crypto/openssl/crypto/asn1/tasn_dec.c

   1 /* tasn_dec.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) 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, int depth);
  73
  74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  75
  76 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  77                                 char *inf, char *cst,
  78                                 const unsigned char **in, long len,
  79                                 int exptag, int expclass, char opt,
  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 const 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 B_ASN1_SEQUENCE,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         c.valid = 0;
 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         c.valid = 0;
 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 **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                 p = *in;
 321                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 322                         {
 323                         pchptr = asn1_get_field_ptr(pval, tt);
 324                         /* We mark field as OPTIONAL so its absence
 325                          * can be recognised.
 326                          */
 327                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 328                         /* If field not present, try the next one */
 329                         if (ret == -1)
 330                                 continue;
 331                         /* If positive return, read OK, break loop */
 332                         if (ret > 0)
 333                                 break;
 334                         /* Otherwise must be an ASN1 parsing error */
 335                         errtt = tt;
 336                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 337                                                 ERR_R_NESTED_ASN1_ERROR);
 338                         goto err;
 339                         }
 340
 341                 /* Did we fall off the end without reading anything? */
 342                 if (i == it->tcount)
 343                         {
 344                         /* If OPTIONAL, this is OK */
 345                         if (opt)
 346                                 {
 347                                 /* Free and zero it */
 348                                 ASN1_item_ex_free(pval, it);
 349                                 return -1;
 350                                 }
 351                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 352                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 353                         goto err;
 354                         }
 355
 356                 asn1_set_choice_selector(pval, i, it);
 357                 *in = p;
 358                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 359                                 goto auxerr;
 360                 return 1;
 361
 362                 case ASN1_ITYPE_NDEF_SEQUENCE:
 363                 case ASN1_ITYPE_SEQUENCE:
 364                 p = *in;
 365                 tmplen = len;
 366
 367                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 368                 if (tag == -1)
 369                         {
 370                         tag = V_ASN1_SEQUENCE;
 371                         aclass = V_ASN1_UNIVERSAL;
 372                         }
 373                 /* Get SEQUENCE length and update len, p */
 374                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 375                                         &p, len, tag, aclass, opt, ctx);
 376                 if (!ret)
 377                         {
 378                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 379                                         ERR_R_NESTED_ASN1_ERROR);
 380                         goto err;
 381                         }
 382                 else if (ret == -1)
 383                         return -1;
 384                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 385                         {
 386                         len = tmplen - (p - *in);
 387                         seq_nolen = 1;
 388                         }
 389                 /* If indefinite we don't do a length check */
 390                 else seq_nolen = seq_eoc;
 391                 if (!cst)
 392                         {
 393                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 394                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 395                         goto err;
 396                         }
 397
 398                 if (!*pval && !ASN1_item_ex_new(pval, it))
 399                         {
 400                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 401                                 ERR_R_NESTED_ASN1_ERROR);
 402                         goto err;
 403                         }
 404
 405                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 406                                 goto auxerr;
 407
 408                 /* Get each field entry */
 409                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 410                         {
 411                         const ASN1_TEMPLATE *seqtt;
 412                         ASN1_VALUE **pseqval;
 413                         seqtt = asn1_do_adb(pval, tt, 1);
 414                         if (!seqtt)
 415                                 goto err;
 416                         pseqval = asn1_get_field_ptr(pval, seqtt);
 417                         /* Have we ran out of data? */
 418                         if (!len)
 419                                 break;
 420                         q = p;
 421                         if (asn1_check_eoc(&p, len))
 422                                 {
 423                                 if (!seq_eoc)
 424                                         {
 425                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 426                                                         ASN1_R_UNEXPECTED_EOC);
 427                                         goto err;
 428                                         }
 429                                 len -= p - q;
 430                                 seq_eoc = 0;
 431                                 q = p;
 432                                 break;
 433                                 }
 434                         /* This determines the OPTIONAL flag value. The field
 435                          * cannot be omitted if it is the last of a SEQUENCE
 436                          * and there is still data to be read. This isn't
 437                          * strictly necessary but it increases efficiency in
 438                          * some cases.
 439                          */
 440                         if (i == (it->tcount - 1))
 441                                 isopt = 0;
 442                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 443                         /* attempt to read in field, allowing each to be
 444                          * OPTIONAL */
 445
 446                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 447                                                         seqtt, isopt, ctx);
 448                         if (!ret)
 449                                 {
 450                                 errtt = seqtt;
 451                                 goto err;
 452                                 }
 453                         else if (ret == -1)
 454                                 {
 455                                 /* OPTIONAL component absent.
 456                                  * Free and zero the field.
 457                                  */
 458                                 ASN1_template_free(pseqval, seqtt);
 459                                 continue;
 460                                 }
 461                         /* Update length */
 462                         len -= p - q;
 463                         }
 464
 465                 /* Check for EOC if expecting one */
 466                 if (seq_eoc && !asn1_check_eoc(&p, len))
 467                         {
 468                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 469                         goto err;
 470                         }
 471                 /* Check all data read */
 472                 if (!seq_nolen && len)
 473                         {
 474                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 475                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 476                         goto err;
 477                         }
 478
 479                 /* If we get here we've got no more data in the SEQUENCE,
 480                  * however we may not have read all fields so check all
 481                  * remaining are OPTIONAL and clear any that are.
 482                  */
 483                 for (; i < it->tcount; tt++, i++)
 484                         {
 485                         const ASN1_TEMPLATE *seqtt;
 486                         seqtt = asn1_do_adb(pval, tt, 1);
 487                         if (!seqtt)
 488                                 goto err;
 489                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 490                                 {
 491                                 ASN1_VALUE **pseqval;
 492                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 493                                 ASN1_template_free(pseqval, seqtt);
 494                                 }
 495                         else
 496                                 {
 497                                 errtt = seqtt;
 498                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 499                                                         ASN1_R_FIELD_MISSING);
 500                                 goto err;
 501                                 }
 502                         }
 503                 /* Save encoding */
 504                 if (!asn1_enc_save(pval, *in, p - *in, it))
 505                         goto auxerr;
 506                 *in = p;
 507                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 508                                 goto auxerr;
 509                 return 1;
 510
 511                 default:
 512                 return 0;
 513                 }
 514         auxerr:
 515         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 516         err:
 517         ASN1_item_ex_free(pval, it);
 518         if (errtt)
 519                 ERR_add_error_data(4, "Field=", errtt->field_name,
 520                                         ", Type=", it->sname);
 521         else
 522                 ERR_add_error_data(2, "Type=", it->sname);
 523         return 0;
 524         }
 525
 526 /* Templates are handled with two separate functions.
 527  * One handles any EXPLICIT tag and the other handles the rest.
 528  */
 529
 530 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 531                                 const unsigned char **in, long inlen,
 532                                 const ASN1_TEMPLATE *tt, char opt,
 533                                                         ASN1_TLC *ctx)
 534         {
 535         int flags, aclass;
 536         int ret;
 537         long len;
 538         const unsigned char *p, *q;
 539         char exp_eoc;
 540         if (!val)
 541                 return 0;
 542         flags = tt->flags;
 543         aclass = flags & ASN1_TFLG_TAG_CLASS;
 544
 545         p = *in;
 546
 547         /* Check if EXPLICIT tag expected */
 548         if (flags & ASN1_TFLG_EXPTAG)
 549                 {
 550                 char cst;
 551                 /* Need to work out amount of data available to the inner
 552                  * content and where it starts: so read in EXPLICIT header to
 553                  * get the info.
 554                  */
 555                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 556                                         &p, inlen, tt->tag, aclass, opt, ctx);
 557                 q = p;
 558                 if (!ret)
 559                         {
 560                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 561                                         ERR_R_NESTED_ASN1_ERROR);
 562                         return 0;
 563                         }
 564                 else if (ret == -1)
 565                         return -1;
 566                 if (!cst)
 567                         {
 568                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 569                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 570                         return 0;
 571                         }
 572                 /* We've found the field so it can't be OPTIONAL now */
 573                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 574                 if (!ret)
 575                         {
 576                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 577                                         ERR_R_NESTED_ASN1_ERROR);
 578                         return 0;
 579                         }
 580                 /* We read the field in OK so update length */
 581                 len -= p - q;
 582                 if (exp_eoc)
 583                         {
 584                         /* If NDEF we must have an EOC here */
 585                         if (!asn1_check_eoc(&p, len))
 586                                 {
 587                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 588                                                 ASN1_R_MISSING_EOC);
 589                                 goto err;
 590                                 }
 591                         }
 592                 else
 593                         {
 594                         /* Otherwise we must hit the EXPLICIT tag end or its
 595                          * an error */
 596                         if (len)
 597                                 {
 598                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 599                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 600                                 goto err;
 601                                 }
 602                         }
 603                 }
 604                 else
 605                         return asn1_template_noexp_d2i(val, in, inlen,
 606                                                                 tt, opt, ctx);
 607
 608         *in = p;
 609         return 1;
 610
 611         err:
 612         ASN1_template_free(val, tt);
 613         return 0;
 614         }
 615
 616 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 617                                 const unsigned char **in, long len,
 618                                 const ASN1_TEMPLATE *tt, char opt,
 619                                 ASN1_TLC *ctx)
 620         {
 621         int flags, aclass;
 622         int ret;
 623         const unsigned char *p, *q;
 624         if (!val)
 625                 return 0;
 626         flags = tt->flags;
 627         aclass = flags & ASN1_TFLG_TAG_CLASS;
 628
 629         p = *in;
 630         q = p;
 631
 632         if (flags & ASN1_TFLG_SK_MASK)
 633                 {
 634                 /* SET OF, SEQUENCE OF */
 635                 int sktag, skaclass;
 636                 char sk_eoc;
 637                 /* First work out expected inner tag value */
 638                 if (flags & ASN1_TFLG_IMPTAG)
 639                         {
 640                         sktag = tt->tag;
 641                         skaclass = aclass;
 642                         }
 643                 else
 644                         {
 645                         skaclass = V_ASN1_UNIVERSAL;
 646                         if (flags & ASN1_TFLG_SET_OF)
 647                                 sktag = V_ASN1_SET;
 648                         else
 649                                 sktag = V_ASN1_SEQUENCE;
 650                         }
 651                 /* Get the tag */
 652                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 653                                         &p, len, sktag, skaclass, opt, ctx);
 654                 if (!ret)
 655                         {
 656                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 657                                                 ERR_R_NESTED_ASN1_ERROR);
 658                         return 0;
 659                         }
 660                 else if (ret == -1)
 661                         return -1;
 662                 if (!*val)
 663                         *val = (ASN1_VALUE *)sk_new_null();
 664                 else
 665                         {
 666                         /* We've got a valid STACK: free up any items present */
 667                         STACK *sktmp = (STACK *)*val;
 668                         ASN1_VALUE *vtmp;
 669                         while(sk_num(sktmp) > 0)
 670                                 {
 671                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
 672                                 ASN1_item_ex_free(&vtmp,
 673                                                 ASN1_ITEM_ptr(tt->item));
 674                                 }
 675                         }
 676
 677                 if (!*val)
 678                         {
 679                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 680                                                 ERR_R_MALLOC_FAILURE);
 681                         goto err;
 682                         }
 683
 684                 /* Read as many items as we can */
 685                 while(len > 0)
 686                         {
 687                         ASN1_VALUE *skfield;
 688                         q = p;
 689                         /* See if EOC found */
 690                         if (asn1_check_eoc(&p, len))
 691                                 {
 692                                 if (!sk_eoc)
 693                                         {
 694                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 695                                                         ASN1_R_UNEXPECTED_EOC);
 696                                         goto err;
 697                                         }
 698                                 len -= p - q;
 699                                 sk_eoc = 0;
 700                                 break;
 701                                 }
 702                         skfield = NULL;
 703                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 704                                                 ASN1_ITEM_ptr(tt->item),
 705                                                 -1, 0, 0, ctx))
 706                                 {
 707                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 708                                         ERR_R_NESTED_ASN1_ERROR);
 709                                 goto err;
 710                                 }
 711                         len -= p - q;
 712                         if (!sk_push((STACK *)*val, (char *)skfield))
 713                                 {
 714                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 715                                                 ERR_R_MALLOC_FAILURE);
 716                                 goto err;
 717                                 }
 718                         }
 719                 if (sk_eoc)
 720                         {
 721                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 722                         goto err;
 723                         }
 724                 }
 725         else if (flags & ASN1_TFLG_IMPTAG)
 726                 {
 727                 /* IMPLICIT tagging */
 728                 ret = ASN1_item_ex_d2i(val, &p, len,
 729                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 730                 if (!ret)
 731                         {
 732                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 733                                                 ERR_R_NESTED_ASN1_ERROR);
 734                         goto err;
 735                         }
 736                 else if (ret == -1)
 737                         return -1;
 738                 }
 739         else
 740                 {
 741                 /* Nothing special */
 742                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 743                                                         -1, 0, opt, ctx);
 744                 if (!ret)
 745                         {
 746                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 747                                         ERR_R_NESTED_ASN1_ERROR);
 748                         goto err;
 749                         }
 750                 else if (ret == -1)
 751                         return -1;
 752                 }
 753
 754         *in = p;
 755         return 1;
 756
 757         err:
 758         ASN1_template_free(val, tt);
 759         return 0;
 760         }
 761
 762 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 763                                 const unsigned char **in, long inlen,
 764                                 const ASN1_ITEM *it,
 765                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 766         {
 767         int ret = 0, utype;
 768         long plen;
 769         char cst, inf, free_cont = 0;
 770         const unsigned char *p;
 771         BUF_MEM buf;
 772         const unsigned char *cont = NULL;
 773         long len;
 774         if (!pval)
 775                 {
 776                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 777                 return 0; /* Should never happen */
 778                 }
 779
 780         if (it->itype == ASN1_ITYPE_MSTRING)
 781                 {
 782                 utype = tag;
 783                 tag = -1;
 784                 }
 785         else
 786                 utype = it->utype;
 787
 788         if (utype == V_ASN1_ANY)
 789                 {
 790                 /* If type is ANY need to figure out type from tag */
 791                 unsigned char oclass;
 792                 if (tag >= 0)
 793                         {
 794                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 795                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 796                         return 0;
 797                         }
 798                 if (opt)
 799                         {
 800                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 801                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 802                         return 0;
 803                         }
 804                 p = *in;
 805                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 806                                         &p, inlen, -1, 0, 0, ctx);
 807                 if (!ret)
 808                         {
 809                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 810                                         ERR_R_NESTED_ASN1_ERROR);
 811                         return 0;
 812                         }
 813                 if (oclass != V_ASN1_UNIVERSAL)
 814                         utype = V_ASN1_OTHER;
 815                 }
 816         if (tag == -1)
 817                 {
 818                 tag = utype;
 819                 aclass = V_ASN1_UNIVERSAL;
 820                 }
 821         p = *in;
 822         /* Check header */
 823         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 824                                 &p, inlen, tag, aclass, opt, ctx);
 825         if (!ret)
 826                 {
 827                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 828                 return 0;
 829                 }
 830         else if (ret == -1)
 831                 return -1;
 832         ret = 0;
 833         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 834         if ((utype == V_ASN1_SEQUENCE)
 835                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 836                 {
 837                 /* Clear context cache for type OTHER because the auto clear
 838                  * when we have a exact match wont work
 839                  */
 840                 if (utype == V_ASN1_OTHER)
 841                         {
 842                         asn1_tlc_clear(ctx);
 843                         }
 844                 /* SEQUENCE and SET must be constructed */
 845                 else if (!cst)
 846                         {
 847                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 848                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 849                         return 0;
 850                         }
 851
 852                 cont = *in;
 853                 /* If indefinite length constructed find the real end */
 854                 if (inf)
 855                         {
 856                         if (!asn1_find_end(&p, plen, inf))
 857                                  goto err;
 858                         len = p - cont;
 859                         }
 860                 else
 861                         {
 862                         len = p - cont + plen;
 863                         p += plen;
 864                         buf.data = NULL;
 865                         }
 866                 }
 867         else if (cst)
 868                 {
 869                 buf.length = 0;
 870                 buf.max = 0;
 871                 buf.data = NULL;
 872                 /* Should really check the internal tags are correct but
 873                  * some things may get this wrong. The relevant specs
 874                  * say that constructed string types should be OCTET STRINGs
 875                  * internally irrespective of the type. So instead just check
 876                  * for UNIVERSAL class and ignore the tag.
 877                  */
 878                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 879                         {
 880                         free_cont = 1;
 881                         goto err;
 882                         }
 883                 len = buf.length;
 884                 /* Append a final null to string */
 885                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 886                         {
 887                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 888                                                 ERR_R_MALLOC_FAILURE);
 889                         return 0;
 890                         }
 891                 buf.data[len] = 0;
 892                 cont = (const unsigned char *)buf.data;
 893                 free_cont = 1;
 894                 }
 895         else
 896                 {
 897                 cont = p;
 898                 len = plen;
 899                 p += plen;
 900                 }
 901
 902         /* We now have content length and type: translate into a structure */
 903         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 904                 goto err;
 905
 906         *in = p;
 907         ret = 1;
 908         err:
 909         if (free_cont && buf.data) OPENSSL_free(buf.data);
 910         return ret;
 911         }
 912
 913 /* Translate ASN1 content octets into a structure */
 914
 915 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 916                         int utype, char *free_cont, const ASN1_ITEM *it)
 917         {
 918         ASN1_VALUE **opval = NULL;
 919         ASN1_STRING *stmp;
 920         ASN1_TYPE *typ = NULL;
 921         int ret = 0;
 922         const ASN1_PRIMITIVE_FUNCS *pf;
 923         ASN1_INTEGER **tint;
 924         pf = it->funcs;
 925
 926         if (pf && pf->prim_c2i)
 927                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 928         /* If ANY type clear type and set pointer to internal value */
 929         if (it->utype == V_ASN1_ANY)
 930                 {
 931                 if (!*pval)
 932                         {
 933                         typ = ASN1_TYPE_new();
 934                         if (typ == NULL)
 935                                 goto err;
 936                         *pval = (ASN1_VALUE *)typ;
 937                         }
 938                 else
 939                         typ = (ASN1_TYPE *)*pval;
 940
 941                 if (utype != typ->type)
 942                         ASN1_TYPE_set(typ, utype, NULL);
 943                 opval = pval;
 944                 pval = &typ->value.asn1_value;
 945                 }
 946         switch(utype)
 947                 {
 948                 case V_ASN1_OBJECT:
 949                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 950                         goto err;
 951                 break;
 952
 953                 case V_ASN1_NULL:
 954                 if (len)
 955                         {
 956                         ASN1err(ASN1_F_ASN1_EX_C2I,
 957                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 958                         goto err;
 959                         }
 960                 *pval = (ASN1_VALUE *)1;
 961                 break;
 962
 963                 case V_ASN1_BOOLEAN:
 964                 if (len != 1)
 965                         {
 966                         ASN1err(ASN1_F_ASN1_EX_C2I,
 967                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 968                         goto err;
 969                         }
 970                 else
 971                         {
 972                         ASN1_BOOLEAN *tbool;
 973                         tbool = (ASN1_BOOLEAN *)pval;
 974                         *tbool = *cont;
 975                         }
 976                 break;
 977
 978                 case V_ASN1_BIT_STRING:
 979                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 980                         goto err;
 981                 break;
 982
 983                 case V_ASN1_INTEGER:
 984                 case V_ASN1_NEG_INTEGER:
 985                 case V_ASN1_ENUMERATED:
 986                 case V_ASN1_NEG_ENUMERATED:
 987                 tint = (ASN1_INTEGER **)pval;
 988                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 989                         goto err;
 990                 /* Fixup type to match the expected form */
 991                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 992                 break;
 993
 994                 case V_ASN1_OCTET_STRING:
 995                 case V_ASN1_NUMERICSTRING:
 996                 case V_ASN1_PRINTABLESTRING:
 997                 case V_ASN1_T61STRING:
 998                 case V_ASN1_VIDEOTEXSTRING:
 999                 case V_ASN1_IA5STRING:
1000                 case V_ASN1_UTCTIME:
1001                 case V_ASN1_GENERALIZEDTIME:
1002                 case V_ASN1_GRAPHICSTRING:
1003                 case V_ASN1_VISIBLESTRING:
1004                 case V_ASN1_GENERALSTRING:
1005                 case V_ASN1_UNIVERSALSTRING:
1006                 case V_ASN1_BMPSTRING:
1007                 case V_ASN1_UTF8STRING:
1008                 case V_ASN1_OTHER:
1009                 case V_ASN1_SET:
1010                 case V_ASN1_SEQUENCE:
1011                 default:
1012                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1013                         {
1014                         ASN1err(ASN1_F_ASN1_EX_C2I,
1015                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1016                         goto err;
1017                         }
1018                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1019                         {
1020                         ASN1err(ASN1_F_ASN1_EX_C2I,
1021                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1022                         goto err;
1023                         }
1024                 /* All based on ASN1_STRING and handled the same */
1025                 if (!*pval)
1026                         {
1027                         stmp = ASN1_STRING_type_new(utype);
1028                         if (!stmp)
1029                                 {
1030                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1031                                                         ERR_R_MALLOC_FAILURE);
1032                                 goto err;
1033                                 }
1034                         *pval = (ASN1_VALUE *)stmp;
1035                         }
1036                 else
1037                         {
1038                         stmp = (ASN1_STRING *)*pval;
1039                         stmp->type = utype;
1040                         }
1041                 /* If we've already allocated a buffer use it */
1042                 if (*free_cont)
1043                         {
1044                         if (stmp->data)
1045                                 OPENSSL_free(stmp->data);
1046                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1047                         stmp->length = len;
1048                         *free_cont = 0;
1049                         }
1050                 else
1051                         {
1052                         if (!ASN1_STRING_set(stmp, cont, len))
1053                                 {
1054                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1055                                                         ERR_R_MALLOC_FAILURE);
1056                                 ASN1_STRING_free(stmp);
1057                                 *pval = NULL;
1058                                 goto err;
1059                                 }
1060                         }
1061                 break;
1062                 }
1063         /* If ASN1_ANY and NULL type fix up value */
1064         if (typ && (utype == V_ASN1_NULL))
1065                  typ->value.ptr = NULL;
1066
1067         ret = 1;
1068         err:
1069         if (!ret)
1070                 {
1071                 ASN1_TYPE_free(typ);
1072                 if (opval)
1073                         *opval = NULL;
1074                 }
1075         return ret;
1076         }
1077
1078
1079 /* This function finds the end of an ASN1 structure when passed its maximum
1080  * length, whether it is indefinite length and a pointer to the content.
1081  * This is more efficient than calling asn1_collect because it does not
1082  * recurse on each indefinite length header.
1083  */
1084
1085 static int asn1_find_end(const unsigned char **in, long len, char inf)
1086         {
1087         int expected_eoc;
1088         long plen;
1089         const unsigned char *p = *in, *q;
1090         /* If not indefinite length constructed just add length */
1091         if (inf == 0)
1092                 {
1093                 *in += len;
1094                 return 1;
1095                 }
1096         expected_eoc = 1;
1097         /* Indefinite length constructed form. Find the end when enough EOCs
1098          * are found. If more indefinite length constructed headers
1099          * are encountered increment the expected eoc count otherwise just
1100          * skip to the end of the data.
1101          */
1102         while (len > 0)
1103                 {
1104                 if(asn1_check_eoc(&p, len))
1105                         {
1106                         expected_eoc--;
1107                         if (expected_eoc == 0)
1108                                 break;
1109                         len -= 2;
1110                         continue;
1111                         }
1112                 q = p;
1113                 /* Just read in a header: only care about the length */
1114                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1115                                 -1, 0, 0, NULL))
1116                         {
1117                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1118                         return 0;
1119                         }
1120                 if (inf)
1121                         expected_eoc++;
1122                 else
1123                         p += plen;
1124                 len -= p - q;
1125                 }
1126         if (expected_eoc)
1127                 {
1128                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1129                 return 0;
1130                 }
1131         *in = p;
1132         return 1;
1133         }
1134 /* This function collects the asn1 data from a constructred string
1135  * type into a buffer. The values of 'in' and 'len' should refer
1136  * to the contents of the constructed type and 'inf' should be set
1137  * if it is indefinite length.
1138  */
1139
1140 #ifndef ASN1_MAX_STRING_NEST
1141 /* This determines how many levels of recursion are permitted in ASN1
1142  * string types. If it is not limited stack overflows can occur. If set
1143  * to zero no recursion is allowed at all. Although zero should be adequate
1144  * examples exist that require a value of 1. So 5 should be more than enough.
1145  */
1146 #define ASN1_MAX_STRING_NEST 5
1147 #endif
1148
1149
1150 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1151                         char inf, int tag, int aclass, int depth)
1152         {
1153         const unsigned char *p, *q;
1154         long plen;
1155         char cst, ininf;
1156         p = *in;
1157         inf &= 1;
1158         /* If no buffer and not indefinite length constructed just pass over
1159          * the encoded data */
1160         if (!buf && !inf)
1161                 {
1162                 *in += len;
1163                 return 1;
1164                 }
1165         while(len > 0)
1166                 {
1167                 q = p;
1168                 /* Check for EOC */
1169                 if (asn1_check_eoc(&p, len))
1170                         {
1171                         /* EOC is illegal outside indefinite length
1172                          * constructed form */
1173                         if (!inf)
1174                                 {
1175                                 ASN1err(ASN1_F_ASN1_COLLECT,
1176                                         ASN1_R_UNEXPECTED_EOC);
1177                                 return 0;
1178                                 }
1179                         inf = 0;
1180                         break;
1181                         }
1182
1183                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1184                                         len, tag, aclass, 0, NULL))
1185                         {
1186                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1187                         return 0;
1188                         }
1189
1190                 /* If indefinite length constructed update max length */
1191                 if (cst)
1192                         {
1193                         if (depth >= ASN1_MAX_STRING_NEST)
1194                                 {
1195                                 ASN1err(ASN1_F_ASN1_COLLECT,
1196                                         ASN1_R_NESTED_ASN1_STRING);
1197                                 return 0;
1198                                 }
1199                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1200                                                 depth + 1))
1201                                 return 0;
1202                         }
1203                 else if (plen && !collect_data(buf, &p, plen))
1204                         return 0;
1205                 len -= p - q;
1206                 }
1207         if (inf)
1208                 {
1209                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1210                 return 0;
1211                 }
1212         *in = p;
1213         return 1;
1214         }
1215
1216 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1217         {
1218         int len;
1219         if (buf)
1220                 {
1221                 len = buf->length;
1222                 if (!BUF_MEM_grow_clean(buf, len + plen))
1223                         {
1224                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1225                         return 0;
1226                         }
1227                 memcpy(buf->data + len, *p, plen);
1228                 }
1229         *p += plen;
1230         return 1;
1231         }
1232
1233 /* Check for ASN1 EOC and swallow it if found */
1234
1235 static int asn1_check_eoc(const unsigned char **in, long len)
1236         {
1237         const unsigned char *p;
1238         if (len < 2) return 0;
1239         p = *in;
1240         if (!p[0] && !p[1])
1241                 {
1242                 *in += 2;
1243                 return 1;
1244                 }
1245         return 0;
1246         }
1247
1248 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1249  * but it sets the length for indefinite length constructed
1250  * form, we don't know the exact length but we can set an
1251  * upper bound to the amount of data available minus the
1252  * header length just read.
1253  */
1254
1255 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1256                                 char *inf, char *cst,
1257                                 const unsigned char **in, long len,
1258                                 int exptag, int expclass, char opt,
1259                                 ASN1_TLC *ctx)
1260         {
1261         int i;
1262         int ptag, pclass;
1263         long plen;
1264         const unsigned char *p, *q;
1265         p = *in;
1266         q = p;
1267
1268         if (ctx && ctx->valid)
1269                 {
1270                 i = ctx->ret;
1271                 plen = ctx->plen;
1272                 pclass = ctx->pclass;
1273                 ptag = ctx->ptag;
1274                 p += ctx->hdrlen;
1275                 }
1276         else
1277                 {
1278                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1279                 if (ctx)
1280                         {
1281                         ctx->ret = i;
1282                         ctx->plen = plen;
1283                         ctx->pclass = pclass;
1284                         ctx->ptag = ptag;
1285                         ctx->hdrlen = p - q;
1286                         ctx->valid = 1;
1287                         /* If definite length, and no error, length +
1288                          * header can't exceed total amount of data available.
1289                          */
1290                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1291                                 {
1292                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1293                                                         ASN1_R_TOO_LONG);
1294                                 asn1_tlc_clear(ctx);
1295                                 return 0;
1296                                 }
1297                         }
1298                 }
1299
1300         if (i & 0x80)
1301                 {
1302                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1303                 asn1_tlc_clear(ctx);
1304                 return 0;
1305                 }
1306         if (exptag >= 0)
1307                 {
1308                 if ((exptag != ptag) || (expclass != pclass))
1309                         {
1310                         /* If type is OPTIONAL, not an error:
1311                          * indicate missing type.
1312                          */
1313                         if (opt) return -1;
1314                         asn1_tlc_clear(ctx);
1315                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1316                         return 0;
1317                         }
1318                 /* We have a tag and class match:
1319                  * assume we are going to do something with it */
1320                 asn1_tlc_clear(ctx);
1321                 }
1322
1323         if (i & 1)
1324                 plen = len - (p - q);
1325
1326         if (inf)
1327                 *inf = i & 1;
1328
1329         if (cst)
1330                 *cst = i & V_ASN1_CONSTRUCTED;
1331
1332         if (olen)
1333                 *olen = plen;
1334
1335         if (oclass)
1336                 *oclass = pclass;
1337
1338         if (otag)
1339                 *otag = ptag;
1340
1341         *in = p;
1342         return 1;
1343         }