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