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 *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         return 0;
 615         }
 616
 617 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 618                                 const unsigned char **in, long len,
 619                                 const ASN1_TEMPLATE *tt, char opt,
 620                                 ASN1_TLC *ctx)
 621         {
 622         int flags, aclass;
 623         int ret;
 624         const unsigned char *p, *q;
 625         if (!val)
 626                 return 0;
 627         flags = tt->flags;
 628         aclass = flags & ASN1_TFLG_TAG_CLASS;
 629
 630         p = *in;
 631         q = p;
 632
 633         if (flags & ASN1_TFLG_SK_MASK)
 634                 {
 635                 /* SET OF, SEQUENCE OF */
 636                 int sktag, skaclass;
 637                 char sk_eoc;
 638                 /* First work out expected inner tag value */
 639                 if (flags & ASN1_TFLG_IMPTAG)
 640                         {
 641                         sktag = tt->tag;
 642                         skaclass = aclass;
 643                         }
 644                 else
 645                         {
 646                         skaclass = V_ASN1_UNIVERSAL;
 647                         if (flags & ASN1_TFLG_SET_OF)
 648                                 sktag = V_ASN1_SET;
 649                         else
 650                                 sktag = V_ASN1_SEQUENCE;
 651                         }
 652                 /* Get the tag */
 653                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 654                                         &p, len, sktag, skaclass, opt, ctx);
 655                 if (!ret)
 656                         {
 657                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 658                                                 ERR_R_NESTED_ASN1_ERROR);
 659                         return 0;
 660                         }
 661                 else if (ret == -1)
 662                         return -1;
 663                 if (!*val)
 664                         *val = (ASN1_VALUE *)sk_new_null();
 665                 else
 666                         {
 667                         /* We've got a valid STACK: free up any items present */
 668                         STACK *sktmp = (STACK *)*val;
 669                         ASN1_VALUE *vtmp;
 670                         while(sk_num(sktmp) > 0)
 671                                 {
 672                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
 673                                 ASN1_item_ex_free(&vtmp,
 674                                                 ASN1_ITEM_ptr(tt->item));
 675                                 }
 676                         }
 677
 678                 if (!*val)
 679                         {
 680                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 681                                                 ERR_R_MALLOC_FAILURE);
 682                         goto err;
 683                         }
 684
 685                 /* Read as many items as we can */
 686                 while(len > 0)
 687                         {
 688                         ASN1_VALUE *skfield;
 689                         q = p;
 690                         /* See if EOC found */
 691                         if (asn1_check_eoc(&p, len))
 692                                 {
 693                                 if (!sk_eoc)
 694                                         {
 695                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 696                                                         ASN1_R_UNEXPECTED_EOC);
 697                                         goto err;
 698                                         }
 699                                 len -= p - q;
 700                                 sk_eoc = 0;
 701                                 break;
 702                                 }
 703                         skfield = NULL;
 704                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 705                                                 ASN1_ITEM_ptr(tt->item),
 706                                                 -1, 0, 0, ctx))
 707                                 {
 708                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 709                                         ERR_R_NESTED_ASN1_ERROR);
 710                                 goto err;
 711                                 }
 712                         len -= p - q;
 713                         if (!sk_push((STACK *)*val, (char *)skfield))
 714                                 {
 715                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 716                                                 ERR_R_MALLOC_FAILURE);
 717                                 goto err;
 718                                 }
 719                         }
 720                 if (sk_eoc)
 721                         {
 722                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 723                         goto err;
 724                         }
 725                 }
 726         else if (flags & ASN1_TFLG_IMPTAG)
 727                 {
 728                 /* IMPLICIT tagging */
 729                 ret = ASN1_item_ex_d2i(val, &p, len,
 730                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 731                 if (!ret)
 732                         {
 733                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 734                                                 ERR_R_NESTED_ASN1_ERROR);
 735                         goto err;
 736                         }
 737                 else if (ret == -1)
 738                         return -1;
 739                 }
 740         else
 741                 {
 742                 /* Nothing special */
 743                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 744                                                         -1, 0, opt, ctx);
 745                 if (!ret)
 746                         {
 747                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 748                                         ERR_R_NESTED_ASN1_ERROR);
 749                         goto err;
 750                         }
 751                 else if (ret == -1)
 752                         return -1;
 753                 }
 754
 755         *in = p;
 756         return 1;
 757
 758         err:
 759         ASN1_template_free(val, tt);
 760         return 0;
 761         }
 762
 763 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 764                                 const unsigned char **in, long inlen,
 765                                 const ASN1_ITEM *it,
 766                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 767         {
 768         int ret = 0, utype;
 769         long plen;
 770         char cst, inf, free_cont = 0;
 771         const unsigned char *p;
 772         BUF_MEM buf;
 773         const unsigned char *cont = NULL;
 774         long len;
 775         if (!pval)
 776                 {
 777                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 778                 return 0; /* Should never happen */
 779                 }
 780
 781         if (it->itype == ASN1_ITYPE_MSTRING)
 782                 {
 783                 utype = tag;
 784                 tag = -1;
 785                 }
 786         else
 787                 utype = it->utype;
 788
 789         if (utype == V_ASN1_ANY)
 790                 {
 791                 /* If type is ANY need to figure out type from tag */
 792                 unsigned char oclass;
 793                 if (tag >= 0)
 794                         {
 795                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 796                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 797                         return 0;
 798                         }
 799                 if (opt)
 800                         {
 801                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 802                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 803                         return 0;
 804                         }
 805                 p = *in;
 806                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 807                                         &p, inlen, -1, 0, 0, ctx);
 808                 if (!ret)
 809                         {
 810                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 811                                         ERR_R_NESTED_ASN1_ERROR);
 812                         return 0;
 813                         }
 814                 if (oclass != V_ASN1_UNIVERSAL)
 815                         utype = V_ASN1_OTHER;
 816                 }
 817         if (tag == -1)
 818                 {
 819                 tag = utype;
 820                 aclass = V_ASN1_UNIVERSAL;
 821                 }
 822         p = *in;
 823         /* Check header */
 824         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 825                                 &p, inlen, tag, aclass, opt, ctx);
 826         if (!ret)
 827                 {
 828                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 829                 return 0;
 830                 }
 831         else if (ret == -1)
 832                 return -1;
 833         ret = 0;
 834         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 835         if ((utype == V_ASN1_SEQUENCE)
 836                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 837                 {
 838                 /* Clear context cache for type OTHER because the auto clear
 839                  * when we have a exact match wont work
 840                  */
 841                 if (utype == V_ASN1_OTHER)
 842                         {
 843                         asn1_tlc_clear(ctx);
 844                         }
 845                 /* SEQUENCE and SET must be constructed */
 846                 else if (!cst)
 847                         {
 848                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 849                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 850                         return 0;
 851                         }
 852
 853                 cont = *in;
 854                 /* If indefinite length constructed find the real end */
 855                 if (inf)
 856                         {
 857                         if (!asn1_find_end(&p, plen, inf))
 858                                  goto err;
 859                         len = p - cont;
 860                         }
 861                 else
 862                         {
 863                         len = p - cont + plen;
 864                         p += plen;
 865                         buf.data = NULL;
 866                         }
 867                 }
 868         else if (cst)
 869                 {
 870                 buf.length = 0;
 871                 buf.max = 0;
 872                 buf.data = NULL;
 873                 /* Should really check the internal tags are correct but
 874                  * some things may get this wrong. The relevant specs
 875                  * say that constructed string types should be OCTET STRINGs
 876                  * internally irrespective of the type. So instead just check
 877                  * for UNIVERSAL class and ignore the tag.
 878                  */
 879                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 880                         {
 881                         free_cont = 1;
 882                         goto err;
 883                         }
 884                 len = buf.length;
 885                 /* Append a final null to string */
 886                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 887                         {
 888                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 889                                                 ERR_R_MALLOC_FAILURE);
 890                         return 0;
 891                         }
 892                 buf.data[len] = 0;
 893                 cont = (const unsigned char *)buf.data;
 894                 free_cont = 1;
 895                 }
 896         else
 897                 {
 898                 cont = p;
 899                 len = plen;
 900                 p += plen;
 901                 }
 902
 903         /* We now have content length and type: translate into a structure */
 904         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 905                 goto err;
 906
 907         *in = p;
 908         ret = 1;
 909         err:
 910         if (free_cont && buf.data) OPENSSL_free(buf.data);
 911         return ret;
 912         }
 913
 914 /* Translate ASN1 content octets into a structure */
 915
 916 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 917                         int utype, char *free_cont, const ASN1_ITEM *it)
 918         {
 919         ASN1_VALUE **opval = NULL;
 920         ASN1_STRING *stmp;
 921         ASN1_TYPE *typ = NULL;
 922         int ret = 0;
 923         const ASN1_PRIMITIVE_FUNCS *pf;
 924         ASN1_INTEGER **tint;
 925         pf = it->funcs;
 926
 927         if (pf && pf->prim_c2i)
 928                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 929         /* If ANY type clear type and set pointer to internal value */
 930         if (it->utype == V_ASN1_ANY)
 931                 {
 932                 if (!*pval)
 933                         {
 934                         typ = ASN1_TYPE_new();
 935                         if (typ == NULL)
 936                                 goto err;
 937                         *pval = (ASN1_VALUE *)typ;
 938                         }
 939                 else
 940                         typ = (ASN1_TYPE *)*pval;
 941
 942                 if (utype != typ->type)
 943                         ASN1_TYPE_set(typ, utype, NULL);
 944                 opval = pval;
 945                 pval = &typ->value.asn1_value;
 946                 }
 947         switch(utype)
 948                 {
 949                 case V_ASN1_OBJECT:
 950                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 951                         goto err;
 952                 break;
 953
 954                 case V_ASN1_NULL:
 955                 if (len)
 956                         {
 957                         ASN1err(ASN1_F_ASN1_EX_C2I,
 958                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 959                         goto err;
 960                         }
 961                 *pval = (ASN1_VALUE *)1;
 962                 break;
 963
 964                 case V_ASN1_BOOLEAN:
 965                 if (len != 1)
 966                         {
 967                         ASN1err(ASN1_F_ASN1_EX_C2I,
 968                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 969                         goto err;
 970                         }
 971                 else
 972                         {
 973                         ASN1_BOOLEAN *tbool;
 974                         tbool = (ASN1_BOOLEAN *)pval;
 975                         *tbool = *cont;
 976                         }
 977                 break;
 978
 979                 case V_ASN1_BIT_STRING:
 980                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 981                         goto err;
 982                 break;
 983
 984                 case V_ASN1_INTEGER:
 985                 case V_ASN1_NEG_INTEGER:
 986                 case V_ASN1_ENUMERATED:
 987                 case V_ASN1_NEG_ENUMERATED:
 988                 tint = (ASN1_INTEGER **)pval;
 989                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 990                         goto err;
 991                 /* Fixup type to match the expected form */
 992                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 993                 break;
 994
 995                 case V_ASN1_OCTET_STRING:
 996                 case V_ASN1_NUMERICSTRING:
 997                 case V_ASN1_PRINTABLESTRING:
 998                 case V_ASN1_T61STRING:
 999                 case V_ASN1_VIDEOTEXSTRING:
1000                 case V_ASN1_IA5STRING:
1001                 case V_ASN1_UTCTIME:
1002                 case V_ASN1_GENERALIZEDTIME:
1003                 case V_ASN1_GRAPHICSTRING:
1004                 case V_ASN1_VISIBLESTRING:
1005                 case V_ASN1_GENERALSTRING:
1006                 case V_ASN1_UNIVERSALSTRING:
1007                 case V_ASN1_BMPSTRING:
1008                 case V_ASN1_UTF8STRING:
1009                 case V_ASN1_OTHER:
1010                 case V_ASN1_SET:
1011                 case V_ASN1_SEQUENCE:
1012                 default:
1013                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1014                         {
1015                         ASN1err(ASN1_F_ASN1_EX_C2I,
1016                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1017                         goto err;
1018                         }
1019                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1020                         {
1021                         ASN1err(ASN1_F_ASN1_EX_C2I,
1022                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1023                         goto err;
1024                         }
1025                 /* All based on ASN1_STRING and handled the same */
1026                 if (!*pval)
1027                         {
1028                         stmp = ASN1_STRING_type_new(utype);
1029                         if (!stmp)
1030                                 {
1031                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1032                                                         ERR_R_MALLOC_FAILURE);
1033                                 goto err;
1034                                 }
1035                         *pval = (ASN1_VALUE *)stmp;
1036                         }
1037                 else
1038                         {
1039                         stmp = (ASN1_STRING *)*pval;
1040                         stmp->type = utype;
1041                         }
1042                 /* If we've already allocated a buffer use it */
1043                 if (*free_cont)
1044                         {
1045                         if (stmp->data)
1046                                 OPENSSL_free(stmp->data);
1047                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1048                         stmp->length = len;
1049                         *free_cont = 0;
1050                         }
1051                 else
1052                         {
1053                         if (!ASN1_STRING_set(stmp, cont, len))
1054                                 {
1055                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1056                                                         ERR_R_MALLOC_FAILURE);
1057                                 ASN1_STRING_free(stmp);
1058                                 *pval = NULL;
1059                                 goto err;
1060                                 }
1061                         }
1062                 break;
1063                 }
1064         /* If ASN1_ANY and NULL type fix up value */
1065         if (typ && (utype == V_ASN1_NULL))
1066                  typ->value.ptr = NULL;
1067
1068         ret = 1;
1069         err:
1070         if (!ret)
1071                 {
1072                 ASN1_TYPE_free(typ);
1073                 if (opval)
1074                         *opval = NULL;
1075                 }
1076         return ret;
1077         }
1078
1079
1080 /* This function finds the end of an ASN1 structure when passed its maximum
1081  * length, whether it is indefinite length and a pointer to the content.
1082  * This is more efficient than calling asn1_collect because it does not
1083  * recurse on each indefinite length header.
1084  */
1085
1086 static int asn1_find_end(const unsigned char **in, long len, char inf)
1087         {
1088         int expected_eoc;
1089         long plen;
1090         const unsigned char *p = *in, *q;
1091         /* If not indefinite length constructed just add length */
1092         if (inf == 0)
1093                 {
1094                 *in += len;
1095                 return 1;
1096                 }
1097         expected_eoc = 1;
1098         /* Indefinite length constructed form. Find the end when enough EOCs
1099          * are found. If more indefinite length constructed headers
1100          * are encountered increment the expected eoc count otherwise just
1101          * skip to the end of the data.
1102          */
1103         while (len > 0)
1104                 {
1105                 if(asn1_check_eoc(&p, len))
1106                         {
1107                         expected_eoc--;
1108                         if (expected_eoc == 0)
1109                                 break;
1110                         len -= 2;
1111                         continue;
1112                         }
1113                 q = p;
1114                 /* Just read in a header: only care about the length */
1115                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1116                                 -1, 0, 0, NULL))
1117                         {
1118                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1119                         return 0;
1120                         }
1121                 if (inf)
1122                         expected_eoc++;
1123                 else
1124                         p += plen;
1125                 len -= p - q;
1126                 }
1127         if (expected_eoc)
1128                 {
1129                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1130                 return 0;
1131                 }
1132         *in = p;
1133         return 1;
1134         }
1135 /* This function collects the asn1 data from a constructred string
1136  * type into a buffer. The values of 'in' and 'len' should refer
1137  * to the contents of the constructed type and 'inf' should be set
1138  * if it is indefinite length.
1139  */
1140
1141 #ifndef ASN1_MAX_STRING_NEST
1142 /* This determines how many levels of recursion are permitted in ASN1
1143  * string types. If it is not limited stack overflows can occur. If set
1144  * to zero no recursion is allowed at all. Although zero should be adequate
1145  * examples exist that require a value of 1. So 5 should be more than enough.
1146  */
1147 #define ASN1_MAX_STRING_NEST 5
1148 #endif
1149
1150
1151 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1152                         char inf, int tag, int aclass, int depth)
1153         {
1154         const unsigned char *p, *q;
1155         long plen;
1156         char cst, ininf;
1157         p = *in;
1158         inf &= 1;
1159         /* If no buffer and not indefinite length constructed just pass over
1160          * the encoded data */
1161         if (!buf && !inf)
1162                 {
1163                 *in += len;
1164                 return 1;
1165                 }
1166         while(len > 0)
1167                 {
1168                 q = p;
1169                 /* Check for EOC */
1170                 if (asn1_check_eoc(&p, len))
1171                         {
1172                         /* EOC is illegal outside indefinite length
1173                          * constructed form */
1174                         if (!inf)
1175                                 {
1176                                 ASN1err(ASN1_F_ASN1_COLLECT,
1177                                         ASN1_R_UNEXPECTED_EOC);
1178                                 return 0;
1179                                 }
1180                         inf = 0;
1181                         break;
1182                         }
1183
1184                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1185                                         len, tag, aclass, 0, NULL))
1186                         {
1187                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1188                         return 0;
1189                         }
1190
1191                 /* If indefinite length constructed update max length */
1192                 if (cst)
1193                         {
1194                         if (depth >= ASN1_MAX_STRING_NEST)
1195                                 {
1196                                 ASN1err(ASN1_F_ASN1_COLLECT,
1197                                         ASN1_R_NESTED_ASN1_STRING);
1198                                 return 0;
1199                                 }
1200                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1201                                                 depth + 1))
1202                                 return 0;
1203                         }
1204                 else if (plen && !collect_data(buf, &p, plen))
1205                         return 0;
1206                 len -= p - q;
1207                 }
1208         if (inf)
1209                 {
1210                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1211                 return 0;
1212                 }
1213         *in = p;
1214         return 1;
1215         }
1216
1217 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1218         {
1219         int len;
1220         if (buf)
1221                 {
1222                 len = buf->length;
1223                 if (!BUF_MEM_grow_clean(buf, len + plen))
1224                         {
1225                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1226                         return 0;
1227                         }
1228                 memcpy(buf->data + len, *p, plen);
1229                 }
1230         *p += plen;
1231         return 1;
1232         }
1233
1234 /* Check for ASN1 EOC and swallow it if found */
1235
1236 static int asn1_check_eoc(const unsigned char **in, long len)
1237         {
1238         const unsigned char *p;
1239         if (len < 2) return 0;
1240         p = *in;
1241         if (!p[0] && !p[1])
1242                 {
1243                 *in += 2;
1244                 return 1;
1245                 }
1246         return 0;
1247         }
1248
1249 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1250  * but it sets the length for indefinite length constructed
1251  * form, we don't know the exact length but we can set an
1252  * upper bound to the amount of data available minus the
1253  * header length just read.
1254  */
1255
1256 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1257                                 char *inf, char *cst,
1258                                 const unsigned char **in, long len,
1259                                 int exptag, int expclass, char opt,
1260                                 ASN1_TLC *ctx)
1261         {
1262         int i;
1263         int ptag, pclass;
1264         long plen;
1265         const unsigned char *p, *q;
1266         p = *in;
1267         q = p;
1268
1269         if (ctx && ctx->valid)
1270                 {
1271                 i = ctx->ret;
1272                 plen = ctx->plen;
1273                 pclass = ctx->pclass;
1274                 ptag = ctx->ptag;
1275                 p += ctx->hdrlen;
1276                 }
1277         else
1278                 {
1279                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1280                 if (ctx)
1281                         {
1282                         ctx->ret = i;
1283                         ctx->plen = plen;
1284                         ctx->pclass = pclass;
1285                         ctx->ptag = ptag;
1286                         ctx->hdrlen = p - q;
1287                         ctx->valid = 1;
1288                         /* If definite length, and no error, length +
1289                          * header can't exceed total amount of data available.
1290                          */
1291                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1292                                 {
1293                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1294                                                         ASN1_R_TOO_LONG);
1295                                 asn1_tlc_clear(ctx);
1296                                 return 0;
1297                                 }
1298                         }
1299                 }
1300
1301         if (i & 0x80)
1302                 {
1303                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1304                 asn1_tlc_clear(ctx);
1305                 return 0;
1306                 }
1307         if (exptag >= 0)
1308                 {
1309                 if ((exptag != ptag) || (expclass != pclass))
1310                         {
1311                         /* If type is OPTIONAL, not an error:
1312                          * indicate missing type.
1313                          */
1314                         if (opt) return -1;
1315                         asn1_tlc_clear(ctx);
1316                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1317                         return 0;
1318                         }
1319                 /* We have a tag and class match:
1320                  * assume we are going to do something with it */
1321                 asn1_tlc_clear(ctx);
1322                 }
1323
1324         if (i & 1)
1325                 plen = len - (p - q);
1326
1327         if (inf)
1328                 *inf = i & 1;
1329
1330         if (cst)
1331                 *cst = i & V_ASN1_CONSTRUCTED;
1332
1333         if (olen)
1334                 *olen = plen;
1335
1336         if (oclass)
1337                 *oclass = pclass;
1338
1339         if (otag)
1340                 *otag = ptag;
1341
1342         *in = p;
1343         return 1;
1344         }