1 /* tasn_dec.c */ 2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 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); 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 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 = 0 117 118 /* 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 */ 125 126 ASN1_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 asn1_tlc_clear(&c); 134 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 135 return *pval; 136 return NULL; 137 } 138 139 int ASN1_template_d2i(ASN1_VALUE **pval, 140 const unsigned char **in, long len, const ASN1_TEMPLATE *tt) 141 { 142 ASN1_TLC c; 143 asn1_tlc_clear(&c); 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 */ 151 152 int 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 *pchval, **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 /* Allocate structure */ 313 if (!*pval && !ASN1_item_ex_new(pval, it)) 314 { 315 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 316 ERR_R_NESTED_ASN1_ERROR); 317 goto err; 318 } 319 /* CHOICE type, try each possibility in turn */ 320 pchval = NULL; 321 p = *in; 322 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++) 323 { 324 pchptr = asn1_get_field_ptr(pval, tt); 325 /* We mark field as OPTIONAL so its absence 326 * can be recognised. 327 */ 328 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx); 329 /* If field not present, try the next one */ 330 if (ret == -1) 331 continue; 332 /* If positive return, read OK, break loop */ 333 if (ret > 0) 334 break; 335 /* Otherwise must be an ASN1 parsing error */ 336 errtt = tt; 337 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 338 ERR_R_NESTED_ASN1_ERROR); 339 goto err; 340 } 341 342 /* Did we fall off the end without reading anything? */ 343 if (i == it->tcount) 344 { 345 /* If OPTIONAL, this is OK */ 346 if (opt) 347 { 348 /* Free and zero it */ 349 ASN1_item_ex_free(pval, it); 350 return -1; 351 } 352 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 353 ASN1_R_NO_MATCHING_CHOICE_TYPE); 354 goto err; 355 } 356 357 asn1_set_choice_selector(pval, i, it); 358 *in = p; 359 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it)) 360 goto auxerr; 361 return 1; 362 363 case ASN1_ITYPE_NDEF_SEQUENCE: 364 case ASN1_ITYPE_SEQUENCE: 365 p = *in; 366 tmplen = len; 367 368 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 369 if (tag == -1) 370 { 371 tag = V_ASN1_SEQUENCE; 372 aclass = V_ASN1_UNIVERSAL; 373 } 374 /* Get SEQUENCE length and update len, p */ 375 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 376 &p, len, tag, aclass, opt, ctx); 377 if (!ret) 378 { 379 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 380 ERR_R_NESTED_ASN1_ERROR); 381 goto err; 382 } 383 else if (ret == -1) 384 return -1; 385 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) 386 { 387 len = tmplen - (p - *in); 388 seq_nolen = 1; 389 } 390 /* If indefinite we don't do a length check */ 391 else seq_nolen = seq_eoc; 392 if (!cst) 393 { 394 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 395 ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 396 goto err; 397 } 398 399 if (!*pval && !ASN1_item_ex_new(pval, it)) 400 { 401 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 402 ERR_R_NESTED_ASN1_ERROR); 403 goto err; 404 } 405 406 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it)) 407 goto auxerr; 408 409 /* Get each field entry */ 410 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) 411 { 412 const ASN1_TEMPLATE *seqtt; 413 ASN1_VALUE **pseqval; 414 seqtt = asn1_do_adb(pval, tt, 1); 415 if (!seqtt) 416 goto err; 417 pseqval = asn1_get_field_ptr(pval, seqtt); 418 /* Have we ran out of data? */ 419 if (!len) 420 break; 421 q = p; 422 if (asn1_check_eoc(&p, len)) 423 { 424 if (!seq_eoc) 425 { 426 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 427 ASN1_R_UNEXPECTED_EOC); 428 goto err; 429 } 430 len -= p - q; 431 seq_eoc = 0; 432 q = p; 433 break; 434 } 435 /* This determines the OPTIONAL flag value. The field 436 * cannot be omitted if it is the last of a SEQUENCE 437 * and there is still data to be read. This isn't 438 * strictly necessary but it increases efficiency in 439 * some cases. 440 */ 441 if (i == (it->tcount - 1)) 442 isopt = 0; 443 else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 444 /* attempt to read in field, allowing each to be 445 * OPTIONAL */ 446 447 ret = asn1_template_ex_d2i(pseqval, &p, len, 448 seqtt, isopt, ctx); 449 if (!ret) 450 { 451 errtt = seqtt; 452 goto err; 453 } 454 else if (ret == -1) 455 { 456 /* OPTIONAL component absent. 457 * Free and zero the field. 458 */ 459 ASN1_template_free(pseqval, seqtt); 460 continue; 461 } 462 /* Update length */ 463 len -= p - q; 464 } 465 466 /* Check for EOC if expecting one */ 467 if (seq_eoc && !asn1_check_eoc(&p, len)) 468 { 469 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC); 470 goto err; 471 } 472 /* Check all data read */ 473 if (!seq_nolen && len) 474 { 475 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 476 ASN1_R_SEQUENCE_LENGTH_MISMATCH); 477 goto err; 478 } 479 480 /* If we get here we've got no more data in the SEQUENCE, 481 * however we may not have read all fields so check all 482 * remaining are OPTIONAL and clear any that are. 483 */ 484 for (; i < it->tcount; tt++, i++) 485 { 486 const ASN1_TEMPLATE *seqtt; 487 seqtt = asn1_do_adb(pval, tt, 1); 488 if (!seqtt) 489 goto err; 490 if (seqtt->flags & ASN1_TFLG_OPTIONAL) 491 { 492 ASN1_VALUE **pseqval; 493 pseqval = asn1_get_field_ptr(pval, seqtt); 494 ASN1_template_free(pseqval, seqtt); 495 } 496 else 497 { 498 errtt = seqtt; 499 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 500 ASN1_R_FIELD_MISSING); 501 goto err; 502 } 503 } 504 /* Save encoding */ 505 if (!asn1_enc_save(pval, *in, p - *in, it)) 506 goto auxerr; 507 *in = p; 508 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it)) 509 goto auxerr; 510 return 1; 511 512 default: 513 return 0; 514 } 515 auxerr: 516 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR); 517 err: 518 ASN1_item_ex_free(pval, it); 519 if (errtt) 520 ERR_add_error_data(4, "Field=", errtt->field_name, 521 ", Type=", it->sname); 522 else 523 ERR_add_error_data(2, "Type=", it->sname); 524 return 0; 525 } 526 527 /* Templates are handled with two separate functions. 528 * One handles any EXPLICIT tag and the other handles the rest. 529 */ 530 531 static int asn1_template_ex_d2i(ASN1_VALUE **val, 532 const unsigned char **in, long inlen, 533 const ASN1_TEMPLATE *tt, char opt, 534 ASN1_TLC *ctx) 535 { 536 int flags, aclass; 537 int ret; 538 long len; 539 const unsigned char *p, *q; 540 char exp_eoc; 541 if (!val) 542 return 0; 543 flags = tt->flags; 544 aclass = flags & ASN1_TFLG_TAG_CLASS; 545 546 p = *in; 547 548 /* Check if EXPLICIT tag expected */ 549 if (flags & ASN1_TFLG_EXPTAG) 550 { 551 char cst; 552 /* Need to work out amount of data available to the inner 553 * content and where it starts: so read in EXPLICIT header to 554 * get the info. 555 */ 556 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 557 &p, inlen, tt->tag, aclass, opt, ctx); 558 q = p; 559 if (!ret) 560 { 561 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 562 ERR_R_NESTED_ASN1_ERROR); 563 return 0; 564 } 565 else if (ret == -1) 566 return -1; 567 if (!cst) 568 { 569 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 570 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 571 return 0; 572 } 573 /* We've found the field so it can't be OPTIONAL now */ 574 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 575 if (!ret) 576 { 577 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 578 ERR_R_NESTED_ASN1_ERROR); 579 return 0; 580 } 581 /* We read the field in OK so update length */ 582 len -= p - q; 583 if (exp_eoc) 584 { 585 /* If NDEF we must have an EOC here */ 586 if (!asn1_check_eoc(&p, len)) 587 { 588 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 589 ASN1_R_MISSING_EOC); 590 goto err; 591 } 592 } 593 else 594 { 595 /* Otherwise we must hit the EXPLICIT tag end or its 596 * an error */ 597 if (len) 598 { 599 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 600 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 601 goto err; 602 } 603 } 604 } 605 else 606 return asn1_template_noexp_d2i(val, in, inlen, 607 tt, opt, ctx); 608 609 *in = p; 610 return 1; 611 612 err: 613 ASN1_template_free(val, tt); 614 *val = NULL; 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 *sktmp = (STACK *)*val; 670 ASN1_VALUE *vtmp; 671 while(sk_num(sktmp) > 0) 672 { 673 vtmp = (ASN1_VALUE *)sk_pop(sktmp); 674 ASN1_item_ex_free(&vtmp, 675 ASN1_ITEM_ptr(tt->item)); 676 } 677 } 678 679 if (!*val) 680 { 681 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 682 ERR_R_MALLOC_FAILURE); 683 goto err; 684 } 685 686 /* Read as many items as we can */ 687 while(len > 0) 688 { 689 ASN1_VALUE *skfield; 690 q = p; 691 /* See if EOC found */ 692 if (asn1_check_eoc(&p, len)) 693 { 694 if (!sk_eoc) 695 { 696 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 697 ASN1_R_UNEXPECTED_EOC); 698 goto err; 699 } 700 len -= p - q; 701 sk_eoc = 0; 702 break; 703 } 704 skfield = NULL; 705 if (!ASN1_item_ex_d2i(&skfield, &p, len, 706 ASN1_ITEM_ptr(tt->item), 707 -1, 0, 0, ctx)) 708 { 709 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 710 ERR_R_NESTED_ASN1_ERROR); 711 goto err; 712 } 713 len -= p - q; 714 if (!sk_push((STACK *)*val, (char *)skfield)) 715 { 716 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 717 ERR_R_MALLOC_FAILURE); 718 goto err; 719 } 720 } 721 if (sk_eoc) 722 { 723 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 724 goto err; 725 } 726 } 727 else if (flags & ASN1_TFLG_IMPTAG) 728 { 729 /* IMPLICIT tagging */ 730 ret = ASN1_item_ex_d2i(val, &p, len, 731 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx); 732 if (!ret) 733 { 734 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 735 ERR_R_NESTED_ASN1_ERROR); 736 goto err; 737 } 738 else if (ret == -1) 739 return -1; 740 } 741 else 742 { 743 /* Nothing special */ 744 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 745 -1, 0, opt, ctx); 746 if (!ret) 747 { 748 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 749 ERR_R_NESTED_ASN1_ERROR); 750 goto err; 751 } 752 else if (ret == -1) 753 return -1; 754 } 755 756 *in = p; 757 return 1; 758 759 err: 760 ASN1_template_free(val, tt); 761 *val = NULL; 762 return 0; 763 } 764 765 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 766 const unsigned char **in, long inlen, 767 const ASN1_ITEM *it, 768 int tag, int aclass, char opt, ASN1_TLC *ctx) 769 { 770 int ret = 0, utype; 771 long plen; 772 char cst, inf, free_cont = 0; 773 const unsigned char *p; 774 BUF_MEM buf; 775 const unsigned char *cont = NULL; 776 long len; 777 if (!pval) 778 { 779 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 780 return 0; /* Should never happen */ 781 } 782 783 if (it->itype == ASN1_ITYPE_MSTRING) 784 { 785 utype = tag; 786 tag = -1; 787 } 788 else 789 utype = it->utype; 790 791 if (utype == V_ASN1_ANY) 792 { 793 /* If type is ANY need to figure out type from tag */ 794 unsigned char oclass; 795 if (tag >= 0) 796 { 797 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 798 ASN1_R_ILLEGAL_TAGGED_ANY); 799 return 0; 800 } 801 if (opt) 802 { 803 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 804 ASN1_R_ILLEGAL_OPTIONAL_ANY); 805 return 0; 806 } 807 p = *in; 808 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 809 &p, inlen, -1, 0, 0, ctx); 810 if (!ret) 811 { 812 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 813 ERR_R_NESTED_ASN1_ERROR); 814 return 0; 815 } 816 if (oclass != V_ASN1_UNIVERSAL) 817 utype = V_ASN1_OTHER; 818 } 819 if (tag == -1) 820 { 821 tag = utype; 822 aclass = V_ASN1_UNIVERSAL; 823 } 824 p = *in; 825 /* Check header */ 826 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 827 &p, inlen, tag, aclass, opt, ctx); 828 if (!ret) 829 { 830 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 831 return 0; 832 } 833 else if (ret == -1) 834 return -1; 835 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 836 if ((utype == V_ASN1_SEQUENCE) 837 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) 838 { 839 /* Clear context cache for type OTHER because the auto clear 840 * when we have a exact match wont work 841 */ 842 if (utype == V_ASN1_OTHER) 843 { 844 asn1_tlc_clear(ctx); 845 } 846 /* SEQUENCE and SET must be constructed */ 847 else if (!cst) 848 { 849 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 850 ASN1_R_TYPE_NOT_CONSTRUCTED); 851 return 0; 852 } 853 854 cont = *in; 855 /* If indefinite length constructed find the real end */ 856 if (inf) 857 { 858 if (!asn1_find_end(&p, plen, inf)) 859 goto err; 860 len = p - cont; 861 } 862 else 863 { 864 len = p - cont + plen; 865 p += plen; 866 buf.data = NULL; 867 } 868 } 869 else if (cst) 870 { 871 buf.length = 0; 872 buf.max = 0; 873 buf.data = NULL; 874 /* Should really check the internal tags are correct but 875 * some things may get this wrong. The relevant specs 876 * say that constructed string types should be OCTET STRINGs 877 * internally irrespective of the type. So instead just check 878 * for UNIVERSAL class and ignore the tag. 879 */ 880 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL)) 881 goto err; 882 len = buf.length; 883 /* Append a final null to string */ 884 if (!BUF_MEM_grow_clean(&buf, len + 1)) 885 { 886 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 887 ERR_R_MALLOC_FAILURE); 888 return 0; 889 } 890 buf.data[len] = 0; 891 cont = (const unsigned char *)buf.data; 892 free_cont = 1; 893 } 894 else 895 { 896 cont = p; 897 len = plen; 898 p += plen; 899 } 900 901 /* We now have content length and type: translate into a structure */ 902 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 903 goto err; 904 905 *in = p; 906 ret = 1; 907 err: 908 if (free_cont && buf.data) OPENSSL_free(buf.data); 909 return ret; 910 } 911 912 /* Translate ASN1 content octets into a structure */ 913 914 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 915 int utype, char *free_cont, const ASN1_ITEM *it) 916 { 917 ASN1_VALUE **opval = NULL; 918 ASN1_STRING *stmp; 919 ASN1_TYPE *typ = NULL; 920 int ret = 0; 921 const ASN1_PRIMITIVE_FUNCS *pf; 922 ASN1_INTEGER **tint; 923 pf = it->funcs; 924 925 if (pf && pf->prim_c2i) 926 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 927 /* If ANY type clear type and set pointer to internal value */ 928 if (it->utype == V_ASN1_ANY) 929 { 930 if (!*pval) 931 { 932 typ = ASN1_TYPE_new(); 933 if (typ == NULL) 934 goto err; 935 *pval = (ASN1_VALUE *)typ; 936 } 937 else 938 typ = (ASN1_TYPE *)*pval; 939 940 if (utype != typ->type) 941 ASN1_TYPE_set(typ, utype, NULL); 942 opval = pval; 943 pval = (ASN1_VALUE **)&typ->value.ptr; 944 } 945 switch(utype) 946 { 947 case V_ASN1_OBJECT: 948 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 949 goto err; 950 break; 951 952 case V_ASN1_NULL: 953 if (len) 954 { 955 ASN1err(ASN1_F_ASN1_EX_C2I, 956 ASN1_R_NULL_IS_WRONG_LENGTH); 957 goto err; 958 } 959 *pval = (ASN1_VALUE *)1; 960 break; 961 962 case V_ASN1_BOOLEAN: 963 if (len != 1) 964 { 965 ASN1err(ASN1_F_ASN1_EX_C2I, 966 ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 967 goto err; 968 } 969 else 970 { 971 ASN1_BOOLEAN *tbool; 972 tbool = (ASN1_BOOLEAN *)pval; 973 *tbool = *cont; 974 } 975 break; 976 977 case V_ASN1_BIT_STRING: 978 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 979 goto err; 980 break; 981 982 case V_ASN1_INTEGER: 983 case V_ASN1_NEG_INTEGER: 984 case V_ASN1_ENUMERATED: 985 case V_ASN1_NEG_ENUMERATED: 986 tint = (ASN1_INTEGER **)pval; 987 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 988 goto err; 989 /* Fixup type to match the expected form */ 990 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 991 break; 992 993 case V_ASN1_OCTET_STRING: 994 case V_ASN1_NUMERICSTRING: 995 case V_ASN1_PRINTABLESTRING: 996 case V_ASN1_T61STRING: 997 case V_ASN1_VIDEOTEXSTRING: 998 case V_ASN1_IA5STRING: 999 case V_ASN1_UTCTIME: 1000 case V_ASN1_GENERALIZEDTIME: 1001 case V_ASN1_GRAPHICSTRING: 1002 case V_ASN1_VISIBLESTRING: 1003 case V_ASN1_GENERALSTRING: 1004 case V_ASN1_UNIVERSALSTRING: 1005 case V_ASN1_BMPSTRING: 1006 case V_ASN1_UTF8STRING: 1007 case V_ASN1_OTHER: 1008 case V_ASN1_SET: 1009 case V_ASN1_SEQUENCE: 1010 default: 1011 /* All based on ASN1_STRING and handled the same */ 1012 if (!*pval) 1013 { 1014 stmp = ASN1_STRING_type_new(utype); 1015 if (!stmp) 1016 { 1017 ASN1err(ASN1_F_ASN1_EX_C2I, 1018 ERR_R_MALLOC_FAILURE); 1019 goto err; 1020 } 1021 *pval = (ASN1_VALUE *)stmp; 1022 } 1023 else 1024 { 1025 stmp = (ASN1_STRING *)*pval; 1026 stmp->type = utype; 1027 } 1028 /* If we've already allocated a buffer use it */ 1029 if (*free_cont) 1030 { 1031 if (stmp->data) 1032 OPENSSL_free(stmp->data); 1033 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 1034 stmp->length = len; 1035 *free_cont = 0; 1036 } 1037 else 1038 { 1039 if (!ASN1_STRING_set(stmp, cont, len)) 1040 { 1041 ASN1err(ASN1_F_ASN1_EX_C2I, 1042 ERR_R_MALLOC_FAILURE); 1043 ASN1_STRING_free(stmp); 1044 *pval = NULL; 1045 goto err; 1046 } 1047 } 1048 break; 1049 } 1050 /* If ASN1_ANY and NULL type fix up value */ 1051 if (typ && (utype == V_ASN1_NULL)) 1052 typ->value.ptr = NULL; 1053 1054 ret = 1; 1055 err: 1056 if (!ret) 1057 { 1058 ASN1_TYPE_free(typ); 1059 if (opval) 1060 *opval = NULL; 1061 } 1062 return ret; 1063 } 1064 1065 1066 /* This function finds the end of an ASN1 structure when passed its maximum 1067 * length, whether it is indefinite length and a pointer to the content. 1068 * This is more efficient than calling asn1_collect because it does not 1069 * recurse on each indefinite length header. 1070 */ 1071 1072 static int asn1_find_end(const unsigned char **in, long len, char inf) 1073 { 1074 int expected_eoc; 1075 long plen; 1076 const unsigned char *p = *in, *q; 1077 /* If not indefinite length constructed just add length */ 1078 if (inf == 0) 1079 { 1080 *in += len; 1081 return 1; 1082 } 1083 expected_eoc = 1; 1084 /* Indefinite length constructed form. Find the end when enough EOCs 1085 * are found. If more indefinite length constructed headers 1086 * are encountered increment the expected eoc count otherwise just 1087 * skip to the end of the data. 1088 */ 1089 while (len > 0) 1090 { 1091 if(asn1_check_eoc(&p, len)) 1092 { 1093 expected_eoc--; 1094 if (expected_eoc == 0) 1095 break; 1096 len -= 2; 1097 continue; 1098 } 1099 q = p; 1100 /* Just read in a header: only care about the length */ 1101 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1102 -1, 0, 0, NULL)) 1103 { 1104 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 1105 return 0; 1106 } 1107 if (inf) 1108 expected_eoc++; 1109 else 1110 p += plen; 1111 len -= p - q; 1112 } 1113 if (expected_eoc) 1114 { 1115 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 1116 return 0; 1117 } 1118 *in = p; 1119 return 1; 1120 } 1121 /* This function collects the asn1 data from a constructred string 1122 * type into a buffer. The values of 'in' and 'len' should refer 1123 * to the contents of the constructed type and 'inf' should be set 1124 * if it is indefinite length. 1125 */ 1126 1127 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1128 char inf, int tag, int aclass) 1129 { 1130 const unsigned char *p, *q; 1131 long plen; 1132 char cst, ininf; 1133 p = *in; 1134 inf &= 1; 1135 /* If no buffer and not indefinite length constructed just pass over 1136 * the encoded data */ 1137 if (!buf && !inf) 1138 { 1139 *in += len; 1140 return 1; 1141 } 1142 while(len > 0) 1143 { 1144 q = p; 1145 /* Check for EOC */ 1146 if (asn1_check_eoc(&p, len)) 1147 { 1148 /* EOC is illegal outside indefinite length 1149 * constructed form */ 1150 if (!inf) 1151 { 1152 ASN1err(ASN1_F_ASN1_COLLECT, 1153 ASN1_R_UNEXPECTED_EOC); 1154 return 0; 1155 } 1156 inf = 0; 1157 break; 1158 } 1159 1160 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1161 len, tag, aclass, 0, NULL)) 1162 { 1163 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1164 return 0; 1165 } 1166 1167 /* If indefinite length constructed update max length */ 1168 if (cst) 1169 { 1170 #ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS 1171 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass)) 1172 return 0; 1173 #else 1174 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); 1175 return 0; 1176 #endif 1177 } 1178 else if (plen && !collect_data(buf, &p, plen)) 1179 return 0; 1180 len -= p - q; 1181 } 1182 if (inf) 1183 { 1184 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1185 return 0; 1186 } 1187 *in = p; 1188 return 1; 1189 } 1190 1191 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1192 { 1193 int len; 1194 if (buf) 1195 { 1196 len = buf->length; 1197 if (!BUF_MEM_grow_clean(buf, len + plen)) 1198 { 1199 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1200 return 0; 1201 } 1202 memcpy(buf->data + len, *p, plen); 1203 } 1204 *p += plen; 1205 return 1; 1206 } 1207 1208 /* Check for ASN1 EOC and swallow it if found */ 1209 1210 static int asn1_check_eoc(const unsigned char **in, long len) 1211 { 1212 const unsigned char *p; 1213 if (len < 2) return 0; 1214 p = *in; 1215 if (!p[0] && !p[1]) 1216 { 1217 *in += 2; 1218 return 1; 1219 } 1220 return 0; 1221 } 1222 1223 /* Check an ASN1 tag and length: a bit like ASN1_get_object 1224 * but it sets the length for indefinite length constructed 1225 * form, we don't know the exact length but we can set an 1226 * upper bound to the amount of data available minus the 1227 * header length just read. 1228 */ 1229 1230 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1231 char *inf, char *cst, 1232 const unsigned char **in, long len, 1233 int exptag, int expclass, char opt, 1234 ASN1_TLC *ctx) 1235 { 1236 int i; 1237 int ptag, pclass; 1238 long plen; 1239 const unsigned char *p, *q; 1240 p = *in; 1241 q = p; 1242 1243 if (ctx && ctx->valid) 1244 { 1245 i = ctx->ret; 1246 plen = ctx->plen; 1247 pclass = ctx->pclass; 1248 ptag = ctx->ptag; 1249 p += ctx->hdrlen; 1250 } 1251 else 1252 { 1253 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1254 if (ctx) 1255 { 1256 ctx->ret = i; 1257 ctx->plen = plen; 1258 ctx->pclass = pclass; 1259 ctx->ptag = ptag; 1260 ctx->hdrlen = p - q; 1261 ctx->valid = 1; 1262 /* If definite length, and no error, length + 1263 * header can't exceed total amount of data available. 1264 */ 1265 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) 1266 { 1267 ASN1err(ASN1_F_ASN1_CHECK_TLEN, 1268 ASN1_R_TOO_LONG); 1269 asn1_tlc_clear(ctx); 1270 return 0; 1271 } 1272 } 1273 } 1274 1275 if (i & 0x80) 1276 { 1277 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1278 asn1_tlc_clear(ctx); 1279 return 0; 1280 } 1281 if (exptag >= 0) 1282 { 1283 if ((exptag != ptag) || (expclass != pclass)) 1284 { 1285 /* If type is OPTIONAL, not an error: 1286 * indicate missing type. 1287 */ 1288 if (opt) return -1; 1289 asn1_tlc_clear(ctx); 1290 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1291 return 0; 1292 } 1293 /* We have a tag and class match: 1294 * assume we are going to do something with it */ 1295 asn1_tlc_clear(ctx); 1296 } 1297 1298 if (i & 1) 1299 plen = len - (p - q); 1300 1301 if (inf) 1302 *inf = i & 1; 1303 1304 if (cst) 1305 *cst = i & V_ASN1_CONSTRUCTED; 1306 1307 if (olen) 1308 *olen = plen; 1309 1310 if (oclass) 1311 *oclass = pclass; 1312 1313 if (otag) 1314 *otag = ptag; 1315 1316 *in = p; 1317 return 1; 1318 } 1319