crypto/openssl/crypto/asn1/tasn_dec.c

   1 /* tasn_dec.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59
  60 #include <stddef.h>
  61 #include <string.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/buffer.h>
  66 #include <openssl/err.h>
  67
  68 static int asn1_check_eoc(const unsigned char **in, long len);
  69 static int asn1_find_end(const unsigned char **in, long len, char inf);
  70
  71 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
  72                         char inf, int tag, int aclass, int depth);
  73
  74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  75
  76 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  77                                 char *inf, char *cst,
  78                                 const unsigned char **in, long len,
  79                                 int exptag, int expclass, char opt,
  80                                 ASN1_TLC *ctx);
  81
  82 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
  83                                 const unsigned char **in, long len,
  84                                 const ASN1_TEMPLATE *tt, char opt,
  85                                 ASN1_TLC *ctx);
  86 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
  87                                 const unsigned char **in, long len,
  88                                 const ASN1_TEMPLATE *tt, char opt,
  89                                 ASN1_TLC *ctx);
  90 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
  91                                 const unsigned char **in, long len,
  92                                 const ASN1_ITEM *it,
  93                                 int tag, int aclass, char opt, ASN1_TLC *ctx);
  94
  95 /* Table to convert tags to bit values, used for MSTRING type */
  96 static const unsigned long tag2bit[32] = {
  97 0,      0,      0,      B_ASN1_BIT_STRING,      /* tags  0 -  3 */
  98 B_ASN1_OCTET_STRING,    0,      0,              B_ASN1_UNKNOWN,/* tags  4- 7 */
  99 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags  8-11 */
 100 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */
 101 B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */
 102 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING,       /* tags 20-22 */
 103 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,                        /* tags 23-24 */
 104 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING,  /* tags 25-27 */
 105 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */
 106         };
 107
 108 unsigned long ASN1_tag2bit(int tag)
 109         {
 110         if ((tag < 0) || (tag > 30)) return 0;
 111         return tag2bit[tag];
 112         }
 113
 114 /* Macro to initialize and invalidate the cache */
 115
 116 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
 117
 118 /* Decode an ASN1 item, this currently behaves just
 119  * like a standard 'd2i' function. 'in' points to
 120  * a buffer to read the data from, in future we will
 121  * have more advanced versions that can input data
 122  * a piece at a time and this will simply be a special
 123  * case.
 124  */
 125
 126 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 127                 const unsigned char **in, long len, const ASN1_ITEM *it)
 128 {
 129         ASN1_TLC c;
 130         ASN1_VALUE *ptmpval = NULL;
 131         c.valid = 0;
 132         if (pval && *pval && it->itype == ASN1_ITYPE_PRIMITIVE)
 133                 ptmpval = *pval;
 134
 135         if (ASN1_item_ex_d2i(&ptmpval, in, len, it, -1, 0, 0, &c) > 0) {
 136                 if (pval && it->itype != ASN1_ITYPE_PRIMITIVE) {
 137                         if (*pval)
 138                                 ASN1_item_free(*pval, it);
 139                         *pval = ptmpval;
 140                 }
 141                 return ptmpval;
 142         }
 143         return NULL;
 144 }
 145
 146 int ASN1_template_d2i(ASN1_VALUE **pval,
 147                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
 148         {
 149         ASN1_TLC c;
 150         c.valid = 0;
 151         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
 152         }
 153
 154
 155 /* Decode an item, taking care of IMPLICIT tagging, if any.
 156  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 157  */
 158
 159 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 160                         const ASN1_ITEM *it,
 161                         int tag, int aclass, char opt, ASN1_TLC *ctx)
 162         {
 163         const ASN1_TEMPLATE *tt, *errtt = NULL;
 164         const ASN1_COMPAT_FUNCS *cf;
 165         const ASN1_EXTERN_FUNCS *ef;
 166         const ASN1_AUX *aux = it->funcs;
 167         ASN1_aux_cb *asn1_cb;
 168         const unsigned char *p = NULL, *q;
 169         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 170         unsigned char imphack = 0, oclass;
 171         char seq_eoc, seq_nolen, cst, isopt;
 172         long tmplen;
 173         int i;
 174         int otag;
 175         int ret = 0;
 176         ASN1_VALUE **pchptr, *ptmpval;
 177         if (!pval)
 178                 return 0;
 179         if (aux && aux->asn1_cb)
 180                 asn1_cb = aux->asn1_cb;
 181         else asn1_cb = 0;
 182
 183         switch(it->itype)
 184                 {
 185                 case ASN1_ITYPE_PRIMITIVE:
 186                 if (it->templates)
 187                         {
 188                         /* tagging or OPTIONAL is currently illegal on an item
 189                          * template because the flags can't get passed down.
 190                          * In practice this isn't a problem: we include the
 191                          * relevant flags from the item template in the
 192                          * template itself.
 193                          */
 194                         if ((tag != -1) || opt)
 195                                 {
 196                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 197                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 198                                 goto err;
 199                                 }
 200                         return asn1_template_ex_d2i(pval, in, len,
 201                                         it->templates, opt, ctx);
 202                 }
 203                 return asn1_d2i_ex_primitive(pval, in, len, it,
 204                                                 tag, aclass, opt, ctx);
 205                 break;
 206
 207                 case ASN1_ITYPE_MSTRING:
 208                 p = *in;
 209                 /* Just read in tag and class */
 210                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 211                                                 &p, len, -1, 0, 1, ctx);
 212                 if (!ret)
 213                         {
 214                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 215                                         ERR_R_NESTED_ASN1_ERROR);
 216                         goto err;
 217                         }
 218
 219                 /* Must be UNIVERSAL class */
 220                 if (oclass != V_ASN1_UNIVERSAL)
 221                         {
 222                         /* If OPTIONAL, assume this is OK */
 223                         if (opt) return -1;
 224                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 225                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 226                         goto err;
 227                         }
 228                 /* Check tag matches bit map */
 229                 if (!(ASN1_tag2bit(otag) & it->utype))
 230                         {
 231                         /* If OPTIONAL, assume this is OK */
 232                         if (opt)
 233                                 return -1;
 234                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 235                                         ASN1_R_MSTRING_WRONG_TAG);
 236                         goto err;
 237                         }
 238                 return asn1_d2i_ex_primitive(pval, in, len,
 239                                                 it, otag, 0, 0, ctx);
 240
 241                 case ASN1_ITYPE_EXTERN:
 242                 /* Use new style d2i */
 243                 ef = it->funcs;
 244                 return ef->asn1_ex_d2i(pval, in, len,
 245                                                 it, tag, aclass, opt, ctx);
 246
 247                 case ASN1_ITYPE_COMPAT:
 248                 /* we must resort to old style evil hackery */
 249                 cf = it->funcs;
 250
 251                 /* If OPTIONAL see if it is there */
 252                 if (opt)
 253                         {
 254                         int exptag;
 255                         p = *in;
 256                         if (tag == -1)
 257                                 exptag = it->utype;
 258                         else exptag = tag;
 259                         /* Don't care about anything other than presence
 260                          * of expected tag */
 261
 262                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 263                                         &p, len, exptag, aclass, 1, ctx);
 264                         if (!ret)
 265                                 {
 266                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 267                                         ERR_R_NESTED_ASN1_ERROR);
 268                                 goto err;
 269                                 }
 270                         if (ret == -1)
 271                                 return -1;
 272                         }
 273
 274                 /* This is the old style evil hack IMPLICIT handling:
 275                  * since the underlying code is expecting a tag and
 276                  * class other than the one present we change the
 277                  * buffer temporarily then change it back afterwards.
 278                  * This doesn't and never did work for tags > 30.
 279                  *
 280                  * Yes this is *horrible* but it is only needed for
 281                  * old style d2i which will hopefully not be around
 282                  * for much longer.
 283                  * FIXME: should copy the buffer then modify it so
 284                  * the input buffer can be const: we should *always*
 285                  * copy because the old style d2i might modify the
 286                  * buffer.
 287                  */
 288
 289                 if (tag != -1)
 290                         {
 291                         wp = *(unsigned char **)in;
 292                         imphack = *wp;
 293                         if (p == NULL)
 294                                 {
 295                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 296                                         ERR_R_NESTED_ASN1_ERROR);
 297                                 goto err;
 298                                 }
 299                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 300                                                                 | it->utype);
 301                         }
 302
 303                 ptmpval = cf->asn1_d2i(pval, in, len);
 304
 305                 if (tag != -1)
 306                         *wp = imphack;
 307
 308                 if (ptmpval)
 309                         return 1;
 310
 311                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 312                 goto err;
 313
 314
 315                 case ASN1_ITYPE_CHOICE:
 316                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 317                                 goto auxerr;
 318
 319                 if (*pval) {
 320                         /* Free up and zero CHOICE value if initialised */
 321                         i = asn1_get_choice_selector(pval, it);
 322                         if ((i >= 0) && (i < it->tcount)) {
 323                                 tt = it->templates + i;
 324                                 pchptr = asn1_get_field_ptr(pval, tt);
 325                                 ASN1_template_free(pchptr, tt);
 326                                 asn1_set_choice_selector(pval, -1, it);
 327                         }
 328                 } else if (!ASN1_item_ex_new(pval, it)) {
 329                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 330                                                 ERR_R_NESTED_ASN1_ERROR);
 331                         goto err;
 332                 }
 333                 /* CHOICE type, try each possibility in turn */
 334                 p = *in;
 335                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 336                         {
 337                         pchptr = asn1_get_field_ptr(pval, tt);
 338                         /* We mark field as OPTIONAL so its absence
 339                          * can be recognised.
 340                          */
 341                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 342                         /* If field not present, try the next one */
 343                         if (ret == -1)
 344                                 continue;
 345                         /* If positive return, read OK, break loop */
 346                         if (ret > 0)
 347                                 break;
 348                         /* Otherwise must be an ASN1 parsing error */
 349                         errtt = tt;
 350                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 351                                                 ERR_R_NESTED_ASN1_ERROR);
 352                         goto err;
 353                         }
 354
 355                 /* Did we fall off the end without reading anything? */
 356                 if (i == it->tcount)
 357                         {
 358                         /* If OPTIONAL, this is OK */
 359                         if (opt)
 360                                 {
 361                                 /* Free and zero it */
 362                                 ASN1_item_ex_free(pval, it);
 363                                 return -1;
 364                                 }
 365                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 366                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 367                         goto err;
 368                         }
 369
 370                 asn1_set_choice_selector(pval, i, it);
 371                 *in = p;
 372                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 373                                 goto auxerr;
 374                 return 1;
 375
 376                 case ASN1_ITYPE_NDEF_SEQUENCE:
 377                 case ASN1_ITYPE_SEQUENCE:
 378                 p = *in;
 379                 tmplen = len;
 380
 381                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 382                 if (tag == -1)
 383                         {
 384                         tag = V_ASN1_SEQUENCE;
 385                         aclass = V_ASN1_UNIVERSAL;
 386                         }
 387                 /* Get SEQUENCE length and update len, p */
 388                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 389                                         &p, len, tag, aclass, opt, ctx);
 390                 if (!ret)
 391                         {
 392                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 393                                         ERR_R_NESTED_ASN1_ERROR);
 394                         goto err;
 395                         }
 396                 else if (ret == -1)
 397                         return -1;
 398                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 399                         {
 400                         len = tmplen - (p - *in);
 401                         seq_nolen = 1;
 402                         }
 403                 /* If indefinite we don't do a length check */
 404                 else seq_nolen = seq_eoc;
 405                 if (!cst)
 406                         {
 407                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 408                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 409                         goto err;
 410                         }
 411
 412                 if (!*pval && !ASN1_item_ex_new(pval, it))
 413                         {
 414                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 415                                 ERR_R_NESTED_ASN1_ERROR);
 416                         goto err;
 417                         }
 418
 419                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
 420                                 goto auxerr;
 421
 422                 /* Free up and zero any ADB found */
 423                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 424                         if (tt->flags & ASN1_TFLG_ADB_MASK) {
 425                                 const ASN1_TEMPLATE *seqtt;
 426                                 ASN1_VALUE **pseqval;
 427                                 seqtt = asn1_do_adb(pval, tt, 1);
 428                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 429                                 ASN1_template_free(pseqval, seqtt);
 430                         }
 431                 }
 432
 433                 /* Get each field entry */
 434                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 435                         {
 436                         const ASN1_TEMPLATE *seqtt;
 437                         ASN1_VALUE **pseqval;
 438                         seqtt = asn1_do_adb(pval, tt, 1);
 439                         if (!seqtt)
 440                                 goto err;
 441                         pseqval = asn1_get_field_ptr(pval, seqtt);
 442                         /* Have we ran out of data? */
 443                         if (!len)
 444                                 break;
 445                         q = p;
 446                         if (asn1_check_eoc(&p, len))
 447                                 {
 448                                 if (!seq_eoc)
 449                                         {
 450                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 451                                                         ASN1_R_UNEXPECTED_EOC);
 452                                         goto err;
 453                                         }
 454                                 len -= p - q;
 455                                 seq_eoc = 0;
 456                                 q = p;
 457                                 break;
 458                                 }
 459                         /* This determines the OPTIONAL flag value. The field
 460                          * cannot be omitted if it is the last of a SEQUENCE
 461                          * and there is still data to be read. This isn't
 462                          * strictly necessary but it increases efficiency in
 463                          * some cases.
 464                          */
 465                         if (i == (it->tcount - 1))
 466                                 isopt = 0;
 467                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 468                         /* attempt to read in field, allowing each to be
 469                          * OPTIONAL */
 470
 471                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 472                                                         seqtt, isopt, ctx);
 473                         if (!ret)
 474                                 {
 475                                 errtt = seqtt;
 476                                 goto err;
 477                                 }
 478                         else if (ret == -1)
 479                                 {
 480                                 /* OPTIONAL component absent.
 481                                  * Free and zero the field.
 482                                  */
 483                                 ASN1_template_free(pseqval, seqtt);
 484                                 continue;
 485                                 }
 486                         /* Update length */
 487                         len -= p - q;
 488                         }
 489
 490                 /* Check for EOC if expecting one */
 491                 if (seq_eoc && !asn1_check_eoc(&p, len))
 492                         {
 493                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 494                         goto err;
 495                         }
 496                 /* Check all data read */
 497                 if (!seq_nolen && len)
 498                         {
 499                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 500                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 501                         goto err;
 502                         }
 503
 504                 /* If we get here we've got no more data in the SEQUENCE,
 505                  * however we may not have read all fields so check all
 506                  * remaining are OPTIONAL and clear any that are.
 507                  */
 508                 for (; i < it->tcount; tt++, i++)
 509                         {
 510                         const ASN1_TEMPLATE *seqtt;
 511                         seqtt = asn1_do_adb(pval, tt, 1);
 512                         if (!seqtt)
 513                                 goto err;
 514                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 515                                 {
 516                                 ASN1_VALUE **pseqval;
 517                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 518                                 ASN1_template_free(pseqval, seqtt);
 519                                 }
 520                         else
 521                                 {
 522                                 errtt = seqtt;
 523                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 524                                                         ASN1_R_FIELD_MISSING);
 525                                 goto err;
 526                                 }
 527                         }
 528                 /* Save encoding */
 529                 if (!asn1_enc_save(pval, *in, p - *in, it))
 530                         goto auxerr;
 531                 *in = p;
 532                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it))
 533                                 goto auxerr;
 534                 return 1;
 535
 536                 default:
 537                 return 0;
 538                 }
 539         auxerr:
 540         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 541         err:
 542         ASN1_item_ex_free(pval, it);
 543         if (errtt)
 544                 ERR_add_error_data(4, "Field=", errtt->field_name,
 545                                         ", Type=", it->sname);
 546         else
 547                 ERR_add_error_data(2, "Type=", it->sname);
 548         return 0;
 549         }
 550
 551 /* Templates are handled with two separate functions.
 552  * One handles any EXPLICIT tag and the other handles the rest.
 553  */
 554
 555 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 556                                 const unsigned char **in, long inlen,
 557                                 const ASN1_TEMPLATE *tt, char opt,
 558                                                         ASN1_TLC *ctx)
 559         {
 560         int flags, aclass;
 561         int ret;
 562         long len;
 563         const unsigned char *p, *q;
 564         char exp_eoc;
 565         if (!val)
 566                 return 0;
 567         flags = tt->flags;
 568         aclass = flags & ASN1_TFLG_TAG_CLASS;
 569
 570         p = *in;
 571
 572         /* Check if EXPLICIT tag expected */
 573         if (flags & ASN1_TFLG_EXPTAG)
 574                 {
 575                 char cst;
 576                 /* Need to work out amount of data available to the inner
 577                  * content and where it starts: so read in EXPLICIT header to
 578                  * get the info.
 579                  */
 580                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 581                                         &p, inlen, tt->tag, aclass, opt, ctx);
 582                 q = p;
 583                 if (!ret)
 584                         {
 585                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 586                                         ERR_R_NESTED_ASN1_ERROR);
 587                         return 0;
 588                         }
 589                 else if (ret == -1)
 590                         return -1;
 591                 if (!cst)
 592                         {
 593                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 594                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 595                         return 0;
 596                         }
 597                 /* We've found the field so it can't be OPTIONAL now */
 598                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 599                 if (!ret)
 600                         {
 601                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 602                                         ERR_R_NESTED_ASN1_ERROR);
 603                         return 0;
 604                         }
 605                 /* We read the field in OK so update length */
 606                 len -= p - q;
 607                 if (exp_eoc)
 608                         {
 609                         /* If NDEF we must have an EOC here */
 610                         if (!asn1_check_eoc(&p, len))
 611                                 {
 612                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 613                                                 ASN1_R_MISSING_EOC);
 614                                 goto err;
 615                                 }
 616                         }
 617                 else
 618                         {
 619                         /* Otherwise we must hit the EXPLICIT tag end or its
 620                          * an error */
 621                         if (len)
 622                                 {
 623                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 624                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 625                                 goto err;
 626                                 }
 627                         }
 628                 }
 629                 else
 630                         return asn1_template_noexp_d2i(val, in, inlen,
 631                                                                 tt, opt, ctx);
 632
 633         *in = p;
 634         return 1;
 635
 636         err:
 637         ASN1_template_free(val, tt);
 638         return 0;
 639         }
 640
 641 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 642                                 const unsigned char **in, long len,
 643                                 const ASN1_TEMPLATE *tt, char opt,
 644                                 ASN1_TLC *ctx)
 645         {
 646         int flags, aclass;
 647         int ret;
 648         const unsigned char *p, *q;
 649         if (!val)
 650                 return 0;
 651         flags = tt->flags;
 652         aclass = flags & ASN1_TFLG_TAG_CLASS;
 653
 654         p = *in;
 655         q = p;
 656
 657         if (flags & ASN1_TFLG_SK_MASK)
 658                 {
 659                 /* SET OF, SEQUENCE OF */
 660                 int sktag, skaclass;
 661                 char sk_eoc;
 662                 /* First work out expected inner tag value */
 663                 if (flags & ASN1_TFLG_IMPTAG)
 664                         {
 665                         sktag = tt->tag;
 666                         skaclass = aclass;
 667                         }
 668                 else
 669                         {
 670                         skaclass = V_ASN1_UNIVERSAL;
 671                         if (flags & ASN1_TFLG_SET_OF)
 672                                 sktag = V_ASN1_SET;
 673                         else
 674                                 sktag = V_ASN1_SEQUENCE;
 675                         }
 676                 /* Get the tag */
 677                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 678                                         &p, len, sktag, skaclass, opt, ctx);
 679                 if (!ret)
 680                         {
 681                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 682                                                 ERR_R_NESTED_ASN1_ERROR);
 683                         return 0;
 684                         }
 685                 else if (ret == -1)
 686                         return -1;
 687                 if (!*val)
 688                         *val = (ASN1_VALUE *)sk_new_null();
 689                 else
 690                         {
 691                         /* We've got a valid STACK: free up any items present */
 692                         STACK *sktmp = (STACK *)*val;
 693                         ASN1_VALUE *vtmp;
 694                         while(sk_num(sktmp) > 0)
 695                                 {
 696                                 vtmp = (ASN1_VALUE *)sk_pop(sktmp);
 697                                 ASN1_item_ex_free(&vtmp,
 698                                                 ASN1_ITEM_ptr(tt->item));
 699                                 }
 700                         }
 701
 702                 if (!*val)
 703                         {
 704                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 705                                                 ERR_R_MALLOC_FAILURE);
 706                         goto err;
 707                         }
 708
 709                 /* Read as many items as we can */
 710                 while(len > 0)
 711                         {
 712                         ASN1_VALUE *skfield;
 713                         q = p;
 714                         /* See if EOC found */
 715                         if (asn1_check_eoc(&p, len))
 716                                 {
 717                                 if (!sk_eoc)
 718                                         {
 719                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 720                                                         ASN1_R_UNEXPECTED_EOC);
 721                                         goto err;
 722                                         }
 723                                 len -= p - q;
 724                                 sk_eoc = 0;
 725                                 break;
 726                                 }
 727                         skfield = NULL;
 728                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 729                                                 ASN1_ITEM_ptr(tt->item),
 730                                                 -1, 0, 0, ctx))
 731                                 {
 732                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 733                                         ERR_R_NESTED_ASN1_ERROR);
 734                                 goto err;
 735                                 }
 736                         len -= p - q;
 737                         if (!sk_push((STACK *)*val, (char *)skfield))
 738                                 {
 739                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 740                                                 ERR_R_MALLOC_FAILURE);
 741                                 goto err;
 742                                 }
 743                         }
 744                 if (sk_eoc)
 745                         {
 746                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 747                         goto err;
 748                         }
 749                 }
 750         else if (flags & ASN1_TFLG_IMPTAG)
 751                 {
 752                 /* IMPLICIT tagging */
 753                 ret = ASN1_item_ex_d2i(val, &p, len,
 754                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 755                 if (!ret)
 756                         {
 757                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 758                                                 ERR_R_NESTED_ASN1_ERROR);
 759                         goto err;
 760                         }
 761                 else if (ret == -1)
 762                         return -1;
 763                 }
 764         else
 765                 {
 766                 /* Nothing special */
 767                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 768                                                         -1, 0, opt, ctx);
 769                 if (!ret)
 770                         {
 771                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 772                                         ERR_R_NESTED_ASN1_ERROR);
 773                         goto err;
 774                         }
 775                 else if (ret == -1)
 776                         return -1;
 777                 }
 778
 779         *in = p;
 780         return 1;
 781
 782         err:
 783         ASN1_template_free(val, tt);
 784         return 0;
 785         }
 786
 787 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 788                                 const unsigned char **in, long inlen,
 789                                 const ASN1_ITEM *it,
 790                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 791         {
 792         int ret = 0, utype;
 793         long plen;
 794         char cst, inf, free_cont = 0;
 795         const unsigned char *p;
 796         BUF_MEM buf;
 797         const unsigned char *cont = NULL;
 798         long len;
 799         if (!pval)
 800                 {
 801                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 802                 return 0; /* Should never happen */
 803                 }
 804
 805         if (it->itype == ASN1_ITYPE_MSTRING)
 806                 {
 807                 utype = tag;
 808                 tag = -1;
 809                 }
 810         else
 811                 utype = it->utype;
 812
 813         if (utype == V_ASN1_ANY)
 814                 {
 815                 /* If type is ANY need to figure out type from tag */
 816                 unsigned char oclass;
 817                 if (tag >= 0)
 818                         {
 819                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 820                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 821                         return 0;
 822                         }
 823                 if (opt)
 824                         {
 825                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 826                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 827                         return 0;
 828                         }
 829                 p = *in;
 830                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 831                                         &p, inlen, -1, 0, 0, ctx);
 832                 if (!ret)
 833                         {
 834                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 835                                         ERR_R_NESTED_ASN1_ERROR);
 836                         return 0;
 837                         }
 838                 if (oclass != V_ASN1_UNIVERSAL)
 839                         utype = V_ASN1_OTHER;
 840                 }
 841         if (tag == -1)
 842                 {
 843                 tag = utype;
 844                 aclass = V_ASN1_UNIVERSAL;
 845                 }
 846         p = *in;
 847         /* Check header */
 848         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 849                                 &p, inlen, tag, aclass, opt, ctx);
 850         if (!ret)
 851                 {
 852                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 853                 return 0;
 854                 }
 855         else if (ret == -1)
 856                 return -1;
 857         ret = 0;
 858         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 859         if ((utype == V_ASN1_SEQUENCE)
 860                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 861                 {
 862                 /* Clear context cache for type OTHER because the auto clear
 863                  * when we have a exact match wont work
 864                  */
 865                 if (utype == V_ASN1_OTHER)
 866                         {
 867                         asn1_tlc_clear(ctx);
 868                         }
 869                 /* SEQUENCE and SET must be constructed */
 870                 else if (!cst)
 871                         {
 872                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 873                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 874                         return 0;
 875                         }
 876
 877                 cont = *in;
 878                 /* If indefinite length constructed find the real end */
 879                 if (inf)
 880                         {
 881                         if (!asn1_find_end(&p, plen, inf))
 882                                  goto err;
 883                         len = p - cont;
 884                         }
 885                 else
 886                         {
 887                         len = p - cont + plen;
 888                         p += plen;
 889                         buf.data = NULL;
 890                         }
 891                 }
 892         else if (cst)
 893                 {
 894                 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
 895                         || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
 896                         || utype == V_ASN1_ENUMERATED)
 897                         {
 898                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 899                                 ASN1_R_TYPE_NOT_PRIMITIVE);
 900                         return 0;
 901                         }
 902                 buf.length = 0;
 903                 buf.max = 0;
 904                 buf.data = NULL;
 905                 /* Should really check the internal tags are correct but
 906                  * some things may get this wrong. The relevant specs
 907                  * say that constructed string types should be OCTET STRINGs
 908                  * internally irrespective of the type. So instead just check
 909                  * for UNIVERSAL class and ignore the tag.
 910                  */
 911                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 912                         {
 913                         free_cont = 1;
 914                         goto err;
 915                         }
 916                 len = buf.length;
 917                 /* Append a final null to string */
 918                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 919                         {
 920                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 921                                                 ERR_R_MALLOC_FAILURE);
 922                         return 0;
 923                         }
 924                 buf.data[len] = 0;
 925                 cont = (const unsigned char *)buf.data;
 926                 free_cont = 1;
 927                 }
 928         else
 929                 {
 930                 cont = p;
 931                 len = plen;
 932                 p += plen;
 933                 }
 934
 935         /* We now have content length and type: translate into a structure */
 936         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 937                 goto err;
 938
 939         *in = p;
 940         ret = 1;
 941         err:
 942         if (free_cont && buf.data) OPENSSL_free(buf.data);
 943         return ret;
 944         }
 945
 946 /* Translate ASN1 content octets into a structure */
 947
 948 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 949                         int utype, char *free_cont, const ASN1_ITEM *it)
 950         {
 951         ASN1_VALUE **opval = NULL;
 952         ASN1_STRING *stmp;
 953         ASN1_TYPE *typ = NULL;
 954         int ret = 0;
 955         const ASN1_PRIMITIVE_FUNCS *pf;
 956         ASN1_INTEGER **tint;
 957         pf = it->funcs;
 958
 959         if (pf && pf->prim_c2i)
 960                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 961         /* If ANY type clear type and set pointer to internal value */
 962         if (it->utype == V_ASN1_ANY)
 963                 {
 964                 if (!*pval)
 965                         {
 966                         typ = ASN1_TYPE_new();
 967                         if (typ == NULL)
 968                                 goto err;
 969                         *pval = (ASN1_VALUE *)typ;
 970                         }
 971                 else
 972                         typ = (ASN1_TYPE *)*pval;
 973
 974                 if (utype != typ->type)
 975                         ASN1_TYPE_set(typ, utype, NULL);
 976                 opval = pval;
 977                 pval = &typ->value.asn1_value;
 978                 }
 979         switch(utype)
 980                 {
 981                 case V_ASN1_OBJECT:
 982                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 983                         goto err;
 984                 break;
 985
 986                 case V_ASN1_NULL:
 987                 if (len)
 988                         {
 989                         ASN1err(ASN1_F_ASN1_EX_C2I,
 990                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 991                         goto err;
 992                         }
 993                 *pval = (ASN1_VALUE *)1;
 994                 break;
 995
 996                 case V_ASN1_BOOLEAN:
 997                 if (len != 1)
 998                         {
 999                         ASN1err(ASN1_F_ASN1_EX_C2I,
1000                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
1001                         goto err;
1002                         }
1003                 else
1004                         {
1005                         ASN1_BOOLEAN *tbool;
1006                         tbool = (ASN1_BOOLEAN *)pval;
1007                         *tbool = *cont;
1008                         }
1009                 break;
1010
1011                 case V_ASN1_BIT_STRING:
1012                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
1013                         goto err;
1014                 break;
1015
1016                 case V_ASN1_INTEGER:
1017                 case V_ASN1_NEG_INTEGER:
1018                 case V_ASN1_ENUMERATED:
1019                 case V_ASN1_NEG_ENUMERATED:
1020                 tint = (ASN1_INTEGER **)pval;
1021                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
1022                         goto err;
1023                 /* Fixup type to match the expected form */
1024                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
1025                 break;
1026
1027                 case V_ASN1_OCTET_STRING:
1028                 case V_ASN1_NUMERICSTRING:
1029                 case V_ASN1_PRINTABLESTRING:
1030                 case V_ASN1_T61STRING:
1031                 case V_ASN1_VIDEOTEXSTRING:
1032                 case V_ASN1_IA5STRING:
1033                 case V_ASN1_UTCTIME:
1034                 case V_ASN1_GENERALIZEDTIME:
1035                 case V_ASN1_GRAPHICSTRING:
1036                 case V_ASN1_VISIBLESTRING:
1037                 case V_ASN1_GENERALSTRING:
1038                 case V_ASN1_UNIVERSALSTRING:
1039                 case V_ASN1_BMPSTRING:
1040                 case V_ASN1_UTF8STRING:
1041                 case V_ASN1_OTHER:
1042                 case V_ASN1_SET:
1043                 case V_ASN1_SEQUENCE:
1044                 default:
1045                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1046                         {
1047                         ASN1err(ASN1_F_ASN1_EX_C2I,
1048                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1049                         goto err;
1050                         }
1051                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1052                         {
1053                         ASN1err(ASN1_F_ASN1_EX_C2I,
1054                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1055                         goto err;
1056                         }
1057                 /* All based on ASN1_STRING and handled the same */
1058                 if (!*pval)
1059                         {
1060                         stmp = ASN1_STRING_type_new(utype);
1061                         if (!stmp)
1062                                 {
1063                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1064                                                         ERR_R_MALLOC_FAILURE);
1065                                 goto err;
1066                                 }
1067                         *pval = (ASN1_VALUE *)stmp;
1068                         }
1069                 else
1070                         {
1071                         stmp = (ASN1_STRING *)*pval;
1072                         stmp->type = utype;
1073                         }
1074                 /* If we've already allocated a buffer use it */
1075                 if (*free_cont)
1076                         {
1077                         if (stmp->data)
1078                                 OPENSSL_free(stmp->data);
1079                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1080                         stmp->length = len;
1081                         *free_cont = 0;
1082                         }
1083                 else
1084                         {
1085                         if (!ASN1_STRING_set(stmp, cont, len))
1086                                 {
1087                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1088                                                         ERR_R_MALLOC_FAILURE);
1089                                 ASN1_STRING_free(stmp);
1090                                 *pval = NULL;
1091                                 goto err;
1092                                 }
1093                         }
1094                 break;
1095                 }
1096         /* If ASN1_ANY and NULL type fix up value */
1097         if (typ && (utype == V_ASN1_NULL))
1098                  typ->value.ptr = NULL;
1099
1100         ret = 1;
1101         err:
1102         if (!ret)
1103                 {
1104                 ASN1_TYPE_free(typ);
1105                 if (opval)
1106                         *opval = NULL;
1107                 }
1108         return ret;
1109         }
1110
1111
1112 /* This function finds the end of an ASN1 structure when passed its maximum
1113  * length, whether it is indefinite length and a pointer to the content.
1114  * This is more efficient than calling asn1_collect because it does not
1115  * recurse on each indefinite length header.
1116  */
1117
1118 static int asn1_find_end(const unsigned char **in, long len, char inf)
1119         {
1120         int expected_eoc;
1121         long plen;
1122         const unsigned char *p = *in, *q;
1123         /* If not indefinite length constructed just add length */
1124         if (inf == 0)
1125                 {
1126                 *in += len;
1127                 return 1;
1128                 }
1129         expected_eoc = 1;
1130         /* Indefinite length constructed form. Find the end when enough EOCs
1131          * are found. If more indefinite length constructed headers
1132          * are encountered increment the expected eoc count otherwise just
1133          * skip to the end of the data.
1134          */
1135         while (len > 0)
1136                 {
1137                 if(asn1_check_eoc(&p, len))
1138                         {
1139                         expected_eoc--;
1140                         if (expected_eoc == 0)
1141                                 break;
1142                         len -= 2;
1143                         continue;
1144                         }
1145                 q = p;
1146                 /* Just read in a header: only care about the length */
1147                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1148                                 -1, 0, 0, NULL))
1149                         {
1150                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1151                         return 0;
1152                         }
1153                 if (inf)
1154                         expected_eoc++;
1155                 else
1156                         p += plen;
1157                 len -= p - q;
1158                 }
1159         if (expected_eoc)
1160                 {
1161                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1162                 return 0;
1163                 }
1164         *in = p;
1165         return 1;
1166         }
1167 /* This function collects the asn1 data from a constructred string
1168  * type into a buffer. The values of 'in' and 'len' should refer
1169  * to the contents of the constructed type and 'inf' should be set
1170  * if it is indefinite length.
1171  */
1172
1173 #ifndef ASN1_MAX_STRING_NEST
1174 /* This determines how many levels of recursion are permitted in ASN1
1175  * string types. If it is not limited stack overflows can occur. If set
1176  * to zero no recursion is allowed at all. Although zero should be adequate
1177  * examples exist that require a value of 1. So 5 should be more than enough.
1178  */
1179 #define ASN1_MAX_STRING_NEST 5
1180 #endif
1181
1182
1183 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1184                         char inf, int tag, int aclass, int depth)
1185         {
1186         const unsigned char *p, *q;
1187         long plen;
1188         char cst, ininf;
1189         p = *in;
1190         inf &= 1;
1191         /* If no buffer and not indefinite length constructed just pass over
1192          * the encoded data */
1193         if (!buf && !inf)
1194                 {
1195                 *in += len;
1196                 return 1;
1197                 }
1198         while(len > 0)
1199                 {
1200                 q = p;
1201                 /* Check for EOC */
1202                 if (asn1_check_eoc(&p, len))
1203                         {
1204                         /* EOC is illegal outside indefinite length
1205                          * constructed form */
1206                         if (!inf)
1207                                 {
1208                                 ASN1err(ASN1_F_ASN1_COLLECT,
1209                                         ASN1_R_UNEXPECTED_EOC);
1210                                 return 0;
1211                                 }
1212                         inf = 0;
1213                         break;
1214                         }
1215
1216                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1217                                         len, tag, aclass, 0, NULL))
1218                         {
1219                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1220                         return 0;
1221                         }
1222
1223                 /* If indefinite length constructed update max length */
1224                 if (cst)
1225                         {
1226                         if (depth >= ASN1_MAX_STRING_NEST)
1227                                 {
1228                                 ASN1err(ASN1_F_ASN1_COLLECT,
1229                                         ASN1_R_NESTED_ASN1_STRING);
1230                                 return 0;
1231                                 }
1232                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1233                                                 depth + 1))
1234                                 return 0;
1235                         }
1236                 else if (plen && !collect_data(buf, &p, plen))
1237                         return 0;
1238                 len -= p - q;
1239                 }
1240         if (inf)
1241                 {
1242                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1243                 return 0;
1244                 }
1245         *in = p;
1246         return 1;
1247         }
1248
1249 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1250         {
1251         int len;
1252         if (buf)
1253                 {
1254                 len = buf->length;
1255                 if (!BUF_MEM_grow_clean(buf, len + plen))
1256                         {
1257                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1258                         return 0;
1259                         }
1260                 memcpy(buf->data + len, *p, plen);
1261                 }
1262         *p += plen;
1263         return 1;
1264         }
1265
1266 /* Check for ASN1 EOC and swallow it if found */
1267
1268 static int asn1_check_eoc(const unsigned char **in, long len)
1269         {
1270         const unsigned char *p;
1271         if (len < 2) return 0;
1272         p = *in;
1273         if (!p[0] && !p[1])
1274                 {
1275                 *in += 2;
1276                 return 1;
1277                 }
1278         return 0;
1279         }
1280
1281 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1282  * but it sets the length for indefinite length constructed
1283  * form, we don't know the exact length but we can set an
1284  * upper bound to the amount of data available minus the
1285  * header length just read.
1286  */
1287
1288 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1289                                 char *inf, char *cst,
1290                                 const unsigned char **in, long len,
1291                                 int exptag, int expclass, char opt,
1292                                 ASN1_TLC *ctx)
1293         {
1294         int i;
1295         int ptag, pclass;
1296         long plen;
1297         const unsigned char *p, *q;
1298         p = *in;
1299         q = p;
1300
1301         if (ctx && ctx->valid)
1302                 {
1303                 i = ctx->ret;
1304                 plen = ctx->plen;
1305                 pclass = ctx->pclass;
1306                 ptag = ctx->ptag;
1307                 p += ctx->hdrlen;
1308                 }
1309         else
1310                 {
1311                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1312                 if (ctx)
1313                         {
1314                         ctx->ret = i;
1315                         ctx->plen = plen;
1316                         ctx->pclass = pclass;
1317                         ctx->ptag = ptag;
1318                         ctx->hdrlen = p - q;
1319                         ctx->valid = 1;
1320                         /* If definite length, and no error, length +
1321                          * header can't exceed total amount of data available.
1322                          */
1323                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1324                                 {
1325                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1326                                                         ASN1_R_TOO_LONG);
1327                                 asn1_tlc_clear(ctx);
1328                                 return 0;
1329                                 }
1330                         }
1331                 }
1332
1333         if (i & 0x80)
1334                 {
1335                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1336                 asn1_tlc_clear(ctx);
1337                 return 0;
1338                 }
1339         if (exptag >= 0)
1340                 {
1341                 if ((exptag != ptag) || (expclass != pclass))
1342                         {
1343                         /* If type is OPTIONAL, not an error:
1344                          * indicate missing type.
1345                          */
1346                         if (opt) return -1;
1347                         asn1_tlc_clear(ctx);
1348                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1349                         return 0;
1350                         }
1351                 /* We have a tag and class match:
1352                  * assume we are going to do something with it */
1353                 asn1_tlc_clear(ctx);
1354                 }
1355
1356         if (i & 1)
1357                 plen = len - (p - q);
1358
1359         if (inf)
1360                 *inf = i & 1;
1361
1362         if (cst)
1363                 *cst = i & V_ASN1_CONSTRUCTED;
1364
1365         if (olen)
1366                 *olen = plen;
1367
1368         if (oclass)
1369                 *oclass = pclass;
1370
1371         if (otag)
1372                 *otag = ptag;
1373
1374         *in = p;
1375         return 1;
1376         }