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                 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
 870                         || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
 871                         || utype == V_ASN1_ENUMERATED)
 872                         {
 873                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 874                                 ASN1_R_TYPE_NOT_PRIMITIVE);
 875                         return 0;
 876                         }
 877                 buf.length = 0;
 878                 buf.max = 0;
 879                 buf.data = NULL;
 880                 /* Should really check the internal tags are correct but
 881                  * some things may get this wrong. The relevant specs
 882                  * say that constructed string types should be OCTET STRINGs
 883                  * internally irrespective of the type. So instead just check
 884                  * for UNIVERSAL class and ignore the tag.
 885                  */
 886                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 887                         {
 888                         free_cont = 1;
 889                         goto err;
 890                         }
 891                 len = buf.length;
 892                 /* Append a final null to string */
 893                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 894                         {
 895                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 896                                                 ERR_R_MALLOC_FAILURE);
 897                         return 0;
 898                         }
 899                 buf.data[len] = 0;
 900                 cont = (const unsigned char *)buf.data;
 901                 free_cont = 1;
 902                 }
 903         else
 904                 {
 905                 cont = p;
 906                 len = plen;
 907                 p += plen;
 908                 }
 909
 910         /* We now have content length and type: translate into a structure */
 911         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 912                 goto err;
 913
 914         *in = p;
 915         ret = 1;
 916         err:
 917         if (free_cont && buf.data) OPENSSL_free(buf.data);
 918         return ret;
 919         }
 920
 921 /* Translate ASN1 content octets into a structure */
 922
 923 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 924                         int utype, char *free_cont, const ASN1_ITEM *it)
 925         {
 926         ASN1_VALUE **opval = NULL;
 927         ASN1_STRING *stmp;
 928         ASN1_TYPE *typ = NULL;
 929         int ret = 0;
 930         const ASN1_PRIMITIVE_FUNCS *pf;
 931         ASN1_INTEGER **tint;
 932         pf = it->funcs;
 933
 934         if (pf && pf->prim_c2i)
 935                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 936         /* If ANY type clear type and set pointer to internal value */
 937         if (it->utype == V_ASN1_ANY)
 938                 {
 939                 if (!*pval)
 940                         {
 941                         typ = ASN1_TYPE_new();
 942                         if (typ == NULL)
 943                                 goto err;
 944                         *pval = (ASN1_VALUE *)typ;
 945                         }
 946                 else
 947                         typ = (ASN1_TYPE *)*pval;
 948
 949                 if (utype != typ->type)
 950                         ASN1_TYPE_set(typ, utype, NULL);
 951                 opval = pval;
 952                 pval = &typ->value.asn1_value;
 953                 }
 954         switch(utype)
 955                 {
 956                 case V_ASN1_OBJECT:
 957                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 958                         goto err;
 959                 break;
 960
 961                 case V_ASN1_NULL:
 962                 if (len)
 963                         {
 964                         ASN1err(ASN1_F_ASN1_EX_C2I,
 965                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 966                         goto err;
 967                         }
 968                 *pval = (ASN1_VALUE *)1;
 969                 break;
 970
 971                 case V_ASN1_BOOLEAN:
 972                 if (len != 1)
 973                         {
 974                         ASN1err(ASN1_F_ASN1_EX_C2I,
 975                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 976                         goto err;
 977                         }
 978                 else
 979                         {
 980                         ASN1_BOOLEAN *tbool;
 981                         tbool = (ASN1_BOOLEAN *)pval;
 982                         *tbool = *cont;
 983                         }
 984                 break;
 985
 986                 case V_ASN1_BIT_STRING:
 987                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 988                         goto err;
 989                 break;
 990
 991                 case V_ASN1_INTEGER:
 992                 case V_ASN1_NEG_INTEGER:
 993                 case V_ASN1_ENUMERATED:
 994                 case V_ASN1_NEG_ENUMERATED:
 995                 tint = (ASN1_INTEGER **)pval;
 996                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 997                         goto err;
 998                 /* Fixup type to match the expected form */
 999                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
1000                 break;
1001
1002                 case V_ASN1_OCTET_STRING:
1003                 case V_ASN1_NUMERICSTRING:
1004                 case V_ASN1_PRINTABLESTRING:
1005                 case V_ASN1_T61STRING:
1006                 case V_ASN1_VIDEOTEXSTRING:
1007                 case V_ASN1_IA5STRING:
1008                 case V_ASN1_UTCTIME:
1009                 case V_ASN1_GENERALIZEDTIME:
1010                 case V_ASN1_GRAPHICSTRING:
1011                 case V_ASN1_VISIBLESTRING:
1012                 case V_ASN1_GENERALSTRING:
1013                 case V_ASN1_UNIVERSALSTRING:
1014                 case V_ASN1_BMPSTRING:
1015                 case V_ASN1_UTF8STRING:
1016                 case V_ASN1_OTHER:
1017                 case V_ASN1_SET:
1018                 case V_ASN1_SEQUENCE:
1019                 default:
1020                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1021                         {
1022                         ASN1err(ASN1_F_ASN1_EX_C2I,
1023                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1024                         goto err;
1025                         }
1026                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1027                         {
1028                         ASN1err(ASN1_F_ASN1_EX_C2I,
1029                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1030                         goto err;
1031                         }
1032                 /* All based on ASN1_STRING and handled the same */
1033                 if (!*pval)
1034                         {
1035                         stmp = ASN1_STRING_type_new(utype);
1036                         if (!stmp)
1037                                 {
1038                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1039                                                         ERR_R_MALLOC_FAILURE);
1040                                 goto err;
1041                                 }
1042                         *pval = (ASN1_VALUE *)stmp;
1043                         }
1044                 else
1045                         {
1046                         stmp = (ASN1_STRING *)*pval;
1047                         stmp->type = utype;
1048                         }
1049                 /* If we've already allocated a buffer use it */
1050                 if (*free_cont)
1051                         {
1052                         if (stmp->data)
1053                                 OPENSSL_free(stmp->data);
1054                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1055                         stmp->length = len;
1056                         *free_cont = 0;
1057                         }
1058                 else
1059                         {
1060                         if (!ASN1_STRING_set(stmp, cont, len))
1061                                 {
1062                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1063                                                         ERR_R_MALLOC_FAILURE);
1064                                 ASN1_STRING_free(stmp);
1065                                 *pval = NULL;
1066                                 goto err;
1067                                 }
1068                         }
1069                 break;
1070                 }
1071         /* If ASN1_ANY and NULL type fix up value */
1072         if (typ && (utype == V_ASN1_NULL))
1073                  typ->value.ptr = NULL;
1074
1075         ret = 1;
1076         err:
1077         if (!ret)
1078                 {
1079                 ASN1_TYPE_free(typ);
1080                 if (opval)
1081                         *opval = NULL;
1082                 }
1083         return ret;
1084         }
1085
1086
1087 /* This function finds the end of an ASN1 structure when passed its maximum
1088  * length, whether it is indefinite length and a pointer to the content.
1089  * This is more efficient than calling asn1_collect because it does not
1090  * recurse on each indefinite length header.
1091  */
1092
1093 static int asn1_find_end(const unsigned char **in, long len, char inf)
1094         {
1095         int expected_eoc;
1096         long plen;
1097         const unsigned char *p = *in, *q;
1098         /* If not indefinite length constructed just add length */
1099         if (inf == 0)
1100                 {
1101                 *in += len;
1102                 return 1;
1103                 }
1104         expected_eoc = 1;
1105         /* Indefinite length constructed form. Find the end when enough EOCs
1106          * are found. If more indefinite length constructed headers
1107          * are encountered increment the expected eoc count otherwise just
1108          * skip to the end of the data.
1109          */
1110         while (len > 0)
1111                 {
1112                 if(asn1_check_eoc(&p, len))
1113                         {
1114                         expected_eoc--;
1115                         if (expected_eoc == 0)
1116                                 break;
1117                         len -= 2;
1118                         continue;
1119                         }
1120                 q = p;
1121                 /* Just read in a header: only care about the length */
1122                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1123                                 -1, 0, 0, NULL))
1124                         {
1125                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1126                         return 0;
1127                         }
1128                 if (inf)
1129                         expected_eoc++;
1130                 else
1131                         p += plen;
1132                 len -= p - q;
1133                 }
1134         if (expected_eoc)
1135                 {
1136                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1137                 return 0;
1138                 }
1139         *in = p;
1140         return 1;
1141         }
1142 /* This function collects the asn1 data from a constructred string
1143  * type into a buffer. The values of 'in' and 'len' should refer
1144  * to the contents of the constructed type and 'inf' should be set
1145  * if it is indefinite length.
1146  */
1147
1148 #ifndef ASN1_MAX_STRING_NEST
1149 /* This determines how many levels of recursion are permitted in ASN1
1150  * string types. If it is not limited stack overflows can occur. If set
1151  * to zero no recursion is allowed at all. Although zero should be adequate
1152  * examples exist that require a value of 1. So 5 should be more than enough.
1153  */
1154 #define ASN1_MAX_STRING_NEST 5
1155 #endif
1156
1157
1158 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1159                         char inf, int tag, int aclass, int depth)
1160         {
1161         const unsigned char *p, *q;
1162         long plen;
1163         char cst, ininf;
1164         p = *in;
1165         inf &= 1;
1166         /* If no buffer and not indefinite length constructed just pass over
1167          * the encoded data */
1168         if (!buf && !inf)
1169                 {
1170                 *in += len;
1171                 return 1;
1172                 }
1173         while(len > 0)
1174                 {
1175                 q = p;
1176                 /* Check for EOC */
1177                 if (asn1_check_eoc(&p, len))
1178                         {
1179                         /* EOC is illegal outside indefinite length
1180                          * constructed form */
1181                         if (!inf)
1182                                 {
1183                                 ASN1err(ASN1_F_ASN1_COLLECT,
1184                                         ASN1_R_UNEXPECTED_EOC);
1185                                 return 0;
1186                                 }
1187                         inf = 0;
1188                         break;
1189                         }
1190
1191                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1192                                         len, tag, aclass, 0, NULL))
1193                         {
1194                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1195                         return 0;
1196                         }
1197
1198                 /* If indefinite length constructed update max length */
1199                 if (cst)
1200                         {
1201                         if (depth >= ASN1_MAX_STRING_NEST)
1202                                 {
1203                                 ASN1err(ASN1_F_ASN1_COLLECT,
1204                                         ASN1_R_NESTED_ASN1_STRING);
1205                                 return 0;
1206                                 }
1207                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1208                                                 depth + 1))
1209                                 return 0;
1210                         }
1211                 else if (plen && !collect_data(buf, &p, plen))
1212                         return 0;
1213                 len -= p - q;
1214                 }
1215         if (inf)
1216                 {
1217                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1218                 return 0;
1219                 }
1220         *in = p;
1221         return 1;
1222         }
1223
1224 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1225         {
1226         int len;
1227         if (buf)
1228                 {
1229                 len = buf->length;
1230                 if (!BUF_MEM_grow_clean(buf, len + plen))
1231                         {
1232                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1233                         return 0;
1234                         }
1235                 memcpy(buf->data + len, *p, plen);
1236                 }
1237         *p += plen;
1238         return 1;
1239         }
1240
1241 /* Check for ASN1 EOC and swallow it if found */
1242
1243 static int asn1_check_eoc(const unsigned char **in, long len)
1244         {
1245         const unsigned char *p;
1246         if (len < 2) return 0;
1247         p = *in;
1248         if (!p[0] && !p[1])
1249                 {
1250                 *in += 2;
1251                 return 1;
1252                 }
1253         return 0;
1254         }
1255
1256 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1257  * but it sets the length for indefinite length constructed
1258  * form, we don't know the exact length but we can set an
1259  * upper bound to the amount of data available minus the
1260  * header length just read.
1261  */
1262
1263 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1264                                 char *inf, char *cst,
1265                                 const unsigned char **in, long len,
1266                                 int exptag, int expclass, char opt,
1267                                 ASN1_TLC *ctx)
1268         {
1269         int i;
1270         int ptag, pclass;
1271         long plen;
1272         const unsigned char *p, *q;
1273         p = *in;
1274         q = p;
1275
1276         if (ctx && ctx->valid)
1277                 {
1278                 i = ctx->ret;
1279                 plen = ctx->plen;
1280                 pclass = ctx->pclass;
1281                 ptag = ctx->ptag;
1282                 p += ctx->hdrlen;
1283                 }
1284         else
1285                 {
1286                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1287                 if (ctx)
1288                         {
1289                         ctx->ret = i;
1290                         ctx->plen = plen;
1291                         ctx->pclass = pclass;
1292                         ctx->ptag = ptag;
1293                         ctx->hdrlen = p - q;
1294                         ctx->valid = 1;
1295                         /* If definite length, and no error, length +
1296                          * header can't exceed total amount of data available.
1297                          */
1298                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1299                                 {
1300                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1301                                                         ASN1_R_TOO_LONG);
1302                                 asn1_tlc_clear(ctx);
1303                                 return 0;
1304                                 }
1305                         }
1306                 }
1307
1308         if (i & 0x80)
1309                 {
1310                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1311                 asn1_tlc_clear(ctx);
1312                 return 0;
1313                 }
1314         if (exptag >= 0)
1315                 {
1316                 if ((exptag != ptag) || (expclass != pclass))
1317                         {
1318                         /* If type is OPTIONAL, not an error:
1319                          * indicate missing type.
1320                          */
1321                         if (opt) return -1;
1322                         asn1_tlc_clear(ctx);
1323                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1324                         return 0;
1325                         }
1326                 /* We have a tag and class match:
1327                  * assume we are going to do something with it */
1328                 asn1_tlc_clear(ctx);
1329                 }
1330
1331         if (i & 1)
1332                 plen = len - (p - q);
1333
1334         if (inf)
1335                 *inf = i & 1;
1336
1337         if (cst)
1338                 *cst = i & V_ASN1_CONSTRUCTED;
1339
1340         if (olen)
1341                 *olen = plen;
1342
1343         if (oclass)
1344                 *oclass = pclass;
1345
1346         if (otag)
1347                 *otag = ptag;
1348
1349         *in = p;
1350         return 1;
1351         }