1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] */ 56 57 #include <openssl/asn1.h> 58 59 #include <limits.h> 60 #include <string.h> 61 62 #include <openssl/asn1t.h> 63 #include <openssl/buf.h> 64 #include <openssl/err.h> 65 #include <openssl/mem.h> 66 67 #include "../internal.h" 68 69 static int asn1_check_eoc(const unsigned char **in, long len); 70 static int asn1_find_end(const unsigned char **in, long len, char inf); 71 72 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 73 char inf, int tag, int aclass, int depth); 74 75 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen); 76 77 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 78 char *inf, char *cst, 79 const unsigned char **in, long len, 80 int exptag, int expclass, char opt, 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, 94 ASN1_TLC *ctx); 95 96 /* Table to convert tags to bit values, used for MSTRING type */ 97 static const unsigned long tag2bit[32] = { 98 0, 0, 0, B_ASN1_BIT_STRING, /* tags 0 - 3 */ 99 B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN, /* tags 4- 7 */ 100 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, /* tags 101 * 8-11 */ 102 B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, /* tags 103 * 12-15 104 */ 105 B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING, /* tags 106 * 16-19 107 */ 108 B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING, /* tags 20-22 */ 109 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, /* tags 23-24 */ 110 B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING, /* tags 111 * 25-27 */ 112 B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN, /* tags 113 * 28-31 114 */ 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 /* 152 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and 153 * tag mismatch return -1 to handle OPTIONAL 154 */ 155 156 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, 157 const ASN1_ITEM *it, 158 int tag, int aclass, char opt, ASN1_TLC *ctx) 159 { 160 const ASN1_TEMPLATE *tt, *errtt = NULL; 161 const ASN1_COMPAT_FUNCS *cf; 162 const ASN1_EXTERN_FUNCS *ef; 163 const ASN1_AUX *aux = it->funcs; 164 ASN1_aux_cb *asn1_cb; 165 const unsigned char *p = NULL, *q; 166 unsigned char *wp = NULL; /* BIG FAT WARNING! BREAKS CONST WHERE USED */ 167 unsigned char imphack = 0, oclass; 168 char seq_eoc, seq_nolen, cst, isopt; 169 long tmplen; 170 int i; 171 int otag; 172 int ret = 0; 173 ASN1_VALUE **pchptr, *ptmpval; 174 int combine = aclass & ASN1_TFLG_COMBINE; 175 aclass &= ~ASN1_TFLG_COMBINE; 176 if (!pval) 177 return 0; 178 if (aux && aux->asn1_cb) 179 asn1_cb = aux->asn1_cb; 180 else 181 asn1_cb = 0; 182 183 /* 184 * Bound |len| to comfortably fit in an int. Lengths in this module often 185 * switch between int and long without overflow checks. 186 */ 187 if (len > INT_MAX/2) { 188 len = INT_MAX/2; 189 } 190 191 switch (it->itype) { 192 case ASN1_ITYPE_PRIMITIVE: 193 if (it->templates) { 194 /* 195 * tagging or OPTIONAL is currently illegal on an item template 196 * because the flags can't get passed down. In practice this 197 * isn't a problem: we include the relevant flags from the item 198 * template in the template itself. 199 */ 200 if ((tag != -1) || opt) { 201 OPENSSL_PUT_ERROR(ASN1, 202 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); 203 goto err; 204 } 205 return asn1_template_ex_d2i(pval, in, len, 206 it->templates, opt, ctx); 207 } 208 return asn1_d2i_ex_primitive(pval, in, len, it, 209 tag, aclass, opt, ctx); 210 break; 211 212 case ASN1_ITYPE_MSTRING: 213 p = *in; 214 /* Just read in tag and class */ 215 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, 216 &p, len, -1, 0, 1, ctx); 217 if (!ret) { 218 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 219 goto err; 220 } 221 222 /* Must be UNIVERSAL class */ 223 if (oclass != V_ASN1_UNIVERSAL) { 224 /* If OPTIONAL, assume this is OK */ 225 if (opt) 226 return -1; 227 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_NOT_UNIVERSAL); 228 goto err; 229 } 230 /* Check tag matches bit map */ 231 if (!(ASN1_tag2bit(otag) & it->utype)) { 232 /* If OPTIONAL, assume this is OK */ 233 if (opt) 234 return -1; 235 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_WRONG_TAG); 236 goto err; 237 } 238 return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); 239 240 case ASN1_ITYPE_EXTERN: 241 /* Use new style d2i */ 242 ef = it->funcs; 243 return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); 244 245 case ASN1_ITYPE_COMPAT: 246 /* we must resort to old style evil hackery */ 247 cf = it->funcs; 248 249 /* If OPTIONAL see if it is there */ 250 if (opt) { 251 int exptag; 252 p = *in; 253 if (tag == -1) 254 exptag = it->utype; 255 else 256 exptag = tag; 257 /* 258 * Don't care about anything other than presence of expected tag 259 */ 260 261 ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL, 262 &p, len, exptag, aclass, 1, ctx); 263 if (!ret) { 264 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 265 goto err; 266 } 267 if (ret == -1) 268 return -1; 269 } 270 271 /* 272 * This is the old style evil hack IMPLICIT handling: since the 273 * underlying code is expecting a tag and class other than the one 274 * present we change the buffer temporarily then change it back 275 * afterwards. This doesn't and never did work for tags > 30. Yes 276 * this is *horrible* but it is only needed for old style d2i which 277 * will hopefully not be around for much longer. FIXME: should copy 278 * the buffer then modify it so the input buffer can be const: we 279 * should *always* copy because the old style d2i might modify the 280 * buffer. 281 */ 282 283 if (tag != -1) { 284 wp = *(unsigned char **)in; 285 imphack = *wp; 286 if (p == NULL) { 287 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 288 goto err; 289 } 290 *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED) 291 | it->utype); 292 } 293 294 ptmpval = cf->asn1_d2i(pval, in, len); 295 296 if (tag != -1) 297 *wp = imphack; 298 299 if (ptmpval) 300 return 1; 301 302 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 303 goto err; 304 305 case ASN1_ITYPE_CHOICE: 306 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) 307 goto auxerr; 308 309 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 OPENSSL_PUT_ERROR(ASN1, ASN1_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 OPENSSL_PUT_ERROR(ASN1, ASN1_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 OPENSSL_PUT_ERROR(ASN1, 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 OPENSSL_PUT_ERROR(ASN1, ASN1_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 OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); 387 goto err; 388 } 389 390 if (!*pval && !ASN1_item_ex_new(pval, it)) { 391 OPENSSL_PUT_ERROR(ASN1, ASN1_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, 0); 404 if (seqtt == NULL) 405 continue; 406 pseqval = asn1_get_field_ptr(pval, seqtt); 407 ASN1_template_free(pseqval, seqtt); 408 } 409 } 410 411 /* Get each field entry */ 412 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { 413 const ASN1_TEMPLATE *seqtt; 414 ASN1_VALUE **pseqval; 415 seqtt = asn1_do_adb(pval, tt, 1); 416 if (seqtt == NULL) 417 goto err; 418 pseqval = asn1_get_field_ptr(pval, seqtt); 419 /* Have we ran out of data? */ 420 if (!len) 421 break; 422 q = p; 423 if (asn1_check_eoc(&p, len)) { 424 if (!seq_eoc) { 425 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNEXPECTED_EOC); 426 goto err; 427 } 428 len -= p - q; 429 seq_eoc = 0; 430 q = p; 431 break; 432 } 433 /* 434 * This determines the OPTIONAL flag value. The field cannot be 435 * omitted if it is the last of a SEQUENCE and there is still 436 * data to be read. This isn't strictly necessary but it 437 * increases efficiency in some cases. 438 */ 439 if (i == (it->tcount - 1)) 440 isopt = 0; 441 else 442 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); 443 /* 444 * attempt to read in field, allowing each to be OPTIONAL 445 */ 446 447 ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx); 448 if (!ret) { 449 errtt = seqtt; 450 goto err; 451 } else if (ret == -1) { 452 /* 453 * OPTIONAL component absent. Free and zero the field. 454 */ 455 ASN1_template_free(pseqval, seqtt); 456 continue; 457 } 458 /* Update length */ 459 len -= p - q; 460 } 461 462 /* Check for EOC if expecting one */ 463 if (seq_eoc && !asn1_check_eoc(&p, len)) { 464 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MISSING_EOC); 465 goto err; 466 } 467 /* Check all data read */ 468 if (!seq_nolen && len) { 469 OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_LENGTH_MISMATCH); 470 goto err; 471 } 472 473 /* 474 * If we get here we've got no more data in the SEQUENCE, however we 475 * may not have read all fields so check all remaining are OPTIONAL 476 * and clear any that are. 477 */ 478 for (; i < it->tcount; tt++, i++) { 479 const ASN1_TEMPLATE *seqtt; 480 seqtt = asn1_do_adb(pval, tt, 1); 481 if (seqtt == NULL) 482 goto err; 483 if (seqtt->flags & ASN1_TFLG_OPTIONAL) { 484 ASN1_VALUE **pseqval; 485 pseqval = asn1_get_field_ptr(pval, seqtt); 486 ASN1_template_free(pseqval, seqtt); 487 } else { 488 errtt = seqtt; 489 OPENSSL_PUT_ERROR(ASN1, ASN1_R_FIELD_MISSING); 490 goto err; 491 } 492 } 493 /* Save encoding */ 494 if (!asn1_enc_save(pval, *in, p - *in, it)) 495 goto auxerr; 496 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) 497 goto auxerr; 498 *in = p; 499 return 1; 500 501 default: 502 return 0; 503 } 504 auxerr: 505 OPENSSL_PUT_ERROR(ASN1, ASN1_R_AUX_ERROR); 506 err: 507 if (combine == 0) 508 ASN1_item_ex_free(pval, it); 509 if (errtt) 510 ERR_add_error_data(4, "Field=", errtt->field_name, 511 ", Type=", it->sname); 512 else 513 ERR_add_error_data(2, "Type=", it->sname); 514 return 0; 515 } 516 517 /* 518 * Templates are handled with two separate functions. One handles any 519 * EXPLICIT tag and the other handles the rest. 520 */ 521 522 static int asn1_template_ex_d2i(ASN1_VALUE **val, 523 const unsigned char **in, long inlen, 524 const ASN1_TEMPLATE *tt, char opt, 525 ASN1_TLC *ctx) 526 { 527 int flags, aclass; 528 int ret; 529 long len; 530 const unsigned char *p, *q; 531 char exp_eoc; 532 if (!val) 533 return 0; 534 flags = tt->flags; 535 aclass = flags & ASN1_TFLG_TAG_CLASS; 536 537 p = *in; 538 539 /* Check if EXPLICIT tag expected */ 540 if (flags & ASN1_TFLG_EXPTAG) { 541 char cst; 542 /* 543 * Need to work out amount of data available to the inner content and 544 * where it starts: so read in EXPLICIT header to get the info. 545 */ 546 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, 547 &p, inlen, tt->tag, aclass, opt, ctx); 548 q = p; 549 if (!ret) { 550 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 551 return 0; 552 } else if (ret == -1) 553 return -1; 554 if (!cst) { 555 OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); 556 return 0; 557 } 558 /* We've found the field so it can't be OPTIONAL now */ 559 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx); 560 if (!ret) { 561 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 562 return 0; 563 } 564 /* We read the field in OK so update length */ 565 len -= p - q; 566 if (exp_eoc) { 567 /* If NDEF we must have an EOC here */ 568 if (!asn1_check_eoc(&p, len)) { 569 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MISSING_EOC); 570 goto err; 571 } 572 } else { 573 /* 574 * Otherwise we must hit the EXPLICIT tag end or its an error 575 */ 576 if (len) { 577 OPENSSL_PUT_ERROR(ASN1, 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; 600 if (!val) 601 return 0; 602 flags = tt->flags; 603 aclass = flags & ASN1_TFLG_TAG_CLASS; 604 605 p = *in; 606 607 if (flags & ASN1_TFLG_SK_MASK) { 608 /* SET OF, SEQUENCE OF */ 609 int sktag, skaclass; 610 char sk_eoc; 611 /* First work out expected inner tag value */ 612 if (flags & ASN1_TFLG_IMPTAG) { 613 sktag = tt->tag; 614 skaclass = aclass; 615 } else { 616 skaclass = V_ASN1_UNIVERSAL; 617 if (flags & ASN1_TFLG_SET_OF) 618 sktag = V_ASN1_SET; 619 else 620 sktag = V_ASN1_SEQUENCE; 621 } 622 /* Get the tag */ 623 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, 624 &p, len, sktag, skaclass, opt, ctx); 625 if (!ret) { 626 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 627 return 0; 628 } else if (ret == -1) 629 return -1; 630 if (!*val) 631 *val = (ASN1_VALUE *)sk_new_null(); 632 else { 633 /* 634 * We've got a valid STACK: free up any items present 635 */ 636 STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; 637 ASN1_VALUE *vtmp; 638 while (sk_ASN1_VALUE_num(sktmp) > 0) { 639 vtmp = sk_ASN1_VALUE_pop(sktmp); 640 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); 641 } 642 } 643 644 if (!*val) { 645 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 646 goto err; 647 } 648 649 /* Read as many items as we can */ 650 while (len > 0) { 651 ASN1_VALUE *skfield; 652 const unsigned char *q = p; 653 /* See if EOC found */ 654 if (asn1_check_eoc(&p, len)) { 655 if (!sk_eoc) { 656 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNEXPECTED_EOC); 657 goto err; 658 } 659 len -= p - q; 660 sk_eoc = 0; 661 break; 662 } 663 skfield = NULL; 664 if (!ASN1_item_ex_d2i(&skfield, &p, len, 665 ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) { 666 OPENSSL_PUT_ERROR(ASN1, ASN1_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 ASN1_item_ex_free(&skfield, ASN1_ITEM_ptr(tt->item)); 672 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 673 goto err; 674 } 675 } 676 if (sk_eoc) { 677 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MISSING_EOC); 678 goto err; 679 } 680 } else if (flags & ASN1_TFLG_IMPTAG) { 681 /* IMPLICIT tagging */ 682 ret = ASN1_item_ex_d2i(val, &p, len, 683 ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, 684 ctx); 685 if (!ret) { 686 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 687 goto err; 688 } else if (ret == -1) 689 return -1; 690 } else { 691 /* Nothing special */ 692 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), 693 -1, tt->flags & ASN1_TFLG_COMBINE, opt, ctx); 694 if (!ret) { 695 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 696 goto err; 697 } else if (ret == -1) 698 return -1; 699 } 700 701 *in = p; 702 return 1; 703 704 err: 705 ASN1_template_free(val, tt); 706 return 0; 707 } 708 709 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, 710 const unsigned char **in, long inlen, 711 const ASN1_ITEM *it, 712 int tag, int aclass, char opt, ASN1_TLC *ctx) 713 { 714 int ret = 0, utype; 715 long plen; 716 char cst, inf, free_cont = 0; 717 const unsigned char *p; 718 BUF_MEM buf = {0, NULL, 0 }; 719 const unsigned char *cont = NULL; 720 long len; 721 if (!pval) { 722 OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_NULL); 723 return 0; /* Should never happen */ 724 } 725 726 if (it->itype == ASN1_ITYPE_MSTRING) { 727 utype = tag; 728 tag = -1; 729 } else 730 utype = it->utype; 731 732 if (utype == V_ASN1_ANY) { 733 /* If type is ANY need to figure out type from tag */ 734 unsigned char oclass; 735 if (tag >= 0) { 736 OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_TAGGED_ANY); 737 return 0; 738 } 739 if (opt) { 740 OPENSSL_PUT_ERROR(ASN1, 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 OPENSSL_PUT_ERROR(ASN1, ASN1_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 OPENSSL_PUT_ERROR(ASN1, ASN1_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 OPENSSL_PUT_ERROR(ASN1, ASN1_R_TYPE_NOT_CONSTRUCTED); 780 return 0; 781 } 782 783 cont = *in; 784 /* If indefinite length constructed find the real end */ 785 if (inf) { 786 if (!asn1_find_end(&p, plen, inf)) 787 goto err; 788 len = p - cont; 789 } else { 790 len = p - cont + plen; 791 p += plen; 792 } 793 } else if (cst) { 794 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN 795 || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER 796 || utype == V_ASN1_ENUMERATED) { 797 /* These types only have primitive encodings. */ 798 OPENSSL_PUT_ERROR(ASN1, ASN1_R_TYPE_NOT_PRIMITIVE); 799 return 0; 800 } 801 802 /* Free any returned 'buf' content */ 803 free_cont = 1; 804 /* 805 * Should really check the internal tags are correct but some things 806 * may get this wrong. The relevant specs say that constructed string 807 * types should be OCTET STRINGs internally irrespective of the type. 808 * So instead just check for UNIVERSAL class and ignore the tag. 809 */ 810 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { 811 goto err; 812 } 813 len = buf.length; 814 /* Append a final null to string */ 815 if (!BUF_MEM_grow_clean(&buf, len + 1)) { 816 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 817 goto err; 818 } 819 buf.data[len] = 0; 820 cont = (const unsigned char *)buf.data; 821 } else { 822 cont = p; 823 len = plen; 824 p += plen; 825 } 826 827 /* We now have content length and type: translate into a structure */ 828 /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */ 829 if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) 830 goto err; 831 832 *in = p; 833 ret = 1; 834 err: 835 if (free_cont && buf.data) 836 OPENSSL_free(buf.data); 837 return ret; 838 } 839 840 /* Translate ASN1 content octets into a structure */ 841 842 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 843 int utype, char *free_cont, const ASN1_ITEM *it) 844 { 845 ASN1_VALUE **opval = NULL; 846 ASN1_STRING *stmp; 847 ASN1_TYPE *typ = NULL; 848 int ret = 0; 849 const ASN1_PRIMITIVE_FUNCS *pf; 850 ASN1_INTEGER **tint; 851 pf = it->funcs; 852 853 if (pf && pf->prim_c2i) 854 return pf->prim_c2i(pval, cont, len, utype, free_cont, it); 855 /* If ANY type clear type and set pointer to internal value */ 856 if (it->utype == V_ASN1_ANY) { 857 if (!*pval) { 858 typ = ASN1_TYPE_new(); 859 if (typ == NULL) 860 goto err; 861 *pval = (ASN1_VALUE *)typ; 862 } else 863 typ = (ASN1_TYPE *)*pval; 864 865 if (utype != typ->type) 866 ASN1_TYPE_set(typ, utype, NULL); 867 opval = pval; 868 pval = &typ->value.asn1_value; 869 } 870 switch (utype) { 871 case V_ASN1_OBJECT: 872 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) 873 goto err; 874 break; 875 876 case V_ASN1_NULL: 877 if (len) { 878 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NULL_IS_WRONG_LENGTH); 879 goto err; 880 } 881 *pval = (ASN1_VALUE *)1; 882 break; 883 884 case V_ASN1_BOOLEAN: 885 if (len != 1) { 886 OPENSSL_PUT_ERROR(ASN1, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); 887 goto err; 888 } else { 889 ASN1_BOOLEAN *tbool; 890 tbool = (ASN1_BOOLEAN *)pval; 891 *tbool = *cont; 892 } 893 break; 894 895 case V_ASN1_BIT_STRING: 896 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) 897 goto err; 898 break; 899 900 case V_ASN1_INTEGER: 901 case V_ASN1_ENUMERATED: 902 tint = (ASN1_INTEGER **)pval; 903 if (!c2i_ASN1_INTEGER(tint, &cont, len)) 904 goto err; 905 /* Fixup type to match the expected form */ 906 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); 907 break; 908 909 case V_ASN1_OCTET_STRING: 910 case V_ASN1_NUMERICSTRING: 911 case V_ASN1_PRINTABLESTRING: 912 case V_ASN1_T61STRING: 913 case V_ASN1_VIDEOTEXSTRING: 914 case V_ASN1_IA5STRING: 915 case V_ASN1_UTCTIME: 916 case V_ASN1_GENERALIZEDTIME: 917 case V_ASN1_GRAPHICSTRING: 918 case V_ASN1_VISIBLESTRING: 919 case V_ASN1_GENERALSTRING: 920 case V_ASN1_UNIVERSALSTRING: 921 case V_ASN1_BMPSTRING: 922 case V_ASN1_UTF8STRING: 923 case V_ASN1_OTHER: 924 case V_ASN1_SET: 925 case V_ASN1_SEQUENCE: 926 default: 927 if (utype == V_ASN1_BMPSTRING && (len & 1)) { 928 OPENSSL_PUT_ERROR(ASN1, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); 929 goto err; 930 } 931 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { 932 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); 933 goto err; 934 } 935 /* All based on ASN1_STRING and handled the same */ 936 if (!*pval) { 937 stmp = ASN1_STRING_type_new(utype); 938 if (!stmp) { 939 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 940 goto err; 941 } 942 *pval = (ASN1_VALUE *)stmp; 943 } else { 944 stmp = (ASN1_STRING *)*pval; 945 stmp->type = utype; 946 } 947 /* If we've already allocated a buffer use it */ 948 if (*free_cont) { 949 if (stmp->data) 950 OPENSSL_free(stmp->data); 951 stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ 952 stmp->length = len; 953 *free_cont = 0; 954 } else { 955 if (!ASN1_STRING_set(stmp, cont, len)) { 956 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 957 ASN1_STRING_free(stmp); 958 *pval = NULL; 959 goto err; 960 } 961 } 962 break; 963 } 964 /* If ASN1_ANY and NULL type fix up value */ 965 if (typ && (utype == V_ASN1_NULL)) 966 typ->value.ptr = NULL; 967 968 ret = 1; 969 err: 970 if (!ret) { 971 ASN1_TYPE_free(typ); 972 if (opval) 973 *opval = NULL; 974 } 975 return ret; 976 } 977 978 /* 979 * This function finds the end of an ASN1 structure when passed its maximum 980 * length, whether it is indefinite length and a pointer to the content. This 981 * is more efficient than calling asn1_collect because it does not recurse on 982 * each indefinite length header. 983 */ 984 985 static int asn1_find_end(const unsigned char **in, long len, char inf) 986 { 987 int expected_eoc; 988 long plen; 989 const unsigned char *p = *in, *q; 990 /* If not indefinite length constructed just add length */ 991 if (inf == 0) { 992 *in += len; 993 return 1; 994 } 995 expected_eoc = 1; 996 /* 997 * Indefinite length constructed form. Find the end when enough EOCs are 998 * found. If more indefinite length constructed headers are encountered 999 * increment the expected eoc count otherwise just skip to the end of the 1000 * data. 1001 */ 1002 while (len > 0) { 1003 if (asn1_check_eoc(&p, len)) { 1004 expected_eoc--; 1005 if (expected_eoc == 0) 1006 break; 1007 len -= 2; 1008 continue; 1009 } 1010 q = p; 1011 /* Just read in a header: only care about the length */ 1012 if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, 1013 -1, 0, 0, NULL)) { 1014 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 1015 return 0; 1016 } 1017 if (inf) 1018 expected_eoc++; 1019 else 1020 p += plen; 1021 len -= p - q; 1022 } 1023 if (expected_eoc) { 1024 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MISSING_EOC); 1025 return 0; 1026 } 1027 *in = p; 1028 return 1; 1029 } 1030 1031 /* 1032 * This function collects the asn1 data from a constructred string type into 1033 * a buffer. The values of 'in' and 'len' should refer to the contents of the 1034 * constructed type and 'inf' should be set if it is indefinite length. 1035 */ 1036 1037 #ifndef ASN1_MAX_STRING_NEST 1038 /* 1039 * This determines how many levels of recursion are permitted in ASN1 string 1040 * types. If it is not limited stack overflows can occur. If set to zero no 1041 * recursion is allowed at all. Although zero should be adequate examples 1042 * exist that require a value of 1. So 5 should be more than enough. 1043 */ 1044 # define ASN1_MAX_STRING_NEST 5 1045 #endif 1046 1047 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, 1048 char inf, int tag, int aclass, int depth) 1049 { 1050 const unsigned char *p, *q; 1051 long plen; 1052 char cst, ininf; 1053 p = *in; 1054 inf &= 1; 1055 /* 1056 * If no buffer and not indefinite length constructed just pass over the 1057 * encoded data 1058 */ 1059 if (!buf && !inf) { 1060 *in += len; 1061 return 1; 1062 } 1063 while (len > 0) { 1064 q = p; 1065 /* Check for EOC */ 1066 if (asn1_check_eoc(&p, len)) { 1067 /* 1068 * EOC is illegal outside indefinite length constructed form 1069 */ 1070 if (!inf) { 1071 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNEXPECTED_EOC); 1072 return 0; 1073 } 1074 inf = 0; 1075 break; 1076 } 1077 1078 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, 1079 len, tag, aclass, 0, NULL)) { 1080 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); 1081 return 0; 1082 } 1083 1084 /* If indefinite length constructed update max length */ 1085 if (cst) { 1086 if (depth >= ASN1_MAX_STRING_NEST) { 1087 OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_STRING); 1088 return 0; 1089 } 1090 if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) 1091 return 0; 1092 } else if (plen && !collect_data(buf, &p, plen)) 1093 return 0; 1094 len -= p - q; 1095 } 1096 if (inf) { 1097 OPENSSL_PUT_ERROR(ASN1, ASN1_R_MISSING_EOC); 1098 return 0; 1099 } 1100 *in = p; 1101 return 1; 1102 } 1103 1104 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) 1105 { 1106 int len; 1107 if (buf) { 1108 len = buf->length; 1109 if (!BUF_MEM_grow_clean(buf, len + plen)) { 1110 OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE); 1111 return 0; 1112 } 1113 OPENSSL_memcpy(buf->data + len, *p, plen); 1114 } 1115 *p += plen; 1116 return 1; 1117 } 1118 1119 /* Check for ASN1 EOC and swallow it if found */ 1120 1121 static int asn1_check_eoc(const unsigned char **in, long len) 1122 { 1123 const unsigned char *p; 1124 if (len < 2) 1125 return 0; 1126 p = *in; 1127 if (!p[0] && !p[1]) { 1128 *in += 2; 1129 return 1; 1130 } 1131 return 0; 1132 } 1133 1134 /* 1135 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the 1136 * length for indefinite length constructed form, we don't know the exact 1137 * length but we can set an upper bound to the amount of data available minus 1138 * the header length just read. 1139 */ 1140 1141 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, 1142 char *inf, char *cst, 1143 const unsigned char **in, long len, 1144 int exptag, int expclass, char opt, ASN1_TLC *ctx) 1145 { 1146 int i; 1147 int ptag, pclass; 1148 long plen; 1149 const unsigned char *p, *q; 1150 p = *in; 1151 q = p; 1152 1153 if (ctx && ctx->valid) { 1154 i = ctx->ret; 1155 plen = ctx->plen; 1156 pclass = ctx->pclass; 1157 ptag = ctx->ptag; 1158 p += ctx->hdrlen; 1159 } else { 1160 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); 1161 if (ctx) { 1162 ctx->ret = i; 1163 ctx->plen = plen; 1164 ctx->pclass = pclass; 1165 ctx->ptag = ptag; 1166 ctx->hdrlen = p - q; 1167 ctx->valid = 1; 1168 /* 1169 * If definite length, and no error, length + header can't exceed 1170 * total amount of data available. 1171 */ 1172 if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { 1173 OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG); 1174 asn1_tlc_clear(ctx); 1175 return 0; 1176 } 1177 } 1178 } 1179 1180 if (i & 0x80) { 1181 OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_OBJECT_HEADER); 1182 asn1_tlc_clear(ctx); 1183 return 0; 1184 } 1185 if (exptag >= 0) { 1186 if ((exptag != ptag) || (expclass != pclass)) { 1187 /* 1188 * If type is OPTIONAL, not an error: indicate missing type. 1189 */ 1190 if (opt) 1191 return -1; 1192 asn1_tlc_clear(ctx); 1193 OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_TAG); 1194 return 0; 1195 } 1196 /* 1197 * We have a tag and class match: assume we are going to do something 1198 * with it 1199 */ 1200 asn1_tlc_clear(ctx); 1201 } 1202 1203 if (i & 1) 1204 plen = len - (p - q); 1205 1206 if (inf) 1207 *inf = i & 1; 1208 1209 if (cst) 1210 *cst = i & V_ASN1_CONSTRUCTED; 1211 1212 if (olen) 1213 *olen = plen; 1214 1215 if (oclass) 1216 *oclass = pclass; 1217 1218 if (otag) 1219 *otag = ptag; 1220 1221 *in = p; 1222 return 1; 1223 } 1224
