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 int combine = aclass & ASN1_TFLG_COMBINE; 184 aclass &= ~ASN1_TFLG_COMBINE; 185 if (!pval) 186 return 0; 187 if (aux && aux->asn1_cb) 188 asn1_cb = aux->asn1_cb; 189 else 190 asn1_cb = 0; 191 192 switch (it->itype) { 193 case ASN1_ITYPE_PRIMITIVE: 194 if (it->templates) { 195 /* 196 * tagging or OPTIONAL is currently illegal on an item template 197 * because the flags can't get passed down. In practice this 198 * isn't a problem: we include the relevant flags from the item 199 * template in the template itself. 200 */ 201 if ((tag != -1) || opt) { 202 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, 203 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 204 goto err; 205 } 206 return asn1_template_ex_d2i(pval, in, len, 207 it->templates, opt, ctx); 208 } 209 return asn1_d2i_ex_primitive(pval, in, len, it, 210 tag, aclass, opt, ctx); 211 break; 212 213 case ASN1_ITYPE_MSTRING: 214 p = *in; 215 /* Just read in tag and class */ 216 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 217 &p, len, -1, 0, 1, ctx); 218 if (!ret) { 219 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 220 goto err; 221 } 222 223 /* Must be UNIVERSAL class */ 224 if (oclass != V_ASN1_UNIVERSAL) { 225 /* If OPTIONAL, assume this is OK */ 226 if (opt) 227 return -1; 228 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL); 229 goto err; 230 } 231 /* Check tag matches bit map */ 232 if (!(ASN1_tag2bit(otag) & it->utype)) { 233 /* If OPTIONAL, assume this is OK */ 234 if (opt) 235 return -1; 236 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_WRONG_TAG); 237 goto err; 238 } 239 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); 240 241 case ASN1_ITYPE_EXTERN: 242 /* Use new style d2i */ 243 ef = it->funcs; 244 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); 245 246 case ASN1_ITYPE_COMPAT: 247 /* we must resort to old style evil hackery */ 248 cf = it->funcs; 249 250 /* If OPTIONAL see if it is there */ 251 if (opt) { 252 int exptag; 253 p = *in; 254 if (tag == -1) 255 exptag = it->utype; 256 else 257 exptag = tag; 258 /* 259 * Don't care about anything other than presence of expected tag 260 */ 261 262 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL, 263 &p, len, exptag, aclass, 1, ctx); 264 if (!ret) { 265 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 266 goto err; 267 } 268 if (ret == -1) 269 return -1; 270 } 271 272 /* 273 * This is the old style evil hack IMPLICIT handling: since the 274 * underlying code is expecting a tag and class other than the one 275 * present we change the buffer temporarily then change it back 276 * afterwards. This doesn't and never did work for tags > 30. Yes 277 * this is *horrible* but it is only needed for old style d2i which 278 * will hopefully not be around for much longer. FIXME: should copy 279 * the buffer then modify it so the input buffer can be const: we 280 * should *always* copy because the old style d2i might modify the 281 * buffer. 282 */ 283 284 if (tag != -1) { 285 wp = *(unsigned char **)in; 286 imphack = *wp; 287 if (p == NULL) { 288 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 289 goto err; 290 } 291 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED) 292 | it->utype); 293 } 294 295 ptmpval = cf->asn1_d2i(pval, in, len); 296 297 if (tag != -1) 298 *wp = imphack; 299 300 if (ptmpval) 301 return 1; 302 303 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 304 goto err; 305 306 case ASN1_ITYPE_CHOICE: 307 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 308 goto auxerr; 309 if (*pval) { 310 /* Free up and zero CHOICE value if initialised */ 311 i = asn1_get_choice_selector(pval, it); 312 if ((i >= 0) && (i < it->tcount)) { 313 tt = it->templates + i; 314 pchptr = asn1_get_field_ptr(pval, tt); 315 ASN1_template_free(pchptr, tt); 316 asn1_set_choice_selector(pval, -1, it); 317 } 318 } else if (!ASN1_item_ex_new(pval, it)) { 319 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 320 goto err; 321 } 322 /* CHOICE type, try each possibility in turn */ 323 p = *in; 324 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 325 pchptr = asn1_get_field_ptr(pval, tt); 326 /* 327 * We mark field as OPTIONAL so its absence 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, 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 /* If OPTIONAL, this is OK */ 345 if (opt) { 346 /* Free and zero it */ 347 ASN1_item_ex_free(pval, it); 348 return -1; 349 } 350 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE); 351 goto err; 352 } 353 354 asn1_set_choice_selector(pval, i, it); 355 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 356 goto auxerr; 357 *in = p; 358 return 1; 359 360 case ASN1_ITYPE_NDEF_SEQUENCE: 361 case ASN1_ITYPE_SEQUENCE: 362 p = *in; 363 tmplen = len; 364 365 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ 366 if (tag == -1) { 367 tag = V_ASN1_SEQUENCE; 368 aclass = V_ASN1_UNIVERSAL; 369 } 370 /* Get SEQUENCE length and update len, p */ 371 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, 372 &p, len, tag, aclass, opt, ctx); 373 if (!ret) { 374 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 375 goto err; 376 } else if (ret == -1) 377 return -1; 378 if (aux && (aux->flags & ASN1_AFLG_BROKEN)) { 379 len = tmplen - (p - *in); 380 seq_nolen = 1; 381 } 382 /* If indefinite we don't do a length check */ 383 else 384 seq_nolen = seq_eoc; 385 if (!cst) { 386 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 387 goto err; 388 } 389 390 if (!*pval && !ASN1_item_ex_new(pval, it)) { 391 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 392 goto err; 393 } 394 395 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 396 goto auxerr; 397 398 /* Free up and zero any ADB found */ 399 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 400 if (tt->flags & ASN1_TFLG_ADB_MASK) { 401 const ASN1_TEMPLATE *seqtt; 402 ASN1_VALUE **pseqval; 403 seqtt = asn1_do_adb(pval, tt, 1); 404 pseqval = asn1_get_field_ptr(pval, seqtt); 405 ASN1_template_free(pseqval, seqtt); 406 } 407 } 408 409 /* Get each field entry */ 410 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 411 const ASN1_TEMPLATE *seqtt; 412 ASN1_VALUE **pseqval; 413 seqtt = asn1_do_adb(pval, tt, 1); 414 if (!seqtt) 415 goto err; 416 pseqval = asn1_get_field_ptr(pval, seqtt); 417 /* Have we ran out of data? */ 418 if (!len) 419 break; 420 q = p; 421 if (asn1_check_eoc(&p, len)) { 422 if (!seq_eoc) { 423 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_UNEXPECTED_EOC); 424 goto err; 425 } 426 len -= p - q; 427 seq_eoc = 0; 428 q = p; 429 break; 430 } 431 /* 432 * This determines the OPTIONAL flag value. The field cannot be 433 * omitted if it is the last of a SEQUENCE and there is still 434 * data to be read. This isn't strictly necessary but it 435 * increases efficiency in some cases. 436 */ 437 if (i == (it->tcount - 1)) 438 isopt = 0; 439 else 440 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 441 /* 442 * attempt to read in field, allowing each to be OPTIONAL 443 */ 444 445 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx); 446 if (!ret) { 447 errtt = seqtt; 448 goto err; 449 } else if (ret == -1) { 450 /* 451 * OPTIONAL component absent. Free and zero the field. 452 */ 453 ASN1_template_free(pseqval, seqtt); 454 continue; 455 } 456 /* Update length */ 457 len -= p - q; 458 } 459 460 /* Check for EOC if expecting one */ 461 if (seq_eoc && !asn1_check_eoc(&p, len)) { 462 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC); 463 goto err; 464 } 465 /* Check all data read */ 466 if (!seq_nolen && len) { 467 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH); 468 goto err; 469 } 470 471 /* 472 * If we get here we've got no more data in the SEQUENCE, however we 473 * may not have read all fields so check all remaining are OPTIONAL 474 * and clear any that are. 475 */ 476 for (; i < it->tcount; tt++, i++) { 477 const ASN1_TEMPLATE *seqtt; 478 seqtt = asn1_do_adb(pval, tt, 1); 479 if (!seqtt) 480 goto err; 481 if (seqtt->flags & ASN1_TFLG_OPTIONAL) { 482 ASN1_VALUE **pseqval; 483 pseqval = asn1_get_field_ptr(pval, seqtt); 484 ASN1_template_free(pseqval, seqtt); 485 } else { 486 errtt = seqtt; 487 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_FIELD_MISSING); 488 goto err; 489 } 490 } 491 /* Save encoding */ 492 if (!asn1_enc_save(pval, *in, p - *in, it)) 493 goto auxerr; 494 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 495 goto auxerr; 496 *in = p; 497 return 1; 498 499 default: 500 return 0; 501 } 502 auxerr: 503 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR); 504 err: 505 if (combine == 0) 506 ASN1_item_ex_free(pval, it); 507 if (errtt) 508 ERR_add_error_data(4, "Field=", errtt->field_name, 509 ", Type=", it->sname); 510 else 511 ERR_add_error_data(2, "Type=", it->sname); 512 return 0; 513 } 514 515 /* 516 * Templates are handled with two separate functions. One handles any 517 * EXPLICIT tag and the other handles the rest. 518 */ 519 520 static int asn1_template_ex_d2i(ASN1_VALUE **val, 521 const unsigned char **in, long inlen, 522 const ASN1_TEMPLATE *tt, char opt, 523 ASN1_TLC *ctx) 524 { 525 int flags, aclass; 526 int ret; 527 long len; 528 const unsigned char *p, *q; 529 char exp_eoc; 530 if (!val) 531 return 0; 532 flags = tt->flags; 533 aclass = flags & ASN1_TFLG_TAG_CLASS; 534 535 p = *in; 536 537 /* Check if EXPLICIT tag expected */ 538 if (flags & ASN1_TFLG_EXPTAG) { 539 char cst; 540 /* 541 * Need to work out amount of data available to the inner content and 542 * where it starts: so read in EXPLICIT header to get the info. 543 */ 544 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 545 &p, inlen, tt->tag, aclass, opt, ctx); 546 q = p; 547 if (!ret) { 548 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 549 return 0; 550 } else if (ret == -1) 551 return -1; 552 if (!cst) { 553 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 554 ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 555 return 0; 556 } 557 /* We've found the field so it can't be OPTIONAL now */ 558 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 559 if (!ret) { 560 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); 561 return 0; 562 } 563 /* We read the field in OK so update length */ 564 len -= p - q; 565 if (exp_eoc) { 566 /* If NDEF we must have an EOC here */ 567 if (!asn1_check_eoc(&p, len)) { 568 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC); 569 goto err; 570 } 571 } else { 572 /* 573 * Otherwise we must hit the EXPLICIT tag end or its an error 574 */ 575 if (len) { 576 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, 577 ASN1_R_EXPLICIT_LENGTH_MISMATCH); 578 goto err; 579 } 580 } 581 } else 582 return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx); 583 584 *in = p; 585 return 1; 586 587 err: 588 ASN1_template_free(val, tt); 589 return 0; 590 } 591 592 static int asn1_template_noexp_d2i(ASN1_VALUE **val, 593 const unsigned char **in, long len, 594 const ASN1_TEMPLATE *tt, char opt, 595 ASN1_TLC *ctx) 596 { 597 int flags, aclass; 598 int ret; 599 const unsigned char *p, *q; 600 if (!val) 601 return 0; 602 flags = tt->flags; 603 aclass = flags & ASN1_TFLG_TAG_CLASS; 604 605 p = *in; 606 q = p; 607 608 if (flags & ASN1_TFLG_SK_MASK) { 609 /* SET OF, SEQUENCE OF */ 610 int sktag, skaclass; 611 char sk_eoc; 612 /* First work out expected inner tag value */ 613 if (flags & ASN1_TFLG_IMPTAG) { 614 sktag = tt->tag; 615 skaclass = aclass; 616 } else { 617 skaclass = V_ASN1_UNIVERSAL; 618 if (flags & ASN1_TFLG_SET_OF) 619 sktag = V_ASN1_SET; 620 else 621 sktag = V_ASN1_SEQUENCE; 622 } 623 /* Get the tag */ 624 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 625 &p, len, sktag, skaclass, opt, ctx); 626 if (!ret) { 627 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 628 return 0; 629 } else if (ret == -1) 630 return -1; 631 if (!*val) 632 *val = (ASN1_VALUE *)sk_new_null(); 633 else { 634 /* 635 * We've got a valid STACK: free up any items present 636 */ 637 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; 638 ASN1_VALUE *vtmp; 639 while (sk_ASN1_VALUE_num(sktmp) > 0) { 640 vtmp = sk_ASN1_VALUE_pop(sktmp); 641 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); 642 } 643 } 644 645 if (!*val) { 646 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 647 goto err; 648 } 649 650 /* Read as many items as we can */ 651 while (len > 0) { 652 ASN1_VALUE *skfield; 653 q = p; 654 /* See if EOC found */ 655 if (asn1_check_eoc(&p, len)) { 656 if (!sk_eoc) { 657 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 658 ASN1_R_UNEXPECTED_EOC); 659 goto err; 660 } 661 len -= p - q; 662 sk_eoc = 0; 663 break; 664 } 665 skfield = NULL; 666 if (!ASN1_item_ex_d2i(&skfield, &p, len, 667 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) { 668 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, 669 ERR_R_NESTED_ASN1_ERROR); 670 goto err; 671 } 672 len -= p - q; 673 if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { 674 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); 675 goto err; 676 } 677 } 678 if (sk_eoc) { 679 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); 680 goto err; 681 } 682 } else if (flags & ASN1_TFLG_IMPTAG) { 683 /* IMPLICIT tagging */ 684 ret = ASN1_item_ex_d2i(val, &p, len, 685 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, 686 ctx); 687 if (!ret) { 688 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 689 goto err; 690 } else if (ret == -1) 691 return -1; 692 } else { 693 /* Nothing special */ 694 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 695 -1, tt->flags & ASN1_TFLG_COMBINE, opt, ctx); 696 if (!ret) { 697 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); 698 goto err; 699 } else if (ret == -1) 700 return -1; 701 } 702 703 *in = p; 704 return 1; 705 706 err: 707 ASN1_template_free(val, tt); 708 return 0; 709 } 710 711 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 712 const unsigned char **in, long inlen, 713 const ASN1_ITEM *it, 714 int tag, int aclass, char opt, ASN1_TLC *ctx) 715 { 716 int ret = 0, utype; 717 long plen; 718 char cst, inf, free_cont = 0; 719 const unsigned char *p; 720 BUF_MEM buf; 721 const unsigned char *cont = NULL; 722 long len; 723 if (!pval) { 724 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); 725 return 0; /* Should never happen */ 726 } 727 728 if (it->itype == ASN1_ITYPE_MSTRING) { 729 utype = tag; 730 tag = -1; 731 } else 732 utype = it->utype; 733 734 if (utype == V_ASN1_ANY) { 735 /* If type is ANY need to figure out type from tag */ 736 unsigned char oclass; 737 if (tag >= 0) { 738 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY); 739 return 0; 740 } 741 if (opt) { 742 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 743 ASN1_R_ILLEGAL_OPTIONAL_ANY); 744 return 0; 745 } 746 p = *in; 747 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, 748 &p, inlen, -1, 0, 0, ctx); 749 if (!ret) { 750 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 751 return 0; 752 } 753 if (oclass != V_ASN1_UNIVERSAL) 754 utype = V_ASN1_OTHER; 755 } 756 if (tag == -1) { 757 tag = utype; 758 aclass = V_ASN1_UNIVERSAL; 759 } 760 p = *in; 761 /* Check header */ 762 ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, 763 &p, inlen, tag, aclass, opt, ctx); 764 if (!ret) { 765 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); 766 return 0; 767 } else if (ret == -1) 768 return -1; 769 ret = 0; 770 /* SEQUENCE, SET and "OTHER" are left in encoded form */ 771 if ((utype == V_ASN1_SEQUENCE) 772 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) { 773 /* 774 * Clear context cache for type OTHER because the auto clear when we 775 * have a exact match wont work 776 */ 777 if (utype == V_ASN1_OTHER) { 778 asn1_tlc_clear(ctx); 779 } 780 /* SEQUENCE and SET must be constructed */ 781 else if (!cst) { 782 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, 783 ASN1_R_TYPE_NOT_CONSTRUCTED); 784 return 0; 785 } 786 787 cont = *in; 788 /* If indefinite length constructed find the real end */ 789 if (inf) { 790 if (!asn1_find_end(&p, plen, inf)) 791 goto err; 792 len = p - cont; 793 } else { 794 len = p - cont + plen; 795 p += plen; 796 buf.data = NULL; 797 } 798 } else if (cst) { 799 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 800 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 801 || utype == V_ASN1_ENUMERATED) { 802 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE); 803 return 0; 804 } 805 buf.length = 0; 806 buf.max = 0; 807 buf.data = NULL; 808 /* 809 * Should really check the internal tags are correct but some things 810 * may get this wrong. The relevant specs say that constructed string 811 * types should be OCTET STRINGs internally irrespective of the type. 812 * So instead just check for UNIVERSAL class and ignore the tag. 813 */ 814 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { 815 free_cont = 1; 816 goto err; 817 } 818 len = buf.length; 819 /* Append a final null to string */ 820 if (!BUF_MEM_grow_clean(&buf, len + 1)) { 821 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE); 822 return 0; 823 } 824 buf.data[len] = 0; 825 cont = (const unsigned char *)buf.data; 826 free_cont = 1; 827 } else { 828 cont = p; 829 len = plen; 830 p += plen; 831 } 832 833 /* We now have content length and type: translate into a structure */ 834 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 835 goto err; 836 837 *in = p; 838 ret = 1; 839 err: 840 if (free_cont && buf.data) 841 OPENSSL_free(buf.data); 842 return ret; 843 } 844 845 /* Translate ASN1 content octets into a structure */ 846 847 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 848 int utype, char *free_cont, const ASN1_ITEM *it) 849 { 850 ASN1_VALUE **opval = NULL; 851 ASN1_STRING *stmp; 852 ASN1_TYPE *typ = NULL; 853 int ret = 0; 854 const ASN1_PRIMITIVE_FUNCS *pf; 855 ASN1_INTEGER **tint; 856 pf = it->funcs; 857 858 if (pf && pf->prim_c2i) 859 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 860 /* If ANY type clear type and set pointer to internal value */ 861 if (it->utype == V_ASN1_ANY) { 862 if (!*pval) { 863 typ = ASN1_TYPE_new(); 864 if (typ == NULL) 865 goto err; 866 *pval = (ASN1_VALUE *)typ; 867 } else 868 typ = (ASN1_TYPE *)*pval; 869 870 if (utype != typ->type) 871 ASN1_TYPE_set(typ, utype, NULL); 872 opval = pval; 873 pval = &typ->value.asn1_value; 874 } 875 switch (utype) { 876 case V_ASN1_OBJECT: 877 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 878 goto err; 879 break; 880 881 case V_ASN1_NULL: 882 if (len) { 883 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH); 884 goto err; 885 } 886 *pval = (ASN1_VALUE *)1; 887 break; 888 889 case V_ASN1_BOOLEAN: 890 if (len != 1) { 891 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 892 goto err; 893 } else { 894 ASN1_BOOLEAN *tbool; 895 tbool = (ASN1_BOOLEAN *)pval; 896 *tbool = *cont; 897 } 898 break; 899 900 case V_ASN1_BIT_STRING: 901 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 902 goto err; 903 break; 904 905 case V_ASN1_INTEGER: 906 case V_ASN1_NEG_INTEGER: 907 case V_ASN1_ENUMERATED: 908 case V_ASN1_NEG_ENUMERATED: 909 tint = (ASN1_INTEGER **)pval; 910 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 911 goto err; 912 /* Fixup type to match the expected form */ 913 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 914 break; 915 916 case V_ASN1_OCTET_STRING: 917 case V_ASN1_NUMERICSTRING: 918 case V_ASN1_PRINTABLESTRING: 919 case V_ASN1_T61STRING: 920 case V_ASN1_VIDEOTEXSTRING: 921 case V_ASN1_IA5STRING: 922 case V_ASN1_UTCTIME: 923 case V_ASN1_GENERALIZEDTIME: 924 case V_ASN1_GRAPHICSTRING: 925 case V_ASN1_VISIBLESTRING: 926 case V_ASN1_GENERALSTRING: 927 case V_ASN1_UNIVERSALSTRING: 928 case V_ASN1_BMPSTRING: 929 case V_ASN1_UTF8STRING: 930 case V_ASN1_OTHER: 931 case V_ASN1_SET: 932 case V_ASN1_SEQUENCE: 933 default: 934 if (utype == V_ASN1_BMPSTRING && (len & 1)) { 935 ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 936 goto err; 937 } 938 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { 939 ASN1err(ASN1_F_ASN1_EX_C2I, 940 ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 941 goto err; 942 } 943 /* All based on ASN1_STRING and handled the same */ 944 if (!*pval) { 945 stmp = ASN1_STRING_type_new(utype); 946 if (!stmp) { 947 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 948 goto err; 949 } 950 *pval = (ASN1_VALUE *)stmp; 951 } else { 952 stmp = (ASN1_STRING *)*pval; 953 stmp->type = utype; 954 } 955 /* If we've already allocated a buffer use it */ 956 if (*free_cont) { 957 if (stmp->data) 958 OPENSSL_free(stmp->data); 959 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 960 stmp->length = len; 961 *free_cont = 0; 962 } else { 963 if (!ASN1_STRING_set(stmp, cont, len)) { 964 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); 965 ASN1_STRING_free(stmp); 966 *pval = NULL; 967 goto err; 968 } 969 } 970 break; 971 } 972 /* If ASN1_ANY and NULL type fix up value */ 973 if (typ && (utype == V_ASN1_NULL)) 974 typ->value.ptr = NULL; 975 976 ret = 1; 977 err: 978 if (!ret) { 979 ASN1_TYPE_free(typ); 980 if (opval) 981 *opval = NULL; 982 } 983 return ret; 984 } 985 986 /* 987 * This function finds the end of an ASN1 structure when passed its maximum 988 * length, whether it is indefinite length and a pointer to the content. This 989 * is more efficient than calling asn1_collect because it does not recurse on 990 * each indefinite length header. 991 */ 992 993 static int asn1_find_end(const unsigned char **in, long len, char inf) 994 { 995 int expected_eoc; 996 long plen; 997 const unsigned char *p = *in, *q; 998 /* If not indefinite length constructed just add length */ 999 if (inf == 0) { 1000 *in += len; 1001 return 1; 1002 } 1003 expected_eoc = 1; 1004 /* 1005 * Indefinite length constructed form. Find the end when enough EOCs are 1006 * found. If more indefinite length constructed headers are encountered 1007 * increment the expected eoc count otherwise just skip to the end of the 1008 * data. 1009 */ 1010 while (len > 0) { 1011 if (asn1_check_eoc(&p, len)) { 1012 expected_eoc--; 1013 if (expected_eoc == 0) 1014 break; 1015 len -= 2; 1016 continue; 1017 } 1018 q = p; 1019 /* Just read in a header: only care about the length */ 1020 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1021 -1, 0, 0, NULL)) { 1022 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); 1023 return 0; 1024 } 1025 if (inf) 1026 expected_eoc++; 1027 else 1028 p += plen; 1029 len -= p - q; 1030 } 1031 if (expected_eoc) { 1032 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); 1033 return 0; 1034 } 1035 *in = p; 1036 return 1; 1037 } 1038 1039 /* 1040 * This function collects the asn1 data from a constructred string type into 1041 * a buffer. The values of 'in' and 'len' should refer to the contents of the 1042 * constructed type and 'inf' should be set if it is indefinite length. 1043 */ 1044 1045 #ifndef ASN1_MAX_STRING_NEST 1046 /* 1047 * This determines how many levels of recursion are permitted in ASN1 string 1048 * types. If it is not limited stack overflows can occur. If set to zero no 1049 * recursion is allowed at all. Although zero should be adequate examples 1050 * exist that require a value of 1. So 5 should be more than enough. 1051 */ 1052 # define ASN1_MAX_STRING_NEST 5 1053 #endif 1054 1055 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1056 char inf, int tag, int aclass, int depth) 1057 { 1058 const unsigned char *p, *q; 1059 long plen; 1060 char cst, ininf; 1061 p = *in; 1062 inf &= 1; 1063 /* 1064 * If no buffer and not indefinite length constructed just pass over the 1065 * encoded data 1066 */ 1067 if (!buf && !inf) { 1068 *in += len; 1069 return 1; 1070 } 1071 while (len > 0) { 1072 q = p; 1073 /* Check for EOC */ 1074 if (asn1_check_eoc(&p, len)) { 1075 /* 1076 * EOC is illegal outside indefinite length constructed form 1077 */ 1078 if (!inf) { 1079 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC); 1080 return 0; 1081 } 1082 inf = 0; 1083 break; 1084 } 1085 1086 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1087 len, tag, aclass, 0, NULL)) { 1088 ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); 1089 return 0; 1090 } 1091 1092 /* If indefinite length constructed update max length */ 1093 if (cst) { 1094 if (depth >= ASN1_MAX_STRING_NEST) { 1095 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); 1096 return 0; 1097 } 1098 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1099 return 0; 1100 } else if (plen && !collect_data(buf, &p, plen)) 1101 return 0; 1102 len -= p - q; 1103 } 1104 if (inf) { 1105 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); 1106 return 0; 1107 } 1108 *in = p; 1109 return 1; 1110 } 1111 1112 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1113 { 1114 int len; 1115 if (buf) { 1116 len = buf->length; 1117 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1118 ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); 1119 return 0; 1120 } 1121 memcpy(buf->data + len, *p, plen); 1122 } 1123 *p += plen; 1124 return 1; 1125 } 1126 1127 /* Check for ASN1 EOC and swallow it if found */ 1128 1129 static int asn1_check_eoc(const unsigned char **in, long len) 1130 { 1131 const unsigned char *p; 1132 if (len < 2) 1133 return 0; 1134 p = *in; 1135 if (!p[0] && !p[1]) { 1136 *in += 2; 1137 return 1; 1138 } 1139 return 0; 1140 } 1141 1142 /* 1143 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1144 * length for indefinite length constructed form, we don't know the exact 1145 * length but we can set an upper bound to the amount of data available minus 1146 * the header length just read. 1147 */ 1148 1149 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1150 char *inf, char *cst, 1151 const unsigned char **in, long len, 1152 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1153 { 1154 int i; 1155 int ptag, pclass; 1156 long plen; 1157 const unsigned char *p, *q; 1158 p = *in; 1159 q = p; 1160 1161 if (ctx && ctx->valid) { 1162 i = ctx->ret; 1163 plen = ctx->plen; 1164 pclass = ctx->pclass; 1165 ptag = ctx->ptag; 1166 p += ctx->hdrlen; 1167 } else { 1168 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1169 if (ctx) { 1170 ctx->ret = i; 1171 ctx->plen = plen; 1172 ctx->pclass = pclass; 1173 ctx->ptag = ptag; 1174 ctx->hdrlen = p - q; 1175 ctx->valid = 1; 1176 /* 1177 * If definite length, and no error, length + header can't exceed 1178 * total amount of data available. 1179 */ 1180 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { 1181 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG); 1182 asn1_tlc_clear(ctx); 1183 return 0; 1184 } 1185 } 1186 } 1187 1188 if (i & 0x80) { 1189 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); 1190 asn1_tlc_clear(ctx); 1191 return 0; 1192 } 1193 if (exptag >= 0) { 1194 if ((exptag != ptag) || (expclass != pclass)) { 1195 /* 1196 * If type is OPTIONAL, not an error: indicate missing type. 1197 */ 1198 if (opt) 1199 return -1; 1200 asn1_tlc_clear(ctx); 1201 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); 1202 return 0; 1203 } 1204 /* 1205 * We have a tag and class match: assume we are going to do something 1206 * with it 1207 */ 1208 asn1_tlc_clear(ctx); 1209 } 1210 1211 if (i & 1) 1212 plen = len - (p - q); 1213 1214 if (inf) 1215 *inf = i & 1; 1216 1217 if (cst) 1218 *cst = i & V_ASN1_CONSTRUCTED; 1219 1220 if (olen) 1221 *olen = plen; 1222 1223 if (oclass) 1224 *oclass = pclass; 1225 1226 if (otag) 1227 *otag = ptag; 1228 1229 *in = p; 1230 return 1; 1231 } 1232