crypto/openssl/crypto/asn1/tasn_dec.c

   1 /* tasn_dec.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59
  60 #include <stddef.h>
  61 #include <string.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/buffer.h>
  66 #include <openssl/err.h>
  67
  68 static int asn1_check_eoc(const unsigned char **in, long len);
  69 static int asn1_find_end(const unsigned char **in, long len, char inf);
  70
  71 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
  72                         char inf, int tag, int aclass, int depth);
  73
  74 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  75
  76 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  77                                 char *inf, char *cst,
  78                                 const unsigned char **in, long len,
  79                                 int exptag, int expclass, char opt,
  80                                 ASN1_TLC *ctx);
  81
  82 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
  83                                 const unsigned char **in, long len,
  84                                 const ASN1_TEMPLATE *tt, char opt,
  85                                 ASN1_TLC *ctx);
  86 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
  87                                 const unsigned char **in, long len,
  88                                 const ASN1_TEMPLATE *tt, char opt,
  89                                 ASN1_TLC *ctx);
  90 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
  91                                 const unsigned char **in, long len,
  92                                 const ASN1_ITEM *it,
  93                                 int tag, int aclass, char opt, ASN1_TLC *ctx);
  94
  95 /* Table to convert tags to bit values, used for MSTRING type */
  96 static const unsigned long tag2bit[32] = {
  97 0,      0,      0,      B_ASN1_BIT_STRING,      /* tags  0 -  3 */
  98 B_ASN1_OCTET_STRING,    0,      0,              B_ASN1_UNKNOWN,/* tags  4- 7 */
  99 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,/* tags  8-11 */
 100 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */
 101 B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */
 102 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING,       /* tags 20-22 */
 103 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,                        /* tags 23-24 */
 104 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING,  /* tags 25-27 */
 105 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */
 106         };
 107
 108 unsigned long ASN1_tag2bit(int tag)
 109         {
 110         if ((tag < 0) || (tag > 30)) return 0;
 111         return tag2bit[tag];
 112         }
 113
 114 /* Macro to initialize and invalidate the cache */
 115
 116 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
 117 /* Version to avoid compiler warning about 'c' always non-NULL */
 118 #define asn1_tlc_clear_nc(c)    (c)->valid = 0
 119
 120 /* Decode an ASN1 item, this currently behaves just
 121  * like a standard 'd2i' function. 'in' points to
 122  * a buffer to read the data from, in future we will
 123  * have more advanced versions that can input data
 124  * a piece at a time and this will simply be a special
 125  * case.
 126  */
 127
 128 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 129                 const unsigned char **in, long len, const ASN1_ITEM *it)
 130         {
 131         ASN1_TLC c;
 132         ASN1_VALUE *ptmpval = NULL;
 133         if (!pval)
 134                 pval = &ptmpval;
 135         asn1_tlc_clear_nc(&c);
 136         if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 137                 return *pval;
 138         return NULL;
 139         }
 140
 141 int ASN1_template_d2i(ASN1_VALUE **pval,
 142                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
 143         {
 144         ASN1_TLC c;
 145         asn1_tlc_clear_nc(&c);
 146         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
 147         }
 148
 149
 150 /* Decode an item, taking care of IMPLICIT tagging, if any.
 151  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 152  */
 153
 154 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 155                         const ASN1_ITEM *it,
 156                         int tag, int aclass, char opt, ASN1_TLC *ctx)
 157         {
 158         const ASN1_TEMPLATE *tt, *errtt = NULL;
 159         const ASN1_COMPAT_FUNCS *cf;
 160         const ASN1_EXTERN_FUNCS *ef;
 161         const ASN1_AUX *aux = it->funcs;
 162         ASN1_aux_cb *asn1_cb;
 163         const unsigned char *p = NULL, *q;
 164         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 165         unsigned char imphack = 0, oclass;
 166         char seq_eoc, seq_nolen, cst, isopt;
 167         long tmplen;
 168         int i;
 169         int otag;
 170         int ret = 0;
 171         ASN1_VALUE **pchptr, *ptmpval;
 172         int combine = aclass & ASN1_TFLG_COMBINE;
 173         aclass &= ~ASN1_TFLG_COMBINE;
 174         if (!pval)
 175                 return 0;
 176         if (aux && aux->asn1_cb)
 177                 asn1_cb = aux->asn1_cb;
 178         else asn1_cb = 0;
 179
 180         switch(it->itype)
 181                 {
 182                 case ASN1_ITYPE_PRIMITIVE:
 183                 if (it->templates)
 184                         {
 185                         /* tagging or OPTIONAL is currently illegal on an item
 186                          * template because the flags can't get passed down.
 187                          * In practice this isn't a problem: we include the
 188                          * relevant flags from the item template in the
 189                          * template itself.
 190                          */
 191                         if ((tag != -1) || opt)
 192                                 {
 193                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 194                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 195                                 goto err;
 196                                 }
 197                         return asn1_template_ex_d2i(pval, in, len,
 198                                         it->templates, opt, ctx);
 199                 }
 200                 return asn1_d2i_ex_primitive(pval, in, len, it,
 201                                                 tag, aclass, opt, ctx);
 202                 break;
 203
 204                 case ASN1_ITYPE_MSTRING:
 205                 p = *in;
 206                 /* Just read in tag and class */
 207                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 208                                                 &p, len, -1, 0, 1, ctx);
 209                 if (!ret)
 210                         {
 211                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 212                                         ERR_R_NESTED_ASN1_ERROR);
 213                         goto err;
 214                         }
 215
 216                 /* Must be UNIVERSAL class */
 217                 if (oclass != V_ASN1_UNIVERSAL)
 218                         {
 219                         /* If OPTIONAL, assume this is OK */
 220                         if (opt) return -1;
 221                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 222                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 223                         goto err;
 224                         }
 225                 /* Check tag matches bit map */
 226                 if (!(ASN1_tag2bit(otag) & it->utype))
 227                         {
 228                         /* If OPTIONAL, assume this is OK */
 229                         if (opt)
 230                                 return -1;
 231                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 232                                         ASN1_R_MSTRING_WRONG_TAG);
 233                         goto err;
 234                         }
 235                 return asn1_d2i_ex_primitive(pval, in, len,
 236                                                 it, otag, 0, 0, ctx);
 237
 238                 case ASN1_ITYPE_EXTERN:
 239                 /* Use new style d2i */
 240                 ef = it->funcs;
 241                 return ef->asn1_ex_d2i(pval, in, len,
 242                                                 it, tag, aclass, opt, ctx);
 243
 244                 case ASN1_ITYPE_COMPAT:
 245                 /* we must resort to old style evil hackery */
 246                 cf = it->funcs;
 247
 248                 /* If OPTIONAL see if it is there */
 249                 if (opt)
 250                         {
 251                         int exptag;
 252                         p = *in;
 253                         if (tag == -1)
 254                                 exptag = it->utype;
 255                         else exptag = tag;
 256                         /* Don't care about anything other than presence
 257                          * of expected tag */
 258
 259                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 260                                         &p, len, exptag, aclass, 1, ctx);
 261                         if (!ret)
 262                                 {
 263                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 264                                         ERR_R_NESTED_ASN1_ERROR);
 265                                 goto err;
 266                                 }
 267                         if (ret == -1)
 268                                 return -1;
 269                         }
 270
 271                 /* This is the old style evil hack IMPLICIT handling:
 272                  * since the underlying code is expecting a tag and
 273                  * class other than the one present we change the
 274                  * buffer temporarily then change it back afterwards.
 275                  * This doesn't and never did work for tags > 30.
 276                  *
 277                  * Yes this is *horrible* but it is only needed for
 278                  * old style d2i which will hopefully not be around
 279                  * for much longer.
 280                  * FIXME: should copy the buffer then modify it so
 281                  * the input buffer can be const: we should *always*
 282                  * copy because the old style d2i might modify the
 283                  * buffer.
 284                  */
 285
 286                 if (tag != -1)
 287                         {
 288                         wp = *(unsigned char **)in;
 289                         imphack = *wp;
 290                         if (p == NULL)
 291                                 {
 292                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 293                                         ERR_R_NESTED_ASN1_ERROR);
 294                                 goto err;
 295                                 }
 296                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 297                                                                 | it->utype);
 298                         }
 299
 300                 ptmpval = cf->asn1_d2i(pval, in, len);
 301
 302                 if (tag != -1)
 303                         *wp = imphack;
 304
 305                 if (ptmpval)
 306                         return 1;
 307
 308                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 309                 goto err;
 310
 311
 312                 case ASN1_ITYPE_CHOICE:
 313                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 314                                 goto auxerr;
 315
 316                 if (*pval) {
 317                         /* Free up and zero CHOICE value if initialised */
 318                         i = asn1_get_choice_selector(pval, it);
 319                         if ((i >= 0) && (i < it->tcount)) {
 320                                 tt = it->templates + i;
 321                                 pchptr = asn1_get_field_ptr(pval, tt);
 322                                 ASN1_template_free(pchptr, tt);
 323                                 asn1_set_choice_selector(pval, -1, it);
 324                         }
 325                 } else if (!ASN1_item_ex_new(pval, it)) {
 326                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 327                                                 ERR_R_NESTED_ASN1_ERROR);
 328                         goto err;
 329                 }
 330                 /* CHOICE type, try each possibility in turn */
 331                 p = *in;
 332                 for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
 333                         {
 334                         pchptr = asn1_get_field_ptr(pval, tt);
 335                         /* We mark field as OPTIONAL so its absence
 336                          * can be recognised.
 337                          */
 338                         ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 339                         /* If field not present, try the next one */
 340                         if (ret == -1)
 341                                 continue;
 342                         /* If positive return, read OK, break loop */
 343                         if (ret > 0)
 344                                 break;
 345                         /* Otherwise must be an ASN1 parsing error */
 346                         errtt = tt;
 347                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 348                                                 ERR_R_NESTED_ASN1_ERROR);
 349                         goto err;
 350                         }
 351
 352                 /* Did we fall off the end without reading anything? */
 353                 if (i == it->tcount)
 354                         {
 355                         /* If OPTIONAL, this is OK */
 356                         if (opt)
 357                                 {
 358                                 /* Free and zero it */
 359                                 ASN1_item_ex_free(pval, it);
 360                                 return -1;
 361                                 }
 362                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 363                                         ASN1_R_NO_MATCHING_CHOICE_TYPE);
 364                         goto err;
 365                         }
 366
 367                 asn1_set_choice_selector(pval, i, it);
 368                 *in = p;
 369                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 370                                 goto auxerr;
 371                 return 1;
 372
 373                 case ASN1_ITYPE_NDEF_SEQUENCE:
 374                 case ASN1_ITYPE_SEQUENCE:
 375                 p = *in;
 376                 tmplen = len;
 377
 378                 /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 379                 if (tag == -1)
 380                         {
 381                         tag = V_ASN1_SEQUENCE;
 382                         aclass = V_ASN1_UNIVERSAL;
 383                         }
 384                 /* Get SEQUENCE length and update len, p */
 385                 ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 386                                         &p, len, tag, aclass, opt, ctx);
 387                 if (!ret)
 388                         {
 389                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 390                                         ERR_R_NESTED_ASN1_ERROR);
 391                         goto err;
 392                         }
 393                 else if (ret == -1)
 394                         return -1;
 395                 if (aux && (aux->flags & ASN1_AFLG_BROKEN))
 396                         {
 397                         len = tmplen - (p - *in);
 398                         seq_nolen = 1;
 399                         }
 400                 /* If indefinite we don't do a length check */
 401                 else seq_nolen = seq_eoc;
 402                 if (!cst)
 403                         {
 404                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 405                                 ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 406                         goto err;
 407                         }
 408
 409                 if (!*pval && !ASN1_item_ex_new(pval, it))
 410                         {
 411                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 412                                 ERR_R_NESTED_ASN1_ERROR);
 413                         goto err;
 414                         }
 415
 416                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 417                                 goto auxerr;
 418
 419                 /* Free up and zero any ADB found */
 420                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 421                         if (tt->flags & ASN1_TFLG_ADB_MASK) {
 422                                 const ASN1_TEMPLATE *seqtt;
 423                                 ASN1_VALUE **pseqval;
 424                                 seqtt = asn1_do_adb(pval, tt, 1);
 425                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 426                                 ASN1_template_free(pseqval, seqtt);
 427                         }
 428                 }
 429
 430                 /* Get each field entry */
 431                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 432                         {
 433                         const ASN1_TEMPLATE *seqtt;
 434                         ASN1_VALUE **pseqval;
 435                         seqtt = asn1_do_adb(pval, tt, 1);
 436                         if (!seqtt)
 437                                 goto err;
 438                         pseqval = asn1_get_field_ptr(pval, seqtt);
 439                         /* Have we ran out of data? */
 440                         if (!len)
 441                                 break;
 442                         q = p;
 443                         if (asn1_check_eoc(&p, len))
 444                                 {
 445                                 if (!seq_eoc)
 446                                         {
 447                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 448                                                         ASN1_R_UNEXPECTED_EOC);
 449                                         goto err;
 450                                         }
 451                                 len -= p - q;
 452                                 seq_eoc = 0;
 453                                 q = p;
 454                                 break;
 455                                 }
 456                         /* This determines the OPTIONAL flag value. The field
 457                          * cannot be omitted if it is the last of a SEQUENCE
 458                          * and there is still data to be read. This isn't
 459                          * strictly necessary but it increases efficiency in
 460                          * some cases.
 461                          */
 462                         if (i == (it->tcount - 1))
 463                                 isopt = 0;
 464                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 465                         /* attempt to read in field, allowing each to be
 466                          * OPTIONAL */
 467
 468                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 469                                                         seqtt, isopt, ctx);
 470                         if (!ret)
 471                                 {
 472                                 errtt = seqtt;
 473                                 goto err;
 474                                 }
 475                         else if (ret == -1)
 476                                 {
 477                                 /* OPTIONAL component absent.
 478                                  * Free and zero the field.
 479                                  */
 480                                 ASN1_template_free(pseqval, seqtt);
 481                                 continue;
 482                                 }
 483                         /* Update length */
 484                         len -= p - q;
 485                         }
 486
 487                 /* Check for EOC if expecting one */
 488                 if (seq_eoc && !asn1_check_eoc(&p, len))
 489                         {
 490                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 491                         goto err;
 492                         }
 493                 /* Check all data read */
 494                 if (!seq_nolen && len)
 495                         {
 496                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 497                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 498                         goto err;
 499                         }
 500
 501                 /* If we get here we've got no more data in the SEQUENCE,
 502                  * however we may not have read all fields so check all
 503                  * remaining are OPTIONAL and clear any that are.
 504                  */
 505                 for (; i < it->tcount; tt++, i++)
 506                         {
 507                         const ASN1_TEMPLATE *seqtt;
 508                         seqtt = asn1_do_adb(pval, tt, 1);
 509                         if (!seqtt)
 510                                 goto err;
 511                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 512                                 {
 513                                 ASN1_VALUE **pseqval;
 514                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 515                                 ASN1_template_free(pseqval, seqtt);
 516                                 }
 517                         else
 518                                 {
 519                                 errtt = seqtt;
 520                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 521                                                         ASN1_R_FIELD_MISSING);
 522                                 goto err;
 523                                 }
 524                         }
 525                 /* Save encoding */
 526                 if (!asn1_enc_save(pval, *in, p - *in, it))
 527                         goto auxerr;
 528                 *in = p;
 529                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 530                                 goto auxerr;
 531                 return 1;
 532
 533                 default:
 534                 return 0;
 535                 }
 536         auxerr:
 537         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 538         err:
 539         if (combine == 0)
 540                 ASN1_item_ex_free(pval, it);
 541         if (errtt)
 542                 ERR_add_error_data(4, "Field=", errtt->field_name,
 543                                         ", Type=", it->sname);
 544         else
 545                 ERR_add_error_data(2, "Type=", it->sname);
 546         return 0;
 547         }
 548
 549 /* Templates are handled with two separate functions.
 550  * One handles any EXPLICIT tag and the other handles the rest.
 551  */
 552
 553 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 554                                 const unsigned char **in, long inlen,
 555                                 const ASN1_TEMPLATE *tt, char opt,
 556                                                         ASN1_TLC *ctx)
 557         {
 558         int flags, aclass;
 559         int ret;
 560         long len;
 561         const unsigned char *p, *q;
 562         char exp_eoc;
 563         if (!val)
 564                 return 0;
 565         flags = tt->flags;
 566         aclass = flags & ASN1_TFLG_TAG_CLASS;
 567
 568         p = *in;
 569
 570         /* Check if EXPLICIT tag expected */
 571         if (flags & ASN1_TFLG_EXPTAG)
 572                 {
 573                 char cst;
 574                 /* Need to work out amount of data available to the inner
 575                  * content and where it starts: so read in EXPLICIT header to
 576                  * get the info.
 577                  */
 578                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 579                                         &p, inlen, tt->tag, aclass, opt, ctx);
 580                 q = p;
 581                 if (!ret)
 582                         {
 583                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 584                                         ERR_R_NESTED_ASN1_ERROR);
 585                         return 0;
 586                         }
 587                 else if (ret == -1)
 588                         return -1;
 589                 if (!cst)
 590                         {
 591                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 592                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 593                         return 0;
 594                         }
 595                 /* We've found the field so it can't be OPTIONAL now */
 596                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 597                 if (!ret)
 598                         {
 599                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 600                                         ERR_R_NESTED_ASN1_ERROR);
 601                         return 0;
 602                         }
 603                 /* We read the field in OK so update length */
 604                 len -= p - q;
 605                 if (exp_eoc)
 606                         {
 607                         /* If NDEF we must have an EOC here */
 608                         if (!asn1_check_eoc(&p, len))
 609                                 {
 610                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 611                                                 ASN1_R_MISSING_EOC);
 612                                 goto err;
 613                                 }
 614                         }
 615                 else
 616                         {
 617                         /* Otherwise we must hit the EXPLICIT tag end or its
 618                          * an error */
 619                         if (len)
 620                                 {
 621                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 622                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 623                                 goto err;
 624                                 }
 625                         }
 626                 }
 627                 else
 628                         return asn1_template_noexp_d2i(val, in, inlen,
 629                                                                 tt, opt, ctx);
 630
 631         *in = p;
 632         return 1;
 633
 634         err:
 635         ASN1_template_free(val, tt);
 636         return 0;
 637         }
 638
 639 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 640                                 const unsigned char **in, long len,
 641                                 const ASN1_TEMPLATE *tt, char opt,
 642                                 ASN1_TLC *ctx)
 643         {
 644         int flags, aclass;
 645         int ret;
 646         const unsigned char *p, *q;
 647         if (!val)
 648                 return 0;
 649         flags = tt->flags;
 650         aclass = flags & ASN1_TFLG_TAG_CLASS;
 651
 652         p = *in;
 653         q = p;
 654
 655         if (flags & ASN1_TFLG_SK_MASK)
 656                 {
 657                 /* SET OF, SEQUENCE OF */
 658                 int sktag, skaclass;
 659                 char sk_eoc;
 660                 /* First work out expected inner tag value */
 661                 if (flags & ASN1_TFLG_IMPTAG)
 662                         {
 663                         sktag = tt->tag;
 664                         skaclass = aclass;
 665                         }
 666                 else
 667                         {
 668                         skaclass = V_ASN1_UNIVERSAL;
 669                         if (flags & ASN1_TFLG_SET_OF)
 670                                 sktag = V_ASN1_SET;
 671                         else
 672                                 sktag = V_ASN1_SEQUENCE;
 673                         }
 674                 /* Get the tag */
 675                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 676                                         &p, len, sktag, skaclass, opt, ctx);
 677                 if (!ret)
 678                         {
 679                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 680                                                 ERR_R_NESTED_ASN1_ERROR);
 681                         return 0;
 682                         }
 683                 else if (ret == -1)
 684                         return -1;
 685                 if (!*val)
 686                         *val = (ASN1_VALUE *)sk_new_null();
 687                 else
 688                         {
 689                         /* We've got a valid STACK: free up any items present */
 690                         STACK_OF(ASN1_VALUE) *sktmp
 691                             = (STACK_OF(ASN1_VALUE) *)*val;
 692                         ASN1_VALUE *vtmp;
 693                         while(sk_ASN1_VALUE_num(sktmp) > 0)
 694                                 {
 695                                 vtmp = sk_ASN1_VALUE_pop(sktmp);
 696                                 ASN1_item_ex_free(&vtmp,
 697                                                 ASN1_ITEM_ptr(tt->item));
 698                                 }
 699                         }
 700
 701                 if (!*val)
 702                         {
 703                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 704                                                 ERR_R_MALLOC_FAILURE);
 705                         goto err;
 706                         }
 707
 708                 /* Read as many items as we can */
 709                 while(len > 0)
 710                         {
 711                         ASN1_VALUE *skfield;
 712                         q = p;
 713                         /* See if EOC found */
 714                         if (asn1_check_eoc(&p, len))
 715                                 {
 716                                 if (!sk_eoc)
 717                                         {
 718                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 719                                                         ASN1_R_UNEXPECTED_EOC);
 720                                         goto err;
 721                                         }
 722                                 len -= p - q;
 723                                 sk_eoc = 0;
 724                                 break;
 725                                 }
 726                         skfield = NULL;
 727                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 728                                                 ASN1_ITEM_ptr(tt->item),
 729                                                 -1, 0, 0, ctx))
 730                                 {
 731                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 732                                         ERR_R_NESTED_ASN1_ERROR);
 733                                 goto err;
 734                                 }
 735                         len -= p - q;
 736                         if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
 737                                                 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, tt->flags & ASN1_TFLG_COMBINE, 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         }