ex_d2i(&skfield, &p, len, 722 ASN1_ITEM_ptr(tt->item), 723 -1, 0, 0, ctx)) 724 { 725 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 726 ERR_R_NESTED_ASN1_ERROR); 727 goto err; 728 } 729 len -= p - q; 730 if (!sk_push((STACK *)*val, (char *)skfield)) 731 { 732 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 733 ERR_R_MALLOC_FAILURE); 734 goto err; 735 } 736 } 737 if (sk_eoc) 738 { 739 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 740 goto err; 741 } 742 } 743 else if (flags & ASN1_TFLG_IMPTAG) 744 { 745 /* IMPLICIT tagging */ 746 ret = ASN1_item_ex_d2i(val, &p, len, 747 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx); 748 if (!ret) 749 { 750 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 751 ERR_R_NESTED_ASN1_ERROR); 752 goto err; 753 } 754 else if (ret == -1) 755 return -1; 756 } 757 else 758 { 759 /* Nothing special */ 760 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 761 -1, 0, opt, ctx); 762 if (!ret) 763 { 764 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 765 ERR_R_NESTED_ASN1_ERROR); 766 goto err; 767 } 768 else if (ret == -1) 769 return -1; 770 } 771 772 *in = p; 773 return 1; 774 775 err: 776 ASN1_template_free(val, tt); 777 return 0; 778 } 779 780static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 781 const unsigned char **in, long inlen, 782 const ASN1_ITEM *it, 783 int tag, int aclass, char opt, ASN1_TLC *ctx) 784 { 785 int ret = 0, utype; 786 long plen; 787 char cst, inf, free_cont = 0; 788 const unsigned char *p; 789 BUF_MEM buf; 790 const unsigned char *cont = NULL; 791 long len; 792 if (!pval) 793 { 794 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 795 return 0; /* Should never happen */ 796 } 797 798 if (it->itype == ASN1_ITYPE_MSTRING) 799 { 800 utype = tag; 801 tag = -1; 802 } 803 else 804 utype = it->utype; 805 806 if (utype == V_ASN1_ANY) 807 { 808 /* If type is ANY need to figure out type from tag */ 809 unsigned char oclass; 810 if (tag >= 0) 811 { 812 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 813 ASN1_R_ILLEGAL_TAGGED_ANY); 814 return 0; 815 } 816 if (opt) 817 { 818 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 819 ASN1_R_ILLEGAL_OPTIONAL_ANY); 820 return 0; 821 } 822 p = *in; 823 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 824 &p, inlen, -1, 0, 0, ctx); 825 if (!ret) 826 { 827 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 828 ERR_R_NESTED_ASN1_ERROR); 829 return 0; 830 } 831 if (oclass != V_ASN1_UNIVERSAL) 832 utype = V_ASN1_OTHER; 833 } 834 if (tag == -1) 835 { 836 tag = utype; 837 aclass = V_ASN1_UNIVERSAL; 838 } 839 p = *in; 840 /* Check header */ 841 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 842 &p, inlen, tag, aclass, opt, ctx); 843 if (!ret) 844 { 845 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 846 return 0; 847 } 848 else if (ret == -1) 849 return -1; 850 ret = 0; 851 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 852 if ((utype == V_ASN1_SEQUENCE) 853 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) 854 { 855 /* Clear context cache for type OTHER because the auto clear 856 * when we have a exact match wont work 857 */ 858 if (utype == V_ASN1_OTHER) 859 { 860 asn1_tlc_clear(ctx); 861 } 862 /* SEQUENCE and SET must be constructed */ 863 else if (!cst) 864 { 865 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 866 ASN1_R_TYPE_NOT_CONSTRUCTED); 867 return 0; 868 } 869 870 cont = *in; 871 /* If indefinite length constructed find the real end */ 872 if (inf) 873 { 874 if (!asn1_find_end(&p, plen, inf)) 875 goto err; 876 len = p - cont; 877 } 878 else 879 { 880 len = p - cont + plen; 881 p += plen; 882 buf.data = NULL; 883 } 884 } 885 else if (cst) 886 { 887 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 888 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 889 || utype == V_ASN1_ENUMERATED) 890 { 891 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 892 ASN1_R_TYPE_NOT_PRIMITIVE); 893 return 0; 894 } 895 buf.length = 0; 896 buf.max = 0; 897 buf.data = NULL; 898 /* Should really check the internal tags are correct but 899 * some things may get this wrong. The relevant specs 900 * say that constructed string types should be OCTET STRINGs 901 * internally irrespective of the type. So instead just check 902 * for UNIVERSAL class and ignore the tag. 903 */ 904 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) 905 { 906 free_cont = 1; 907 goto err; 908 } 909 len = buf.length; 910 /* Append a final null to string */ 911 if (!BUF_MEM_grow_clean(&buf, len + 1)) 912 { 913 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 914 ERR_R_MALLOC_FAILURE); 915 return 0; 916 } 917 buf.data[len] = 0; 918 cont = (const unsigned char *)buf.data; 919 free_cont = 1; 920 } 921 else 922 { 923 cont = p; 924 len = plen; 925 p += plen; 926 } 927 928 /* We now have content length and type: translate into a structure */ 929 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 930 goto err; 931 932 *in = p; 933 ret = 1; 934 err: 935 if (free_cont && buf.data) OPENSSL_free(buf.data); 936 return ret; 937 } 938 939/* Translate ASN1 content octets into a structure */ 940 941int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 942 int utype, char *free_cont, const ASN1_ITEM *it) 943 { 944 ASN1_VALUE **opval = NULL; 945 ASN1_STRING *stmp; 946 ASN1_TYPE *typ = NULL; 947 int ret = 0; 948 const ASN1_PRIMITIVE_FUNCS *pf; 949 ASN1_INTEGER **tint; 950 pf = it->funcs; 951 952 if (pf && pf->prim_c2i) 953 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 954 /* If ANY type clear type and set pointer to internal value */ 955 if (it->utype == V_ASN1_ANY) 956 { 957 if (!*pval) 958 { 959 typ = ASN1_TYPE_new(); 960 if (typ == NULL) 961 goto err; 962 *pval = (ASN1_VALUE *)typ; 963 } 964 else 965 typ = (ASN1_TYPE *)*pval; 966 967 if (utype != typ->type) 968 ASN1_TYPE_set(typ, utype, NULL); 969 opval = pval; 970 pval = &typ->value.asn1_value; 971 } 972 switch(utype) 973 { 974 case V_ASN1_OBJECT: 975 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 976 goto err; 977 break; 978 979 case V_ASN1_NULL: 980 if (len) 981 { 982 ASN1err(ASN1_F_ASN1_EX_C2I, 983 ASN1_R_NULL_IS_WRONG_LENGTH); 984 goto err; 985 } 986 *pval = (ASN1_VALUE *)1; 987 break; 988 989 case V_ASN1_BOOLEAN: 990 if (len != 1) 991 { 992 ASN1err(ASN1_F_ASN1_EX_C2I, 993 ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 994 goto err; 995 } 996 else 997 { 998 ASN1_BOOLEAN *tbool; 999 tbool = (ASN1_BOOLEAN *)pval; 1000 *tbool = *cont; 1001 } 1002 break; 1003 1004 case V_ASN1_BIT_STRING: 1005 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 1006 goto err; 1007 break; 1008 1009 case V_ASN1_INTEGER: 1010 case V_ASN1_NEG_INTEGER: 1011 case V_ASN1_ENUMERATED: 1012 case V_ASN1_NEG_ENUMERATED: 1013 tint = (ASN1_INTEGER **)pval; 1014 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 1015 goto err; 1016 /* Fixup type to match the expected form */ 1017 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 1018 break; 1019 1020 case V_ASN1_OCTET_STRING: 1021 case V_ASN1_NUMERICSTRING: 1022 case V_ASN1_PRINTABLESTRING: 1023 case V_ASN1_T61STRING: 1024 case V_ASN1_VIDEOTEXSTRING: 1025 case V_ASN1_IA5STRING: 1026 case V_ASN1_UTCTIME: 1027 case V_ASN1_GENERALIZEDTIME: 1028 case V_ASN1_GRAPHICSTRING: 1029 case V_ASN1_VISIBLESTRING: 1030 case V_ASN1_GENERALSTRING: 1031 case V_ASN1_UNIVERSALSTRING: 1032 case V_ASN1_BMPSTRING: 1033 case V_ASN1_UTF8STRING: 1034 case V_ASN1_OTHER: 1035 case V_ASN1_SET: 1036 case V_ASN1_SEQUENCE: 1037 default: 1038 if (utype == V_ASN1_BMPSTRING && (len & 1)) 1039 { 1040 ASN1err(ASN1_F_ASN1_EX_C2I, 1041 ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 1042 goto err; 1043 } 1044 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) 1045 { 1046 ASN1err(ASN1_F_ASN1_EX_C2I, 1047 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 1048 goto err; 1049 } 1050 /* All based on ASN1_STRING and handled the same */ 1051 if (!*pval) 1052 { 1053 stmp = ASN1_STRING_type_new(utype); 1054 if (!stmp) 1055 { 1056 ASN1err(ASN1_F_ASN1_EX_C2I, 1057 ERR_R_MALLOC_FAILURE); 1058 goto err; 1059 } 1060 *pval = (ASN1_VALUE *)stmp; 1061 } 1062 else 1063 { 1064 stmp = (ASN1_STRING *)*pval; 1065 stmp->type = utype; 1066 } 1067 /* If we've already allocated a buffer use it */ 1068 if (*free_cont) 1069 { 1070 if (stmp->data) 1071 OPENSSL_free(stmp->data); 1072 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 1073 stmp->length = len; 1074 *free_cont = 0; 1075 } 1076 else 1077 { 1078 if (!ASN1_STRING_set(stmp, cont, len)) 1079 { 1080 ASN1err(ASN1_F_ASN1_EX_C2I, 1081 ERR_R_MALLOC_FAILURE); 1082 ASN1_STRING_free(stmp); 1083 *pval = NULL; 1084 goto err; 1085 } 1086 } 1087 break; 1088 } 1089 /* If ASN1_ANY and NULL type fix up value */ 1090 if (typ && (utype == V_ASN1_NULL)) 1091 typ->value.ptr = NULL; 1092 1093 ret = 1; 1094 err: 1095 if (!ret) 1096 { 1097 ASN1_TYPE_free(typ); 1098 if (opval) 1099 *opval = NULL; 1100 } 1101 return ret; 1102 } 1103 1104 1105/* This function finds the end of an ASN1 structure when passed its maximum 1106 * length, whether it is indefinite length and a pointer to the content. 1107 * This is more efficient than calling asn1_collect because it does not 1108 * recurse on each indefinite length header. 1109 */ 1110 1111static int asn1_find_end(const unsigned char **in, long len, char inf) 1112 { 1113 int expected_eoc; 1114 long plen; 1115 const unsigned char *p = *in, *q; 1116 /* If not indefinite length constructed just add length */ 1117 if (inf == 0) 1118 { 1119 *in += len; 1120 return 1; 1121 } 1122 expected_eoc = 1; 1123 /* Indefinite length constructed form. Find the end when enough EOCs 1124 * are found. If more indefinite length constructed headers 1125 * are encountered increment the expected eoc count otherwise just 1126 * skip to the end of the data. 1127 */ 1128 while (len > 0) 1129 { 1130 if(asn1_check_eoc(&p, len)) 1131 { 1132 expected_eoc--; 1133 if (expected_eoc == 0) 1134 break; 1135 len -= 2; 1136 continue; 1137 } 1138 q = p; 1139 /* Just read in a header: only care about the length */ 1140 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1141 -1, 0, 0, NULL)) 1142 { 1143 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 1144 return 0; 1145 } 1146 if (inf) 1147 expected_eoc++; 1148 else 1149 p += plen; 1150 len -= p - q; 1151 } 1152 if (expected_eoc) 1153 { 1154 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 1155 return 0; 1156 } 1157 *in = p; 1158 return 1; 1159 } 1160/* This function collects the asn1 data from a constructred string 1161 * type into a buffer. The values of 'in' and 'len' should refer 1162 * to the contents of the constructed type and 'inf' should be set 1163 * if it is indefinite length. 1164 */ 1165 1166#ifndef ASN1_MAX_STRING_NEST 1167/* This determines how many levels of recursion are permitted in ASN1 1168 * string types. If it is not limited stack overflows can occur. If set 1169 * to zero no recursion is allowed at all. Although zero should be adequate 1170 * examples exist that require a value of 1. So 5 should be more than enough. 1171 */ 1172#define ASN1_MAX_STRING_NEST 5 1173#endif 1174 1175 1176static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1177 char inf, int tag, int aclass, int depth) 1178 { 1179 const unsigned char *p, *q; 1180 long plen; 1181 char cst, ininf; 1182 p = *in; 1183 inf &= 1; 1184 /* If no buffer and not indefinite length constructed just pass over 1185 * the encoded data */ 1186 if (!buf && !inf) 1187 { 1188 *in += len; 1189 return 1; 1190 } 1191 while(len > 0) 1192 { 1193 q = p; 1194 /* Check for EOC */ 1195 if (asn1_check_eoc(&p, len)) 1196 { 1197 /* EOC is illegal outside indefinite length 1198 * constructed form */ 1199 if (!inf) 1200 { 1201 ASN1err(ASN1_F_ASN1_COLLECT, 1202 ASN1_R_UNEXPECTED_EOC); 1203 return 0; 1204 } 1205 inf = 0; 1206 break; 1207 } 1208 1209 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1210 len, tag, aclass, 0, NULL)) 1211 { 1212 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1213 return 0; 1214 } 1215 1216 /* If indefinite length constructed update max length */ 1217 if (cst) 1218 { 1219 if (depth >= ASN1_MAX_STRING_NEST) 1220 { 1221 ASN1err(ASN1_F_ASN1_COLLECT, 1222 ASN1_R_NESTED_ASN1_STRING); 1223 return 0; 1224 } 1225 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, 1226 depth + 1)) 1227 return 0; 1228 } 1229 else if (plen && !collect_data(buf, &p, plen)) 1230 return 0; 1231 len -= p - q; 1232 } 1233 if (inf) 1234 { 1235 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1236 return 0; 1237 } 1238 *in = p; 1239 return 1; 1240 } 1241 1242static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1243 { 1244 int len; 1245 if (buf) 1246 { 1247 len = buf->length; 1248 if (!BUF_MEM_grow_clean(buf, len + plen)) 1249 { 1250 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1251 return 0; 1252 } 1253 memcpy(buf->data + len, *p, plen); 1254 } 1255 *p += plen; 1256 return 1; 1257 } 1258 1259/* Check for ASN1 EOC and swallow it if found */ 1260 1261static int asn1_check_eoc(const unsigned char **in, long len) 1262 { 1263 const unsigned char *p; 1264 if (len < 2) return 0; 1265 p = *in; 1266 if (!p[0] && !p[1]) 1267 { 1268 *in += 2; 1269 return 1; 1270 } 1271 return 0; 1272 } 1273 1274/* Check an ASN1 tag and length: a bit like ASN1_get_object 1275 * but it sets the length for indefinite length constructed 1276 * form, we don't know the exact length but we can set an 1277 * upper bound to the amount of data available minus the 1278 * header length just read. 1279 */ 1280 1281static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1282 char *inf, char *cst, 1283 const unsigned char **in, long len, 1284 int exptag, int expclass, char opt, 1285 ASN1_TLC *ctx) 1286 { 1287 int i; 1288 int ptag, pclass; 1289 long plen; 1290 const unsigned char *p, *q; 1291 p = *in; 1292 q = p; 1293 1294 if (ctx && ctx->valid) 1295 { 1296 i = ctx->ret; 1297 plen = ctx->plen; 1298 pclass = ctx->pclass; 1299 ptag = ctx->ptag; 1300 p += ctx->hdrlen; 1301 } 1302 else 1303 { 1304 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1305 if (ctx) 1306 { 1307 ctx->ret = i; 1308 ctx->plen = plen; 1309 ctx->pclass = pclass; 1310 ctx->ptag = ptag; 1311 ctx->hdrlen = p - q; 1312 ctx->valid = 1; 1313 /* If definite length, and no error, length + 1314 * header can't exceed total amount of data available. 1315 */ 1316 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) 1317 { 1318 ASN1err(ASN1_F_ASN1_CHECK_TLEN, 1319 ASN1_R_TOO_LONG); 1320 asn1_tlc_clear(ctx); 1321 return 0; 1322 } 1323 } 1324 } 1325 1326 if (i & 0x80) 1327 { 1328 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1329 asn1_tlc_clear(ctx); 1330 return 0; 1331 } 1332 if (exptag >= 0) 1333 { 1334 if ((exptag != ptag) || (expclass != pclass)) 1335 { 1336 /* If type is OPTIONAL, not an error: 1337 * indicate missing type. 1338 */ 1339 if (opt) return -1; 1340 asn1_tlc_clear(ctx); 1341 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1342 return 0; 1343 } 1344 /* We have a tag and class match: 1345 * assume we are going to do something with it */ 1346 asn1_tlc_clear(ctx); 1347 } 1348 1349 if (i & 1) 1350 plen = len - (p - q); 1351 1352 if (inf) 1353 *inf = i & 1; 1354 1355 if (cst) 1356 *cst = i & V_ASN1_CONSTRUCTED; 1357 1358 if (olen) 1359 *olen = plen; 1360 1361 if (oclass) 1362 *oclass = pclass; 1363 1364 if (otag) 1365 *otag = ptag; 1366 1367 *in = p; 1368 return 1; 1369 } 1370