1 /* tasn_dec.c */ 2 /* Written by Dr Stephen N Henson (steve (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh (at) 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 68 static int asn1_check_eoc(const unsigned char **in, long len); 69 static int asn1_find_end(const unsigned char **in, long len, char inf); 70 71 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 72 char inf, int tag, int aclass, int depth); 73 74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen); 75 76 static 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 82 static 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); 86 static 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); 90 static 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 */ 96 static const unsigned long tag2bit[32] = { 97 0, 0, 0, B_ASN1_BIT_STRING, /* tags 0 - 3 */ 98 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,/* tags 4- 7 */ 99 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags 8-11 */ 100 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */ 101 B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */ 102 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING, /* tags 20-22 */ 103 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, /* tags 23-24 */ 104 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING, /* tags 25-27 */ 105 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */ 106 }; 107 108 unsigned 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 /* Version to avoid compiler warning about 'c' always non-NULL */ 118 #define asn1_tlc_clear_nc(c) (c)->valid = 0 119 120 /* Decode an ASN1 item, this currently behaves just 121 * like a standard 'd2i' function. 'in' points to 122 * a buffer to read the data from, in future we will 123 * have more advanced versions that can input data 124 * a piece at a time and this will simply be a special 125 * case. 126 */ 127 128 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, 129 const unsigned char **in, long len, const ASN1_ITEM *it) 130 { 131 ASN1_TLC c; 132 ASN1_VALUE *ptmpval = NULL; 133 if (!pval) 134 pval = &ptmpval; 135 asn1_tlc_clear_nc(&c); 136 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 137 return *pval; 138 return NULL; 139 } 140 141 int ASN1_template_d2i(ASN1_VALUE **pval, 142 const unsigned char **in, long len, const ASN1_TEMPLATE *tt) 143 { 144 ASN1_TLC c; 145 asn1_tlc_clear_nc(&c); 146 return asn1_template_ex_d2i(pval, in, len, tt, 0, &c); 147 } 148 149 150 /* Decode an item, taking care of IMPLICIT tagging, if any. 151 * If 'opt' set and tag mismatch return -1 to handle OPTIONAL 152 */ 153 154 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, 155 const ASN1_ITEM *it, 156 int tag, int aclass, char opt, ASN1_TLC *ctx) 157 { 158 const ASN1_TEMPLATE *tt, *errtt = NULL; 159 const ASN1_COMPAT_FUNCS *cf; 160 const ASN1_EXTERN_FUNCS *ef; 161 const ASN1_AUX *aux = it->funcs; 162 ASN1_aux_cb *asn1_cb; 163 const unsigned char *p = NULL, *q; 164 unsigned char *wp=NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */ 165 unsigned char imphack = 0, oclass; 166 char seq_eoc, seq_nolen, cst, isopt; 167 long tmplen; 168 int i; 169 int otag; 170 int ret = 0; 171 ASN1_VALUE **pchptr, *ptmpval; 172 if (!pval) 173 return 0; 174 if (aux && aux->asn1_cb) 175 asn1_cb = aux->asn1_cb; 176 else asn1_cb = 0; 177 178 switch(it->itype) 179 { 180 case ASN1_ITYPE_PRIMITIVE: 181 if (it->templates) 182 { 183 /* tagging or OPTIONAL is currently illegal on an item 184 * template because the flags can't get passed down. 185 * In practice this isn't a problem: we include the 186 * relevant flags from the item template in the 187 * template itself. 188 */ 189 if ((tag != -1) || opt) 190 { 191 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 192 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 193 goto err; 194 } 195 return asn1_template_ex_d2i(pval, in, len, 196 it->templates, opt, ctx); 197 } 198 return asn1_d2i_ex_primitive(pval, in, len, it, 199 tag, aclass, opt, ctx); 200 break; 201 202 case ASN1_ITYPE_MSTRING: 203 p = *in; 204 /* Just read in tag and class */ 205 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 206 &p, len, -1, 0, 1, ctx); 207 if (!ret) 208 { 209 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 210 ERR_R_NESTED_ASN1_ERROR); 211 goto err; 212 } 213 214 /* Must be UNIVERSAL class */ 215 if (oclass != V_ASN1_UNIVERSAL) 216 { 217 /* If OPTIONAL, assume this is OK */ 218 if (opt) return -1; 219 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 220 ASN1_R_MSTRING_NOT_UNIVERSAL); 221 goto err; 222 } 223 /* Check tag matches bit map */ 224 if (!(ASN1_tag2bit(otag) & it->utype)) 225 { 226 /* If OPTIONAL, assume this is OK */ 227 if (opt) 228 return -1; 229 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 230 ASN1_R_MSTRING_WRONG_TAG); 231 goto err; 232 } 233 return asn1_d2i_ex_primitive(pval, in, len, 234 it, otag, 0, 0, ctx); 235 236 case ASN1_ITYPE_EXTERN: 237 /* Use new style d2i */ 238 ef = it->funcs; 239 return ef->asn1_ex_d2i(pval, in, len, 240 it, tag, aclass, opt, ctx); 241 242 case ASN1_ITYPE_COMPAT: 243 /* we must resort to old style evil hackery */ 244 cf = it->funcs; 245 246 /* If OPTIONAL see if it is there */ 247 if (opt) 248 { 249 int exptag; 250 p = *in; 251 if (tag == -1) 252 exptag = it->utype; 253 else exptag = tag; 254 /* Don't care about anything other than presence 255 * of expected tag */ 256 257 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL, 258 &p, len, exptag, aclass, 1, ctx); 259 if (!ret) 260 { 261 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 262 ERR_R_NESTED_ASN1_ERROR); 263 goto err; 264 } 265 if (ret == -1) 266 return -1; 267 } 268 269 /* This is the old style evil hack IMPLICIT handling: 270 * since the underlying code is expecting a tag and 271 * class other than the one present we change the 272 * buffer temporarily then change it back afterwards. 273 * This doesn't and never did work for tags > 30. 274 * 275 * Yes this is *horrible* but it is only needed for 276 * old style d2i which will hopefully not be around 277 * for much longer. 278 * FIXME: should copy the buffer then modify it so 279 * the input buffer can be const: we should *always* 280 * copy because the old style d2i might modify the 281 * buffer. 282 */ 283 284 if (tag != -1) 285 { 286 wp = *(unsigned char **)in; 287 imphack = *wp; 288 if (p == NULL) 289 { 290 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 291 ERR_R_NESTED_ASN1_ERROR); 292 goto err; 293 } 294 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED) 295 | it->utype); 296 } 297 298 ptmpval = cf->asn1_d2i(pval, in, len); 299 300 if (tag != -1) 301 *wp = imphack; 302 303 if (ptmpval) 304 return 1; 305 306 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 307 goto err; 308 309 310 case ASN1_ITYPE_CHOICE: 311 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 312 goto auxerr; 313 314 /* Allocate structure */ 315 if (!*pval && !ASN1_item_ex_new(pval, it)) 316 { 317 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 318 ERR_R_NESTED_ASN1_ERROR); 319 goto err; 320 } 321 /* CHOICE type, try each possibility in turn */ 322 p = *in; 323 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++) 324 { 325 pchptr = asn1_get_field_ptr(pval, tt); 326 /* We mark field as OPTIONAL so its absence 327 * can be recognised. 328 */ 329 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx); 330 /* If field not present, try the next one */ 331 if (ret == -1) 332 continue; 333 /* If positive return, read OK, break loop */ 334 if (ret > 0) 335 break; 336 /* Otherwise must be an ASN1 parsing error */ 337 errtt = tt; 338 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 339 ERR_R_NESTED_ASN1_ERROR); 340 goto err; 341 } 342 343 /* Did we fall off the end without reading anything? */ 344 if (i == it->tcount) 345 { 346 /* If OPTIONAL, this is OK */ 347 if (opt) 348 { 349 /* Free and zero it */ 350 ASN1_item_ex_free(pval, it); 351 return -1; 352 } 353 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 354 ASN1_R_NO_MATCHING_CHOICE_TYPE); 355 goto err; 356 } 357 358 asn1_set_choice_selector(pval, i, it); 359 *in = p; 360 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 361 goto auxerr; 362 return 1; 363 364 case ASN1_ITYPE_NDEF_SEQUENCE: 365 case ASN1_ITYPE_SEQUENCE: 366 p = *in; 367 tmplen = len; 368 369 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 370 if (tag == -1) 371 { 372 tag = V_ASN1_SEQUENCE; 373 aclass = V_ASN1_UNIVERSAL; 374 } 375 /* Get SEQUENCE length and update len, p */ 376 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 377 &p, len, tag, aclass, opt, ctx); 378 if (!ret) 379 { 380 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 381 ERR_R_NESTED_ASN1_ERROR); 382 goto err; 383 } 384 else if (ret == -1) 385 return -1; 386 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) 387 { 388 len = tmplen - (p - *in); 389 seq_nolen = 1; 390 } 391 /* If indefinite we don't do a length check */ 392 else seq_nolen = seq_eoc; 393 if (!cst) 394 { 395 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 396 ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 397 goto err; 398 } 399 400 if (!*pval && !ASN1_item_ex_new(pval, it)) 401 { 402 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 403 ERR_R_NESTED_ASN1_ERROR); 404 goto err; 405 } 406 407 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 408 goto auxerr; 409 410 /* Get each field entry */ 411 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) 412 { 413 const ASN1_TEMPLATE *seqtt; 414 ASN1_VALUE **pseqval; 415 seqtt = asn1_do_adb(pval, tt, 1); 416 if (!seqtt) 417 goto err; 418 pseqval = asn1_get_field_ptr(pval, seqtt); 419 /* Have we ran out of data? */ 420 if (!len) 421 break; 422 q = p; 423 if (asn1_check_eoc(&p, len)) 424 { 425 if (!seq_eoc) 426 { 427 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 428 ASN1_R_UNEXPECTED_EOC); 429 goto err; 430 } 431 len -= p - q; 432 seq_eoc = 0; 433 q = p; 434 break; 435 } 436 /* This determines the OPTIONAL flag value. The field 437 * cannot be omitted if it is the last of a SEQUENCE 438 * and there is still data to be read. This isn't 439 * strictly necessary but it increases efficiency in 440 * some cases. 441 */ 442 if (i == (it->tcount - 1)) 443 isopt = 0; 444 else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 445 /* attempt to read in field, allowing each to be 446 * OPTIONAL */ 447 448 ret = asn1_template_ex_d2i(pseqval, &p, len, 449 seqtt, isopt, ctx); 450 if (!ret) 451 { 452 errtt = seqtt; 453 goto err; 454 } 455 else if (ret == -1) 456 { 457 /* OPTIONAL component absent. 458 * Free and zero the field. 459 */ 460 ASN1_template_free(pseqval, seqtt); 461 continue; 462 } 463 /* Update length */ 464 len -= p - q; 465 } 466 467 /* Check for EOC if expecting one */ 468 if (seq_eoc && !asn1_check_eoc(&p, len)) 469 { 470 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC); 471 goto err; 472 } 473 /* Check all data read */ 474 if (!seq_nolen && len) 475 { 476 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 477 ASN1_R_SEQUENCE_LENGTH_MISMATCH); 478 goto err; 479 } 480 481 /* If we get here we've got no more data in the SEQUENCE, 482 * however we may not have read all fields so check all 483 * remaining are OPTIONAL and clear any that are. 484 */ 485 for (; i < it->tcount; tt++, i++) 486 { 487 const ASN1_TEMPLATE *seqtt; 488 seqtt = asn1_do_adb(pval, tt, 1); 489 if (!seqtt) 490 goto err; 491 if (seqtt->flags & ASN1_TFLG_OPTIONAL) 492 { 493 ASN1_VALUE **pseqval; 494 pseqval = asn1_get_field_ptr(pval, seqtt); 495 ASN1_template_free(pseqval, seqtt); 496 } 497 else 498 { 499 errtt = seqtt; 500 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 501 ASN1_R_FIELD_MISSING); 502 goto err; 503 } 504 } 505 /* Save encoding */ 506 if (!asn1_enc_save(pval, *in, p - *in, it)) 507 goto auxerr; 508 *in = p; 509 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 510 goto auxerr; 511 return 1; 512 513 default: 514 return 0; 515 } 516 auxerr: 517 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR); 518 err: 519 ASN1_item_ex_free(pval, it); 520 if (errtt) 521 ERR_add_error_data(4, "Field=", errtt->field_name, 522 ", Type=", it->sname); 523 else 524 ERR_add_error_data(2, "Type=", it->sname); 525 return 0; 526 } 527 528 /* Templates are handled with two separate functions. 529 * One handles any EXPLICIT tag and the other handles the rest. 530 */ 531 532 static int asn1_template_ex_d2i(ASN1_VALUE **val, 533 const unsigned char **in, long inlen, 534 const ASN1_TEMPLATE *tt, char opt, 535 ASN1_TLC *ctx) 536 { 537 int flags, aclass; 538 int ret; 539 long len; 540 const unsigned char *p, *q; 541 char exp_eoc; 542 if (!val) 543 return 0; 544 flags = tt->flags; 545 aclass = flags & ASN1_TFLG_TAG_CLASS; 546 547 p = *in; 548 549 /* Check if EXPLICIT tag expected */ 550 if (flags & ASN1_TFLG_EXPTAG) 551 { 552 char cst; 553 /* Need to work out amount of data available to the inner 554 * content and where it starts: so read in EXPLICIT header to 555 * get the info. 556 */ 557 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 558 &p, inlen, tt->tag, aclass, opt, ctx); 559 q = p; 560 if (!ret) 561 { 562 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 563 ERR_R_NESTED_ASN1_ERROR); 564 return 0; 565 } 566 else if (ret == -1) 567 return -1; 568 if (!cst) 569 { 570 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 571 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 572 return 0; 573 } 574 /* We've found the field so it can't be OPTIONAL now */ 575 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 576 if (!ret) 577 { 578 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 579 ERR_R_NESTED_ASN1_ERROR); 580 return 0; 581 } 582 /* We read the field in OK so update length */ 583 len -= p - q; 584 if (exp_eoc) 585 { 586 /* If NDEF we must have an EOC here */ 587 if (!asn1_check_eoc(&p, len)) 588 { 589 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 590 ASN1_R_MISSING_EOC); 591 goto err; 592 } 593 } 594 else 595 { 596 /* Otherwise we must hit the EXPLICIT tag end or its 597 * an error */ 598 if (len) 599 { 600 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 601 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 602 goto err; 603 } 604 } 605 } 606 else 607 return asn1_template_noexp_d2i(val, in, inlen, 608 tt, opt, ctx); 609 610 *in = p; 611 return 1; 612 613 err: 614 ASN1_template_free(val, tt); 615 return 0; 616 } 617 618 static int asn1_template_noexp_d2i(ASN1_VALUE **val, 619 const unsigned char **in, long len, 620 const ASN1_TEMPLATE *tt, char opt, 621 ASN1_TLC *ctx) 622 { 623 int flags, aclass; 624 int ret; 625 const unsigned char *p, *q; 626 if (!val) 627 return 0; 628 flags = tt->flags; 629 aclass = flags & ASN1_TFLG_TAG_CLASS; 630 631 p = *in; 632 q = p; 633 634 if (flags & ASN1_TFLG_SK_MASK) 635 { 636 /* SET OF, SEQUENCE OF */ 637 int sktag, skaclass; 638 char sk_eoc; 639 /* First work out expected inner tag value */ 640 if (flags & ASN1_TFLG_IMPTAG) 641 { 642 sktag = tt->tag; 643 skaclass = aclass; 644 } 645 else 646 { 647 skaclass = V_ASN1_UNIVERSAL; 648 if (flags & ASN1_TFLG_SET_OF) 649 sktag = V_ASN1_SET; 650 else 651 sktag = V_ASN1_SEQUENCE; 652 } 653 /* Get the tag */ 654 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 655 &p, len, sktag, skaclass, opt, ctx); 656 if (!ret) 657 { 658 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 659 ERR_R_NESTED_ASN1_ERROR); 660 return 0; 661 } 662 else if (ret == -1) 663 return -1; 664 if (!*val) 665 *val = (ASN1_VALUE *)sk_new_null(); 666 else 667 { 668 /* We've got a valid STACK: free up any items present */ 669 STACK_OF(ASN1_VALUE) *sktmp 670 = (STACK_OF(ASN1_VALUE) *)*val; 671 ASN1_VALUE *vtmp; 672 while(sk_ASN1_VALUE_num(sktmp) > 0) 673 { 674 vtmp = sk_ASN1_VALUE_pop(sktmp); 675 ASN1_item_ex_free(&vtmp, 676 ASN1_ITEM_ptr(tt->item)); 677 } 678 } 679 680 if (!*val) 681 { 682 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 683 ERR_R_MALLOC_FAILURE); 684 goto err; 685 } 686 687 /* Read as many items as we can */ 688 while(len > 0) 689 { 690 ASN1_VALUE *skfield; 691 q = p; 692 /* See if EOC found */ 693 if (asn1_check_eoc(&p, len)) 694 { 695 if (!sk_eoc) 696 { 697 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 698 ASN1_R_UNEXPECTED_EOC); 699 goto err; 700 } 701 len -= p - q; 702 sk_eoc = 0; 703 break; 704 } 705 skfield = NULL; 706 if (!ASN1_item_ex_d2i(&skfield, &p, len, 707 ASN1_ITEM_ptr(tt->item), 708 -1, 0, 0, ctx)) 709 { 710 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 711 ERR_R_NESTED_ASN1_ERROR); 712 goto err; 713 } 714 len -= p - q; 715 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, 716 skfield)) 717 { 718 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 719 ERR_R_MALLOC_FAILURE); 720 goto err; 721 } 722 } 723 if (sk_eoc) 724 { 725 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 726 goto err; 727 } 728 } 729 else if (flags & ASN1_TFLG_IMPTAG) 730 { 731 /* IMPLICIT tagging */ 732 ret = ASN1_item_ex_d2i(val, &p, len, 733 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx); 734 if (!ret) 735 { 736 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 737 ERR_R_NESTED_ASN1_ERROR); 738 goto err; 739 } 740 else if (ret == -1) 741 return -1; 742 } 743 else 744 { 745 /* Nothing special */ 746 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 747 -1, 0, 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 } 757 758 *in = p; 759 return 1; 760 761 err: 762 ASN1_template_free(val, tt); 763 return 0; 764 } 765 766 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 767 const unsigned char **in, long inlen, 768 const ASN1_ITEM *it, 769 int tag, int aclass, char opt, ASN1_TLC *ctx) 770 { 771 int ret = 0, utype; 772 long plen; 773 char cst, inf, free_cont = 0; 774 const unsigned char *p; 775 BUF_MEM buf; 776 const unsigned char *cont = NULL; 777 long len; 778 if (!pval) 779 { 780 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 781 return 0; /* Should never happen */ 782 } 783 784 if (it->itype == ASN1_ITYPE_MSTRING) 785 { 786 utype = tag; 787 tag = -1; 788 } 789 else 790 utype = it->utype; 791 792 if (utype == V_ASN1_ANY) 793 { 794 /* If type is ANY need to figure out type from tag */ 795 unsigned char oclass; 796 if (tag >= 0) 797 { 798 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 799 ASN1_R_ILLEGAL_TAGGED_ANY); 800 return 0; 801 } 802 if (opt) 803 { 804 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 805 ASN1_R_ILLEGAL_OPTIONAL_ANY); 806 return 0; 807 } 808 p = *in; 809 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 810 &p, inlen, -1, 0, 0, ctx); 811 if (!ret) 812 { 813 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 814 ERR_R_NESTED_ASN1_ERROR); 815 return 0; 816 } 817 if (oclass != V_ASN1_UNIVERSAL) 818 utype = V_ASN1_OTHER; 819 } 820 if (tag == -1) 821 { 822 tag = utype; 823 aclass = V_ASN1_UNIVERSAL; 824 } 825 p = *in; 826 /* Check header */ 827 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 828 &p, inlen, tag, aclass, opt, ctx); 829 if (!ret) 830 { 831 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 832 return 0; 833 } 834 else if (ret == -1) 835 return -1; 836 ret = 0; 837 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 838 if ((utype == V_ASN1_SEQUENCE) 839 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) 840 { 841 /* Clear context cache for type OTHER because the auto clear 842 * when we have a exact match wont work 843 */ 844 if (utype == V_ASN1_OTHER) 845 { 846 asn1_tlc_clear(ctx); 847 } 848 /* SEQUENCE and SET must be constructed */ 849 else if (!cst) 850 { 851 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 852 ASN1_R_TYPE_NOT_CONSTRUCTED); 853 return 0; 854 } 855 856 cont = *in; 857 /* If indefinite length constructed find the real end */ 858 if (inf) 859 { 860 if (!asn1_find_end(&p, plen, inf)) 861 goto err; 862 len = p - cont; 863 } 864 else 865 { 866 len = p - cont + plen; 867 p += plen; 868 buf.data = NULL; 869 } 870 } 871 else if (cst) 872 { 873 buf.length = 0; 874 buf.max = 0; 875 buf.data = NULL; 876 /* Should really check the internal tags are correct but 877 * some things may get this wrong. The relevant specs 878 * say that constructed string types should be OCTET STRINGs 879 * internally irrespective of the type. So instead just check 880 * for UNIVERSAL class and ignore the tag. 881 */ 882 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) 883 { 884 free_cont = 1; 885 goto err; 886 } 887 len = buf.length; 888 /* Append a final null to string */ 889 if (!BUF_MEM_grow_clean(&buf, len + 1)) 890 { 891 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 892 ERR_R_MALLOC_FAILURE); 893 return 0; 894 } 895 buf.data[len] = 0; 896 cont = (const unsigned char *)buf.data; 897 free_cont = 1; 898 } 899 else 900 { 901 cont = p; 902 len = plen; 903 p += plen; 904 } 905 906 /* We now have content length and type: translate into a structure */ 907 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 908 goto err; 909 910 *in = p; 911 ret = 1; 912 err: 913 if (free_cont && buf.data) OPENSSL_free(buf.data); 914 return ret; 915 } 916 917 /* Translate ASN1 content octets into a structure */ 918 919 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 920 int utype, char *free_cont, const ASN1_ITEM *it) 921 { 922 ASN1_VALUE **opval = NULL; 923 ASN1_STRING *stmp; 924 ASN1_TYPE *typ = NULL; 925 int ret = 0; 926 const ASN1_PRIMITIVE_FUNCS *pf; 927 ASN1_INTEGER **tint; 928 pf = it->funcs; 929 930 if (pf && pf->prim_c2i) 931 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 932 /* If ANY type clear type and set pointer to internal value */ 933 if (it->utype == V_ASN1_ANY) 934 { 935 if (!*pval) 936 { 937 typ = ASN1_TYPE_new(); 938 if (typ == NULL) 939 goto err; 940 *pval = (ASN1_VALUE *)typ; 941 } 942 else 943 typ = (ASN1_TYPE *)*pval; 944 945 if (utype != typ->type) 946 ASN1_TYPE_set(typ, utype, NULL); 947 opval = pval; 948 pval = &typ->value.asn1_value; 949 } 950 switch(utype) 951 { 952 case V_ASN1_OBJECT: 953 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 954 goto err; 955 break; 956 957 case V_ASN1_NULL: 958 if (len) 959 { 960 ASN1err(ASN1_F_ASN1_EX_C2I, 961 ASN1_R_NULL_IS_WRONG_LENGTH); 962 goto err; 963 } 964 *pval = (ASN1_VALUE *)1; 965 break; 966 967 case V_ASN1_BOOLEAN: 968 if (len != 1) 969 { 970 ASN1err(ASN1_F_ASN1_EX_C2I, 971 ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 972 goto err; 973 } 974 else 975 { 976 ASN1_BOOLEAN *tbool; 977 tbool = (ASN1_BOOLEAN *)pval; 978 *tbool = *cont; 979 } 980 break; 981 982 case V_ASN1_BIT_STRING: 983 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 984 goto err; 985 break; 986 987 case V_ASN1_INTEGER: 988 case V_ASN1_NEG_INTEGER: 989 case V_ASN1_ENUMERATED: 990 case V_ASN1_NEG_ENUMERATED: 991 tint = (ASN1_INTEGER **)pval; 992 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 993 goto err; 994 /* Fixup type to match the expected form */ 995 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 996 break; 997 998 case V_ASN1_OCTET_STRING: 999 case V_ASN1_NUMERICSTRING: 1000 case V_ASN1_PRINTABLESTRING: 1001 case V_ASN1_T61STRING: 1002 case V_ASN1_VIDEOTEXSTRING: 1003 case V_ASN1_IA5STRING: 1004 case V_ASN1_UTCTIME: 1005 case V_ASN1_GENERALIZEDTIME: 1006 case V_ASN1_GRAPHICSTRING: 1007 case V_ASN1_VISIBLESTRING: 1008 case V_ASN1_GENERALSTRING: 1009 case V_ASN1_UNIVERSALSTRING: 1010 case V_ASN1_BMPSTRING: 1011 case V_ASN1_UTF8STRING: 1012 case V_ASN1_OTHER: 1013 case V_ASN1_SET: 1014 case V_ASN1_SEQUENCE: 1015 default: 1016 if (utype == V_ASN1_BMPSTRING && (len & 1)) 1017 { 1018 ASN1err(ASN1_F_ASN1_EX_C2I, 1019 ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 1020 goto err; 1021 } 1022 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) 1023 { 1024 ASN1err(ASN1_F_ASN1_EX_C2I, 1025 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 1026 goto err; 1027 } 1028 /* All based on ASN1_STRING and handled the same */ 1029 if (!*pval) 1030 { 1031 stmp = ASN1_STRING_type_new(utype); 1032 if (!stmp) 1033 { 1034 ASN1err(ASN1_F_ASN1_EX_C2I, 1035 ERR_R_MALLOC_FAILURE); 1036 goto err; 1037 } 1038 *pval = (ASN1_VALUE *)stmp; 1039 } 1040 else 1041 { 1042 stmp = (ASN1_STRING *)*pval; 1043 stmp->type = utype; 1044 } 1045 /* If we've already allocated a buffer use it */ 1046 if (*free_cont) 1047 { 1048 if (stmp->data) 1049 OPENSSL_free(stmp->data); 1050 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 1051 stmp->length = len; 1052 *free_cont = 0; 1053 } 1054 else 1055 { 1056 if (!ASN1_STRING_set(stmp, cont, len)) 1057 { 1058 ASN1err(ASN1_F_ASN1_EX_C2I, 1059 ERR_R_MALLOC_FAILURE); 1060 ASN1_STRING_free(stmp); 1061 *pval = NULL; 1062 goto err; 1063 } 1064 } 1065 break; 1066 } 1067 /* If ASN1_ANY and NULL type fix up value */ 1068 if (typ && (utype == V_ASN1_NULL)) 1069 typ->value.ptr = NULL; 1070 1071 ret = 1; 1072 err: 1073 if (!ret) 1074 { 1075 ASN1_TYPE_free(typ); 1076 if (opval) 1077 *opval = NULL; 1078 } 1079 return ret; 1080 } 1081 1082 1083 /* This function finds the end of an ASN1 structure when passed its maximum 1084 * length, whether it is indefinite length and a pointer to the content. 1085 * This is more efficient than calling asn1_collect because it does not 1086 * recurse on each indefinite length header. 1087 */ 1088 1089 static int asn1_find_end(const unsigned char **in, long len, char inf) 1090 { 1091 int expected_eoc; 1092 long plen; 1093 const unsigned char *p = *in, *q; 1094 /* If not indefinite length constructed just add length */ 1095 if (inf == 0) 1096 { 1097 *in += len; 1098 return 1; 1099 } 1100 expected_eoc = 1; 1101 /* Indefinite length constructed form. Find the end when enough EOCs 1102 * are found. If more indefinite length constructed headers 1103 * are encountered increment the expected eoc count otherwise just 1104 * skip to the end of the data. 1105 */ 1106 while (len > 0) 1107 { 1108 if(asn1_check_eoc(&p, len)) 1109 { 1110 expected_eoc--; 1111 if (expected_eoc == 0) 1112 break; 1113 len -= 2; 1114 continue; 1115 } 1116 q = p; 1117 /* Just read in a header: only care about the length */ 1118 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1119 -1, 0, 0, NULL)) 1120 { 1121 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 1122 return 0; 1123 } 1124 if (inf) 1125 expected_eoc++; 1126 else 1127 p += plen; 1128 len -= p - q; 1129 } 1130 if (expected_eoc) 1131 { 1132 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 1133 return 0; 1134 } 1135 *in = p; 1136 return 1; 1137 } 1138 /* This function collects the asn1 data from a constructred string 1139 * type into a buffer. The values of 'in' and 'len' should refer 1140 * to the contents of the constructed type and 'inf' should be set 1141 * if it is indefinite length. 1142 */ 1143 1144 #ifndef ASN1_MAX_STRING_NEST 1145 /* This determines how many levels of recursion are permitted in ASN1 1146 * string types. If it is not limited stack overflows can occur. If set 1147 * to zero no recursion is allowed at all. Although zero should be adequate 1148 * examples exist that require a value of 1. So 5 should be more than enough. 1149 */ 1150 #define ASN1_MAX_STRING_NEST 5 1151 #endif 1152 1153 1154 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1155 char inf, int tag, int aclass, int depth) 1156 { 1157 const unsigned char *p, *q; 1158 long plen; 1159 char cst, ininf; 1160 p = *in; 1161 inf &= 1; 1162 /* If no buffer and not indefinite length constructed just pass over 1163 * the encoded data */ 1164 if (!buf && !inf) 1165 { 1166 *in += len; 1167 return 1; 1168 } 1169 while(len > 0) 1170 { 1171 q = p; 1172 /* Check for EOC */ 1173 if (asn1_check_eoc(&p, len)) 1174 { 1175 /* EOC is illegal outside indefinite length 1176 * constructed form */ 1177 if (!inf) 1178 { 1179 ASN1err(ASN1_F_ASN1_COLLECT, 1180 ASN1_R_UNEXPECTED_EOC); 1181 return 0; 1182 } 1183 inf = 0; 1184 break; 1185 } 1186 1187 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1188 len, tag, aclass, 0, NULL)) 1189 { 1190 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1191 return 0; 1192 } 1193 1194 /* If indefinite length constructed update max length */ 1195 if (cst) 1196 { 1197 if (depth >= ASN1_MAX_STRING_NEST) 1198 { 1199 ASN1err(ASN1_F_ASN1_COLLECT, 1200 ASN1_R_NESTED_ASN1_STRING); 1201 return 0; 1202 } 1203 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, 1204 depth + 1)) 1205 return 0; 1206 } 1207 else if (plen && !collect_data(buf, &p, plen)) 1208 return 0; 1209 len -= p - q; 1210 } 1211 if (inf) 1212 { 1213 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1214 return 0; 1215 } 1216 *in = p; 1217 return 1; 1218 } 1219 1220 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1221 { 1222 int len; 1223 if (buf) 1224 { 1225 len = buf->length; 1226 if (!BUF_MEM_grow_clean(buf, len + plen)) 1227 { 1228 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1229 return 0; 1230 } 1231 memcpy(buf->data + len, *p, plen); 1232 } 1233 *p += plen; 1234 return 1; 1235 } 1236 1237 /* Check for ASN1 EOC and swallow it if found */ 1238 1239 static int asn1_check_eoc(const unsigned char **in, long len) 1240 { 1241 const unsigned char *p; 1242 if (len < 2) return 0; 1243 p = *in; 1244 if (!p[0] && !p[1]) 1245 { 1246 *in += 2; 1247 return 1; 1248 } 1249 return 0; 1250 } 1251 1252 /* Check an ASN1 tag and length: a bit like ASN1_get_object 1253 * but it sets the length for indefinite length constructed 1254 * form, we don't know the exact length but we can set an 1255 * upper bound to the amount of data available minus the 1256 * header length just read. 1257 */ 1258 1259 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1260 char *inf, char *cst, 1261 const unsigned char **in, long len, 1262 int exptag, int expclass, char opt, 1263 ASN1_TLC *ctx) 1264 { 1265 int i; 1266 int ptag, pclass; 1267 long plen; 1268 const unsigned char *p, *q; 1269 p = *in; 1270 q = p; 1271 1272 if (ctx && ctx->valid) 1273 { 1274 i = ctx->ret; 1275 plen = ctx->plen; 1276 pclass = ctx->pclass; 1277 ptag = ctx->ptag; 1278 p += ctx->hdrlen; 1279 } 1280 else 1281 { 1282 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1283 if (ctx) 1284 { 1285 ctx->ret = i; 1286 ctx->plen = plen; 1287 ctx->pclass = pclass; 1288 ctx->ptag = ptag; 1289 ctx->hdrlen = p - q; 1290 ctx->valid = 1; 1291 /* If definite length, and no error, length + 1292 * header can't exceed total amount of data available. 1293 */ 1294 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) 1295 { 1296 ASN1err(ASN1_F_ASN1_CHECK_TLEN, 1297 ASN1_R_TOO_LONG); 1298 asn1_tlc_clear(ctx); 1299 return 0; 1300 } 1301 } 1302 } 1303 1304 if (i & 0x80) 1305 { 1306 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1307 asn1_tlc_clear(ctx); 1308 return 0; 1309 } 1310 if (exptag >= 0) 1311 { 1312 if ((exptag != ptag) || (expclass != pclass)) 1313 { 1314 /* If type is OPTIONAL, not an error: 1315 * indicate missing type. 1316 */ 1317 if (opt) return -1; 1318 asn1_tlc_clear(ctx); 1319 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1320 return 0; 1321 } 1322 /* We have a tag and class match: 1323 * assume we are going to do something with it */ 1324 asn1_tlc_clear(ctx); 1325 } 1326 1327 if (i & 1) 1328 plen = len - (p - q); 1329 1330 if (inf) 1331 *inf = i & 1; 1332 1333 if (cst) 1334 *cst = i & V_ASN1_CONSTRUCTED; 1335 1336 if (olen) 1337 *olen = plen; 1338 1339 if (oclass) 1340 *oclass = pclass; 1341 1342 if (otag) 1343 *otag = ptag; 1344 1345 *in = p; 1346 return 1; 1347 } 1348
