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     /* tags  0 -  3 */
  98 0,      0,      0,      B_ASN1_BIT_STRING,
  99     /* tags  4- 7 */
 100 B_ASN1_OCTET_STRING,    0,      0,              B_ASN1_UNKNOWN,
 101     /* tags  8-11 */
 102 B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
 103     /* tags 12-15 */
 104 B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,
 105     /* tags 16-19 */
 106 B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING,
 107     /* tags 20-22 */
 108 B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING,
 109     /* tags 23-24 */
 110 B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
 111     /* tags 25-27 */
 112 B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING,
 113     /* tags 28-31 */
 114 B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN,
 115         };
 116
 117 unsigned long ASN1_tag2bit(int tag)
 118         {
 119         if ((tag < 0) || (tag > 30)) return 0;
 120         return tag2bit[tag];
 121         }
 122
 123 /* Macro to initialize and invalidate the cache */
 124
 125 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
 126 /* Version to avoid compiler warning about 'c' always non-NULL */
 127 #define asn1_tlc_clear_nc(c)    (c)->valid = 0
 128
 129 /* Decode an ASN1 item, this currently behaves just
 130  * like a standard 'd2i' function. 'in' points to
 131  * a buffer to read the data from, in future we will
 132  * have more advanced versions that can input data
 133  * a piece at a time and this will simply be a special
 134  * case.
 135  */
 136
 137 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 138                 const unsigned char **in, long len, const ASN1_ITEM *it)
 139         {
 140         ASN1_TLC c;
 141         ASN1_VALUE *ptmpval = NULL;
 142         if (!pval)
 143                 pval = &ptmpval;
 144         asn1_tlc_clear_nc(&c);
 145         if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 146                 return *pval;
 147         return NULL;
 148         }
 149
 150 int ASN1_template_d2i(ASN1_VALUE **pval,
 151                 const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
 152         {
 153         ASN1_TLC c;
 154         asn1_tlc_clear_nc(&c);
 155         return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
 156         }
 157
 158
 159 /* Decode an item, taking care of IMPLICIT tagging, if any.
 160  * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 161  */
 162
 163 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 164                         const ASN1_ITEM *it,
 165                         int tag, int aclass, char opt, ASN1_TLC *ctx)
 166         {
 167         const ASN1_TEMPLATE *tt, *errtt = NULL;
 168         const ASN1_COMPAT_FUNCS *cf;
 169         const ASN1_EXTERN_FUNCS *ef;
 170         const ASN1_AUX *aux = it->funcs;
 171         ASN1_aux_cb *asn1_cb;
 172         const unsigned char *p = NULL, *q;
 173         unsigned char *wp=NULL; /* BIG FAT WARNING!  BREAKS CONST WHERE USED */
 174         unsigned char imphack = 0, oclass;
 175         char seq_eoc, seq_nolen, cst, isopt;
 176         long tmplen;
 177         int i;
 178         int otag;
 179         int ret = 0;
 180         ASN1_VALUE **pchptr, *ptmpval;
 181         if (!pval)
 182                 return 0;
 183         if (aux && aux->asn1_cb)
 184                 asn1_cb = aux->asn1_cb;
 185         else asn1_cb = 0;
 186
 187         switch(it->itype)
 188                 {
 189                 case ASN1_ITYPE_PRIMITIVE:
 190                 if (it->templates)
 191                         {
 192                         /* tagging or OPTIONAL is currently illegal on an item
 193                          * template because the flags can't get passed down.
 194                          * In practice this isn't a problem: we include the
 195                          * relevant flags from the item template in the
 196                          * template itself.
 197                          */
 198                         if ((tag != -1) || opt)
 199                                 {
 200                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 201                                 ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 202                                 goto err;
 203                                 }
 204                         return asn1_template_ex_d2i(pval, in, len,
 205                                         it->templates, opt, ctx);
 206                 }
 207                 return asn1_d2i_ex_primitive(pval, in, len, it,
 208                                                 tag, aclass, opt, ctx);
 209                 break;
 210
 211                 case ASN1_ITYPE_MSTRING:
 212                 p = *in;
 213                 /* Just read in tag and class */
 214                 ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 215                                                 &p, len, -1, 0, 1, ctx);
 216                 if (!ret)
 217                         {
 218                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 219                                         ERR_R_NESTED_ASN1_ERROR);
 220                         goto err;
 221                         }
 222
 223                 /* Must be UNIVERSAL class */
 224                 if (oclass != V_ASN1_UNIVERSAL)
 225                         {
 226                         /* If OPTIONAL, assume this is OK */
 227                         if (opt) return -1;
 228                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 229                                         ASN1_R_MSTRING_NOT_UNIVERSAL);
 230                         goto err;
 231                         }
 232                 /* Check tag matches bit map */
 233                 if (!(ASN1_tag2bit(otag) & it->utype))
 234                         {
 235                         /* If OPTIONAL, assume this is OK */
 236                         if (opt)
 237                                 return -1;
 238                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 239                                         ASN1_R_MSTRING_WRONG_TAG);
 240                         goto err;
 241                         }
 242                 return asn1_d2i_ex_primitive(pval, in, len,
 243                                                 it, otag, 0, 0, ctx);
 244
 245                 case ASN1_ITYPE_EXTERN:
 246                 /* Use new style d2i */
 247                 ef = it->funcs;
 248                 return ef->asn1_ex_d2i(pval, in, len,
 249                                                 it, tag, aclass, opt, ctx);
 250
 251                 case ASN1_ITYPE_COMPAT:
 252                 /* we must resort to old style evil hackery */
 253                 cf = it->funcs;
 254
 255                 /* If OPTIONAL see if it is there */
 256                 if (opt)
 257                         {
 258                         int exptag;
 259                         p = *in;
 260                         if (tag == -1)
 261                                 exptag = it->utype;
 262                         else exptag = tag;
 263                         /* Don't care about anything other than presence
 264                          * of expected tag */
 265
 266                         ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
 267                                         &p, len, exptag, aclass, 1, ctx);
 268                         if (!ret)
 269                                 {
 270                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 271                                         ERR_R_NESTED_ASN1_ERROR);
 272                                 goto err;
 273                                 }
 274                         if (ret == -1)
 275                                 return -1;
 276                         }
 277
 278                 /* This is the old style evil hack IMPLICIT handling:
 279                  * since the underlying code is expecting a tag and
 280                  * class other than the one present we change the
 281                  * buffer temporarily then change it back afterwards.
 282                  * This doesn't and never did work for tags > 30.
 283                  *
 284                  * Yes this is *horrible* but it is only needed for
 285                  * old style d2i which will hopefully not be around
 286                  * for much longer.
 287                  * FIXME: should copy the buffer then modify it so
 288                  * the input buffer can be const: we should *always*
 289                  * copy because the old style d2i might modify the
 290                  * buffer.
 291                  */
 292
 293                 if (tag != -1)
 294                         {
 295                         wp = *(unsigned char **)in;
 296                         imphack = *wp;
 297                         if (p == NULL)
 298                                 {
 299                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 300                                         ERR_R_NESTED_ASN1_ERROR);
 301                                 goto err;
 302                                 }
 303                         *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
 304                                                                 | it->utype);
 305                         }
 306
 307                 ptmpval = cf->asn1_d2i(pval, in, len);
 308
 309                 if (tag != -1)
 310                         *wp = imphack;
 311
 312                 if (ptmpval)
 313                         return 1;
 314
 315                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 316                 goto err;
 317
 318
 319                 case ASN1_ITYPE_CHOICE:
 320                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 321                                 goto auxerr;
 322
 323                 /* Allocate structure */
 324                 if (!*pval && !ASN1_item_ex_new(pval, it))
 325                         {
 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                 /* Get each field entry */
 420                 for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
 421                         {
 422                         const ASN1_TEMPLATE *seqtt;
 423                         ASN1_VALUE **pseqval;
 424                         seqtt = asn1_do_adb(pval, tt, 1);
 425                         if (!seqtt)
 426                                 goto err;
 427                         pseqval = asn1_get_field_ptr(pval, seqtt);
 428                         /* Have we ran out of data? */
 429                         if (!len)
 430                                 break;
 431                         q = p;
 432                         if (asn1_check_eoc(&p, len))
 433                                 {
 434                                 if (!seq_eoc)
 435                                         {
 436                                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 437                                                         ASN1_R_UNEXPECTED_EOC);
 438                                         goto err;
 439                                         }
 440                                 len -= p - q;
 441                                 seq_eoc = 0;
 442                                 q = p;
 443                                 break;
 444                                 }
 445                         /* This determines the OPTIONAL flag value. The field
 446                          * cannot be omitted if it is the last of a SEQUENCE
 447                          * and there is still data to be read. This isn't
 448                          * strictly necessary but it increases efficiency in
 449                          * some cases.
 450                          */
 451                         if (i == (it->tcount - 1))
 452                                 isopt = 0;
 453                         else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 454                         /* attempt to read in field, allowing each to be
 455                          * OPTIONAL */
 456
 457                         ret = asn1_template_ex_d2i(pseqval, &p, len,
 458                                                         seqtt, isopt, ctx);
 459                         if (!ret)
 460                                 {
 461                                 errtt = seqtt;
 462                                 goto err;
 463                                 }
 464                         else if (ret == -1)
 465                                 {
 466                                 /* OPTIONAL component absent.
 467                                  * Free and zero the field.
 468                                  */
 469                                 ASN1_template_free(pseqval, seqtt);
 470                                 continue;
 471                                 }
 472                         /* Update length */
 473                         len -= p - q;
 474                         }
 475
 476                 /* Check for EOC if expecting one */
 477                 if (seq_eoc && !asn1_check_eoc(&p, len))
 478                         {
 479                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
 480                         goto err;
 481                         }
 482                 /* Check all data read */
 483                 if (!seq_nolen && len)
 484                         {
 485                         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 486                                         ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 487                         goto err;
 488                         }
 489
 490                 /* If we get here we've got no more data in the SEQUENCE,
 491                  * however we may not have read all fields so check all
 492                  * remaining are OPTIONAL and clear any that are.
 493                  */
 494                 for (; i < it->tcount; tt++, i++)
 495                         {
 496                         const ASN1_TEMPLATE *seqtt;
 497                         seqtt = asn1_do_adb(pval, tt, 1);
 498                         if (!seqtt)
 499                                 goto err;
 500                         if (seqtt->flags & ASN1_TFLG_OPTIONAL)
 501                                 {
 502                                 ASN1_VALUE **pseqval;
 503                                 pseqval = asn1_get_field_ptr(pval, seqtt);
 504                                 ASN1_template_free(pseqval, seqtt);
 505                                 }
 506                         else
 507                                 {
 508                                 errtt = seqtt;
 509                                 ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
 510                                                         ASN1_R_FIELD_MISSING);
 511                                 goto err;
 512                                 }
 513                         }
 514                 /* Save encoding */
 515                 if (!asn1_enc_save(pval, *in, p - *in, it))
 516                         goto auxerr;
 517                 *in = p;
 518                 if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 519                                 goto auxerr;
 520                 return 1;
 521
 522                 default:
 523                 return 0;
 524                 }
 525         auxerr:
 526         ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
 527         err:
 528         ASN1_item_ex_free(pval, it);
 529         if (errtt)
 530                 ERR_add_error_data(4, "Field=", errtt->field_name,
 531                                         ", Type=", it->sname);
 532         else
 533                 ERR_add_error_data(2, "Type=", it->sname);
 534         return 0;
 535         }
 536
 537 /* Templates are handled with two separate functions.
 538  * One handles any EXPLICIT tag and the other handles the rest.
 539  */
 540
 541 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 542                                 const unsigned char **in, long inlen,
 543                                 const ASN1_TEMPLATE *tt, char opt,
 544                                                         ASN1_TLC *ctx)
 545         {
 546         int flags, aclass;
 547         int ret;
 548         long len;
 549         const unsigned char *p, *q;
 550         char exp_eoc;
 551         if (!val)
 552                 return 0;
 553         flags = tt->flags;
 554         aclass = flags & ASN1_TFLG_TAG_CLASS;
 555
 556         p = *in;
 557
 558         /* Check if EXPLICIT tag expected */
 559         if (flags & ASN1_TFLG_EXPTAG)
 560                 {
 561                 char cst;
 562                 /* Need to work out amount of data available to the inner
 563                  * content and where it starts: so read in EXPLICIT header to
 564                  * get the info.
 565                  */
 566                 ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 567                                         &p, inlen, tt->tag, aclass, opt, ctx);
 568                 q = p;
 569                 if (!ret)
 570                         {
 571                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 572                                         ERR_R_NESTED_ASN1_ERROR);
 573                         return 0;
 574                         }
 575                 else if (ret == -1)
 576                         return -1;
 577                 if (!cst)
 578                         {
 579                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 580                                         ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 581                         return 0;
 582                         }
 583                 /* We've found the field so it can't be OPTIONAL now */
 584                 ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 585                 if (!ret)
 586                         {
 587                         ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 588                                         ERR_R_NESTED_ASN1_ERROR);
 589                         return 0;
 590                         }
 591                 /* We read the field in OK so update length */
 592                 len -= p - q;
 593                 if (exp_eoc)
 594                         {
 595                         /* If NDEF we must have an EOC here */
 596                         if (!asn1_check_eoc(&p, len))
 597                                 {
 598                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 599                                                 ASN1_R_MISSING_EOC);
 600                                 goto err;
 601                                 }
 602                         }
 603                 else
 604                         {
 605                         /* Otherwise we must hit the EXPLICIT tag end or its
 606                          * an error */
 607                         if (len)
 608                                 {
 609                                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 610                                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 611                                 goto err;
 612                                 }
 613                         }
 614                 }
 615                 else
 616                         return asn1_template_noexp_d2i(val, in, inlen,
 617                                                                 tt, opt, ctx);
 618
 619         *in = p;
 620         return 1;
 621
 622         err:
 623         ASN1_template_free(val, tt);
 624         return 0;
 625         }
 626
 627 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 628                                 const unsigned char **in, long len,
 629                                 const ASN1_TEMPLATE *tt, char opt,
 630                                 ASN1_TLC *ctx)
 631         {
 632         int flags, aclass;
 633         int ret;
 634         const unsigned char *p, *q;
 635         if (!val)
 636                 return 0;
 637         flags = tt->flags;
 638         aclass = flags & ASN1_TFLG_TAG_CLASS;
 639
 640         p = *in;
 641         q = p;
 642
 643         if (flags & ASN1_TFLG_SK_MASK)
 644                 {
 645                 /* SET OF, SEQUENCE OF */
 646                 int sktag, skaclass;
 647                 char sk_eoc;
 648                 /* First work out expected inner tag value */
 649                 if (flags & ASN1_TFLG_IMPTAG)
 650                         {
 651                         sktag = tt->tag;
 652                         skaclass = aclass;
 653                         }
 654                 else
 655                         {
 656                         skaclass = V_ASN1_UNIVERSAL;
 657                         if (flags & ASN1_TFLG_SET_OF)
 658                                 sktag = V_ASN1_SET;
 659                         else
 660                                 sktag = V_ASN1_SEQUENCE;
 661                         }
 662                 /* Get the tag */
 663                 ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 664                                         &p, len, sktag, skaclass, opt, ctx);
 665                 if (!ret)
 666                         {
 667                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 668                                                 ERR_R_NESTED_ASN1_ERROR);
 669                         return 0;
 670                         }
 671                 else if (ret == -1)
 672                         return -1;
 673                 if (!*val)
 674                         *val = (ASN1_VALUE *)sk_new_null();
 675                 else
 676                         {
 677                         /* We've got a valid STACK: free up any items present */
 678                         STACK_OF(ASN1_VALUE) *sktmp
 679                             = (STACK_OF(ASN1_VALUE) *)*val;
 680                         ASN1_VALUE *vtmp;
 681                         while(sk_ASN1_VALUE_num(sktmp) > 0)
 682                                 {
 683                                 vtmp = sk_ASN1_VALUE_pop(sktmp);
 684                                 ASN1_item_ex_free(&vtmp,
 685                                                 ASN1_ITEM_ptr(tt->item));
 686                                 }
 687                         }
 688
 689                 if (!*val)
 690                         {
 691                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 692                                                 ERR_R_MALLOC_FAILURE);
 693                         goto err;
 694                         }
 695
 696                 /* Read as many items as we can */
 697                 while(len > 0)
 698                         {
 699                         ASN1_VALUE *skfield;
 700                         q = p;
 701                         /* See if EOC found */
 702                         if (asn1_check_eoc(&p, len))
 703                                 {
 704                                 if (!sk_eoc)
 705                                         {
 706                                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 707                                                         ASN1_R_UNEXPECTED_EOC);
 708                                         goto err;
 709                                         }
 710                                 len -= p - q;
 711                                 sk_eoc = 0;
 712                                 break;
 713                                 }
 714                         skfield = NULL;
 715                         if (!ASN1_item_ex_d2i(&skfield, &p, len,
 716                                                 ASN1_ITEM_ptr(tt->item),
 717                                                 -1, 0, 0, ctx))
 718                                 {
 719                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 720                                         ERR_R_NESTED_ASN1_ERROR);
 721                                 goto err;
 722                                 }
 723                         len -= p - q;
 724                         if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
 725                                                 skfield))
 726                                 {
 727                                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 728                                                 ERR_R_MALLOC_FAILURE);
 729                                 goto err;
 730                                 }
 731                         }
 732                 if (sk_eoc)
 733                         {
 734                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 735                         goto err;
 736                         }
 737                 }
 738         else if (flags & ASN1_TFLG_IMPTAG)
 739                 {
 740                 /* IMPLICIT tagging */
 741                 ret = ASN1_item_ex_d2i(val, &p, len,
 742                         ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
 743                 if (!ret)
 744                         {
 745                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 746                                                 ERR_R_NESTED_ASN1_ERROR);
 747                         goto err;
 748                         }
 749                 else if (ret == -1)
 750                         return -1;
 751                 }
 752         else
 753                 {
 754                 /* Nothing special */
 755                 ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 756                                                         -1, 0, opt, ctx);
 757                 if (!ret)
 758                         {
 759                         ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 760                                         ERR_R_NESTED_ASN1_ERROR);
 761                         goto err;
 762                         }
 763                 else if (ret == -1)
 764                         return -1;
 765                 }
 766
 767         *in = p;
 768         return 1;
 769
 770         err:
 771         ASN1_template_free(val, tt);
 772         return 0;
 773         }
 774
 775 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 776                                 const unsigned char **in, long inlen,
 777                                 const ASN1_ITEM *it,
 778                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
 779         {
 780         int ret = 0, utype;
 781         long plen;
 782         char cst, inf, free_cont = 0;
 783         const unsigned char *p;
 784         BUF_MEM buf;
 785         const unsigned char *cont = NULL;
 786         long len;
 787         if (!pval)
 788                 {
 789                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 790                 return 0; /* Should never happen */
 791                 }
 792
 793         if (it->itype == ASN1_ITYPE_MSTRING)
 794                 {
 795                 utype = tag;
 796                 tag = -1;
 797                 }
 798         else
 799                 utype = it->utype;
 800
 801         if (utype == V_ASN1_ANY)
 802                 {
 803                 /* If type is ANY need to figure out type from tag */
 804                 unsigned char oclass;
 805                 if (tag >= 0)
 806                         {
 807                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 808                                         ASN1_R_ILLEGAL_TAGGED_ANY);
 809                         return 0;
 810                         }
 811                 if (opt)
 812                         {
 813                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 814                                         ASN1_R_ILLEGAL_OPTIONAL_ANY);
 815                         return 0;
 816                         }
 817                 p = *in;
 818                 ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 819                                         &p, inlen, -1, 0, 0, ctx);
 820                 if (!ret)
 821                         {
 822                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 823                                         ERR_R_NESTED_ASN1_ERROR);
 824                         return 0;
 825                         }
 826                 if (oclass != V_ASN1_UNIVERSAL)
 827                         utype = V_ASN1_OTHER;
 828                 }
 829         if (tag == -1)
 830                 {
 831                 tag = utype;
 832                 aclass = V_ASN1_UNIVERSAL;
 833                 }
 834         p = *in;
 835         /* Check header */
 836         ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 837                                 &p, inlen, tag, aclass, opt, ctx);
 838         if (!ret)
 839                 {
 840                 ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 841                 return 0;
 842                 }
 843         else if (ret == -1)
 844                 return -1;
 845         ret = 0;
 846         /* SEQUENCE, SET and "OTHER" are left in encoded form */
 847         if ((utype == V_ASN1_SEQUENCE)
 848                 || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
 849                 {
 850                 /* Clear context cache for type OTHER because the auto clear
 851                  * when we have a exact match wont work
 852                  */
 853                 if (utype == V_ASN1_OTHER)
 854                         {
 855                         asn1_tlc_clear(ctx);
 856                         }
 857                 /* SEQUENCE and SET must be constructed */
 858                 else if (!cst)
 859                         {
 860                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 861                                 ASN1_R_TYPE_NOT_CONSTRUCTED);
 862                         return 0;
 863                         }
 864
 865                 cont = *in;
 866                 /* If indefinite length constructed find the real end */
 867                 if (inf)
 868                         {
 869                         if (!asn1_find_end(&p, plen, inf))
 870                                  goto err;
 871                         len = p - cont;
 872                         }
 873                 else
 874                         {
 875                         len = p - cont + plen;
 876                         p += plen;
 877                         buf.data = NULL;
 878                         }
 879                 }
 880         else if (cst)
 881                 {
 882                 if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
 883                         || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
 884                         || utype == V_ASN1_ENUMERATED)
 885                         {
 886                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 887                                 ASN1_R_TYPE_NOT_PRIMITIVE);
 888                         return 0;
 889                         }
 890                 buf.length = 0;
 891                 buf.max = 0;
 892                 buf.data = NULL;
 893                 /* Should really check the internal tags are correct but
 894                  * some things may get this wrong. The relevant specs
 895                  * say that constructed string types should be OCTET STRINGs
 896                  * internally irrespective of the type. So instead just check
 897                  * for UNIVERSAL class and ignore the tag.
 898                  */
 899                 if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
 900                         {
 901                         free_cont = 1;
 902                         goto err;
 903                         }
 904                 len = buf.length;
 905                 /* Append a final null to string */
 906                 if (!BUF_MEM_grow_clean(&buf, len + 1))
 907                         {
 908                         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 909                                                 ERR_R_MALLOC_FAILURE);
 910                         return 0;
 911                         }
 912                 buf.data[len] = 0;
 913                 cont = (const unsigned char *)buf.data;
 914                 free_cont = 1;
 915                 }
 916         else
 917                 {
 918                 cont = p;
 919                 len = plen;
 920                 p += plen;
 921                 }
 922
 923         /* We now have content length and type: translate into a structure */
 924         if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 925                 goto err;
 926
 927         *in = p;
 928         ret = 1;
 929         err:
 930         if (free_cont && buf.data) OPENSSL_free(buf.data);
 931         return ret;
 932         }
 933
 934 /* Translate ASN1 content octets into a structure */
 935
 936 int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 937                         int utype, char *free_cont, const ASN1_ITEM *it)
 938         {
 939         ASN1_VALUE **opval = NULL;
 940         ASN1_STRING *stmp;
 941         ASN1_TYPE *typ = NULL;
 942         int ret = 0;
 943         const ASN1_PRIMITIVE_FUNCS *pf;
 944         ASN1_INTEGER **tint;
 945         pf = it->funcs;
 946
 947         if (pf && pf->prim_c2i)
 948                 return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 949         /* If ANY type clear type and set pointer to internal value */
 950         if (it->utype == V_ASN1_ANY)
 951                 {
 952                 if (!*pval)
 953                         {
 954                         typ = ASN1_TYPE_new();
 955                         if (typ == NULL)
 956                                 goto err;
 957                         *pval = (ASN1_VALUE *)typ;
 958                         }
 959                 else
 960                         typ = (ASN1_TYPE *)*pval;
 961
 962                 if (utype != typ->type)
 963                         ASN1_TYPE_set(typ, utype, NULL);
 964                 opval = pval;
 965                 pval = &typ->value.asn1_value;
 966                 }
 967         switch(utype)
 968                 {
 969                 case V_ASN1_OBJECT:
 970                 if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 971                         goto err;
 972                 break;
 973
 974                 case V_ASN1_NULL:
 975                 if (len)
 976                         {
 977                         ASN1err(ASN1_F_ASN1_EX_C2I,
 978                                                 ASN1_R_NULL_IS_WRONG_LENGTH);
 979                         goto err;
 980                         }
 981                 *pval = (ASN1_VALUE *)1;
 982                 break;
 983
 984                 case V_ASN1_BOOLEAN:
 985                 if (len != 1)
 986                         {
 987                         ASN1err(ASN1_F_ASN1_EX_C2I,
 988                                                 ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 989                         goto err;
 990                         }
 991                 else
 992                         {
 993                         ASN1_BOOLEAN *tbool;
 994                         tbool = (ASN1_BOOLEAN *)pval;
 995                         *tbool = *cont;
 996                         }
 997                 break;
 998
 999                 case V_ASN1_BIT_STRING:
1000                 if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
1001                         goto err;
1002                 break;
1003
1004                 case V_ASN1_INTEGER:
1005                 case V_ASN1_NEG_INTEGER:
1006                 case V_ASN1_ENUMERATED:
1007                 case V_ASN1_NEG_ENUMERATED:
1008                 tint = (ASN1_INTEGER **)pval;
1009                 if (!c2i_ASN1_INTEGER(tint, &cont, len))
1010                         goto err;
1011                 /* Fixup type to match the expected form */
1012                 (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
1013                 break;
1014
1015                 case V_ASN1_OCTET_STRING:
1016                 case V_ASN1_NUMERICSTRING:
1017                 case V_ASN1_PRINTABLESTRING:
1018                 case V_ASN1_T61STRING:
1019                 case V_ASN1_VIDEOTEXSTRING:
1020                 case V_ASN1_IA5STRING:
1021                 case V_ASN1_UTCTIME:
1022                 case V_ASN1_GENERALIZEDTIME:
1023                 case V_ASN1_GRAPHICSTRING:
1024                 case V_ASN1_VISIBLESTRING:
1025                 case V_ASN1_GENERALSTRING:
1026                 case V_ASN1_UNIVERSALSTRING:
1027                 case V_ASN1_BMPSTRING:
1028                 case V_ASN1_UTF8STRING:
1029                 case V_ASN1_OTHER:
1030                 case V_ASN1_SET:
1031                 case V_ASN1_SEQUENCE:
1032                 default:
1033                 if (utype == V_ASN1_BMPSTRING && (len & 1))
1034                         {
1035                         ASN1err(ASN1_F_ASN1_EX_C2I,
1036                                         ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
1037                         goto err;
1038                         }
1039                 if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
1040                         {
1041                         ASN1err(ASN1_F_ASN1_EX_C2I,
1042                                         ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
1043                         goto err;
1044                         }
1045                 /* All based on ASN1_STRING and handled the same */
1046                 if (!*pval)
1047                         {
1048                         stmp = ASN1_STRING_type_new(utype);
1049                         if (!stmp)
1050                                 {
1051                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1052                                                         ERR_R_MALLOC_FAILURE);
1053                                 goto err;
1054                                 }
1055                         *pval = (ASN1_VALUE *)stmp;
1056                         }
1057                 else
1058                         {
1059                         stmp = (ASN1_STRING *)*pval;
1060                         stmp->type = utype;
1061                         }
1062                 /* If we've already allocated a buffer use it */
1063                 if (*free_cont)
1064                         {
1065                         if (stmp->data)
1066                                 OPENSSL_free(stmp->data);
1067                         stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
1068                         stmp->length = len;
1069                         *free_cont = 0;
1070                         }
1071                 else
1072                         {
1073                         if (!ASN1_STRING_set(stmp, cont, len))
1074                                 {
1075                                 ASN1err(ASN1_F_ASN1_EX_C2I,
1076                                                         ERR_R_MALLOC_FAILURE);
1077                                 ASN1_STRING_free(stmp);
1078                                 *pval = NULL;
1079                                 goto err;
1080                                 }
1081                         }
1082                 break;
1083                 }
1084         /* If ASN1_ANY and NULL type fix up value */
1085         if (typ && (utype == V_ASN1_NULL))
1086                  typ->value.ptr = NULL;
1087
1088         ret = 1;
1089         err:
1090         if (!ret)
1091                 {
1092                 ASN1_TYPE_free(typ);
1093                 if (opval)
1094                         *opval = NULL;
1095                 }
1096         return ret;
1097         }
1098
1099
1100 /* This function finds the end of an ASN1 structure when passed its maximum
1101  * length, whether it is indefinite length and a pointer to the content.
1102  * This is more efficient than calling asn1_collect because it does not
1103  * recurse on each indefinite length header.
1104  */
1105
1106 static int asn1_find_end(const unsigned char **in, long len, char inf)
1107         {
1108         int expected_eoc;
1109         long plen;
1110         const unsigned char *p = *in, *q;
1111         /* If not indefinite length constructed just add length */
1112         if (inf == 0)
1113                 {
1114                 *in += len;
1115                 return 1;
1116                 }
1117         expected_eoc = 1;
1118         /* Indefinite length constructed form. Find the end when enough EOCs
1119          * are found. If more indefinite length constructed headers
1120          * are encountered increment the expected eoc count otherwise just
1121          * skip to the end of the data.
1122          */
1123         while (len > 0)
1124                 {
1125                 if(asn1_check_eoc(&p, len))
1126                         {
1127                         expected_eoc--;
1128                         if (expected_eoc == 0)
1129                                 break;
1130                         len -= 2;
1131                         continue;
1132                         }
1133                 q = p;
1134                 /* Just read in a header: only care about the length */
1135                 if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1136                                 -1, 0, 0, NULL))
1137                         {
1138                         ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1139                         return 0;
1140                         }
1141                 if (inf)
1142                         expected_eoc++;
1143                 else
1144                         p += plen;
1145                 len -= p - q;
1146                 }
1147         if (expected_eoc)
1148                 {
1149                 ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1150                 return 0;
1151                 }
1152         *in = p;
1153         return 1;
1154         }
1155 /* This function collects the asn1 data from a constructred string
1156  * type into a buffer. The values of 'in' and 'len' should refer
1157  * to the contents of the constructed type and 'inf' should be set
1158  * if it is indefinite length.
1159  */
1160
1161 #ifndef ASN1_MAX_STRING_NEST
1162 /* This determines how many levels of recursion are permitted in ASN1
1163  * string types. If it is not limited stack overflows can occur. If set
1164  * to zero no recursion is allowed at all. Although zero should be adequate
1165  * examples exist that require a value of 1. So 5 should be more than enough.
1166  */
1167 #define ASN1_MAX_STRING_NEST 5
1168 #endif
1169
1170
1171 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1172                         char inf, int tag, int aclass, int depth)
1173         {
1174         const unsigned char *p, *q;
1175         long plen;
1176         char cst, ininf;
1177         p = *in;
1178         inf &= 1;
1179         /* If no buffer and not indefinite length constructed just pass over
1180          * the encoded data */
1181         if (!buf && !inf)
1182                 {
1183                 *in += len;
1184                 return 1;
1185                 }
1186         while(len > 0)
1187                 {
1188                 q = p;
1189                 /* Check for EOC */
1190                 if (asn1_check_eoc(&p, len))
1191                         {
1192                         /* EOC is illegal outside indefinite length
1193                          * constructed form */
1194                         if (!inf)
1195                                 {
1196                                 ASN1err(ASN1_F_ASN1_COLLECT,
1197                                         ASN1_R_UNEXPECTED_EOC);
1198                                 return 0;
1199                                 }
1200                         inf = 0;
1201                         break;
1202                         }
1203
1204                 if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1205                                         len, tag, aclass, 0, NULL))
1206                         {
1207                         ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1208                         return 0;
1209                         }
1210
1211                 /* If indefinite length constructed update max length */
1212                 if (cst)
1213                         {
1214                         if (depth >= ASN1_MAX_STRING_NEST)
1215                                 {
1216                                 ASN1err(ASN1_F_ASN1_COLLECT,
1217                                         ASN1_R_NESTED_ASN1_STRING);
1218                                 return 0;
1219                                 }
1220                         if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
1221                                                 depth + 1))
1222                                 return 0;
1223                         }
1224                 else if (plen && !collect_data(buf, &p, plen))
1225                         return 0;
1226                 len -= p - q;
1227                 }
1228         if (inf)
1229                 {
1230                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1231                 return 0;
1232                 }
1233         *in = p;
1234         return 1;
1235         }
1236
1237 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1238         {
1239         int len;
1240         if (buf)
1241                 {
1242                 len = buf->length;
1243                 if (!BUF_MEM_grow_clean(buf, len + plen))
1244                         {
1245                         ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1246                         return 0;
1247                         }
1248                 memcpy(buf->data + len, *p, plen);
1249                 }
1250         *p += plen;
1251         return 1;
1252         }
1253
1254 /* Check for ASN1 EOC and swallow it if found */
1255
1256 static int asn1_check_eoc(const unsigned char **in, long len)
1257         {
1258         const unsigned char *p;
1259         if (len < 2) return 0;
1260         p = *in;
1261         if (!p[0] && !p[1])
1262                 {
1263                 *in += 2;
1264                 return 1;
1265                 }
1266         return 0;
1267         }
1268
1269 /* Check an ASN1 tag and length: a bit like ASN1_get_object
1270  * but it sets the length for indefinite length constructed
1271  * form, we don't know the exact length but we can set an
1272  * upper bound to the amount of data available minus the
1273  * header length just read.
1274  */
1275
1276 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1277                                 char *inf, char *cst,
1278                                 const unsigned char **in, long len,
1279                                 int exptag, int expclass, char opt,
1280                                 ASN1_TLC *ctx)
1281         {
1282         int i;
1283         int ptag, pclass;
1284         long plen;
1285         const unsigned char *p, *q;
1286         p = *in;
1287         q = p;
1288
1289         if (ctx && ctx->valid)
1290                 {
1291                 i = ctx->ret;
1292                 plen = ctx->plen;
1293                 pclass = ctx->pclass;
1294                 ptag = ctx->ptag;
1295                 p += ctx->hdrlen;
1296                 }
1297         else
1298                 {
1299                 i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1300                 if (ctx)
1301                         {
1302                         ctx->ret = i;
1303                         ctx->plen = plen;
1304                         ctx->pclass = pclass;
1305                         ctx->ptag = ptag;
1306                         ctx->hdrlen = p - q;
1307                         ctx->valid = 1;
1308                         /* If definite length, and no error, length +
1309                          * header can't exceed total amount of data available.
1310                          */
1311                         if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
1312                                 {
1313                                 ASN1err(ASN1_F_ASN1_CHECK_TLEN,
1314                                                         ASN1_R_TOO_LONG);
1315                                 asn1_tlc_clear(ctx);
1316                                 return 0;
1317                                 }
1318                         }
1319                 }
1320
1321         if (i & 0x80)
1322                 {
1323                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1324                 asn1_tlc_clear(ctx);
1325                 return 0;
1326                 }
1327         if (exptag >= 0)
1328                 {
1329                 if ((exptag != ptag) || (expclass != pclass))
1330                         {
1331                         /* If type is OPTIONAL, not an error:
1332                          * indicate missing type.
1333                          */
1334                         if (opt) return -1;
1335                         asn1_tlc_clear(ctx);
1336                         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1337                         return 0;
1338                         }
1339                 /* We have a tag and class match:
1340                  * assume we are going to do something with it */
1341                 asn1_tlc_clear(ctx);
1342                 }
1343
1344         if (i & 1)
1345                 plen = len - (p - q);
1346
1347         if (inf)
1348                 *inf = i & 1;
1349
1350         if (cst)
1351                 *cst = i & V_ASN1_CONSTRUCTED;
1352
1353         if (olen)
1354                 *olen = plen;
1355
1356         if (oclass)
1357                 *oclass = pclass;
1358
1359         if (otag)
1360                 *otag = ptag;
1361
1362         *in = p;
1363         return 1;
1364         }