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 = NULL, *q;
 162         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 163         unsigned char imphack = 0, oclass;
 164         char seq_eoc, seq_nolen, cst, isopt;
 165         long tmplen;
 166         int i;
 167         int otag;
 168         int ret = 0;
 169         ASN1_VALUE *pchval, **pchptr, *ptmpval;
 170         if (!pval)
 171                 return 0;
 172         if (aux && aux->asn1_cb)
 173                 asn1_cb = aux->asn1_cb;
 174         else asn1_cb = 0;
 175
 176         switch(it->itype)
 177                 {
 178                 case ASN1_ITYPE_PRIMITIVE:
 179                 if (it->templates)
 180                         {
 181                         /* tagging or OPTIONAL is currently illegal on an item
 182                          * template because the flags can't get passed down.
 183                          * In practice this isn't a problem: we include the
 184                          * relevant flags from the item template in the
 185                          * template itself.
 186                          */
 187                         if ((tag != -1) || opt)
 188                                 {
 189                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 190                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 191                                 goto err;
 192                                 }
 193                         return asn1_template_ex_d2i(pval, in, len,
 194                                         it->templates, opt, ctx);
 195                 }
 196                 return asn1_d2i_ex_primitive(pval, in, len, it,
 197                                                 tag, aclass, opt, ctx);
 198                 break;
 199
 200                 case ASN1_ITYPE_MSTRING:
 201                 p = *in;
 202                 /* Just read in tag and class */
 203                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 204                                                 &p, len, -1, 0, 1, ctx);
 205                 if (!ret)
 206                         {
 207                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 208                                         ERR_R_NESTED_ASN1_ERROR);
 209                         goto err;
 210                         }
 211
 212                 /* Must be UNIVERSAL class */
 213                 if (oclass != V_ASN1_UNIVERSAL)
 214                         {
 215                         /* If OPTIONAL, assume this is OK */
 216                         if (opt) return -1;
 217                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 218                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 219                         goto err;
 220                         }
 221                 /* Check tag matches bit map */
 222                 if (!(ASN1_tag2bit(otag) & it->utype))
 223                         {
 224                         /* If OPTIONAL, assume this is OK */
 225                         if (opt)
 226                                 return -1;
 227                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 228                                         ASN1_R_MSTRING_WRONG_TAG);
 229                         goto err;
 230                         }
 231                 return asn1_d2i_ex_primitive(pval, in, len,
 232                                                 it, otag, 0, 0, ctx);
 233
 234                 case ASN1_ITYPE_EXTERN:
 235                 /* Use new style d2i */
 236                 ef = it->funcs;
 237                 return ef->asn1_ex_d2i(pval, in, len,
 238                                                 it, tag, aclass, opt, ctx);
 239
 240                 case ASN1_ITYPE_COMPAT:
 241                 /* we must resort to old style evil hackery */
 242                 cf = it->funcs;
 243
 244                 /* If OPTIONAL see if it is there */
 245                 if (opt)
 246                         {
 247                         int exptag;
 248                         p = *in;
 249                         if (tag == -1)
 250                                 exptag = it->utype;
 251                         else exptag = tag;
 252                         /* Don't care about anything other than presence
 253                          * of expected tag */
 254
 255                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 256                                         &p, len, exptag, aclass, 1, ctx);
 257                         if (!ret)
 258                                 {
 259                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 260                                         ERR_R_NESTED_ASN1_ERROR);
 261                                 goto err;
 262                                 }
 263                         if (ret == -1)
 264                                 return -1;
 265                         }
 266
 267                 /* This is the old style evil hack IMPLICIT handling:
 268                  * since the underlying code is expecting a tag and
 269                  * class other than the one present we change the
 270                  * buffer temporarily then change it back afterwards.
 271                  * This doesn't and never did work for tags > 30.
 272                  *
 273                  * Yes this is *horrible* but it is only needed for
 274                  * old style d2i which will hopefully not be around
 275                  * for much longer.
 276                  * FIXME: should copy the buffer then modify it so
 277                  * the input buffer can be const: we should *always*
 278                  * copy because the old style d2i might modify the
 279                  * buffer.
 280                  */
 281
 282                 if (tag != -1)
 283                         {
 284                         wp = *(unsigned char **)in;
 285                         imphack = *wp;
 286                         if (p == NULL)
 287                                 {
 288                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 289                                         ERR_R_NESTED_ASN1_ERROR);
 290                                 goto err;
 291                                 }
 292                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 293                                                                 | it->utype);
 294                         }
 295
 296                 ptmpval = cf->asn1_d2i(pval, in, len);
 297
 298                 if (tag != -1)
 299                         *wp = imphack;
 300
 301                 if (ptmpval)
 302                         return 1;
 303
 304                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 305                 goto err;
 306
 307
 308                 case ASN1_ITYPE_CHOICE:
 309                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 310                                 goto auxerr;
 311
 312                 /* Allocate structure */
 313                 if (!*pval && !ASN1_item_ex_new(pval, it))
 314                         {
 315                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 316                                                 ERR_R_NESTED_ASN1_ERROR);
 317                         goto err;
 318                         }
 319                 /* CHOICE type, try each possibility in turn */
 320                 pchval = NULL;
 321                 p = *in;
 322                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 323                         {
 324                         pchptr = asn1_get_field_ptr(pval, tt);
 325                         /* We mark field as OPTIONAL so its absence
 326                          * can be recognised.
 327                          */
 328                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 329                         /* If field not present, try the next one */
 330                         if (ret == -1)
 331                                 continue;
 332                         /* If positive return, read OK, break loop */
 333                         if (ret > 0)
 334                                 break;
 335                         /* Otherwise must be an ASN1 parsing error */
 336                         errtt = tt;
 337                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 338                                                 ERR_R_NESTED_ASN1_ERROR);
 339                         goto err;
 340                         }
 341
 342                 /* Did we fall off the end without reading anything? */
 343                 if (i == it->tcount)
 344                         {
 345                         /* If OPTIONAL, this is OK */
 346                         if (opt)
 347                                 {
 348                                 /* Free and zero it */
 349                                 ASN1_item_ex_free(pval, it);
 350                                 return -1;
 351                                 }
 352                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 353                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 354                         goto err;
 355                         }
 356
 357                 asn1_set_choice_selector(pval, i, it);
 358                 *in = p;
 359                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 360                                 goto auxerr;
 361                 return 1;
 362
 363                 case ASN1_ITYPE_NDEF_SEQUENCE:
 364                 case ASN1_ITYPE_SEQUENCE:
 365                 p = *in;
 366                 tmplen = len;
 367
 368                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 369                 if (tag == -1)
 370                         {
 371                         tag = V_ASN1_SEQUENCE;
 372                         aclass = V_ASN1_UNIVERSAL;
 373                         }
 374                 /* Get SEQUENCE length and update len, p */
 375                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 376                                         &p, len, tag, aclass, opt, ctx);
 377                 if (!ret)
 378                         {
 379                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 380                                         ERR_R_NESTED_ASN1_ERROR);
 381                         goto err;
 382                         }
 383                 else if (ret == -1)
 384                         return -1;
 385                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 386                         {
 387                         len = tmplen - (p - *in);
 388                         seq_nolen = 1;
 389                         }
 390                 /* If indefinite we don't do a length check */
 391                 else seq_nolen = seq_eoc;
 392                 if (!cst)
 393                         {
 394                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 395                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 396                         goto err;
 397                         }
 398
 399                 if (!*pval && !ASN1_item_ex_new(pval, it))
 400                         {
 401                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 402                                 ERR_R_NESTED_ASN1_ERROR);
 403                         goto err;
 404                         }
 405
 406                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 407                                 goto auxerr;
 408
 409                 /* Get each field entry */
 410                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 411                         {
 412                         const ASN1_TEMPLATE *seqtt;
 413                         ASN1_VALUE **pseqval;
 414                         seqtt = asn1_do_adb(pval, tt, 1);
 415                         if (!seqtt)
 416                                 goto err;
 417                         pseqval = asn1_get_field_ptr(pval, seqtt);
 418                         /* Have we ran out of data? */
 419                         if (!len)
 420                                 break;
 421                         q = p;
 422                         if (asn1_check_eoc(&p, len))
 423                                 {
 424                                 if (!seq_eoc)
 425                                         {
 426                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 427                                                         ASN1_R_UNEXPECTED_EOC);
 428                                         goto err;
 429                                         }
 430                                 len -= p - q;
 431                                 seq_eoc = 0;
 432                                 q = p;
 433                                 break;
 434                                 }
 435                         /* This determines the OPTIONAL flag value. The field
 436                          * cannot be omitted if it is the last of a SEQUENCE
 437                          * and there is still data to be read. This isn't
 438                          * strictly necessary but it increases efficiency in
 439                          * some cases.
 440                          */
 441                         if (i == (it->tcount - 1))
 442                                 isopt = 0;
 443                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 444                         /* attempt to read in field, allowing each to be
 445                          * OPTIONAL */
 446
 447                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 448                                                         seqtt, isopt, ctx);
 449                         if (!ret)
 450                                 {
 451                                 errtt = seqtt;
 452                                 goto err;
 453                                 }
 454                         else if (ret == -1)
 455                                 {
 456                                 /* OPTIONAL component absent.
 457                                  * Free and zero the field.
 458                                  */
 459                                 ASN1_template_free(pseqval, seqtt);
 460                                 continue;
 461                                 }
 462                         /* Update length */
 463                         len -= p - q;
 464                         }
 465
 466                 /* Check for EOC if expecting one */
 467                 if (seq_eoc && !asn1_check_eoc(&p, len))
 468                         {
 469                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 470                         goto err;
 471                         }
 472                 /* Check all data read */
 473                 if (!seq_nolen && len)
 474                         {
 475                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 476                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 477                         goto err;
 478                         }
 479
 480                 /* If we get here we've got no more data in the SEQUENCE,
 481                  * however we may not have read all fields so check all
 482                  * remaining are OPTIONAL and clear any that are.
 483                  */
 484                 for (; i < it->tcount; tt++, i++)
 485                         {
 486                         const ASN1_TEMPLATE *seqtt;
 487                         seqtt = asn1_do_adb(pval, tt, 1);
 488                         if (!seqtt)
 489                                 goto err;
 490                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 491                                 {
 492                                 ASN1_VALUE **pseqval;
 493                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 494                                 ASN1_template_free(pseqval, seqtt);
 495                                 }
 496                         else
 497                                 {
 498                                 errtt = seqtt;
 499                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 500                                                         ASN1_R_FIELD_MISSING);
 501                                 goto err;
 502                                 }
 503                         }
 504                 /* Save encoding */
 505                 if (!asn1_enc_save(pval, *in, p - *in, it))
 506                         goto auxerr;
 507                 *in = p;
 508                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 509                                 goto auxerr;
 510                 return 1;
 511
 512                 default:
 513                 return 0;
 514                 }
 515         auxerr:
 516         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 517         err:
 518         ASN1_item_ex_free(pval, it);
 519         if (errtt)
 520                 ERR_add_error_data(4, "Field=", errtt->field_name,
 521                                         ", Type=", it->sname);
 522         else
 523                 ERR_add_error_data(2, "Type=", it->sname);
 524         return 0;
 525         }
 526
 527 /* Templates are handled with two separate functions.
 528  * One handles any EXPLICIT tag and the other handles the rest.
 529  */
 530
 531 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 532                                 const unsigned char **in, long inlen,
 533                                 const ASN1_TEMPLATE *tt, char opt,
 534                                                         ASN1_TLC *ctx)
 535         {
 536         int flags, aclass;
 537         int ret;
 538         long len;
 539         const unsigned char *p, *q;
 540         char exp_eoc;
 541         if (!val)
 542                 return 0;
 543         flags = tt->flags;
 544         aclass = flags & ASN1_TFLG_TAG_CLASS;
 545
 546         p = *in;
 547
 548         /* Check if EXPLICIT tag expected */
 549         if (flags & ASN1_TFLG_EXPTAG)
 550                 {
 551                 char cst;
 552                 /* Need to work out amount of data available to the inner
 553                  * content and where it starts: so read in EXPLICIT header to
 554                  * get the info.
 555                  */
 556                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 557                                         &p, inlen, tt->tag, aclass, opt, ctx);
 558                 q = p;
 559                 if (!ret)
 560                         {
 561                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 562                                         ERR_R_NESTED_ASN1_ERROR);
 563                         return 0;
 564                         }
 565                 else if (ret == -1)
 566                         return -1;
 567                 if (!cst)
 568                         {
 569                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 570                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 571                         return 0;
 572                         }
 573                 /* We've found the field so it can't be OPTIONAL now */
 574                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 575                 if (!ret)
 576                         {
 577                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 578                                         ERR_R_NESTED_ASN1_ERROR);
 579                         return 0;
 580                         }
 581                 /* We read the field in OK so update length */
 582                 len -= p - q;
 583                 if (exp_eoc)
 584                         {
 585                         /* If NDEF we must have an EOC here */
 586                         if (!asn1_check_eoc(&p, len))
 587                                 {
 588                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 589                                                 ASN1_R_MISSING_EOC);
 590                                 goto err;
 591                                 }
 592                         }
 593                 else
 594                         {
 595                         /* Otherwise we must hit the EXPLICIT tag end or its
 596                          * an error */
 597                         if (len)
 598                                 {
 599                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 600                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 601                                 goto err;
 602                                 }
 603                         }
 604                 }
 605                 else
 606                         return asn1_template_noexp_d2i(val, in, inlen,
 607                                                                 tt, opt, ctx);
 608
 609         *in = p;
 610         return 1;
 611
 612         err:
 613         ASN1_template_free(val, tt);
 614         *val = NULL;
 615         return 0;
 616         }
 617
 618 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 619                                 const unsigned char **in, long len,
 620                                 const ASN1_TEMPLATE *tt, char opt,
 621                                 ASN1_TLC *ctx)
 622         {
 623         int flags, aclass;
 624         int ret;
 625         const unsigned char *p, *q;
 626         if (!val)
 627                 return 0;
 628         flags = tt->flags;
 629         aclass = flags & ASN1_TFLG_TAG_CLASS;
 630
 631         p = *in;
 632         q = p;
 633
 634         if (flags & ASN1_TFLG_SK_MASK)
 635                 {
 636                 /* SET OF, SEQUENCE OF */
 637                 int sktag, skaclass;
 638                 char sk_eoc;
 639                 /* First work out expected inner tag value */
 640                 if (flags & ASN1_TFLG_IMPTAG)
 641                         {
 642                         sktag = tt->tag;
 643                         skaclass = aclass;
 644                         }
 645                 else
 646                         {
 647                         skaclass = V_ASN1_UNIVERSAL;
 648                         if (flags & ASN1_TFLG_SET_OF)
 649                                 sktag = V_ASN1_SET;
 650                         else
 651                                 sktag = V_ASN1_SEQUENCE;
 652                         }
 653                 /* Get the tag */
 654                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 655                                         &p, len, sktag, skaclass, opt, ctx);
 656                 if (!ret)
 657                         {
 658                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 659                                                 ERR_R_NESTED_ASN1_ERROR);
 660                         return 0;
 661                         }
 662                 else if (ret == -1)
 663                         return -1;
 664                 if (!*val)
 665                         *val = (ASN1_VALUE *)sk_new_null();
 666                 else
 667                         {
 668                         /* We've got a valid STACK: free up any items present */
 669                         STACK *sktmp = (STACK *)*val;
 670                         ASN1_VALUE *vtmp;
 671                         while(sk_num(sktmp) > 0)
 672                                 {
 673                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
 674                                 ASN1_item_ex_free(&vtmp,
 675                                                 ASN1_ITEM_ptr(tt->item));
 676                                 }
 677                         }
 678
 679                 if (!*val)
 680                         {
 681                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 682                                                 ERR_R_MALLOC_FAILURE);
 683                         goto err;
 684                         }
 685
 686                 /* Read as many items as we can */
 687                 while(len > 0)
 688                         {
 689                         ASN1_VALUE *skfield;
 690                         q = p;
 691                         /* See if EOC found */
 692                         if (asn1_check_eoc(&p, len))
 693                                 {
 694                                 if (!sk_eoc)
 695                                         {
 696                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 697                                                         ASN1_R_UNEXPECTED_EOC);
 698                                         goto err;
 699                                         }
 700                                 len -= p - q;
 701                                 sk_eoc = 0;
 702                                 break;
 703                                 }
 704                         skfield = NULL;
 705                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 706                                                 ASN1_ITEM_ptr(tt->item),
 707                                                 -1, 0, 0, ctx))
 708                                 {
 709                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 710                                         ERR_R_NESTED_ASN1_ERROR);
 711                                 goto err;
 712                                 }
 713                         len -= p - q;
 714                         if (!sk_push((STACK *)*val, (char *)skfield))
 715                                 {
 716                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 717                                                 ERR_R_MALLOC_FAILURE);
 718                                 goto err;
 719                                 }
 720                         }
 721                 if (sk_eoc)
 722                         {
 723                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 724                         goto err;
 725                         }
 726                 }
 727         else if (flags & ASN1_TFLG_IMPTAG)
 728                 {
 729                 /* IMPLICIT tagging */
 730                 ret = ASN1_item_ex_d2i(val, &p, len,
 731                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 732                 if (!ret)
 733                         {
 734                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 735                                                 ERR_R_NESTED_ASN1_ERROR);
 736                         goto err;
 737                         }
 738                 else if (ret == -1)
 739                         return -1;
 740                 }
 741         else
 742                 {
 743                 /* Nothing special */
 744                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 745                                                         -1, 0, opt, ctx);
 746                 if (!ret)
 747                         {
 748                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 749                                         ERR_R_NESTED_ASN1_ERROR);
 750                         goto err;
 751                         }
 752                 else if (ret == -1)
 753                         return -1;
 754                 }
 755
 756         *in = p;
 757         return 1;
 758
 759         err:
 760         ASN1_template_free(val, tt);
 761         *val = NULL;
 762         return 0;
 763         }
 764
 765 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 766                                 const unsigned char **in, long inlen,
 767                                 const ASN1_ITEM *it,
 768                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 769         {
 770         int ret = 0, utype;
 771         long plen;
 772         char cst, inf, free_cont = 0;
 773         const unsigned char *p;
 774         BUF_MEM buf;
 775         const unsigned char *cont = NULL;
 776         long len;
 777         if (!pval)
 778                 {
 779                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 780                 return 0; /* Should never happen */
 781                 }
 782
 783         if (it->itype == ASN1_ITYPE_MSTRING)
 784                 {
 785                 utype = tag;
 786                 tag = -1;
 787                 }
 788         else
 789                 utype = it->utype;
 790
 791         if (utype == V_ASN1_ANY)
 792                 {
 793                 /* If type is ANY need to figure out type from tag */
 794                 unsigned char oclass;
 795                 if (tag >= 0)
 796                         {
 797                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 798                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 799                         return 0;
 800                         }
 801                 if (opt)
 802                         {
 803                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 804                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 805                         return 0;
 806                         }
 807                 p = *in;
 808                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 809                                         &p, inlen, -1, 0, 0, ctx);
 810                 if (!ret)
 811                         {
 812                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 813                                         ERR_R_NESTED_ASN1_ERROR);
 814                         return 0;
 815                         }
 816                 if (oclass != V_ASN1_UNIVERSAL)
 817                         utype = V_ASN1_OTHER;
 818                 }
 819         if (tag == -1)
 820                 {
 821                 tag = utype;
 822                 aclass = V_ASN1_UNIVERSAL;
 823                 }
 824         p = *in;
 825         /* Check header */
 826         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 827                                 &p, inlen, tag, aclass, opt, ctx);
 828         if (!ret)
 829                 {
 830                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 831                 return 0;
 832                 }
 833         else if (ret == -1)
 834                 return -1;
 835         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 836         if ((utype == V_ASN1_SEQUENCE)
 837                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 838                 {
 839                 /* Clear context cache for type OTHER because the auto clear
 840                  * when we have a exact match wont work
 841                  */
 842                 if (utype == V_ASN1_OTHER)
 843                         {
 844                         asn1_tlc_clear(ctx);
 845                         }
 846                 /* SEQUENCE and SET must be constructed */
 847                 else if (!cst)
 848                         {
 849                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 850                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 851                         return 0;
 852                         }
 853
 854                 cont = *in;
 855                 /* If indefinite length constructed find the real end */
 856                 if (inf)
 857                         {
 858                         if (!asn1_find_end(&p, plen, inf))
 859                                  goto err;
 860                         len = p - cont;
 861                         }
 862                 else
 863                         {
 864                         len = p - cont + plen;
 865                         p += plen;
 866                         buf.data = NULL;
 867                         }
 868                 }
 869         else if (cst)
 870                 {
 871                 buf.length = 0;
 872                 buf.max = 0;
 873                 buf.data = NULL;
 874                 /* Should really check the internal tags are correct but
 875                  * some things may get this wrong. The relevant specs
 876                  * say that constructed string types should be OCTET STRINGs
 877                  * internally irrespective of the type. So instead just check
 878                  * for UNIVERSAL class and ignore the tag.
 879                  */
 880                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL))
 881                         goto err;
 882                 len = buf.length;
 883                 /* Append a final null to string */
 884                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 885                         {
 886                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 887                                                 ERR_R_MALLOC_FAILURE);
 888                         return 0;
 889                         }
 890                 buf.data[len] = 0;
 891                 cont = (const unsigned char *)buf.data;
 892                 free_cont = 1;
 893                 }
 894         else
 895                 {
 896                 cont = p;
 897                 len = plen;
 898                 p += plen;
 899                 }
 900
 901         /* We now have content length and type: translate into a structure */
 902         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 903                 goto err;
 904
 905         *in = p;
 906         ret = 1;
 907         err:
 908         if (free_cont && buf.data) OPENSSL_free(buf.data);
 909         return ret;
 910         }
 911
 912 /* Translate ASN1 content octets into a structure */
 913
 914 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 915                         int utype, char *free_cont, const ASN1_ITEM *it)
 916         {
 917         ASN1_VALUE **opval = NULL;
 918         ASN1_STRING *stmp;
 919         ASN1_TYPE *typ = NULL;
 920         int ret = 0;
 921         const ASN1_PRIMITIVE_FUNCS *pf;
 922         ASN1_INTEGER **tint;
 923         pf = it->funcs;
 924
 925         if (pf && pf->prim_c2i)
 926                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 927         /* If ANY type clear type and set pointer to internal value */
 928         if (it->utype == V_ASN1_ANY)
 929                 {
 930                 if (!*pval)
 931                         {
 932                         typ = ASN1_TYPE_new();
 933                         if (typ == NULL)
 934                                 goto err;
 935                         *pval = (ASN1_VALUE *)typ;
 936                         }
 937                 else
 938                         typ = (ASN1_TYPE *)*pval;
 939
 940                 if (utype != typ->type)
 941                         ASN1_TYPE_set(typ, utype, NULL);
 942                 opval = pval;
 943                 pval = (ASN1_VALUE **)&typ->value.ptr;
 944                 }
 945         switch(utype)
 946                 {
 947                 case V_ASN1_OBJECT:
 948                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 949                         goto err;
 950                 break;
 951
 952                 case V_ASN1_NULL:
 953                 if (len)
 954                         {
 955                         ASN1err(ASN1_F_ASN1_EX_C2I,
 956                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 957                         goto err;
 958                         }
 959                 *pval = (ASN1_VALUE *)1;
 960                 break;
 961
 962                 case V_ASN1_BOOLEAN:
 963                 if (len != 1)
 964                         {
 965                         ASN1err(ASN1_F_ASN1_EX_C2I,
 966                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 967                         goto err;
 968                         }
 969                 else
 970                         {
 971                         ASN1_BOOLEAN *tbool;
 972                         tbool = (ASN1_BOOLEAN *)pval;
 973                         *tbool = *cont;
 974                         }
 975                 break;
 976
 977                 case V_ASN1_BIT_STRING:
 978                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 979                         goto err;
 980                 break;
 981
 982                 case V_ASN1_INTEGER:
 983                 case V_ASN1_NEG_INTEGER:
 984                 case V_ASN1_ENUMERATED:
 985                 case V_ASN1_NEG_ENUMERATED:
 986                 tint = (ASN1_INTEGER **)pval;
 987                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 988                         goto err;
 989                 /* Fixup type to match the expected form */
 990                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 991                 break;
 992
 993                 case V_ASN1_OCTET_STRING:
 994                 case V_ASN1_NUMERICSTRING:
 995                 case V_ASN1_PRINTABLESTRING:
 996                 case V_ASN1_T61STRING:
 997                 case V_ASN1_VIDEOTEXSTRING:
 998                 case V_ASN1_IA5STRING:
 999                 case V_ASN1_UTCTIME:
1000                 case V_ASN1_GENERALIZEDTIME:
1001                 case V_ASN1_GRAPHICSTRING:
1002                 case V_ASN1_VISIBLESTRING:
1003                 case V_ASN1_GENERALSTRING:
1004                 case V_ASN1_UNIVERSALSTRING:
1005                 case V_ASN1_BMPSTRING:
1006                 case V_ASN1_UTF8STRING:
1007                 case V_ASN1_OTHER:
1008                 case V_ASN1_SET:
1009                 case V_ASN1_SEQUENCE:
1010                 default:
1011                 /* All based on ASN1_STRING and handled the same */
1012                 if (!*pval)
1013                         {
1014                         stmp = ASN1_STRING_type_new(utype);
1015                         if (!stmp)
1016                                 {
1017                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1018                                                         ERR_R_MALLOC_FAILURE);
1019                                 goto err;
1020                                 }
1021                         *pval = (ASN1_VALUE *)stmp;
1022                         }
1023                 else
1024                         {
1025                         stmp = (ASN1_STRING *)*pval;
1026                         stmp->type = utype;
1027                         }
1028                 /* If we've already allocated a buffer use it */
1029                 if (*free_cont)
1030                         {
1031                         if (stmp->data)
1032                                 OPENSSL_free(stmp->data);
1033                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1034                         stmp->length = len;
1035                         *free_cont = 0;
1036                         }
1037                 else
1038                         {
1039                         if (!ASN1_STRING_set(stmp, cont, len))
1040                                 {
1041                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1042                                                         ERR_R_MALLOC_FAILURE);
1043                                 ASN1_STRING_free(stmp);
1044                                 *pval = NULL;
1045                                 goto err;
1046                                 }
1047                         }
1048                 break;
1049                 }
1050         /* If ASN1_ANY and NULL type fix up value */
1051         if (typ && (utype == V_ASN1_NULL))
1052                  typ->value.ptr = NULL;
1053
1054         ret = 1;
1055         err:
1056         if (!ret)
1057                 {
1058                 ASN1_TYPE_free(typ);
1059                 if (opval)
1060                         *opval = NULL;
1061                 }
1062         return ret;
1063         }
1064
1065
1066 /* This function finds the end of an ASN1 structure when passed its maximum
1067  * length, whether it is indefinite length and a pointer to the content.
1068  * This is more efficient than calling asn1_collect because it does not
1069  * recurse on each indefinite length header.
1070  */
1071
1072 static int asn1_find_end(const unsigned char **in, long len, char inf)
1073         {
1074         int expected_eoc;
1075         long plen;
1076         const unsigned char *p = *in, *q;
1077         /* If not indefinite length constructed just add length */
1078         if (inf == 0)
1079                 {
1080                 *in += len;
1081                 return 1;
1082                 }
1083         expected_eoc = 1;
1084         /* Indefinite length constructed form. Find the end when enough EOCs
1085          * are found. If more indefinite length constructed headers
1086          * are encountered increment the expected eoc count otherwise just
1087          * skip to the end of the data.
1088          */
1089         while (len > 0)
1090                 {
1091                 if(asn1_check_eoc(&p, len))
1092                         {
1093                         expected_eoc--;
1094                         if (expected_eoc == 0)
1095                                 break;
1096                         len -= 2;
1097                         continue;
1098                         }
1099                 q = p;
1100                 /* Just read in a header: only care about the length */
1101                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1102                                 -1, 0, 0, NULL))
1103                         {
1104                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1105                         return 0;
1106                         }
1107                 if (inf)
1108                         expected_eoc++;
1109                 else
1110                         p += plen;
1111                 len -= p - q;
1112                 }
1113         if (expected_eoc)
1114                 {
1115                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1116                 return 0;
1117                 }
1118         *in = p;
1119         return 1;
1120         }
1121 /* This function collects the asn1 data from a constructred string
1122  * type into a buffer. The values of 'in' and 'len' should refer
1123  * to the contents of the constructed type and 'inf' should be set
1124  * if it is indefinite length.
1125  */
1126
1127 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1128                                 char inf, int tag, int aclass)
1129         {
1130         const unsigned char *p, *q;
1131         long plen;
1132         char cst, ininf;
1133         p = *in;
1134         inf &= 1;
1135         /* If no buffer and not indefinite length constructed just pass over
1136          * the encoded data */
1137         if (!buf && !inf)
1138                 {
1139                 *in += len;
1140                 return 1;
1141                 }
1142         while(len > 0)
1143                 {
1144                 q = p;
1145                 /* Check for EOC */
1146                 if (asn1_check_eoc(&p, len))
1147                         {
1148                         /* EOC is illegal outside indefinite length
1149                          * constructed form */
1150                         if (!inf)
1151                                 {
1152                                 ASN1err(ASN1_F_ASN1_COLLECT,
1153                                         ASN1_R_UNEXPECTED_EOC);
1154                                 return 0;
1155                                 }
1156                         inf = 0;
1157                         break;
1158                         }
1159
1160                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1161                                         len, tag, aclass, 0, NULL))
1162                         {
1163                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1164                         return 0;
1165                         }
1166
1167                 /* If indefinite length constructed update max length */
1168                 if (cst)
1169                         {
1170 #ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS
1171                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass))
1172                                 return 0;
1173 #else
1174                         ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1175                         return 0;
1176 #endif
1177                         }
1178                 else if (plen && !collect_data(buf, &p, plen))
1179                         return 0;
1180                 len -= p - q;
1181                 }
1182         if (inf)
1183                 {
1184                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1185                 return 0;
1186                 }
1187         *in = p;
1188         return 1;
1189         }
1190
1191 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1192         {
1193         int len;
1194         if (buf)
1195                 {
1196                 len = buf->length;
1197                 if (!BUF_MEM_grow_clean(buf, len + plen))
1198                         {
1199                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1200                         return 0;
1201                         }
1202                 memcpy(buf->data + len, *p, plen);
1203                 }
1204         *p += plen;
1205         return 1;
1206         }
1207
1208 /* Check for ASN1 EOC and swallow it if found */
1209
1210 static int asn1_check_eoc(const unsigned char **in, long len)
1211         {
1212         const unsigned char *p;
1213         if (len < 2) return 0;
1214         p = *in;
1215         if (!p[0] && !p[1])
1216                 {
1217                 *in += 2;
1218                 return 1;
1219                 }
1220         return 0;
1221         }
1222
1223 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1224  * but it sets the length for indefinite length constructed
1225  * form, we don't know the exact length but we can set an
1226  * upper bound to the amount of data available minus the
1227  * header length just read.
1228  */
1229
1230 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1231                                 char *inf, char *cst,
1232                                 const unsigned char **in, long len,
1233                                 int exptag, int expclass, char opt,
1234                                 ASN1_TLC *ctx)
1235         {
1236         int i;
1237         int ptag, pclass;
1238         long plen;
1239         const unsigned char *p, *q;
1240         p = *in;
1241         q = p;
1242
1243         if (ctx && ctx->valid)
1244                 {
1245                 i = ctx->ret;
1246                 plen = ctx->plen;
1247                 pclass = ctx->pclass;
1248                 ptag = ctx->ptag;
1249                 p += ctx->hdrlen;
1250                 }
1251         else
1252                 {
1253                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1254                 if (ctx)
1255                         {
1256                         ctx->ret = i;
1257                         ctx->plen = plen;
1258                         ctx->pclass = pclass;
1259                         ctx->ptag = ptag;
1260                         ctx->hdrlen = p - q;
1261                         ctx->valid = 1;
1262                         /* If definite length, and no error, length +
1263                          * header can't exceed total amount of data available.
1264                          */
1265                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1266                                 {
1267                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1268                                                         ASN1_R_TOO_LONG);
1269                                 asn1_tlc_clear(ctx);
1270                                 return 0;
1271                                 }
1272                         }
1273                 }
1274
1275         if (i & 0x80)
1276                 {
1277                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1278                 asn1_tlc_clear(ctx);
1279                 return 0;
1280                 }
1281         if (exptag >= 0)
1282                 {
1283                 if ((exptag != ptag) || (expclass != pclass))
1284                         {
1285                         /* If type is OPTIONAL, not an error:
1286                          * indicate missing type.
1287                          */
1288                         if (opt) return -1;
1289                         asn1_tlc_clear(ctx);
1290                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1291                         return 0;
1292                         }
1293                 /* We have a tag and class match:
1294                  * assume we are going to do something with it */
1295                 asn1_tlc_clear(ctx);
1296                 }
1297
1298         if (i & 1)
1299                 plen = len - (p - q);
1300
1301         if (inf)
1302                 *inf = i & 1;
1303
1304         if (cst)
1305                 *cst = i & V_ASN1_CONSTRUCTED;
1306
1307         if (olen)
1308                 *olen = plen;
1309
1310         if (oclass)
1311                 *oclass = pclass;
1312
1313         if (otag)
1314                 *otag = ptag;
1315
1316         *in = p;
1317         return 1;
1318         }