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 /* Version to avoid compiler warning about 'c' always non-NULL */
 118 #define asn1_tlc_clear_nc(c)    (c)->valid = 0
 119
 120 /* Decode an ASN1 item, this currently behaves just
 121  * like a standard 'd2i' function. 'in' points to
 122  * a buffer to read the data from, in future we will
 123  * have more advanced versions that can input data
 124  * a piece at a time and this will simply be a special
 125  * case.
 126  */
 127
 128 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 129                 const unsigned char **in, long len, const ASN1_ITEM *it)
 130         {
 131         ASN1_TLC c;
 132         ASN1_VALUE *ptmpval = NULL;
 133         if (!pval)
 134                 pval = &ptmpval;
 135         asn1_tlc_clear_nc(&c);
 136         if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 137                 return *pval;
 138         return NULL;
 139         }
 140
 141 int ASN1_template_d2i(ASN1_VALUE **pval,
 142                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
 143         {
 144         ASN1_TLC c;
 145         asn1_tlc_clear_nc(&c);
 146         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
 147         }
 148
 149
 150 /* Decode an item, taking care of IMPLICIT tagging, if any.
 151  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 152  */
 153
 154 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 155                         const ASN1_ITEM *it,
 156                         int tag, int aclass, char opt, ASN1_TLC *ctx)
 157         {
 158         const ASN1_TEMPLATE *tt, *errtt = NULL;
 159         const ASN1_COMPAT_FUNCS *cf;
 160         const ASN1_EXTERN_FUNCS *ef;
 161         const ASN1_AUX *aux = it->funcs;
 162         ASN1_aux_cb *asn1_cb;
 163         const unsigned char *p = NULL, *q;
 164         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 165         unsigned char imphack = 0, oclass;
 166         char seq_eoc, seq_nolen, cst, isopt;
 167         long tmplen;
 168         int i;
 169         int otag;
 170         int ret = 0;
 171         ASN1_VALUE *pchval, **pchptr, *ptmpval;
 172         if (!pval)
 173                 return 0;
 174         if (aux && aux->asn1_cb)
 175                 asn1_cb = aux->asn1_cb;
 176         else asn1_cb = 0;
 177
 178         switch(it->itype)
 179                 {
 180                 case ASN1_ITYPE_PRIMITIVE:
 181                 if (it->templates)
 182                         {
 183                         /* tagging or OPTIONAL is currently illegal on an item
 184                          * template because the flags can't get passed down.
 185                          * In practice this isn't a problem: we include the
 186                          * relevant flags from the item template in the
 187                          * template itself.
 188                          */
 189                         if ((tag != -1) || opt)
 190                                 {
 191                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 192                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 193                                 goto err;
 194                                 }
 195                         return asn1_template_ex_d2i(pval, in, len,
 196                                         it->templates, opt, ctx);
 197                 }
 198                 return asn1_d2i_ex_primitive(pval, in, len, it,
 199                                                 tag, aclass, opt, ctx);
 200                 break;
 201
 202                 case ASN1_ITYPE_MSTRING:
 203                 p = *in;
 204                 /* Just read in tag and class */
 205                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 206                                                 &p, len, -1, 0, 1, ctx);
 207                 if (!ret)
 208                         {
 209                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 210                                         ERR_R_NESTED_ASN1_ERROR);
 211                         goto err;
 212                         }
 213
 214                 /* Must be UNIVERSAL class */
 215                 if (oclass != V_ASN1_UNIVERSAL)
 216                         {
 217                         /* If OPTIONAL, assume this is OK */
 218                         if (opt) return -1;
 219                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 220                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 221                         goto err;
 222                         }
 223                 /* Check tag matches bit map */
 224                 if (!(ASN1_tag2bit(otag) & it->utype))
 225                         {
 226                         /* If OPTIONAL, assume this is OK */
 227                         if (opt)
 228                                 return -1;
 229                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 230                                         ASN1_R_MSTRING_WRONG_TAG);
 231                         goto err;
 232                         }
 233                 return asn1_d2i_ex_primitive(pval, in, len,
 234                                                 it, otag, 0, 0, ctx);
 235
 236                 case ASN1_ITYPE_EXTERN:
 237                 /* Use new style d2i */
 238                 ef = it->funcs;
 239                 return ef->asn1_ex_d2i(pval, in, len,
 240                                                 it, tag, aclass, opt, ctx);
 241
 242                 case ASN1_ITYPE_COMPAT:
 243                 /* we must resort to old style evil hackery */
 244                 cf = it->funcs;
 245
 246                 /* If OPTIONAL see if it is there */
 247                 if (opt)
 248                         {
 249                         int exptag;
 250                         p = *in;
 251                         if (tag == -1)
 252                                 exptag = it->utype;
 253                         else exptag = tag;
 254                         /* Don't care about anything other than presence
 255                          * of expected tag */
 256
 257                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 258                                         &p, len, exptag, aclass, 1, ctx);
 259                         if (!ret)
 260                                 {
 261                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 262                                         ERR_R_NESTED_ASN1_ERROR);
 263                                 goto err;
 264                                 }
 265                         if (ret == -1)
 266                                 return -1;
 267                         }
 268
 269                 /* This is the old style evil hack IMPLICIT handling:
 270                  * since the underlying code is expecting a tag and
 271                  * class other than the one present we change the
 272                  * buffer temporarily then change it back afterwards.
 273                  * This doesn't and never did work for tags > 30.
 274                  *
 275                  * Yes this is *horrible* but it is only needed for
 276                  * old style d2i which will hopefully not be around
 277                  * for much longer.
 278                  * FIXME: should copy the buffer then modify it so
 279                  * the input buffer can be const: we should *always*
 280                  * copy because the old style d2i might modify the
 281                  * buffer.
 282                  */
 283
 284                 if (tag != -1)
 285                         {
 286                         wp = *(unsigned char **)in;
 287                         imphack = *wp;
 288                         if (p == NULL)
 289                                 {
 290                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 291                                         ERR_R_NESTED_ASN1_ERROR);
 292                                 goto err;
 293                                 }
 294                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 295                                                                 | it->utype);
 296                         }
 297
 298                 ptmpval = cf->asn1_d2i(pval, in, len);
 299
 300                 if (tag != -1)
 301                         *wp = imphack;
 302
 303                 if (ptmpval)
 304                         return 1;
 305
 306                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 307                 goto err;
 308
 309
 310                 case ASN1_ITYPE_CHOICE:
 311                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 312                                 goto auxerr;
 313
 314                 /* Allocate structure */
 315                 if (!*pval && !ASN1_item_ex_new(pval, it))
 316                         {
 317                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 318                                                 ERR_R_NESTED_ASN1_ERROR);
 319                         goto err;
 320                         }
 321                 /* CHOICE type, try each possibility in turn */
 322                 pchval = NULL;
 323                 p = *in;
 324                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 325                         {
 326                         pchptr = asn1_get_field_ptr(pval, tt);
 327                         /* We mark field as OPTIONAL so its absence
 328                          * can be recognised.
 329                          */
 330                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 331                         /* If field not present, try the next one */
 332                         if (ret == -1)
 333                                 continue;
 334                         /* If positive return, read OK, break loop */
 335                         if (ret > 0)
 336                                 break;
 337                         /* Otherwise must be an ASN1 parsing error */
 338                         errtt = tt;
 339                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 340                                                 ERR_R_NESTED_ASN1_ERROR);
 341                         goto err;
 342                         }
 343
 344                 /* Did we fall off the end without reading anything? */
 345                 if (i == it->tcount)
 346                         {
 347                         /* If OPTIONAL, this is OK */
 348                         if (opt)
 349                                 {
 350                                 /* Free and zero it */
 351                                 ASN1_item_ex_free(pval, it);
 352                                 return -1;
 353                                 }
 354                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 355                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 356                         goto err;
 357                         }
 358
 359                 asn1_set_choice_selector(pval, i, it);
 360                 *in = p;
 361                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 362                                 goto auxerr;
 363                 return 1;
 364
 365                 case ASN1_ITYPE_NDEF_SEQUENCE:
 366                 case ASN1_ITYPE_SEQUENCE:
 367                 p = *in;
 368                 tmplen = len;
 369
 370                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 371                 if (tag == -1)
 372                         {
 373                         tag = V_ASN1_SEQUENCE;
 374                         aclass = V_ASN1_UNIVERSAL;
 375                         }
 376                 /* Get SEQUENCE length and update len, p */
 377                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 378                                         &p, len, tag, aclass, opt, ctx);
 379                 if (!ret)
 380                         {
 381                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 382                                         ERR_R_NESTED_ASN1_ERROR);
 383                         goto err;
 384                         }
 385                 else if (ret == -1)
 386                         return -1;
 387                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 388                         {
 389                         len = tmplen - (p - *in);
 390                         seq_nolen = 1;
 391                         }
 392                 /* If indefinite we don't do a length check */
 393                 else seq_nolen = seq_eoc;
 394                 if (!cst)
 395                         {
 396                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 397                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 398                         goto err;
 399                         }
 400
 401                 if (!*pval && !ASN1_item_ex_new(pval, it))
 402                         {
 403                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 404                                 ERR_R_NESTED_ASN1_ERROR);
 405                         goto err;
 406                         }
 407
 408                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 409                                 goto auxerr;
 410
 411                 /* Get each field entry */
 412                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 413                         {
 414                         const ASN1_TEMPLATE *seqtt;
 415                         ASN1_VALUE **pseqval;
 416                         seqtt = asn1_do_adb(pval, tt, 1);
 417                         if (!seqtt)
 418                                 goto err;
 419                         pseqval = asn1_get_field_ptr(pval, seqtt);
 420                         /* Have we ran out of data? */
 421                         if (!len)
 422                                 break;
 423                         q = p;
 424                         if (asn1_check_eoc(&p, len))
 425                                 {
 426                                 if (!seq_eoc)
 427                                         {
 428                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 429                                                         ASN1_R_UNEXPECTED_EOC);
 430                                         goto err;
 431                                         }
 432                                 len -= p - q;
 433                                 seq_eoc = 0;
 434                                 q = p;
 435                                 break;
 436                                 }
 437                         /* This determines the OPTIONAL flag value. The field
 438                          * cannot be omitted if it is the last of a SEQUENCE
 439                          * and there is still data to be read. This isn't
 440                          * strictly necessary but it increases efficiency in
 441                          * some cases.
 442                          */
 443                         if (i == (it->tcount - 1))
 444                                 isopt = 0;
 445                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 446                         /* attempt to read in field, allowing each to be
 447                          * OPTIONAL */
 448
 449                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 450                                                         seqtt, isopt, ctx);
 451                         if (!ret)
 452                                 {
 453                                 errtt = seqtt;
 454                                 goto err;
 455                                 }
 456                         else if (ret == -1)
 457                                 {
 458                                 /* OPTIONAL component absent.
 459                                  * Free and zero the field.
 460                                  */
 461                                 ASN1_template_free(pseqval, seqtt);
 462                                 continue;
 463                                 }
 464                         /* Update length */
 465                         len -= p - q;
 466                         }
 467
 468                 /* Check for EOC if expecting one */
 469                 if (seq_eoc && !asn1_check_eoc(&p, len))
 470                         {
 471                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 472                         goto err;
 473                         }
 474                 /* Check all data read */
 475                 if (!seq_nolen && len)
 476                         {
 477                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 478                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 479                         goto err;
 480                         }
 481
 482                 /* If we get here we've got no more data in the SEQUENCE,
 483                  * however we may not have read all fields so check all
 484                  * remaining are OPTIONAL and clear any that are.
 485                  */
 486                 for (; i < it->tcount; tt++, i++)
 487                         {
 488                         const ASN1_TEMPLATE *seqtt;
 489                         seqtt = asn1_do_adb(pval, tt, 1);
 490                         if (!seqtt)
 491                                 goto err;
 492                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 493                                 {
 494                                 ASN1_VALUE **pseqval;
 495                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 496                                 ASN1_template_free(pseqval, seqtt);
 497                                 }
 498                         else
 499                                 {
 500                                 errtt = seqtt;
 501                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 502                                                         ASN1_R_FIELD_MISSING);
 503                                 goto err;
 504                                 }
 505                         }
 506                 /* Save encoding */
 507                 if (!asn1_enc_save(pval, *in, p - *in, it))
 508                         goto auxerr;
 509                 *in = p;
 510                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 511                                 goto auxerr;
 512                 return 1;
 513
 514                 default:
 515                 return 0;
 516                 }
 517         auxerr:
 518         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 519         err:
 520         ASN1_item_ex_free(pval, it);
 521         if (errtt)
 522                 ERR_add_error_data(4, "Field=", errtt->field_name,
 523                                         ", Type=", it->sname);
 524         else
 525                 ERR_add_error_data(2, "Type=", it->sname);
 526         return 0;
 527         }
 528
 529 /* Templates are handled with two separate functions.
 530  * One handles any EXPLICIT tag and the other handles the rest.
 531  */
 532
 533 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 534                                 const unsigned char **in, long inlen,
 535                                 const ASN1_TEMPLATE *tt, char opt,
 536                                                         ASN1_TLC *ctx)
 537         {
 538         int flags, aclass;
 539         int ret;
 540         long len;
 541         const unsigned char *p, *q;
 542         char exp_eoc;
 543         if (!val)
 544                 return 0;
 545         flags = tt->flags;
 546         aclass = flags & ASN1_TFLG_TAG_CLASS;
 547
 548         p = *in;
 549
 550         /* Check if EXPLICIT tag expected */
 551         if (flags & ASN1_TFLG_EXPTAG)
 552                 {
 553                 char cst;
 554                 /* Need to work out amount of data available to the inner
 555                  * content and where it starts: so read in EXPLICIT header to
 556                  * get the info.
 557                  */
 558                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 559                                         &p, inlen, tt->tag, aclass, opt, ctx);
 560                 q = p;
 561                 if (!ret)
 562                         {
 563                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 564                                         ERR_R_NESTED_ASN1_ERROR);
 565                         return 0;
 566                         }
 567                 else if (ret == -1)
 568                         return -1;
 569                 if (!cst)
 570                         {
 571                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 572                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 573                         return 0;
 574                         }
 575                 /* We've found the field so it can't be OPTIONAL now */
 576                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 577                 if (!ret)
 578                         {
 579                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 580                                         ERR_R_NESTED_ASN1_ERROR);
 581                         return 0;
 582                         }
 583                 /* We read the field in OK so update length */
 584                 len -= p - q;
 585                 if (exp_eoc)
 586                         {
 587                         /* If NDEF we must have an EOC here */
 588                         if (!asn1_check_eoc(&p, len))
 589                                 {
 590                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 591                                                 ASN1_R_MISSING_EOC);
 592                                 goto err;
 593                                 }
 594                         }
 595                 else
 596                         {
 597                         /* Otherwise we must hit the EXPLICIT tag end or its
 598                          * an error */
 599                         if (len)
 600                                 {
 601                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 602                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 603                                 goto err;
 604                                 }
 605                         }
 606                 }
 607                 else
 608                         return asn1_template_noexp_d2i(val, in, inlen,
 609                                                                 tt, opt, ctx);
 610
 611         *in = p;
 612         return 1;
 613
 614         err:
 615         ASN1_template_free(val, tt);
 616         return 0;
 617         }
 618
 619 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 620                                 const unsigned char **in, long len,
 621                                 const ASN1_TEMPLATE *tt, char opt,
 622                                 ASN1_TLC *ctx)
 623         {
 624         int flags, aclass;
 625         int ret;
 626         const unsigned char *p, *q;
 627         if (!val)
 628                 return 0;
 629         flags = tt->flags;
 630         aclass = flags & ASN1_TFLG_TAG_CLASS;
 631
 632         p = *in;
 633         q = p;
 634
 635         if (flags & ASN1_TFLG_SK_MASK)
 636                 {
 637                 /* SET OF, SEQUENCE OF */
 638                 int sktag, skaclass;
 639                 char sk_eoc;
 640                 /* First work out expected inner tag value */
 641                 if (flags & ASN1_TFLG_IMPTAG)
 642                         {
 643                         sktag = tt->tag;
 644                         skaclass = aclass;
 645                         }
 646                 else
 647                         {
 648                         skaclass = V_ASN1_UNIVERSAL;
 649                         if (flags & ASN1_TFLG_SET_OF)
 650                                 sktag = V_ASN1_SET;
 651                         else
 652                                 sktag = V_ASN1_SEQUENCE;
 653                         }
 654                 /* Get the tag */
 655                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 656                                         &p, len, sktag, skaclass, opt, ctx);
 657                 if (!ret)
 658                         {
 659                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 660                                                 ERR_R_NESTED_ASN1_ERROR);
 661                         return 0;
 662                         }
 663                 else if (ret == -1)
 664                         return -1;
 665                 if (!*val)
 666                         *val = (ASN1_VALUE *)sk_new_null();
 667                 else
 668                         {
 669                         /* We've got a valid STACK: free up any items present */
 670                         STACK_OF(ASN1_VALUE) *sktmp
 671                             = (STACK_OF(ASN1_VALUE) *)*val;
 672                         ASN1_VALUE *vtmp;
 673                         while(sk_ASN1_VALUE_num(sktmp) > 0)
 674                                 {
 675                                 vtmp = sk_ASN1_VALUE_pop(sktmp);
 676                                 ASN1_item_ex_free(&vtmp,
 677                                                 ASN1_ITEM_ptr(tt->item));
 678                                 }
 679                         }
 680
 681                 if (!*val)
 682                         {
 683                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 684                                                 ERR_R_MALLOC_FAILURE);
 685                         goto err;
 686                         }
 687
 688                 /* Read as many items as we can */
 689                 while(len > 0)
 690                         {
 691                         ASN1_VALUE *skfield;
 692                         q = p;
 693                         /* See if EOC found */
 694                         if (asn1_check_eoc(&p, len))
 695                                 {
 696                                 if (!sk_eoc)
 697                                         {
 698                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 699                                                         ASN1_R_UNEXPECTED_EOC);
 700                                         goto err;
 701                                         }
 702                                 len -= p - q;
 703                                 sk_eoc = 0;
 704                                 break;
 705                                 }
 706                         skfield = NULL;
 707                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 708                                                 ASN1_ITEM_ptr(tt->item),
 709                                                 -1, 0, 0, ctx))
 710                                 {
 711                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 712                                         ERR_R_NESTED_ASN1_ERROR);
 713                                 goto err;
 714                                 }
 715                         len -= p - q;
 716                         if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
 717                                                 skfield))
 718                                 {
 719                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 720                                                 ERR_R_MALLOC_FAILURE);
 721                                 goto err;
 722                                 }
 723                         }
 724                 if (sk_eoc)
 725                         {
 726                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 727                         goto err;
 728                         }
 729                 }
 730         else if (flags & ASN1_TFLG_IMPTAG)
 731                 {
 732                 /* IMPLICIT tagging */
 733                 ret = ASN1_item_ex_d2i(val, &p, len,
 734                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 735                 if (!ret)
 736                         {
 737                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 738                                                 ERR_R_NESTED_ASN1_ERROR);
 739                         goto err;
 740                         }
 741                 else if (ret == -1)
 742                         return -1;
 743                 }
 744         else
 745                 {
 746                 /* Nothing special */
 747                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 748                                                         -1, 0, opt, ctx);
 749                 if (!ret)
 750                         {
 751                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 752                                         ERR_R_NESTED_ASN1_ERROR);
 753                         goto err;
 754                         }
 755                 else if (ret == -1)
 756                         return -1;
 757                 }
 758
 759         *in = p;
 760         return 1;
 761
 762         err:
 763         ASN1_template_free(val, tt);
 764         return 0;
 765         }
 766
 767 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 768                                 const unsigned char **in, long inlen,
 769                                 const ASN1_ITEM *it,
 770                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 771         {
 772         int ret = 0, utype;
 773         long plen;
 774         char cst, inf, free_cont = 0;
 775         const unsigned char *p;
 776         BUF_MEM buf;
 777         const unsigned char *cont = NULL;
 778         long len;
 779         if (!pval)
 780                 {
 781                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 782                 return 0; /* Should never happen */
 783                 }
 784
 785         if (it->itype == ASN1_ITYPE_MSTRING)
 786                 {
 787                 utype = tag;
 788                 tag = -1;
 789                 }
 790         else
 791                 utype = it->utype;
 792
 793         if (utype == V_ASN1_ANY)
 794                 {
 795                 /* If type is ANY need to figure out type from tag */
 796                 unsigned char oclass;
 797                 if (tag >= 0)
 798                         {
 799                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 800                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 801                         return 0;
 802                         }
 803                 if (opt)
 804                         {
 805                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 806                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 807                         return 0;
 808                         }
 809                 p = *in;
 810                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 811                                         &p, inlen, -1, 0, 0, ctx);
 812                 if (!ret)
 813                         {
 814                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 815                                         ERR_R_NESTED_ASN1_ERROR);
 816                         return 0;
 817                         }
 818                 if (oclass != V_ASN1_UNIVERSAL)
 819                         utype = V_ASN1_OTHER;
 820                 }
 821         if (tag == -1)
 822                 {
 823                 tag = utype;
 824                 aclass = V_ASN1_UNIVERSAL;
 825                 }
 826         p = *in;
 827         /* Check header */
 828         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 829                                 &p, inlen, tag, aclass, opt, ctx);
 830         if (!ret)
 831                 {
 832                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 833                 return 0;
 834                 }
 835         else if (ret == -1)
 836                 return -1;
 837         ret = 0;
 838         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 839         if ((utype == V_ASN1_SEQUENCE)
 840                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 841                 {
 842                 /* Clear context cache for type OTHER because the auto clear
 843                  * when we have a exact match wont work
 844                  */
 845                 if (utype == V_ASN1_OTHER)
 846                         {
 847                         asn1_tlc_clear(ctx);
 848                         }
 849                 /* SEQUENCE and SET must be constructed */
 850                 else if (!cst)
 851                         {
 852                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 853                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 854                         return 0;
 855                         }
 856
 857                 cont = *in;
 858                 /* If indefinite length constructed find the real end */
 859                 if (inf)
 860                         {
 861                         if (!asn1_find_end(&p, plen, inf))
 862                                  goto err;
 863                         len = p - cont;
 864                         }
 865                 else
 866                         {
 867                         len = p - cont + plen;
 868                         p += plen;
 869                         buf.data = NULL;
 870                         }
 871                 }
 872         else if (cst)
 873                 {
 874                 buf.length = 0;
 875                 buf.max = 0;
 876                 buf.data = NULL;
 877                 /* Should really check the internal tags are correct but
 878                  * some things may get this wrong. The relevant specs
 879                  * say that constructed string types should be OCTET STRINGs
 880                  * internally irrespective of the type. So instead just check
 881                  * for UNIVERSAL class and ignore the tag.
 882                  */
 883                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 884                         {
 885                         free_cont = 1;
 886                         goto err;
 887                         }
 888                 len = buf.length;
 889                 /* Append a final null to string */
 890                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 891                         {
 892                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 893                                                 ERR_R_MALLOC_FAILURE);
 894                         return 0;
 895                         }
 896                 buf.data[len] = 0;
 897                 cont = (const unsigned char *)buf.data;
 898                 free_cont = 1;
 899                 }
 900         else
 901                 {
 902                 cont = p;
 903                 len = plen;
 904                 p += plen;
 905                 }
 906
 907         /* We now have content length and type: translate into a structure */
 908         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 909                 goto err;
 910
 911         *in = p;
 912         ret = 1;
 913         err:
 914         if (free_cont && buf.data) OPENSSL_free(buf.data);
 915         return ret;
 916         }
 917
 918 /* Translate ASN1 content octets into a structure */
 919
 920 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 921                         int utype, char *free_cont, const ASN1_ITEM *it)
 922         {
 923         ASN1_VALUE **opval = NULL;
 924         ASN1_STRING *stmp;
 925         ASN1_TYPE *typ = NULL;
 926         int ret = 0;
 927         const ASN1_PRIMITIVE_FUNCS *pf;
 928         ASN1_INTEGER **tint;
 929         pf = it->funcs;
 930
 931         if (pf && pf->prim_c2i)
 932                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 933         /* If ANY type clear type and set pointer to internal value */
 934         if (it->utype == V_ASN1_ANY)
 935                 {
 936                 if (!*pval)
 937                         {
 938                         typ = ASN1_TYPE_new();
 939                         if (typ == NULL)
 940                                 goto err;
 941                         *pval = (ASN1_VALUE *)typ;
 942                         }
 943                 else
 944                         typ = (ASN1_TYPE *)*pval;
 945
 946                 if (utype != typ->type)
 947                         ASN1_TYPE_set(typ, utype, NULL);
 948                 opval = pval;
 949                 pval = &typ->value.asn1_value;
 950                 }
 951         switch(utype)
 952                 {
 953                 case V_ASN1_OBJECT:
 954                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 955                         goto err;
 956                 break;
 957
 958                 case V_ASN1_NULL:
 959                 if (len)
 960                         {
 961                         ASN1err(ASN1_F_ASN1_EX_C2I,
 962                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 963                         goto err;
 964                         }
 965                 *pval = (ASN1_VALUE *)1;
 966                 break;
 967
 968                 case V_ASN1_BOOLEAN:
 969                 if (len != 1)
 970                         {
 971                         ASN1err(ASN1_F_ASN1_EX_C2I,
 972                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 973                         goto err;
 974                         }
 975                 else
 976                         {
 977                         ASN1_BOOLEAN *tbool;
 978                         tbool = (ASN1_BOOLEAN *)pval;
 979                         *tbool = *cont;
 980                         }
 981                 break;
 982
 983                 case V_ASN1_BIT_STRING:
 984                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 985                         goto err;
 986                 break;
 987
 988                 case V_ASN1_INTEGER:
 989                 case V_ASN1_NEG_INTEGER:
 990                 case V_ASN1_ENUMERATED:
 991                 case V_ASN1_NEG_ENUMERATED:
 992                 tint = (ASN1_INTEGER **)pval;
 993                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
 994                         goto err;
 995                 /* Fixup type to match the expected form */
 996                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 997                 break;
 998
 999                 case V_ASN1_OCTET_STRING:
1000                 case V_ASN1_NUMERICSTRING:
1001                 case V_ASN1_PRINTABLESTRING:
1002                 case V_ASN1_T61STRING:
1003                 case V_ASN1_VIDEOTEXSTRING:
1004                 case V_ASN1_IA5STRING:
1005                 case V_ASN1_UTCTIME:
1006                 case V_ASN1_GENERALIZEDTIME:
1007                 case V_ASN1_GRAPHICSTRING:
1008                 case V_ASN1_VISIBLESTRING:
1009                 case V_ASN1_GENERALSTRING:
1010                 case V_ASN1_UNIVERSALSTRING:
1011                 case V_ASN1_BMPSTRING:
1012                 case V_ASN1_UTF8STRING:
1013                 case V_ASN1_OTHER:
1014                 case V_ASN1_SET:
1015                 case V_ASN1_SEQUENCE:
1016                 default:
1017                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1018                         {
1019                         ASN1err(ASN1_F_ASN1_EX_C2I,
1020                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1021                         goto err;
1022                         }
1023                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1024                         {
1025                         ASN1err(ASN1_F_ASN1_EX_C2I,
1026                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1027                         goto err;
1028                         }
1029                 /* All based on ASN1_STRING and handled the same */
1030                 if (!*pval)
1031                         {
1032                         stmp = ASN1_STRING_type_new(utype);
1033                         if (!stmp)
1034                                 {
1035                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1036                                                         ERR_R_MALLOC_FAILURE);
1037                                 goto err;
1038                                 }
1039                         *pval = (ASN1_VALUE *)stmp;
1040                         }
1041                 else
1042                         {
1043                         stmp = (ASN1_STRING *)*pval;
1044                         stmp->type = utype;
1045                         }
1046                 /* If we've already allocated a buffer use it */
1047                 if (*free_cont)
1048                         {
1049                         if (stmp->data)
1050                                 OPENSSL_free(stmp->data);
1051                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1052                         stmp->length = len;
1053                         *free_cont = 0;
1054                         }
1055                 else
1056                         {
1057                         if (!ASN1_STRING_set(stmp, cont, len))
1058                                 {
1059                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1060                                                         ERR_R_MALLOC_FAILURE);
1061                                 ASN1_STRING_free(stmp);
1062                                 *pval = NULL;
1063                                 goto err;
1064                                 }
1065                         }
1066                 break;
1067                 }
1068         /* If ASN1_ANY and NULL type fix up value */
1069         if (typ && (utype == V_ASN1_NULL))
1070                  typ->value.ptr = NULL;
1071
1072         ret = 1;
1073         err:
1074         if (!ret)
1075                 {
1076                 ASN1_TYPE_free(typ);
1077                 if (opval)
1078                         *opval = NULL;
1079                 }
1080         return ret;
1081         }
1082
1083
1084 /* This function finds the end of an ASN1 structure when passed its maximum
1085  * length, whether it is indefinite length and a pointer to the content.
1086  * This is more efficient than calling asn1_collect because it does not
1087  * recurse on each indefinite length header.
1088  */
1089
1090 static int asn1_find_end(const unsigned char **in, long len, char inf)
1091         {
1092         int expected_eoc;
1093         long plen;
1094         const unsigned char *p = *in, *q;
1095         /* If not indefinite length constructed just add length */
1096         if (inf == 0)
1097                 {
1098                 *in += len;
1099                 return 1;
1100                 }
1101         expected_eoc = 1;
1102         /* Indefinite length constructed form. Find the end when enough EOCs
1103          * are found. If more indefinite length constructed headers
1104          * are encountered increment the expected eoc count otherwise just
1105          * skip to the end of the data.
1106          */
1107         while (len > 0)
1108                 {
1109                 if(asn1_check_eoc(&p, len))
1110                         {
1111                         expected_eoc--;
1112                         if (expected_eoc == 0)
1113                                 break;
1114                         len -= 2;
1115                         continue;
1116                         }
1117                 q = p;
1118                 /* Just read in a header: only care about the length */
1119                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1120                                 -1, 0, 0, NULL))
1121                         {
1122                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1123                         return 0;
1124                         }
1125                 if (inf)
1126                         expected_eoc++;
1127                 else
1128                         p += plen;
1129                 len -= p - q;
1130                 }
1131         if (expected_eoc)
1132                 {
1133                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1134                 return 0;
1135                 }
1136         *in = p;
1137         return 1;
1138         }
1139 /* This function collects the asn1 data from a constructred string
1140  * type into a buffer. The values of 'in' and 'len' should refer
1141  * to the contents of the constructed type and 'inf' should be set
1142  * if it is indefinite length.
1143  */
1144
1145 #ifndef ASN1_MAX_STRING_NEST
1146 /* This determines how many levels of recursion are permitted in ASN1
1147  * string types. If it is not limited stack overflows can occur. If set
1148  * to zero no recursion is allowed at all. Although zero should be adequate
1149  * examples exist that require a value of 1. So 5 should be more than enough.
1150  */
1151 #define ASN1_MAX_STRING_NEST 5
1152 #endif
1153
1154
1155 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1156                         char inf, int tag, int aclass, int depth)
1157         {
1158         const unsigned char *p, *q;
1159         long plen;
1160         char cst, ininf;
1161         p = *in;
1162         inf &= 1;
1163         /* If no buffer and not indefinite length constructed just pass over
1164          * the encoded data */
1165         if (!buf && !inf)
1166                 {
1167                 *in += len;
1168                 return 1;
1169                 }
1170         while(len > 0)
1171                 {
1172                 q = p;
1173                 /* Check for EOC */
1174                 if (asn1_check_eoc(&p, len))
1175                         {
1176                         /* EOC is illegal outside indefinite length
1177                          * constructed form */
1178                         if (!inf)
1179                                 {
1180                                 ASN1err(ASN1_F_ASN1_COLLECT,
1181                                         ASN1_R_UNEXPECTED_EOC);
1182                                 return 0;
1183                                 }
1184                         inf = 0;
1185                         break;
1186                         }
1187
1188                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1189                                         len, tag, aclass, 0, NULL))
1190                         {
1191                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1192                         return 0;
1193                         }
1194
1195                 /* If indefinite length constructed update max length */
1196                 if (cst)
1197                         {
1198                         if (depth >= ASN1_MAX_STRING_NEST)
1199                                 {
1200                                 ASN1err(ASN1_F_ASN1_COLLECT,
1201                                         ASN1_R_NESTED_ASN1_STRING);
1202                                 return 0;
1203                                 }
1204                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1205                                                 depth + 1))
1206                                 return 0;
1207                         }
1208                 else if (plen && !collect_data(buf, &p, plen))
1209                         return 0;
1210                 len -= p - q;
1211                 }
1212         if (inf)
1213                 {
1214                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1215                 return 0;
1216                 }
1217         *in = p;
1218         return 1;
1219         }
1220
1221 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1222         {
1223         int len;
1224         if (buf)
1225                 {
1226                 len = buf->length;
1227                 if (!BUF_MEM_grow_clean(buf, len + plen))
1228                         {
1229                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1230                         return 0;
1231                         }
1232                 memcpy(buf->data + len, *p, plen);
1233                 }
1234         *p += plen;
1235         return 1;
1236         }
1237
1238 /* Check for ASN1 EOC and swallow it if found */
1239
1240 static int asn1_check_eoc(const unsigned char **in, long len)
1241         {
1242         const unsigned char *p;
1243         if (len < 2) return 0;
1244         p = *in;
1245         if (!p[0] && !p[1])
1246                 {
1247                 *in += 2;
1248                 return 1;
1249                 }
1250         return 0;
1251         }
1252
1253 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1254  * but it sets the length for indefinite length constructed
1255  * form, we don't know the exact length but we can set an
1256  * upper bound to the amount of data available minus the
1257  * header length just read.
1258  */
1259
1260 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1261                                 char *inf, char *cst,
1262                                 const unsigned char **in, long len,
1263                                 int exptag, int expclass, char opt,
1264                                 ASN1_TLC *ctx)
1265         {
1266         int i;
1267         int ptag, pclass;
1268         long plen;
1269         const unsigned char *p, *q;
1270         p = *in;
1271         q = p;
1272
1273         if (ctx && ctx->valid)
1274                 {
1275                 i = ctx->ret;
1276                 plen = ctx->plen;
1277                 pclass = ctx->pclass;
1278                 ptag = ctx->ptag;
1279                 p += ctx->hdrlen;
1280                 }
1281         else
1282                 {
1283                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1284                 if (ctx)
1285                         {
1286                         ctx->ret = i;
1287                         ctx->plen = plen;
1288                         ctx->pclass = pclass;
1289                         ctx->ptag = ptag;
1290                         ctx->hdrlen = p - q;
1291                         ctx->valid = 1;
1292                         /* If definite length, and no error, length +
1293                          * header can't exceed total amount of data available.
1294                          */
1295                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1296                                 {
1297                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1298                                                         ASN1_R_TOO_LONG);
1299                                 asn1_tlc_clear(ctx);
1300                                 return 0;
1301                                 }
1302                         }
1303                 }
1304
1305         if (i & 0x80)
1306                 {
1307                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1308                 asn1_tlc_clear(ctx);
1309                 return 0;
1310                 }
1311         if (exptag >= 0)
1312                 {
1313                 if ((exptag != ptag) || (expclass != pclass))
1314                         {
1315                         /* If type is OPTIONAL, not an error:
1316                          * indicate missing type.
1317                          */
1318                         if (opt) return -1;
1319                         asn1_tlc_clear(ctx);
1320                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1321                         return 0;
1322                         }
1323                 /* We have a tag and class match:
1324                  * assume we are going to do something with it */
1325                 asn1_tlc_clear(ctx);
1326                 }
1327
1328         if (i & 1)
1329                 plen = len - (p - q);
1330
1331         if (inf)
1332                 *inf = i & 1;
1333
1334         if (cst)
1335                 *cst = i & V_ASN1_CONSTRUCTED;
1336
1337         if (olen)
1338                 *olen = plen;
1339
1340         if (oclass)
1341                 *oclass = pclass;
1342
1343         if (otag)
1344                 *otag = ptag;
1345
1346         *in = p;
1347         return 1;
1348         }