crypto/asn1/tasn_dec.c

   1 /* tasn_dec.c */
   2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59
  60 #include <stddef.h>
  61 #include <string.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/buffer.h>
  66 #include <openssl/err.h>
  67
  68 static int asn1_check_eoc(const unsigned char **in, long len);
  69 static int asn1_find_end(const unsigned char **in, long len, char inf);
  70
  71 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
  72                                 char inf, int tag, int aclass);
  73
  74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  75
  76 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  77                                 char *inf, char *cst,
  78                                 const unsigned char **in, long len,
  79                                 int exptag, int expclass, char opt,
  80                                 ASN1_TLC *ctx);
  81
  82 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
  83                                 const unsigned char **in, long len,
  84                                 const ASN1_TEMPLATE *tt, char opt,
  85                                 ASN1_TLC *ctx);
  86 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
  87                                 const unsigned char **in, long len,
  88                                 const ASN1_TEMPLATE *tt, char opt,
  89                                 ASN1_TLC *ctx);
  90 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
  91                                 const unsigned char **in, long len,
  92                                 const ASN1_ITEM *it,
  93                                 int tag, int aclass, char opt, ASN1_TLC *ctx);
  94
  95 /* Table to convert tags to bit values, used for MSTRING type */
  96 static unsigned long tag2bit[32] = {
  97 0,      0,      0,      B_ASN1_BIT_STRING,      /* tags  0 -  3 */
  98 B_ASN1_OCTET_STRING,    0,      0,              B_ASN1_UNKNOWN,/* tags  4- 7 */
  99 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags  8-11 */
 100 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */
 101 0,      0,      B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING,   /* tags 16-19 */
 102 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING,       /* tags 20-22 */
 103 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,                        /* tags 23-24 */
 104 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING,  /* tags 25-27 */
 105 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */
 106         };
 107
 108 unsigned long ASN1_tag2bit(int tag)
 109         {
 110         if ((tag < 0) || (tag > 30)) return 0;
 111         return tag2bit[tag];
 112         }
 113
 114 /* Macro to initialize and invalidate the cache */
 115
 116 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
 117
 118 /* Decode an ASN1 item, this currently behaves just
 119  * like a standard 'd2i' function. 'in' points to
 120  * a buffer to read the data from, in future we will
 121  * have more advanced versions that can input data
 122  * a piece at a time and this will simply be a special
 123  * case.
 124  */
 125
 126 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 127                 const unsigned char **in, long len, const ASN1_ITEM *it)
 128         {
 129         ASN1_TLC c;
 130         ASN1_VALUE *ptmpval = NULL;
 131         if (!pval)
 132                 pval = &ptmpval;
 133         asn1_tlc_clear(&c);
 134         if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 135                 return *pval;
 136         return NULL;
 137         }
 138
 139 int ASN1_template_d2i(ASN1_VALUE **pval,
 140                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
 141         {
 142         ASN1_TLC c;
 143         asn1_tlc_clear(&c);
 144         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
 145         }
 146
 147
 148 /* Decode an item, taking care of IMPLICIT tagging, if any.
 149  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 150  */
 151
 152 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 153                         const ASN1_ITEM *it,
 154                         int tag, int aclass, char opt, ASN1_TLC *ctx)
 155         {
 156         const ASN1_TEMPLATE *tt, *errtt = NULL;
 157         const ASN1_COMPAT_FUNCS *cf;
 158         const ASN1_EXTERN_FUNCS *ef;
 159         const ASN1_AUX *aux = it->funcs;
 160         ASN1_aux_cb *asn1_cb;
 161         const unsigned char *p, *q;
 162         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 163         unsigned char imphack = 0, oclass;
 164         char seq_eoc, seq_nolen, cst, isopt;
 165         long tmplen;
 166         int i;
 167         int otag;
 168         int ret = 0;
 169         ASN1_VALUE *pchval, **pchptr, *ptmpval;
 170         if (!pval)
 171                 return 0;
 172         if (aux && aux->asn1_cb)
 173                 asn1_cb = aux->asn1_cb;
 174         else asn1_cb = 0;
 175
 176         switch(it->itype)
 177                 {
 178                 case ASN1_ITYPE_PRIMITIVE:
 179                 if (it->templates)
 180                         {
 181                         /* tagging or OPTIONAL is currently illegal on an item
 182                          * template because the flags can't get passed down.
 183                          * In practice this isn't a problem: we include the
 184                          * relevant flags from the item template in the
 185                          * template itself.
 186                          */
 187                         if ((tag != -1) || opt)
 188                                 {
 189                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 190                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 191                                 goto err;
 192                                 }
 193                         return asn1_template_ex_d2i(pval, in, len,
 194                                         it->templates, opt, ctx);
 195                 }
 196                 return asn1_d2i_ex_primitive(pval, in, len, it,
 197                                                 tag, aclass, opt, ctx);
 198                 break;
 199
 200                 case ASN1_ITYPE_MSTRING:
 201                 p = *in;
 202                 /* Just read in tag and class */
 203                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 204                                                 &p, len, -1, 0, 1, ctx);
 205                 if (!ret)
 206                         {
 207                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 208                                         ERR_R_NESTED_ASN1_ERROR);
 209                         goto err;
 210                         }
 211
 212                 /* Must be UNIVERSAL class */
 213                 if (oclass != V_ASN1_UNIVERSAL)
 214                         {
 215                         /* If OPTIONAL, assume this is OK */
 216                         if (opt) return -1;
 217                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 218                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 219                         goto err;
 220                         }
 221                 /* Check tag matches bit map */
 222                 if (!(ASN1_tag2bit(otag) & it->utype))
 223                         {
 224                         /* If OPTIONAL, assume this is OK */
 225                         if (opt)
 226                                 return -1;
 227                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 228                                         ASN1_R_MSTRING_WRONG_TAG);
 229                         goto err;
 230                         }
 231                 return asn1_d2i_ex_primitive(pval, in, len,
 232                                                 it, otag, 0, 0, ctx);
 233
 234                 case ASN1_ITYPE_EXTERN:
 235                 /* Use new style d2i */
 236                 ef = it->funcs;
 237                 return ef->asn1_ex_d2i(pval, in, len,
 238                                                 it, tag, aclass, opt, ctx);
 239
 240                 case ASN1_ITYPE_COMPAT:
 241                 /* we must resort to old style evil hackery */
 242                 cf = it->funcs;
 243
 244                 /* If OPTIONAL see if it is there */
 245                 if (opt)
 246                         {
 247                         int exptag;
 248                         p = *in;
 249                         if (tag == -1)
 250                                 exptag = it->utype;
 251                         else exptag = tag;
 252                         /* Don't care about anything other than presence
 253                          * of expected tag */
 254
 255                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 256                                         &p, len, exptag, aclass, 1, ctx);
 257                         if (!ret)
 258                                 {
 259                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 260                                         ERR_R_NESTED_ASN1_ERROR);
 261                                 goto err;
 262                                 }
 263                         if (ret == -1)
 264                                 return -1;
 265                         }
 266
 267                 /* This is the old style evil hack IMPLICIT handling:
 268                  * since the underlying code is expecting a tag and
 269                  * class other than the one present we change the
 270                  * buffer temporarily then change it back afterwards.
 271                  * This doesn't and never did work for tags > 30.
 272                  *
 273                  * Yes this is *horrible* but it is only needed for
 274                  * old style d2i which will hopefully not be around
 275                  * for much longer.
 276                  * FIXME: should copy the buffer then modify it so
 277                  * the input buffer can be const: we should *always*
 278                  * copy because the old style d2i might modify the
 279                  * buffer.
 280                  */
 281
 282                 if (tag != -1)
 283                         {
 284                         wp = *(unsigned char **)in;
 285                         imphack = *wp;
 286                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 287                                                                 | it->utype);
 288                         }
 289
 290                 ptmpval = cf->asn1_d2i(pval, in, len);
 291
 292                 if (tag != -1)
 293                         *wp = imphack;
 294
 295                 if (ptmpval)
 296                         return 1;
 297
 298                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 299                 goto err;
 300
 301
 302                 case ASN1_ITYPE_CHOICE:
 303                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 304                                 goto auxerr;
 305
 306                 /* Allocate structure */
 307                 if (!*pval && !ASN1_item_ex_new(pval, it))
 308                         {
 309                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 310                                                 ERR_R_NESTED_ASN1_ERROR);
 311                         goto err;
 312                         }
 313                 /* CHOICE type, try each possibility in turn */
 314                 pchval = NULL;
 315                 p = *in;
 316                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 317                         {
 318                         pchptr = asn1_get_field_ptr(pval, tt);
 319                         /* We mark field as OPTIONAL so its absence
 320                          * can be recognised.
 321                          */
 322                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 323                         /* If field not present, try the next one */
 324                         if (ret == -1)
 325                                 continue;
 326                         /* If positive return, read OK, break loop */
 327                         if (ret > 0)
 328                                 break;
 329                         /* Otherwise must be an ASN1 parsing error */
 330                         errtt = tt;
 331                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 332                                                 ERR_R_NESTED_ASN1_ERROR);
 333                         goto err;
 334                         }
 335
 336                 /* Did we fall off the end without reading anything? */
 337                 if (i == it->tcount)
 338                         {
 339                         /* If OPTIONAL, this is OK */
 340                         if (opt)
 341                                 {
 342                                 /* Free and zero it */
 343                                 ASN1_item_ex_free(pval, it);
 344                                 return -1;
 345                                 }
 346                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 347                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 348                         goto err;
 349                         }
 350
 351                 asn1_set_choice_selector(pval, i, it);
 352                 *in = p;
 353                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 354                                 goto auxerr;
 355                 return 1;
 356
 357                 case ASN1_ITYPE_NDEF_SEQUENCE:
 358                 case ASN1_ITYPE_SEQUENCE:
 359                 p = *in;
 360                 tmplen = len;
 361
 362                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 363                 if (tag == -1)
 364                         {
 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                         {
 373                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 374                                         ERR_R_NESTED_ASN1_ERROR);
 375                         goto err;
 376                         }
 377                 else if (ret == -1)
 378                         return -1;
 379                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 380                         {
 381                         len = tmplen - (p - *in);
 382                         seq_nolen = 1;
 383                         }
 384                 /* If indefinite we don't do a length check */
 385                 else seq_nolen = seq_eoc;
 386                 if (!cst)
 387                         {
 388                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 389                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 390                         goto err;
 391                         }
 392
 393                 if (!*pval && !ASN1_item_ex_new(pval, it))
 394                         {
 395                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 396                                 ERR_R_NESTED_ASN1_ERROR);
 397                         goto err;
 398                         }
 399
 400                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 401                                 goto auxerr;
 402
 403                 /* Get each field entry */
 404                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 405                         {
 406                         const ASN1_TEMPLATE *seqtt;
 407                         ASN1_VALUE **pseqval;
 408                         seqtt = asn1_do_adb(pval, tt, 1);
 409                         if (!seqtt)
 410                                 goto err;
 411                         pseqval = asn1_get_field_ptr(pval, seqtt);
 412                         /* Have we ran out of data? */
 413                         if (!len)
 414                                 break;
 415                         q = p;
 416                         if (asn1_check_eoc(&p, len))
 417                                 {
 418                                 if (!seq_eoc)
 419                                         {
 420                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 421                                                         ASN1_R_UNEXPECTED_EOC);
 422                                         goto err;
 423                                         }
 424                                 len -= p - q;
 425                                 seq_eoc = 0;
 426                                 q = p;
 427                                 break;
 428                                 }
 429                         /* This determines the OPTIONAL flag value. The field
 430                          * cannot be omitted if it is the last of a SEQUENCE
 431                          * and there is still data to be read. This isn't
 432                          * strictly necessary but it increases efficiency in
 433                          * some cases.
 434                          */
 435                         if (i == (it->tcount - 1))
 436                                 isopt = 0;
 437                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 438                         /* attempt to read in field, allowing each to be
 439                          * OPTIONAL */
 440
 441                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 442                                                         seqtt, isopt, ctx);
 443                         if (!ret)
 444                                 {
 445                                 errtt = seqtt;
 446                                 goto err;
 447                                 }
 448                         else if (ret == -1)
 449                                 {
 450                                 /* OPTIONAL component absent.
 451                                  * 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                         {
 463                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 464                         goto err;
 465                         }
 466                 /* Check all data read */
 467                 if (!seq_nolen && len)
 468                         {
 469                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 470                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 471                         goto err;
 472                         }
 473
 474                 /* If we get here we've got no more data in the SEQUENCE,
 475                  * however we may not have read all fields so check all
 476                  * remaining are OPTIONAL and clear any that are.
 477                  */
 478                 for (; i < it->tcount; tt++, i++)
 479                         {
 480                         const ASN1_TEMPLATE *seqtt;
 481                         seqtt = asn1_do_adb(pval, tt, 1);
 482                         if (!seqtt)
 483                                 goto err;
 484                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 485                                 {
 486                                 ASN1_VALUE **pseqval;
 487                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 488                                 ASN1_template_free(pseqval, seqtt);
 489                                 }
 490                         else
 491                                 {
 492                                 errtt = seqtt;
 493                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 494                                                         ASN1_R_FIELD_MISSING);
 495                                 goto err;
 496                                 }
 497                         }
 498                 /* Save encoding */
 499                 if (!asn1_enc_save(pval, *in, p - *in, it))
 500                         goto auxerr;
 501                 *in = p;
 502                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 503                                 goto auxerr;
 504                 return 1;
 505
 506                 default:
 507                 return 0;
 508                 }
 509         auxerr:
 510         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 511         err:
 512         ASN1_item_ex_free(pval, it);
 513         if (errtt)
 514                 ERR_add_error_data(4, "Field=", errtt->field_name,
 515                                         ", Type=", it->sname);
 516         else
 517                 ERR_add_error_data(2, "Type=", it->sname);
 518         return 0;
 519         }
 520
 521 /* Templates are handled with two separate functions.
 522  * One handles any EXPLICIT tag and the other handles the rest.
 523  */
 524
 525 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 526                                 const unsigned char **in, long inlen,
 527                                 const ASN1_TEMPLATE *tt, char opt,
 528                                                         ASN1_TLC *ctx)
 529         {
 530         int flags, aclass;
 531         int ret;
 532         long len;
 533         const unsigned char *p, *q;
 534         char exp_eoc;
 535         if (!val)
 536                 return 0;
 537         flags = tt->flags;
 538         aclass = flags & ASN1_TFLG_TAG_CLASS;
 539
 540         p = *in;
 541
 542         /* Check if EXPLICIT tag expected */
 543         if (flags & ASN1_TFLG_EXPTAG)
 544                 {
 545                 char cst;
 546                 /* Need to work out amount of data available to the inner
 547                  * content and where it starts: so read in EXPLICIT header to
 548                  * get the info.
 549                  */
 550                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 551                                         &p, inlen, tt->tag, aclass, opt, ctx);
 552                 q = p;
 553                 if (!ret)
 554                         {
 555                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 556                                         ERR_R_NESTED_ASN1_ERROR);
 557                         return 0;
 558                         }
 559                 else if (ret == -1)
 560                         return -1;
 561                 if (!cst)
 562                         {
 563                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 564                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 565                         return 0;
 566                         }
 567                 /* We've found the field so it can't be OPTIONAL now */
 568                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 569                 if (!ret)
 570                         {
 571                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 572                                         ERR_R_NESTED_ASN1_ERROR);
 573                         return 0;
 574                         }
 575                 /* We read the field in OK so update length */
 576                 len -= p - q;
 577                 if (exp_eoc)
 578                         {
 579                         /* If NDEF we must have an EOC here */
 580                         if (!asn1_check_eoc(&p, len))
 581                                 {
 582                                 ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 583                                                 ASN1_R_MISSING_EOC);
 584                                 goto err;
 585                                 }
 586                         }
 587                 else
 588                         {
 589                         /* Otherwise we must hit the EXPLICIT tag end or its
 590                          * an error */
 591                         if (len)
 592                                 {
 593                                 ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 594                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 595                                 goto err;
 596                                 }
 597                         }
 598                 }
 599                 else
 600                         return asn1_template_noexp_d2i(val, in, inlen,
 601                                                                 tt, opt, ctx);
 602
 603         *in = p;
 604         return 1;
 605
 606         err:
 607         ASN1_template_free(val, tt);
 608         *val = NULL;
 609         return 0;
 610         }
 611
 612 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 613                                 const unsigned char **in, long len,
 614                                 const ASN1_TEMPLATE *tt, char opt,
 615                                 ASN1_TLC *ctx)
 616         {
 617         int flags, aclass;
 618         int ret;
 619         const unsigned char *p, *q;
 620         if (!val)
 621                 return 0;
 622         flags = tt->flags;
 623         aclass = flags & ASN1_TFLG_TAG_CLASS;
 624
 625         p = *in;
 626         q = p;
 627
 628         if (flags & ASN1_TFLG_SK_MASK)
 629                 {
 630                 /* SET OF, SEQUENCE OF */
 631                 int sktag, skaclass;
 632                 char sk_eoc;
 633                 /* First work out expected inner tag value */
 634                 if (flags & ASN1_TFLG_IMPTAG)
 635                         {
 636                         sktag = tt->tag;
 637                         skaclass = aclass;
 638                         }
 639                 else
 640                         {
 641                         skaclass = V_ASN1_UNIVERSAL;
 642                         if (flags & ASN1_TFLG_SET_OF)
 643                                 sktag = V_ASN1_SET;
 644                         else
 645                                 sktag = V_ASN1_SEQUENCE;
 646                         }
 647                 /* Get the tag */
 648                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 649                                         &p, len, sktag, skaclass, opt, ctx);
 650                 if (!ret)
 651                         {
 652                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 653                                                 ERR_R_NESTED_ASN1_ERROR);
 654                         return 0;
 655                         }
 656                 else if (ret == -1)
 657                         return -1;
 658                 if (!*val)
 659                         *val = (ASN1_VALUE *)sk_new_null();
 660                 else
 661                         {
 662                         /* We've got a valid STACK: free up any items present */
 663                         STACK *sktmp = (STACK *)*val;
 664                         ASN1_VALUE *vtmp;
 665                         while(sk_num(sktmp) > 0)
 666                                 {
 667                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
 668                                 ASN1_item_ex_free(&vtmp,
 669                                                 ASN1_ITEM_ptr(tt->item));
 670                                 }
 671                         }
 672
 673                 if (!*val)
 674                         {
 675                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 676                                                 ERR_R_MALLOC_FAILURE);
 677                         goto err;
 678                         }
 679
 680                 /* Read as many items as we can */
 681                 while(len > 0)
 682                         {
 683                         ASN1_VALUE *skfield;
 684                         q = p;
 685                         /* See if EOC found */
 686                         if (asn1_check_eoc(&p, len))
 687                                 {
 688                                 if (!sk_eoc)
 689                                         {
 690                                         ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 691                                                         ASN1_R_UNEXPECTED_EOC);
 692                                         goto err;
 693                                         }
 694                                 len -= p - q;
 695                                 sk_eoc = 0;
 696                                 break;
 697                                 }
 698                         skfield = NULL;
 699                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 700                                                 ASN1_ITEM_ptr(tt->item),
 701                                                 -1, 0, 0, ctx))
 702                                 {
 703                                 ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 704                                         ERR_R_NESTED_ASN1_ERROR);
 705                                 goto err;
 706                                 }
 707                         len -= p - q;
 708                         if (!sk_push((STACK *)*val, (char *)skfield))
 709                                 {
 710                                 ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 711                                                 ERR_R_MALLOC_FAILURE);
 712                                 goto err;
 713                                 }
 714                         }
 715                 if (sk_eoc)
 716                         {
 717                         ASN1err(ASN1_F_ASN1_TEMPLATE_D2I, ASN1_R_MISSING_EOC);
 718                         goto err;
 719                         }
 720                 }
 721         else if (flags & ASN1_TFLG_IMPTAG)
 722                 {
 723                 /* IMPLICIT tagging */
 724                 ret = ASN1_item_ex_d2i(val, &p, len,
 725                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 726                 if (!ret)
 727                         {
 728                         ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 729                                                 ERR_R_NESTED_ASN1_ERROR);
 730                         goto err;
 731                         }
 732                 else if (ret == -1)
 733                         return -1;
 734                 }
 735         else
 736                 {
 737                 /* Nothing special */
 738                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 739                                                         -1, 0, opt, ctx);
 740                 if (!ret)
 741                         {
 742                         ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
 743                                         ERR_R_NESTED_ASN1_ERROR);
 744                         goto err;
 745                         }
 746                 else if (ret == -1)
 747                         return -1;
 748                 }
 749
 750         *in = p;
 751         return 1;
 752
 753         err:
 754         ASN1_template_free(val, tt);
 755         *val = NULL;
 756         return 0;
 757         }
 758
 759 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 760                                 const unsigned char **in, long inlen,
 761                                 const ASN1_ITEM *it,
 762                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 763         {
 764         int ret = 0, utype;
 765         long plen;
 766         char cst, inf, free_cont = 0;
 767         const unsigned char *p;
 768         BUF_MEM buf;
 769         const unsigned char *cont = NULL;
 770         long len;
 771         if (!pval)
 772                 {
 773                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 774                 return 0; /* Should never happen */
 775                 }
 776
 777         if (it->itype == ASN1_ITYPE_MSTRING)
 778                 {
 779                 utype = tag;
 780                 tag = -1;
 781                 }
 782         else
 783                 utype = it->utype;
 784
 785         if (utype == V_ASN1_ANY)
 786                 {
 787                 /* If type is ANY need to figure out type from tag */
 788                 unsigned char oclass;
 789                 if (tag >= 0)
 790                         {
 791                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 792                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 793                         return 0;
 794                         }
 795                 if (opt)
 796                         {
 797                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 798                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 799                         return 0;
 800                         }
 801                 p = *in;
 802                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 803                                         &p, inlen, -1, 0, 0, ctx);
 804                 if (!ret)
 805                         {
 806                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 807                                         ERR_R_NESTED_ASN1_ERROR);
 808                         return 0;
 809                         }
 810                 if (oclass != V_ASN1_UNIVERSAL)
 811                         utype = V_ASN1_OTHER;
 812                 }
 813         if (tag == -1)
 814                 {
 815                 tag = utype;
 816                 aclass = V_ASN1_UNIVERSAL;
 817                 }
 818         p = *in;
 819         /* Check header */
 820         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 821                                 &p, inlen, tag, aclass, opt, ctx);
 822         if (!ret)
 823                 {
 824                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 825                 return 0;
 826                 }
 827         else if (ret == -1)
 828                 return -1;
 829         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 830         if ((utype == V_ASN1_SEQUENCE)
 831                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 832                 {
 833                 /* Clear context cache for type OTHER because the auto clear
 834                  * when we have a exact match wont work
 835                  */
 836                 if (utype == V_ASN1_OTHER)
 837                         {
 838                         asn1_tlc_clear(ctx);
 839                         }
 840                 /* SEQUENCE and SET must be constructed */
 841                 else if (!cst)
 842                         {
 843                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 844                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 845                         return 0;
 846                         }
 847
 848                 cont = *in;
 849                 /* If indefinite length constructed find the real end */
 850                 if (inf)
 851                         {
 852                         if (!asn1_find_end(&p, plen, inf))
 853                                  goto err;
 854                         len = p - cont;
 855                         }
 856                 else
 857                         {
 858                         len = p - cont + plen;
 859                         p += plen;
 860                         buf.data = NULL;
 861                         }
 862                 }
 863         else if (cst)
 864                 {
 865                 buf.length = 0;
 866                 buf.max = 0;
 867                 buf.data = NULL;
 868                 /* Should really check the internal tags are correct but
 869                  * some things may get this wrong. The relevant specs
 870                  * say that constructed string types should be OCTET STRINGs
 871                  * internally irrespective of the type. So instead just check
 872                  * for UNIVERSAL class and ignore the tag.
 873                  */
 874                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL))
 875                         goto err;
 876                 len = buf.length;
 877                 /* Append a final null to string */
 878                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 879                         {
 880                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 881                                                 ERR_R_MALLOC_FAILURE);
 882                         return 0;
 883                         }
 884                 buf.data[len] = 0;
 885                 cont = (const unsigned char *)buf.data;
 886                 free_cont = 1;
 887                 }
 888         else
 889                 {
 890                 cont = p;
 891                 len = plen;
 892                 p += plen;
 893                 }
 894
 895         /* We now have content length and type: translate into a structure */
 896         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 897                 goto err;
 898
 899         *in = p;
 900         ret = 1;
 901         err:
 902         if (free_cont && buf.data) OPENSSL_free(buf.data);
 903         return ret;
 904         }
 905
 906 /* Translate ASN1 content octets into a structure */
 907
 908 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 909                         int utype, char *free_cont, const ASN1_ITEM *it)
 910         {
 911         ASN1_VALUE **opval = NULL;
 912         ASN1_STRING *stmp;
 913         ASN1_TYPE *typ = NULL;
 914         int ret = 0;
 915         const ASN1_PRIMITIVE_FUNCS *pf;
 916         ASN1_INTEGER **tint;
 917         pf = it->funcs;
 918
 919         if (pf && pf->prim_c2i)
 920                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 921         /* If ANY type clear type and set pointer to internal value */
 922         if (it->utype == V_ASN1_ANY)
 923                 {
 924                 if (!*pval)
 925                         {
 926                         typ = ASN1_TYPE_new();
 927                         *pval = (ASN1_VALUE *)typ;
 928                         }
 929                 else
 930                         typ = (ASN1_TYPE *)*pval;
 931
 932                 if (utype != typ->type)
 933                         ASN1_TYPE_set(typ, utype, NULL);
 934                 opval = pval;
 935                 pval = (ASN1_VALUE **)&typ->value.ptr;
 936                 }
 937         switch(utype)
 938                 {
 939                 case V_ASN1_OBJECT:
 940                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 941                         goto err;
 942                 break;
 943
 944                 case V_ASN1_NULL:
 945                 if (len)
 946                         {
 947                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 948                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 949                         goto err;
 950                         }
 951                 *pval = (ASN1_VALUE *)1;
 952                 break;
 953
 954                 case V_ASN1_BOOLEAN:
 955                 if (len != 1)
 956                         {
 957                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 958                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 959                         goto err;
 960                         }
 961                 else
 962                         {
 963                         ASN1_BOOLEAN *tbool;
 964                         tbool = (ASN1_BOOLEAN *)pval;
 965                         *tbool = *cont;
 966                         }
 967                 break;
 968
 969                 case V_ASN1_BIT_STRING:
 970                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 971                         goto err;
 972                 break;
 973
 974                 case V_ASN1_INTEGER:
 975                 case V_ASN1_NEG_INTEGER:
 976                 case V_ASN1_ENUMERATED:
 977                 case V_ASN1_NEG_ENUMERATED:
 978                 tint = (ASN1_INTEGER **)pval;
 979                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 980                         goto err;
 981                 /* Fixup type to match the expected form */
 982                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 983                 break;
 984
 985                 case V_ASN1_OCTET_STRING:
 986                 case V_ASN1_NUMERICSTRING:
 987                 case V_ASN1_PRINTABLESTRING:
 988                 case V_ASN1_T61STRING:
 989                 case V_ASN1_VIDEOTEXSTRING:
 990                 case V_ASN1_IA5STRING:
 991                 case V_ASN1_UTCTIME:
 992                 case V_ASN1_GENERALIZEDTIME:
 993                 case V_ASN1_GRAPHICSTRING:
 994                 case V_ASN1_VISIBLESTRING:
 995                 case V_ASN1_GENERALSTRING:
 996                 case V_ASN1_UNIVERSALSTRING:
 997                 case V_ASN1_BMPSTRING:
 998                 case V_ASN1_UTF8STRING:
 999                 case V_ASN1_OTHER:
1000                 case V_ASN1_SET:
1001                 case V_ASN1_SEQUENCE:
1002                 default:
1003                 /* All based on ASN1_STRING and handled the same */
1004                 if (!*pval)
1005                         {
1006                         stmp = ASN1_STRING_type_new(utype);
1007                         if (!stmp)
1008                                 {
1009                                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
1010                                                         ERR_R_MALLOC_FAILURE);
1011                                 goto err;
1012                                 }
1013                         *pval = (ASN1_VALUE *)stmp;
1014                         }
1015                 else
1016                         {
1017                         stmp = (ASN1_STRING *)*pval;
1018                         stmp->type = utype;
1019                         }
1020                 /* If we've already allocated a buffer use it */
1021                 if (*free_cont)
1022                         {
1023                         if (stmp->data)
1024                                 OPENSSL_free(stmp->data);
1025                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1026                         stmp->length = len;
1027                         *free_cont = 0;
1028                         }
1029                 else
1030                         {
1031                         if (!ASN1_STRING_set(stmp, cont, len))
1032                                 {
1033                                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
1034                                                         ERR_R_MALLOC_FAILURE);
1035                                 ASN1_STRING_free(stmp);
1036                                 *pval = NULL;
1037                                 goto err;
1038                                 }
1039                         }
1040                 break;
1041                 }
1042         /* If ASN1_ANY and NULL type fix up value */
1043         if (typ && (utype == V_ASN1_NULL))
1044                  typ->value.ptr = NULL;
1045
1046         ret = 1;
1047         err:
1048         if (!ret)
1049                 {
1050                 ASN1_TYPE_free(typ);
1051                 if (opval)
1052                         *opval = NULL;
1053                 }
1054         return ret;
1055         }
1056
1057
1058 /* This function finds the end of an ASN1 structure when passed its maximum
1059  * length, whether it is indefinite length and a pointer to the content.
1060  * This is more efficient than calling asn1_collect because it does not
1061  * recurse on each indefinite length header.
1062  */
1063
1064 static int asn1_find_end(const unsigned char **in, long len, char inf)
1065         {
1066         int expected_eoc;
1067         long plen;
1068         const unsigned char *p = *in, *q;
1069         /* If not indefinite length constructed just add length */
1070         if (inf == 0)
1071                 {
1072                 *in += len;
1073                 return 1;
1074                 }
1075         expected_eoc = 1;
1076         /* Indefinite length constructed form. Find the end when enough EOCs
1077          * are found. If more indefinite length constructed headers
1078          * are encountered increment the expected eoc count otherwise justi
1079          * skip to the end of the data.
1080          */
1081         while (len > 0)
1082                 {
1083                 if(asn1_check_eoc(&p, len))
1084                         {
1085                         expected_eoc--;
1086                         if (expected_eoc == 0)
1087                                 break;
1088                         len -= 2;
1089                         continue;
1090                         }
1091                 q = p;
1092                 /* Just read in a header: only care about the length */
1093                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1094                                 -1, 0, 0, NULL))
1095                         {
1096                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1097                         return 0;
1098                         }
1099                 if (inf)
1100                         expected_eoc++;
1101                 else
1102                         p += plen;
1103                 len -= p - q;
1104                 }
1105         if (expected_eoc)
1106                 {
1107                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1108                 return 0;
1109                 }
1110         *in = p;
1111         return 1;
1112         }
1113 /* This function collects the asn1 data from a constructred string
1114  * type into a buffer. The values of 'in' and 'len' should refer
1115  * to the contents of the constructed type and 'inf' should be set
1116  * if it is indefinite length.
1117  */
1118
1119 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1120                                 char inf, int tag, int aclass)
1121         {
1122         const unsigned char *p, *q;
1123         long plen;
1124         char cst, ininf;
1125         p = *in;
1126         inf &= 1;
1127         /* If no buffer and not indefinite length constructed just pass over
1128          * the encoded data */
1129         if (!buf && !inf)
1130                 {
1131                 *in += len;
1132                 return 1;
1133                 }
1134         while(len > 0)
1135                 {
1136                 q = p;
1137                 /* Check for EOC */
1138                 if (asn1_check_eoc(&p, len))
1139                         {
1140                         /* EOC is illegal outside indefinite length
1141                          * constructed form */
1142                         if (!inf)
1143                                 {
1144                                 ASN1err(ASN1_F_ASN1_COLLECT,
1145                                         ASN1_R_UNEXPECTED_EOC);
1146                                 return 0;
1147                                 }
1148                         inf = 0;
1149                         break;
1150                         }
1151
1152                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1153                                         len, tag, aclass, 0, NULL))
1154                         {
1155                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1156                         return 0;
1157                         }
1158
1159                 /* If indefinite length constructed update max length */
1160                 if (cst)
1161                         {
1162 #ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS
1163                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass))
1164                                 return 0;
1165 #else
1166                         ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1167                         return 0;
1168 #endif
1169                         }
1170                 else if (!collect_data(buf, &p, plen))
1171                         return 0;
1172                 len -= p - q;
1173                 }
1174         if (inf)
1175                 {
1176                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1177                 return 0;
1178                 }
1179         *in = p;
1180         return 1;
1181         }
1182
1183 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1184         {
1185         int len;
1186         if (buf)
1187                 {
1188                 len = buf->length;
1189                 if (!BUF_MEM_grow_clean(buf, len + plen))
1190                         {
1191                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1192                         return 0;
1193                         }
1194                 memcpy(buf->data + len, *p, plen);
1195                 }
1196         *p += plen;
1197         return 1;
1198         }
1199
1200 /* Check for ASN1 EOC and swallow it if found */
1201
1202 static int asn1_check_eoc(const unsigned char **in, long len)
1203         {
1204         const unsigned char *p;
1205         if (len < 2) return 0;
1206         p = *in;
1207         if (!p[0] && !p[1])
1208                 {
1209                 *in += 2;
1210                 return 1;
1211                 }
1212         return 0;
1213         }
1214
1215 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1216  * but it sets the length for indefinite length constructed
1217  * form, we don't know the exact length but we can set an
1218  * upper bound to the amount of data available minus the
1219  * header length just read.
1220  */
1221
1222 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1223                                 char *inf, char *cst,
1224                                 const unsigned char **in, long len,
1225                                 int exptag, int expclass, char opt,
1226                                 ASN1_TLC *ctx)
1227         {
1228         int i;
1229         int ptag, pclass;
1230         long plen;
1231         const unsigned char *p, *q;
1232         p = *in;
1233         q = p;
1234
1235         if (ctx && ctx->valid)
1236                 {
1237                 i = ctx->ret;
1238                 plen = ctx->plen;
1239                 pclass = ctx->pclass;
1240                 ptag = ctx->ptag;
1241                 p += ctx->hdrlen;
1242                 }
1243         else
1244                 {
1245                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1246                 if (ctx)
1247                         {
1248                         ctx->ret = i;
1249                         ctx->plen = plen;
1250                         ctx->pclass = pclass;
1251                         ctx->ptag = ptag;
1252                         ctx->hdrlen = p - q;
1253                         ctx->valid = 1;
1254                         /* If definite length, and no error, length +
1255                          * header can't exceed total amount of data available.
1256                          */
1257                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1258                                 {
1259                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1260                                                         ASN1_R_TOO_LONG);
1261                                 asn1_tlc_clear(ctx);
1262                                 return 0;
1263                                 }
1264                         }
1265                 }
1266
1267         if (i & 0x80)
1268                 {
1269                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1270                 asn1_tlc_clear(ctx);
1271                 return 0;
1272                 }
1273         if (exptag >= 0)
1274                 {
1275                 if ((exptag != ptag) || (expclass != pclass))
1276                         {
1277                         /* If type is OPTIONAL, not an error:
1278                          * indicate missing type.
1279                          */
1280                         if (opt) return -1;
1281                         asn1_tlc_clear(ctx);
1282                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1283                         return 0;
1284                         }
1285                 /* We have a tag and class match:
1286                  * assume we are going to do something with it */
1287                 asn1_tlc_clear(ctx);
1288                 }
1289
1290         if (i & 1)
1291                 plen = len - (p - q);
1292
1293         if (inf)
1294                 *inf = i & 1;
1295
1296         if (cst)
1297                 *cst = i & V_ASN1_CONSTRUCTED;
1298
1299         if (olen)
1300                 *olen = plen;
1301
1302         if (oclass)
1303                 *oclass = pclass;
1304
1305         if (otag)
1306                 *otag = ptag;
1307
1308         *in = p;
1309         return 1;
1310         }