1 /* tasn_dec.c */ 2 /* 3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project 4 * 2000. 5 */ 6 /* ==================================================================== 7 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * licensing@OpenSSL.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 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, ASN1_TLC *ctx); 80 81 static int asn1_template_ex_d2i(ASN1_VALUE **pval, 82 const unsigned char **in, long len, 83 const ASN1_TEMPLATE *tt, char opt, 84 ASN1_TLC *ctx); 85 static int asn1_template_noexp_d2i(ASN1_VALUE **val, 86 const unsigned char **in, long len, 87 const ASN1_TEMPLATE *tt, char opt, 88 ASN1_TLC *ctx); 89 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 90 const unsigned char **in, long len, 91 const ASN1_ITEM *it, 92 int tag, int aclass, char opt, 93 ASN1_TLC *ctx); 94 95 /* Table to convert tags to bit values, used for MSTRING type */ 96 static const unsigned long tag2bit[32] = { 97 /* tags 0 - 3 */ 98 0, 0, 0, B_ASN1_BIT_STRING, 99 /* tags 4- 7 */ 100 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN, 101 /* tags 8-11 */ 102 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, 103 /* tags 12-15 */ 104 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, 105 /* tags 16-19 */ 106 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING, 107 /* tags 20-22 */ 108 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING, 109 /* tags 23-24 */ 110 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, 111 /* tags 25-27 */ 112 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING, 113 /* tags 28-31 */ 114 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN, 115 }; 116 117 unsigned long ASN1_tag2bit(int tag) 118 { 119 if ((tag < 0) || (tag > 30)) 120 return 0; 121 return tag2bit[tag]; 122 } 123 124 /* Macro to initialize and invalidate the cache */ 125 126 #define asn1_tlc_clear(c) if (c) (c)->valid = 0 127 /* Version to avoid compiler warning about 'c' always non-NULL */ 128 #define asn1_tlc_clear_nc(c) (c)->valid = 0 129 130 /* 131 * Decode an ASN1 item, this currently behaves just like a standard 'd2i' 132 * function. 'in' points to a buffer to read the data from, in future we 133 * will have more advanced versions that can input data a piece at a time and 134 * this will simply be a special case. 135 */ 136 137 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, 138 const unsigned char **in, long len, 139 const ASN1_ITEM *it) 140 { 141 ASN1_TLC c; 142 ASN1_VALUE *ptmpval = NULL; 143 if (!pval) 144 pval = &ptmpval; 145 asn1_tlc_clear_nc(&c); 146 if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 147 return *pval; 148 return NULL; 149 } 150 151 int ASN1_template_d2i(ASN1_VALUE **pval, 152 const unsigned char **in, long len, 153 const ASN1_TEMPLATE *tt) 154 { 155 ASN1_TLC c; 156 asn1_tlc_clear_nc(&c); 157 return asn1_template_ex_d2i(pval, in, len, tt, 0, &c); 158 } 159 160 /* 161 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and 162 * tag mismatch return -1 to handle OPTIONAL 163 */ 164 165 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, 166 const ASN1_ITEM *it, 167 int tag, int aclass, char opt, ASN1_TLC *ctx) 168 { 169 const ASN1_TEMPLATE *tt, *errtt = NULL; 170 const ASN1_COMPAT_FUNCS *cf; 171 const ASN1_EXTERN_FUNCS *ef; 172 const ASN1_AUX *aux = it->funcs; 173 ASN1_aux_cb *asn1_cb; 174 const unsigned char *p = NULL, *q; 175 unsigned char *wp = NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */ 176 unsigned char imphack = 0, oclass; 177 char seq_eoc, seq_nolen, cst, isopt; 178 long tmplen; 179 int i; 180 int otag; 181 int ret = 0; 182 ASN1_VALUE **pchptr, *ptmpval; 183 if (!pval) 184 return 0; 185 if (aux && aux->asn1_cb) 186 asn1_cb = aux->asn1_cb; 187 else 188 asn1_cb = 0; 189 190 switch (it->itype) { 191 case ASN1_ITYPE_PRIMITIVE: 192 if (it->templates) { 193 /* 194 * tagging or OPTIONAL is currently illegal on an item template 195 * because the flags can't get passed down. In practice this 196 * isn't a problem: we include the relevant flags from the item 197 * template in the template itself. 198 */ 199 if ((tag != -1) || opt) { 200 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 201 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 202 goto err; 203 } 204 return asn1_template_ex_d2i(pval, in, len, 205 it->templates, opt, ctx); 206 } 207 return asn1_d2i_ex_primitive(pval, in, len, it, 208 tag, aclass, opt, ctx); 209 break; 210 211 case ASN1_ITYPE_MSTRING: 212 p = *in; 213 /* Just read in tag and class */ 214 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 215 &p, len, -1, 0, 1, ctx); 216 if (!ret) { 217 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 218 goto err; 219 } 220 221 /* Must be UNIVERSAL class */ 222 if (oclass != V_ASN1_UNIVERSAL) { 223 /* If OPTIONAL, assume this is OK */ 224 if (opt) 225 return -1; 226 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL); 227 goto err; 228 } 229 /* Check tag matches bit map */ 230 if (!(ASN1_tag2bit(otag) & it->utype)) { 231 /* If OPTIONAL, assume this is OK */ 232 if (opt) 233 return -1; 234 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_WRONG_TAG); 235 goto err; 236 } 237 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); 238 239 case ASN1_ITYPE_EXTERN: 240 /* Use new style d2i */ 241 ef = it->funcs; 242 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); 243 244 case ASN1_ITYPE_COMPAT: 245 /* we must resort to old style evil hackery */ 246 cf = it->funcs; 247 248 /* If OPTIONAL see if it is there */ 249 if (opt) { 250 int exptag; 251 p = *in; 252 if (tag == -1) 253 exptag = it->utype; 254 else 255 exptag = tag; 256 /* 257 * Don't care about anything other than presence of expected tag 258 */ 259 260 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL, 261 &p, len, exptag, aclass, 1, ctx); 262 if (!ret) { 263 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 264 goto err; 265 } 266 if (ret == -1) 267 return -1; 268 } 269 270 /* 271 * This is the old style evil hack IMPLICIT handling: since the 272 * underlying code is expecting a tag and class other than the one 273 * present we change the buffer temporarily then change it back 274 * afterwards. This doesn't and never did work for tags > 30. Yes 275 * this is *horrible* but it is only needed for old style d2i which 276 * will hopefully not be around for much longer. FIXME: should copy 277 * the buffer then modify it so the input buffer can be const: we 278 * should *always* copy because the old style d2i might modify the 279 * buffer. 280 */ 281 282 if (tag != -1) { 283 wp = *(unsigned char **)in; 284 imphack = *wp; 285 if (p == NULL) { 286 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 287 goto err; 288 } 289 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED) 290 | it->utype); 291 } 292 293 ptmpval = cf->asn1_d2i(pval, in, len); 294 295 if (tag != -1) 296 *wp = imphack; 297 298 if (ptmpval) 299 return 1; 300 301 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 302 goto err; 303 304 case ASN1_ITYPE_CHOICE: 305 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 306 goto auxerr; 307 if (*pval) { 308 /* Free up and zero CHOICE value if initialised */ 309 i = asn1_get_choice_selector(pval, it); 310 if ((i >= 0) && (i < it->tcount)) { 311 tt = it->templates + i; 312 pchptr = asn1_get_field_ptr(pval, tt); 313 ASN1_template_free(pchptr, tt); 314 asn1_set_choice_selector(pval, -1, it); 315 } 316 } else if (!ASN1_item_ex_new(pval, it)) { 317 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 318 goto err; 319 } 320 /* CHOICE type, try each possibility in turn */ 321 p = *in; 322 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 323 pchptr = asn1_get_field_ptr(pval, tt); 324 /* 325 * We mark field as OPTIONAL so its absence can be recognised. 326 */ 327 ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx); 328 /* If field not present, try the next one */ 329 if (ret == -1) 330 continue; 331 /* If positive return, read OK, break loop */ 332 if (ret > 0) 333 break; 334 /* Otherwise must be an ASN1 parsing error */ 335 errtt = tt; 336 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 337 goto err; 338 } 339 340 /* Did we fall off the end without reading anything? */ 341 if (i == it->tcount) { 342 /* If OPTIONAL, this is OK */ 343 if (opt) { 344 /* Free and zero it */ 345 ASN1_item_ex_free(pval, it); 346 return -1; 347 } 348 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE); 349 goto err; 350 } 351 352 asn1_set_choice_selector(pval, i, it); 353 *in = p; 354 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 355 goto auxerr; 356 return 1; 357 358 case ASN1_ITYPE_NDEF_SEQUENCE: 359 case ASN1_ITYPE_SEQUENCE: 360 p = *in; 361 tmplen = len; 362 363 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 364 if (tag == -1) { 365 tag = V_ASN1_SEQUENCE; 366 aclass = V_ASN1_UNIVERSAL; 367 } 368 /* Get SEQUENCE length and update len, p */ 369 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 370 &p, len, tag, aclass, opt, ctx); 371 if (!ret) { 372 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 373 goto err; 374 } else if (ret == -1) 375 return -1; 376 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) { 377 len = tmplen - (p - *in); 378 seq_nolen = 1; 379 } 380 /* If indefinite we don't do a length check */ 381 else 382 seq_nolen = seq_eoc; 383 if (!cst) { 384 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 385 goto err; 386 } 387 388 if (!*pval && !ASN1_item_ex_new(pval, it)) { 389 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 390 goto err; 391 } 392 393 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 394 goto auxerr; 395 396 /* Free up and zero any ADB found */ 397 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 398 if (tt->flags & ASN1_TFLG_ADB_MASK) { 399 const ASN1_TEMPLATE *seqtt; 400 ASN1_VALUE **pseqval; 401 seqtt = asn1_do_adb(pval, tt, 1); 402 pseqval = asn1_get_field_ptr(pval, seqtt); 403 ASN1_template_free(pseqval, seqtt); 404 } 405 } 406 407 /* Get each field entry */ 408 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 409 const ASN1_TEMPLATE *seqtt; 410 ASN1_VALUE **pseqval; 411 seqtt = asn1_do_adb(pval, tt, 1); 412 if (!seqtt) 413 goto err; 414 pseqval = asn1_get_field_ptr(pval, seqtt); 415 /* Have we ran out of data? */ 416 if (!len) 417 break; 418 q = p; 419 if (asn1_check_eoc(&p, len)) { 420 if (!seq_eoc) { 421 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_UNEXPECTED_EOC); 422 goto err; 423 } 424 len -= p - q; 425 seq_eoc = 0; 426 q = p; 427 break; 428 } 429 /* 430 * This determines the OPTIONAL flag value. The field cannot be 431 * omitted if it is the last of a SEQUENCE and there is still 432 * data to be read. This isn't strictly necessary but it 433 * increases efficiency in some cases. 434 */ 435 if (i == (it->tcount - 1)) 436 isopt = 0; 437 else 438 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 439 /* 440 * attempt to read in field, allowing each to be OPTIONAL 441 */ 442 443 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx); 444 if (!ret) { 445 errtt = seqtt; 446 goto err; 447 } else if (ret == -1) { 448 /* 449 * OPTIONAL component absent. Free and zero the field. 450 */ 451 ASN1_template_free(pseqval, seqtt); 452 continue; 453 } 454 /* Update length */ 455 len -= p - q; 456 } 457 458 /* Check for EOC if expecting one */ 459 if (seq_eoc && !asn1_check_eoc(&p, len)) { 460 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC); 461 goto err; 462 } 463 /* Check all data read */ 464 if (!seq_nolen && len) { 465 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH); 466 goto err; 467 } 468 469 /* 470 * If we get here we've got no more data in the SEQUENCE, however we 471 * may not have read all fields so check all remaining are OPTIONAL 472 * and clear any that are. 473 */ 474 for (; i < it->tcount; tt++, i++) { 475 const ASN1_TEMPLATE *seqtt; 476 seqtt = asn1_do_adb(pval, tt, 1); 477 if (!seqtt) 478 goto err; 479 if (seqtt->flags & ASN1_TFLG_OPTIONAL) { 480 ASN1_VALUE **pseqval; 481 pseqval = asn1_get_field_ptr(pval, seqtt); 482 ASN1_template_free(pseqval, seqtt); 483 } else { 484 errtt = seqtt; 485 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_FIELD_MISSING); 486 goto err; 487 } 488 } 489 /* Save encoding */ 490 if (!asn1_enc_save(pval, *in, p - *in, it)) 491 goto auxerr; 492 *in = p; 493 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 494 goto auxerr; 495 return 1; 496 497 default: 498 return 0; 499 } 500 auxerr: 501 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR); 502 err: 503 ASN1_item_ex_free(pval, it); 504 if (errtt) 505 ERR_add_error_data(4, "Field=", errtt->field_name, 506 ", Type=", it->sname); 507 else 508 ERR_add_error_data(2, "Type=", it->sname); 509 return 0; 510 } 511 512 /* 513 * Templates are handled with two separate functions. One handles any 514 * EXPLICIT tag and the other handles the rest. 515 */ 516 517 static int asn1_template_ex_d2i(ASN1_VALUE **val, 518 const unsigned char **in, long inlen, 519 const ASN1_TEMPLATE *tt, char opt, 520 ASN1_TLC *ctx) 521 { 522 int flags, aclass; 523 int ret; 524 long len; 525 const unsigned char *p, *q; 526 char exp_eoc; 527 if (!val) 528 return 0; 529 flags = tt->flags; 530 aclass = flags & ASN1_TFLG_TAG_CLASS; 531 532 p = *in; 533 534 /* Check if EXPLICIT tag expected */ 535 if (flags & ASN1_TFLG_EXPTAG) { 536 char cst; 537 /* 538 * Need to work out amount of data available to the inner content and 539 * where it starts: so read in EXPLICIT header to get the info. 540 */ 541 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 542 &p, inlen, tt->tag, aclass, opt, ctx); 543 q = p; 544 if (!ret) { 545 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 546 return 0; 547 } else if (ret == -1) 548 return -1; 549 if (!cst) { 550 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 551 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 552 return 0; 553 } 554 /* We've found the field so it can't be OPTIONAL now */ 555 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 556 if (!ret) { 557 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 558 return 0; 559 } 560 /* We read the field in OK so update length */ 561 len -= p - q; 562 if (exp_eoc) { 563 /* If NDEF we must have an EOC here */ 564 if (!asn1_check_eoc(&p, len)) { 565 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC); 566 goto err; 567 } 568 } else { 569 /* 570 * Otherwise we must hit the EXPLICIT tag end or its an error 571 */ 572 if (len) { 573 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 574 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 575 goto err; 576 } 577 } 578 } else 579 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx); 580 581 *in = p; 582 return 1; 583 584 err: 585 ASN1_template_free(val, tt); 586 return 0; 587 } 588 589 static int asn1_template_noexp_d2i(ASN1_VALUE **val, 590 const unsigned char **in, long len, 591 const ASN1_TEMPLATE *tt, char opt, 592 ASN1_TLC *ctx) 593 { 594 int flags, aclass; 595 int ret; 596 const unsigned char *p, *q; 597 if (!val) 598 return 0; 599 flags = tt->flags; 600 aclass = flags & ASN1_TFLG_TAG_CLASS; 601 602 p = *in; 603 q = p; 604 605 if (flags & ASN1_TFLG_SK_MASK) { 606 /* SET OF, SEQUENCE OF */ 607 int sktag, skaclass; 608 char sk_eoc; 609 /* First work out expected inner tag value */ 610 if (flags & ASN1_TFLG_IMPTAG) { 611 sktag = tt->tag; 612 skaclass = aclass; 613 } else { 614 skaclass = V_ASN1_UNIVERSAL; 615 if (flags & ASN1_TFLG_SET_OF) 616 sktag = V_ASN1_SET; 617 else 618 sktag = V_ASN1_SEQUENCE; 619 } 620 /* Get the tag */ 621 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 622 &p, len, sktag, skaclass, opt, ctx); 623 if (!ret) { 624 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 625 return 0; 626 } else if (ret == -1) 627 return -1; 628 if (!*val) 629 *val = (ASN1_VALUE *)sk_new_null(); 630 else { 631 /* 632 * We've got a valid STACK: free up any items present 633 */ 634 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; 635 ASN1_VALUE *vtmp; 636 while (sk_ASN1_VALUE_num(sktmp) > 0) { 637 vtmp = sk_ASN1_VALUE_pop(sktmp); 638 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); 639 } 640 } 641 642 if (!*val) { 643 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 644 goto err; 645 } 646 647 /* Read as many items as we can */ 648 while (len > 0) { 649 ASN1_VALUE *skfield; 650 q = p; 651 /* See if EOC found */ 652 if (asn1_check_eoc(&p, len)) { 653 if (!sk_eoc) { 654 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 655 ASN1_R_UNEXPECTED_EOC); 656 goto err; 657 } 658 len -= p - q; 659 sk_eoc = 0; 660 break; 661 } 662 skfield = NULL; 663 if (!ASN1_item_ex_d2i(&skfield, &p, len, 664 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) { 665 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 666 ERR_R_NESTED_ASN1_ERROR); 667 goto err; 668 } 669 len -= p - q; 670 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { 671 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 672 goto err; 673 } 674 } 675 if (sk_eoc) { 676 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 677 goto err; 678 } 679 } else if (flags & ASN1_TFLG_IMPTAG) { 680 /* IMPLICIT tagging */ 681 ret = ASN1_item_ex_d2i(val, &p, len, 682 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, 683 ctx); 684 if (!ret) { 685 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 686 goto err; 687 } else if (ret == -1) 688 return -1; 689 } else { 690 /* Nothing special */ 691 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 692 -1, 0, opt, ctx); 693 if (!ret) { 694 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 695 goto err; 696 } else if (ret == -1) 697 return -1; 698 } 699 700 *in = p; 701 return 1; 702 703 err: 704 ASN1_template_free(val, tt); 705 return 0; 706 } 707 708 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 709 const unsigned char **in, long inlen, 710 const ASN1_ITEM *it, 711 int tag, int aclass, char opt, ASN1_TLC *ctx) 712 { 713 int ret = 0, utype; 714 long plen; 715 char cst, inf, free_cont = 0; 716 const unsigned char *p; 717 BUF_MEM buf; 718 const unsigned char *cont = NULL; 719 long len; 720 if (!pval) { 721 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 722 return 0; /* Should never happen */ 723 } 724 725 if (it->itype == ASN1_ITYPE_MSTRING) { 726 utype = tag; 727 tag = -1; 728 } else 729 utype = it->utype; 730 731 if (utype == V_ASN1_ANY) { 732 /* If type is ANY need to figure out type from tag */ 733 unsigned char oclass; 734 if (tag >= 0) { 735 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY); 736 return 0; 737 } 738 if (opt) { 739 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 740 ASN1_R_ILLEGAL_OPTIONAL_ANY); 741 return 0; 742 } 743 p = *in; 744 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 745 &p, inlen, -1, 0, 0, ctx); 746 if (!ret) { 747 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 748 return 0; 749 } 750 if (oclass != V_ASN1_UNIVERSAL) 751 utype = V_ASN1_OTHER; 752 } 753 if (tag == -1) { 754 tag = utype; 755 aclass = V_ASN1_UNIVERSAL; 756 } 757 p = *in; 758 /* Check header */ 759 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 760 &p, inlen, tag, aclass, opt, ctx); 761 if (!ret) { 762 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 763 return 0; 764 } else if (ret == -1) 765 return -1; 766 ret = 0; 767 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 768 if ((utype == V_ASN1_SEQUENCE) 769 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) { 770 /* 771 * Clear context cache for type OTHER because the auto clear when we 772 * have a exact match wont work 773 */ 774 if (utype == V_ASN1_OTHER) { 775 asn1_tlc_clear(ctx); 776 } 777 /* SEQUENCE and SET must be constructed */ 778 else if (!cst) { 779 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 780 ASN1_R_TYPE_NOT_CONSTRUCTED); 781 return 0; 782 } 783 784 cont = *in; 785 /* If indefinite length constructed find the real end */ 786 if (inf) { 787 if (!asn1_find_end(&p, plen, inf)) 788 goto err; 789 len = p - cont; 790 } else { 791 len = p - cont + plen; 792 p += plen; 793 buf.data = NULL; 794 } 795 } else if (cst) { 796 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 797 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 798 || utype == V_ASN1_ENUMERATED) { 799 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE); 800 return 0; 801 } 802 buf.length = 0; 803 buf.max = 0; 804 buf.data = NULL; 805 /* 806 * Should really check the internal tags are correct but some things 807 * may get this wrong. The relevant specs say that constructed string 808 * types should be OCTET STRINGs internally irrespective of the type. 809 * So instead just check for UNIVERSAL class and ignore the tag. 810 */ 811 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { 812 free_cont = 1; 813 goto err; 814 } 815 len = buf.length; 816 /* Append a final null to string */ 817 if (!BUF_MEM_grow_clean(&buf, len + 1)) { 818 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE); 819 return 0; 820 } 821 buf.data[len] = 0; 822 cont = (const unsigned char *)buf.data; 823 free_cont = 1; 824 } else { 825 cont = p; 826 len = plen; 827 p += plen; 828 } 829 830 /* We now have content length and type: translate into a structure */ 831 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 832 goto err; 833 834 *in = p; 835 ret = 1; 836 err: 837 if (free_cont && buf.data) 838 OPENSSL_free(buf.data); 839 return ret; 840 } 841 842 /* Translate ASN1 content octets into a structure */ 843 844 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 845 int utype, char *free_cont, const ASN1_ITEM *it) 846 { 847 ASN1_VALUE **opval = NULL; 848 ASN1_STRING *stmp; 849 ASN1_TYPE *typ = NULL; 850 int ret = 0; 851 const ASN1_PRIMITIVE_FUNCS *pf; 852 ASN1_INTEGER **tint; 853 pf = it->funcs; 854 855 if (pf && pf->prim_c2i) 856 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 857 /* If ANY type clear type and set pointer to internal value */ 858 if (it->utype == V_ASN1_ANY) { 859 if (!*pval) { 860 typ = ASN1_TYPE_new(); 861 if (typ == NULL) 862 goto err; 863 *pval = (ASN1_VALUE *)typ; 864 } else 865 typ = (ASN1_TYPE *)*pval; 866 867 if (utype != typ->type) 868 ASN1_TYPE_set(typ, utype, NULL); 869 opval = pval; 870 pval = &typ->value.asn1_value; 871 } 872 switch (utype) { 873 case V_ASN1_OBJECT: 874 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 875 goto err; 876 break; 877 878 case V_ASN1_NULL: 879 if (len) { 880 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH); 881 goto err; 882 } 883 *pval = (ASN1_VALUE *)1; 884 break; 885 886 case V_ASN1_BOOLEAN: 887 if (len != 1) { 888 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 889 goto err; 890 } else { 891 ASN1_BOOLEAN *tbool; 892 tbool = (ASN1_BOOLEAN *)pval; 893 *tbool = *cont; 894 } 895 break; 896 897 case V_ASN1_BIT_STRING: 898 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 899 goto err; 900 break; 901 902 case V_ASN1_INTEGER: 903 case V_ASN1_NEG_INTEGER: 904 case V_ASN1_ENUMERATED: 905 case V_ASN1_NEG_ENUMERATED: 906 tint = (ASN1_INTEGER **)pval; 907 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 908 goto err; 909 /* Fixup type to match the expected form */ 910 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 911 break; 912 913 case V_ASN1_OCTET_STRING: 914 case V_ASN1_NUMERICSTRING: 915 case V_ASN1_PRINTABLESTRING: 916 case V_ASN1_T61STRING: 917 case V_ASN1_VIDEOTEXSTRING: 918 case V_ASN1_IA5STRING: 919 case V_ASN1_UTCTIME: 920 case V_ASN1_GENERALIZEDTIME: 921 case V_ASN1_GRAPHICSTRING: 922 case V_ASN1_VISIBLESTRING: 923 case V_ASN1_GENERALSTRING: 924 case V_ASN1_UNIVERSALSTRING: 925 case V_ASN1_BMPSTRING: 926 case V_ASN1_UTF8STRING: 927 case V_ASN1_OTHER: 928 case V_ASN1_SET: 929 case V_ASN1_SEQUENCE: 930 default: 931 if (utype == V_ASN1_BMPSTRING && (len & 1)) { 932 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 933 goto err; 934 } 935 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { 936 ASN1err(ASN1_F_ASN1_EX_C2I, 937 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 938 goto err; 939 } 940 /* All based on ASN1_STRING and handled the same */ 941 if (!*pval) { 942 stmp = ASN1_STRING_type_new(utype); 943 if (!stmp) { 944 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 945 goto err; 946 } 947 *pval = (ASN1_VALUE *)stmp; 948 } else { 949 stmp = (ASN1_STRING *)*pval; 950 stmp->type = utype; 951 } 952 /* If we've already allocated a buffer use it */ 953 if (*free_cont) { 954 if (stmp->data) 955 OPENSSL_free(stmp->data); 956 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 957 stmp->length = len; 958 *free_cont = 0; 959 } else { 960 if (!ASN1_STRING_set(stmp, cont, len)) { 961 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 962 ASN1_STRING_free(stmp); 963 *pval = NULL; 964 goto err; 965 } 966 } 967 break; 968 } 969 /* If ASN1_ANY and NULL type fix up value */ 970 if (typ && (utype == V_ASN1_NULL)) 971 typ->value.ptr = NULL; 972 973 ret = 1; 974 err: 975 if (!ret) { 976 ASN1_TYPE_free(typ); 977 if (opval) 978 *opval = NULL; 979 } 980 return ret; 981 } 982 983 /* 984 * This function finds the end of an ASN1 structure when passed its maximum 985 * length, whether it is indefinite length and a pointer to the content. This 986 * is more efficient than calling asn1_collect because it does not recurse on 987 * each indefinite length header. 988 */ 989 990 static int asn1_find_end(const unsigned char **in, long len, char inf) 991 { 992 int expected_eoc; 993 long plen; 994 const unsigned char *p = *in, *q; 995 /* If not indefinite length constructed just add length */ 996 if (inf == 0) { 997 *in += len; 998 return 1; 999 } 1000 expected_eoc = 1; 1001 /* 1002 * Indefinite length constructed form. Find the end when enough EOCs are 1003 * found. If more indefinite length constructed headers are encountered 1004 * increment the expected eoc count otherwise just skip to the end of the 1005 * data. 1006 */ 1007 while (len > 0) { 1008 if (asn1_check_eoc(&p, len)) { 1009 expected_eoc--; 1010 if (expected_eoc == 0) 1011 break; 1012 len -= 2; 1013 continue; 1014 } 1015 q = p; 1016 /* Just read in a header: only care about the length */ 1017 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1018 -1, 0, 0, NULL)) { 1019 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 1020 return 0; 1021 } 1022 if (inf) 1023 expected_eoc++; 1024 else 1025 p += plen; 1026 len -= p - q; 1027 } 1028 if (expected_eoc) { 1029 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 1030 return 0; 1031 } 1032 *in = p; 1033 return 1; 1034 } 1035 1036 /* 1037 * This function collects the asn1 data from a constructred string type into 1038 * a buffer. The values of 'in' and 'len' should refer to the contents of the 1039 * constructed type and 'inf' should be set if it is indefinite length. 1040 */ 1041 1042 #ifndef ASN1_MAX_STRING_NEST 1043 /* 1044 * This determines how many levels of recursion are permitted in ASN1 string 1045 * types. If it is not limited stack overflows can occur. If set to zero no 1046 * recursion is allowed at all. Although zero should be adequate examples 1047 * exist that require a value of 1. So 5 should be more than enough. 1048 */ 1049 # define ASN1_MAX_STRING_NEST 5 1050 #endif 1051 1052 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1053 char inf, int tag, int aclass, int depth) 1054 { 1055 const unsigned char *p, *q; 1056 long plen; 1057 char cst, ininf; 1058 p = *in; 1059 inf &= 1; 1060 /* 1061 * If no buffer and not indefinite length constructed just pass over the 1062 * encoded data 1063 */ 1064 if (!buf && !inf) { 1065 *in += len; 1066 return 1; 1067 } 1068 while (len > 0) { 1069 q = p; 1070 /* Check for EOC */ 1071 if (asn1_check_eoc(&p, len)) { 1072 /* 1073 * EOC is illegal outside indefinite length constructed form 1074 */ 1075 if (!inf) { 1076 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC); 1077 return 0; 1078 } 1079 inf = 0; 1080 break; 1081 } 1082 1083 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1084 len, tag, aclass, 0, NULL)) { 1085 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1086 return 0; 1087 } 1088 1089 /* If indefinite length constructed update max length */ 1090 if (cst) { 1091 if (depth >= ASN1_MAX_STRING_NEST) { 1092 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); 1093 return 0; 1094 } 1095 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1096 return 0; 1097 } else if (plen && !collect_data(buf, &p, plen)) 1098 return 0; 1099 len -= p - q; 1100 } 1101 if (inf) { 1102 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1103 return 0; 1104 } 1105 *in = p; 1106 return 1; 1107 } 1108 1109 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1110 { 1111 int len; 1112 if (buf) { 1113 len = buf->length; 1114 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1115 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1116 return 0; 1117 } 1118 memcpy(buf->data + len, *p, plen); 1119 } 1120 *p += plen; 1121 return 1; 1122 } 1123 1124 /* Check for ASN1 EOC and swallow it if found */ 1125 1126 static int asn1_check_eoc(const unsigned char **in, long len) 1127 { 1128 const unsigned char *p; 1129 if (len < 2) 1130 return 0; 1131 p = *in; 1132 if (!p[0] && !p[1]) { 1133 *in += 2; 1134 return 1; 1135 } 1136 return 0; 1137 } 1138 1139 /* 1140 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1141 * length for indefinite length constructed form, we don't know the exact 1142 * length but we can set an upper bound to the amount of data available minus 1143 * the header length just read. 1144 */ 1145 1146 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1147 char *inf, char *cst, 1148 const unsigned char **in, long len, 1149 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1150 { 1151 int i; 1152 int ptag, pclass; 1153 long plen; 1154 const unsigned char *p, *q; 1155 p = *in; 1156 q = p; 1157 1158 if (ctx && ctx->valid) { 1159 i = ctx->ret; 1160 plen = ctx->plen; 1161 pclass = ctx->pclass; 1162 ptag = ctx->ptag; 1163 p += ctx->hdrlen; 1164 } else { 1165 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1166 if (ctx) { 1167 ctx->ret = i; 1168 ctx->plen = plen; 1169 ctx->pclass = pclass; 1170 ctx->ptag = ptag; 1171 ctx->hdrlen = p - q; 1172 ctx->valid = 1; 1173 /* 1174 * If definite length, and no error, length + header can't exceed 1175 * total amount of data available. 1176 */ 1177 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { 1178 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG); 1179 asn1_tlc_clear(ctx); 1180 return 0; 1181 } 1182 } 1183 } 1184 1185 if (i & 0x80) { 1186 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1187 asn1_tlc_clear(ctx); 1188 return 0; 1189 } 1190 if (exptag >= 0) { 1191 if ((exptag != ptag) || (expclass != pclass)) { 1192 /* 1193 * If type is OPTIONAL, not an error: indicate missing type. 1194 */ 1195 if (opt) 1196 return -1; 1197 asn1_tlc_clear(ctx); 1198 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1199 return 0; 1200 } 1201 /* 1202 * We have a tag and class match: assume we are going to do something 1203 * with it 1204 */ 1205 asn1_tlc_clear(ctx); 1206 } 1207 1208 if (i & 1) 1209 plen = len - (p - q); 1210 1211 if (inf) 1212 *inf = i & 1; 1213 1214 if (cst) 1215 *cst = i & V_ASN1_CONSTRUCTED; 1216 1217 if (olen) 1218 *olen = plen; 1219 1220 if (oclass) 1221 *oclass = pclass; 1222 1223 if (otag) 1224 *otag = ptag; 1225 1226 *in = p; 1227 return 1; 1228 } 1229