crypto/asn1/tasn_dec.c

   1 /*
   2  * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stddef.h>
  11 #include <string.h>
  12 #include <openssl/asn1.h>
  13 #include <openssl/asn1t.h>
  14 #include <openssl/objects.h>
  15 #include <openssl/buffer.h>
  16 #include <openssl/err.h>
  17 #include "asn1_locl.h"
  18
  19 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
  20                                long len, const ASN1_ITEM *it,
  21                                int tag, int aclass, char opt, ASN1_TLC *ctx);
  22
  23 static int asn1_check_eoc(const unsigned char **in, long len);
  24 static int asn1_find_end(const unsigned char **in, long len, char inf);
  25
  26 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
  27                         char inf, int tag, int aclass, int depth);
  28
  29 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  30
  31 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  32                            char *inf, char *cst,
  33                            const unsigned char **in, long len,
  34                            int exptag, int expclass, char opt, ASN1_TLC *ctx);
  35
  36 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
  37                                 const unsigned char **in, long len,
  38                                 const ASN1_TEMPLATE *tt, char opt,
  39                                 ASN1_TLC *ctx);
  40 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
  41                                    const unsigned char **in, long len,
  42                                    const ASN1_TEMPLATE *tt, char opt,
  43                                    ASN1_TLC *ctx);
  44 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
  45                                  const unsigned char **in, long len,
  46                                  const ASN1_ITEM *it,
  47                                  int tag, int aclass, char opt,
  48                                  ASN1_TLC *ctx);
  49 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
  50                        int utype, char *free_cont, const ASN1_ITEM *it);
  51
  52 /* Table to convert tags to bit values, used for MSTRING type */
  53 static const unsigned long tag2bit[32] = {
  54     /* tags  0 -  3 */
  55     0, 0, 0, B_ASN1_BIT_STRING,
  56     /* tags  4- 7 */
  57     B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
  58     /* tags  8-11 */
  59     B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
  60     /* tags 12-15 */
  61     B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
  62     /* tags 16-19 */
  63     B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
  64     /* tags 20-22 */
  65     B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
  66     /* tags 23-24 */
  67     B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
  68     /* tags 25-27 */
  69     B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
  70     /* tags 28-31 */
  71     B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
  72 };
  73
  74 unsigned long ASN1_tag2bit(int tag)
  75 {
  76     if ((tag < 0) || (tag > 30))
  77         return 0;
  78     return tag2bit[tag];
  79 }
  80
  81 /* Macro to initialize and invalidate the cache */
  82
  83 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
  84 /* Version to avoid compiler warning about 'c' always non-NULL */
  85 #define asn1_tlc_clear_nc(c)    (c)->valid = 0
  86
  87 /*
  88  * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
  89  * function. 'in' points to a buffer to read the data from, in future we
  90  * will have more advanced versions that can input data a piece at a time and
  91  * this will simply be a special case.
  92  */
  93
  94 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
  95                           const unsigned char **in, long len,
  96                           const ASN1_ITEM *it)
  97 {
  98     ASN1_TLC c;
  99     ASN1_VALUE *ptmpval = NULL;
 100     if (!pval)
 101         pval = &ptmpval;
 102     asn1_tlc_clear_nc(&c);
 103     if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 104         return *pval;
 105     return NULL;
 106 }
 107
 108 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 109                      const ASN1_ITEM *it,
 110                      int tag, int aclass, char opt, ASN1_TLC *ctx)
 111 {
 112     int rv;
 113     rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx);
 114     if (rv <= 0)
 115         ASN1_item_ex_free(pval, it);
 116     return rv;
 117 }
 118
 119 /*
 120  * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
 121  * tag mismatch return -1 to handle OPTIONAL
 122  */
 123
 124 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
 125                                long len, const ASN1_ITEM *it,
 126                                int tag, int aclass, char opt, ASN1_TLC *ctx)
 127 {
 128     const ASN1_TEMPLATE *tt, *errtt = NULL;
 129     const ASN1_EXTERN_FUNCS *ef;
 130     const ASN1_AUX *aux = it->funcs;
 131     ASN1_aux_cb *asn1_cb;
 132     const unsigned char *p = NULL, *q;
 133     unsigned char oclass;
 134     char seq_eoc, seq_nolen, cst, isopt;
 135     long tmplen;
 136     int i;
 137     int otag;
 138     int ret = 0;
 139     ASN1_VALUE **pchptr;
 140     if (!pval)
 141         return 0;
 142     if (aux && aux->asn1_cb)
 143         asn1_cb = aux->asn1_cb;
 144     else
 145         asn1_cb = 0;
 146
 147     switch (it->itype) {
 148     case ASN1_ITYPE_PRIMITIVE:
 149         if (it->templates) {
 150             /*
 151              * tagging or OPTIONAL is currently illegal on an item template
 152              * because the flags can't get passed down. In practice this
 153              * isn't a problem: we include the relevant flags from the item
 154              * template in the template itself.
 155              */
 156             if ((tag != -1) || opt) {
 157                 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I,
 158                         ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 159                 goto err;
 160             }
 161             return asn1_template_ex_d2i(pval, in, len,
 162                                         it->templates, opt, ctx);
 163         }
 164         return asn1_d2i_ex_primitive(pval, in, len, it,
 165                                      tag, aclass, opt, ctx);
 166
 167     case ASN1_ITYPE_MSTRING:
 168         p = *in;
 169         /* Just read in tag and class */
 170         ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 171                               &p, len, -1, 0, 1, ctx);
 172         if (!ret) {
 173             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 174             goto err;
 175         }
 176
 177         /* Must be UNIVERSAL class */
 178         if (oclass != V_ASN1_UNIVERSAL) {
 179             /* If OPTIONAL, assume this is OK */
 180             if (opt)
 181                 return -1;
 182             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
 183             goto err;
 184         }
 185         /* Check tag matches bit map */
 186         if (!(ASN1_tag2bit(otag) & it->utype)) {
 187             /* If OPTIONAL, assume this is OK */
 188             if (opt)
 189                 return -1;
 190             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG);
 191             goto err;
 192         }
 193         return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
 194
 195     case ASN1_ITYPE_EXTERN:
 196         /* Use new style d2i */
 197         ef = it->funcs;
 198         return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
 199
 200     case ASN1_ITYPE_CHOICE:
 201         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 202             goto auxerr;
 203         if (*pval) {
 204             /* Free up and zero CHOICE value if initialised */
 205             i = asn1_get_choice_selector(pval, it);
 206             if ((i >= 0) && (i < it->tcount)) {
 207                 tt = it->templates + i;
 208                 pchptr = asn1_get_field_ptr(pval, tt);
 209                 asn1_template_free(pchptr, tt);
 210                 asn1_set_choice_selector(pval, -1, it);
 211             }
 212         } else if (!ASN1_item_ex_new(pval, it)) {
 213             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 214             goto err;
 215         }
 216         /* CHOICE type, try each possibility in turn */
 217         p = *in;
 218         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 219             pchptr = asn1_get_field_ptr(pval, tt);
 220             /*
 221              * We mark field as OPTIONAL so its absence can be recognised.
 222              */
 223             ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
 224             /* If field not present, try the next one */
 225             if (ret == -1)
 226                 continue;
 227             /*
 228              * Set the choice selector here to ensure that the value is
 229              * correctly freed upon error. It may be partially initialized
 230              * even if parsing failed.
 231              */
 232             asn1_set_choice_selector(pval, i, it);
 233             /* If positive return, read OK, break loop */
 234             if (ret > 0)
 235                 break;
 236             /* Otherwise must be an ASN1 parsing error */
 237             errtt = tt;
 238             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 239             goto err;
 240         }
 241
 242         /* Did we fall off the end without reading anything? */
 243         if (i == it->tcount) {
 244             /* If OPTIONAL, this is OK */
 245             if (opt) {
 246                 /* Free and zero it */
 247                 ASN1_item_ex_free(pval, it);
 248                 return -1;
 249             }
 250             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
 251             goto err;
 252         }
 253
 254         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 255             goto auxerr;
 256         *in = p;
 257         return 1;
 258
 259     case ASN1_ITYPE_NDEF_SEQUENCE:
 260     case ASN1_ITYPE_SEQUENCE:
 261         p = *in;
 262         tmplen = len;
 263
 264         /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 265         if (tag == -1) {
 266             tag = V_ASN1_SEQUENCE;
 267             aclass = V_ASN1_UNIVERSAL;
 268         }
 269         /* Get SEQUENCE length and update len, p */
 270         ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 271                               &p, len, tag, aclass, opt, ctx);
 272         if (!ret) {
 273             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 274             goto err;
 275         } else if (ret == -1)
 276             return -1;
 277         if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
 278             len = tmplen - (p - *in);
 279             seq_nolen = 1;
 280         }
 281         /* If indefinite we don't do a length check */
 282         else
 283             seq_nolen = seq_eoc;
 284         if (!cst) {
 285             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 286             goto err;
 287         }
 288
 289         if (!*pval && !ASN1_item_ex_new(pval, it)) {
 290             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 291             goto err;
 292         }
 293
 294         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 295             goto auxerr;
 296
 297         /* Free up and zero any ADB found */
 298         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 299             if (tt->flags & ASN1_TFLG_ADB_MASK) {
 300                 const ASN1_TEMPLATE *seqtt;
 301                 ASN1_VALUE **pseqval;
 302                 seqtt = asn1_do_adb(pval, tt, 1);
 303                 pseqval = asn1_get_field_ptr(pval, seqtt);
 304                 asn1_template_free(pseqval, seqtt);
 305             }
 306         }
 307
 308         /* Get each field entry */
 309         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 310             const ASN1_TEMPLATE *seqtt;
 311             ASN1_VALUE **pseqval;
 312             seqtt = asn1_do_adb(pval, tt, 1);
 313             if (!seqtt)
 314                 goto err;
 315             pseqval = asn1_get_field_ptr(pval, seqtt);
 316             /* Have we ran out of data? */
 317             if (!len)
 318                 break;
 319             q = p;
 320             if (asn1_check_eoc(&p, len)) {
 321                 if (!seq_eoc) {
 322                     ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC);
 323                     goto err;
 324                 }
 325                 len -= p - q;
 326                 seq_eoc = 0;
 327                 q = p;
 328                 break;
 329             }
 330             /*
 331              * This determines the OPTIONAL flag value. The field cannot be
 332              * omitted if it is the last of a SEQUENCE and there is still
 333              * data to be read. This isn't strictly necessary but it
 334              * increases efficiency in some cases.
 335              */
 336             if (i == (it->tcount - 1))
 337                 isopt = 0;
 338             else
 339                 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 340             /*
 341              * attempt to read in field, allowing each to be OPTIONAL
 342              */
 343
 344             ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx);
 345             if (!ret) {
 346                 errtt = seqtt;
 347                 goto err;
 348             } else if (ret == -1) {
 349                 /*
 350                  * OPTIONAL component absent. Free and zero the field.
 351                  */
 352                 asn1_template_free(pseqval, seqtt);
 353                 continue;
 354             }
 355             /* Update length */
 356             len -= p - q;
 357         }
 358
 359         /* Check for EOC if expecting one */
 360         if (seq_eoc && !asn1_check_eoc(&p, len)) {
 361             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC);
 362             goto err;
 363         }
 364         /* Check all data read */
 365         if (!seq_nolen && len) {
 366             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 367             goto err;
 368         }
 369
 370         /*
 371          * If we get here we've got no more data in the SEQUENCE, however we
 372          * may not have read all fields so check all remaining are OPTIONAL
 373          * and clear any that are.
 374          */
 375         for (; i < it->tcount; tt++, i++) {
 376             const ASN1_TEMPLATE *seqtt;
 377             seqtt = asn1_do_adb(pval, tt, 1);
 378             if (!seqtt)
 379                 goto err;
 380             if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
 381                 ASN1_VALUE **pseqval;
 382                 pseqval = asn1_get_field_ptr(pval, seqtt);
 383                 asn1_template_free(pseqval, seqtt);
 384             } else {
 385                 errtt = seqtt;
 386                 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING);
 387                 goto err;
 388             }
 389         }
 390         /* Save encoding */
 391         if (!asn1_enc_save(pval, *in, p - *in, it))
 392             goto auxerr;
 393         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 394             goto auxerr;
 395         *in = p;
 396         return 1;
 397
 398     default:
 399         return 0;
 400     }
 401  auxerr:
 402     ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR);
 403  err:
 404     if (errtt)
 405         ERR_add_error_data(4, "Field=", errtt->field_name,
 406                            ", Type=", it->sname);
 407     else
 408         ERR_add_error_data(2, "Type=", it->sname);
 409     return 0;
 410 }
 411
 412 /*
 413  * Templates are handled with two separate functions. One handles any
 414  * EXPLICIT tag and the other handles the rest.
 415  */
 416
 417 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 418                                 const unsigned char **in, long inlen,
 419                                 const ASN1_TEMPLATE *tt, char opt,
 420                                 ASN1_TLC *ctx)
 421 {
 422     int flags, aclass;
 423     int ret;
 424     long len;
 425     const unsigned char *p, *q;
 426     char exp_eoc;
 427     if (!val)
 428         return 0;
 429     flags = tt->flags;
 430     aclass = flags & ASN1_TFLG_TAG_CLASS;
 431
 432     p = *in;
 433
 434     /* Check if EXPLICIT tag expected */
 435     if (flags & ASN1_TFLG_EXPTAG) {
 436         char cst;
 437         /*
 438          * Need to work out amount of data available to the inner content and
 439          * where it starts: so read in EXPLICIT header to get the info.
 440          */
 441         ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 442                               &p, inlen, tt->tag, aclass, opt, ctx);
 443         q = p;
 444         if (!ret) {
 445             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 446             return 0;
 447         } else if (ret == -1)
 448             return -1;
 449         if (!cst) {
 450             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 451                     ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 452             return 0;
 453         }
 454         /* We've found the field so it can't be OPTIONAL now */
 455         ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
 456         if (!ret) {
 457             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 458             return 0;
 459         }
 460         /* We read the field in OK so update length */
 461         len -= p - q;
 462         if (exp_eoc) {
 463             /* If NDEF we must have an EOC here */
 464             if (!asn1_check_eoc(&p, len)) {
 465                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
 466                 goto err;
 467             }
 468         } else {
 469             /*
 470              * Otherwise we must hit the EXPLICIT tag end or its an error
 471              */
 472             if (len) {
 473                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 474                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 475                 goto err;
 476             }
 477         }
 478     } else
 479         return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx);
 480
 481     *in = p;
 482     return 1;
 483
 484  err:
 485     return 0;
 486 }
 487
 488 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 489                                    const unsigned char **in, long len,
 490                                    const ASN1_TEMPLATE *tt, char opt,
 491                                    ASN1_TLC *ctx)
 492 {
 493     int flags, aclass;
 494     int ret;
 495     ASN1_VALUE *tval;
 496     const unsigned char *p, *q;
 497     if (!val)
 498         return 0;
 499     flags = tt->flags;
 500     aclass = flags & ASN1_TFLG_TAG_CLASS;
 501
 502     p = *in;
 503     q = p;
 504
 505     /*
 506      * If field is embedded then val needs fixing so it is a pointer to
 507      * a pointer to a field.
 508      */
 509     if (tt->flags & ASN1_TFLG_EMBED) {
 510         tval = (ASN1_VALUE *)val;
 511         val = &tval;
 512     }
 513
 514     if (flags & ASN1_TFLG_SK_MASK) {
 515         /* SET OF, SEQUENCE OF */
 516         int sktag, skaclass;
 517         char sk_eoc;
 518         /* First work out expected inner tag value */
 519         if (flags & ASN1_TFLG_IMPTAG) {
 520             sktag = tt->tag;
 521             skaclass = aclass;
 522         } else {
 523             skaclass = V_ASN1_UNIVERSAL;
 524             if (flags & ASN1_TFLG_SET_OF)
 525                 sktag = V_ASN1_SET;
 526             else
 527                 sktag = V_ASN1_SEQUENCE;
 528         }
 529         /* Get the tag */
 530         ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 531                               &p, len, sktag, skaclass, opt, ctx);
 532         if (!ret) {
 533             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 534             return 0;
 535         } else if (ret == -1)
 536             return -1;
 537         if (!*val)
 538             *val = (ASN1_VALUE *)OPENSSL_sk_new_null();
 539         else {
 540             /*
 541              * We've got a valid STACK: free up any items present
 542              */
 543             STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
 544             ASN1_VALUE *vtmp;
 545             while (sk_ASN1_VALUE_num(sktmp) > 0) {
 546                 vtmp = sk_ASN1_VALUE_pop(sktmp);
 547                 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
 548             }
 549         }
 550
 551         if (!*val) {
 552             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
 553             goto err;
 554         }
 555
 556         /* Read as many items as we can */
 557         while (len > 0) {
 558             ASN1_VALUE *skfield;
 559             q = p;
 560             /* See if EOC found */
 561             if (asn1_check_eoc(&p, len)) {
 562                 if (!sk_eoc) {
 563                     ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 564                             ASN1_R_UNEXPECTED_EOC);
 565                     goto err;
 566                 }
 567                 len -= p - q;
 568                 sk_eoc = 0;
 569                 break;
 570             }
 571             skfield = NULL;
 572             if (!asn1_item_embed_d2i(&skfield, &p, len,
 573                                      ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) {
 574                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 575                         ERR_R_NESTED_ASN1_ERROR);
 576                 /* |skfield| may be partially allocated despite failure. */
 577                 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
 578                 goto err;
 579             }
 580             len -= p - q;
 581             if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
 582                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
 583                 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
 584                 goto err;
 585             }
 586         }
 587         if (sk_eoc) {
 588             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 589             goto err;
 590         }
 591     } else if (flags & ASN1_TFLG_IMPTAG) {
 592         /* IMPLICIT tagging */
 593         ret = asn1_item_embed_d2i(val, &p, len,
 594                                   ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
 595                                   ctx);
 596         if (!ret) {
 597             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 598             goto err;
 599         } else if (ret == -1)
 600             return -1;
 601     } else {
 602         /* Nothing special */
 603         ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 604                                   -1, 0, opt, ctx);
 605         if (!ret) {
 606             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 607             goto err;
 608         } else if (ret == -1)
 609             return -1;
 610     }
 611
 612     *in = p;
 613     return 1;
 614
 615  err:
 616     return 0;
 617 }
 618
 619 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 620                                  const unsigned char **in, long inlen,
 621                                  const ASN1_ITEM *it,
 622                                  int tag, int aclass, char opt, ASN1_TLC *ctx)
 623 {
 624     int ret = 0, utype;
 625     long plen;
 626     char cst, inf, free_cont = 0;
 627     const unsigned char *p;
 628     BUF_MEM buf = { 0, NULL, 0, 0 };
 629     const unsigned char *cont = NULL;
 630     long len;
 631     if (!pval) {
 632         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 633         return 0;               /* Should never happen */
 634     }
 635
 636     if (it->itype == ASN1_ITYPE_MSTRING) {
 637         utype = tag;
 638         tag = -1;
 639     } else
 640         utype = it->utype;
 641
 642     if (utype == V_ASN1_ANY) {
 643         /* If type is ANY need to figure out type from tag */
 644         unsigned char oclass;
 645         if (tag >= 0) {
 646             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
 647             return 0;
 648         }
 649         if (opt) {
 650             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 651                     ASN1_R_ILLEGAL_OPTIONAL_ANY);
 652             return 0;
 653         }
 654         p = *in;
 655         ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 656                               &p, inlen, -1, 0, 0, ctx);
 657         if (!ret) {
 658             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 659             return 0;
 660         }
 661         if (oclass != V_ASN1_UNIVERSAL)
 662             utype = V_ASN1_OTHER;
 663     }
 664     if (tag == -1) {
 665         tag = utype;
 666         aclass = V_ASN1_UNIVERSAL;
 667     }
 668     p = *in;
 669     /* Check header */
 670     ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 671                           &p, inlen, tag, aclass, opt, ctx);
 672     if (!ret) {
 673         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 674         return 0;
 675     } else if (ret == -1)
 676         return -1;
 677     ret = 0;
 678     /* SEQUENCE, SET and "OTHER" are left in encoded form */
 679     if ((utype == V_ASN1_SEQUENCE)
 680         || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
 681         /*
 682          * Clear context cache for type OTHER because the auto clear when we
 683          * have a exact match wont work
 684          */
 685         if (utype == V_ASN1_OTHER) {
 686             asn1_tlc_clear(ctx);
 687         }
 688         /* SEQUENCE and SET must be constructed */
 689         else if (!cst) {
 690             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 691                     ASN1_R_TYPE_NOT_CONSTRUCTED);
 692             return 0;
 693         }
 694
 695         cont = *in;
 696         /* If indefinite length constructed find the real end */
 697         if (inf) {
 698             if (!asn1_find_end(&p, plen, inf))
 699                 goto err;
 700             len = p - cont;
 701         } else {
 702             len = p - cont + plen;
 703             p += plen;
 704         }
 705     } else if (cst) {
 706         if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
 707             || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
 708             || utype == V_ASN1_ENUMERATED) {
 709             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
 710             return 0;
 711         }
 712
 713         /* Free any returned 'buf' content */
 714         free_cont = 1;
 715         /*
 716          * Should really check the internal tags are correct but some things
 717          * may get this wrong. The relevant specs say that constructed string
 718          * types should be OCTET STRINGs internally irrespective of the type.
 719          * So instead just check for UNIVERSAL class and ignore the tag.
 720          */
 721         if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
 722             goto err;
 723         }
 724         len = buf.length;
 725         /* Append a final null to string */
 726         if (!BUF_MEM_grow_clean(&buf, len + 1)) {
 727             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
 728             goto err;
 729         }
 730         buf.data[len] = 0;
 731         cont = (const unsigned char *)buf.data;
 732     } else {
 733         cont = p;
 734         len = plen;
 735         p += plen;
 736     }
 737
 738     /* We now have content length and type: translate into a structure */
 739     /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */
 740     if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 741         goto err;
 742
 743     *in = p;
 744     ret = 1;
 745  err:
 746     if (free_cont)
 747         OPENSSL_free(buf.data);
 748     return ret;
 749 }
 750
 751 /* Translate ASN1 content octets into a structure */
 752
 753 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 754                        int utype, char *free_cont, const ASN1_ITEM *it)
 755 {
 756     ASN1_VALUE **opval = NULL;
 757     ASN1_STRING *stmp;
 758     ASN1_TYPE *typ = NULL;
 759     int ret = 0;
 760     const ASN1_PRIMITIVE_FUNCS *pf;
 761     ASN1_INTEGER **tint;
 762     pf = it->funcs;
 763
 764     if (pf && pf->prim_c2i)
 765         return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 766     /* If ANY type clear type and set pointer to internal value */
 767     if (it->utype == V_ASN1_ANY) {
 768         if (!*pval) {
 769             typ = ASN1_TYPE_new();
 770             if (typ == NULL)
 771                 goto err;
 772             *pval = (ASN1_VALUE *)typ;
 773         } else
 774             typ = (ASN1_TYPE *)*pval;
 775
 776         if (utype != typ->type)
 777             ASN1_TYPE_set(typ, utype, NULL);
 778         opval = pval;
 779         pval = &typ->value.asn1_value;
 780     }
 781     switch (utype) {
 782     case V_ASN1_OBJECT:
 783         if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 784             goto err;
 785         break;
 786
 787     case V_ASN1_NULL:
 788         if (len) {
 789             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
 790             goto err;
 791         }
 792         *pval = (ASN1_VALUE *)1;
 793         break;
 794
 795     case V_ASN1_BOOLEAN:
 796         if (len != 1) {
 797             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 798             goto err;
 799         } else {
 800             ASN1_BOOLEAN *tbool;
 801             tbool = (ASN1_BOOLEAN *)pval;
 802             *tbool = *cont;
 803         }
 804         break;
 805
 806     case V_ASN1_BIT_STRING:
 807         if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 808             goto err;
 809         break;
 810
 811     case V_ASN1_INTEGER:
 812     case V_ASN1_ENUMERATED:
 813         tint = (ASN1_INTEGER **)pval;
 814         if (!c2i_ASN1_INTEGER(tint, &cont, len))
 815             goto err;
 816         /* Fixup type to match the expected form */
 817         (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 818         break;
 819
 820     case V_ASN1_OCTET_STRING:
 821     case V_ASN1_NUMERICSTRING:
 822     case V_ASN1_PRINTABLESTRING:
 823     case V_ASN1_T61STRING:
 824     case V_ASN1_VIDEOTEXSTRING:
 825     case V_ASN1_IA5STRING:
 826     case V_ASN1_UTCTIME:
 827     case V_ASN1_GENERALIZEDTIME:
 828     case V_ASN1_GRAPHICSTRING:
 829     case V_ASN1_VISIBLESTRING:
 830     case V_ASN1_GENERALSTRING:
 831     case V_ASN1_UNIVERSALSTRING:
 832     case V_ASN1_BMPSTRING:
 833     case V_ASN1_UTF8STRING:
 834     case V_ASN1_OTHER:
 835     case V_ASN1_SET:
 836     case V_ASN1_SEQUENCE:
 837     default:
 838         if (utype == V_ASN1_BMPSTRING && (len & 1)) {
 839             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
 840             goto err;
 841         }
 842         if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
 843             ASN1err(ASN1_F_ASN1_EX_C2I,
 844                     ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
 845             goto err;
 846         }
 847         /* All based on ASN1_STRING and handled the same */
 848         if (!*pval) {
 849             stmp = ASN1_STRING_type_new(utype);
 850             if (stmp == NULL) {
 851                 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
 852                 goto err;
 853             }
 854             *pval = (ASN1_VALUE *)stmp;
 855         } else {
 856             stmp = (ASN1_STRING *)*pval;
 857             stmp->type = utype;
 858         }
 859         /* If we've already allocated a buffer use it */
 860         if (*free_cont) {
 861             OPENSSL_free(stmp->data);
 862             stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
 863             stmp->length = len;
 864             *free_cont = 0;
 865         } else {
 866             if (!ASN1_STRING_set(stmp, cont, len)) {
 867                 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
 868                 ASN1_STRING_free(stmp);
 869                 *pval = NULL;
 870                 goto err;
 871             }
 872         }
 873         break;
 874     }
 875     /* If ASN1_ANY and NULL type fix up value */
 876     if (typ && (utype == V_ASN1_NULL))
 877         typ->value.ptr = NULL;
 878
 879     ret = 1;
 880  err:
 881     if (!ret) {
 882         ASN1_TYPE_free(typ);
 883         if (opval)
 884             *opval = NULL;
 885     }
 886     return ret;
 887 }
 888
 889 /*
 890  * This function finds the end of an ASN1 structure when passed its maximum
 891  * length, whether it is indefinite length and a pointer to the content. This
 892  * is more efficient than calling asn1_collect because it does not recurse on
 893  * each indefinite length header.
 894  */
 895
 896 static int asn1_find_end(const unsigned char **in, long len, char inf)
 897 {
 898     int expected_eoc;
 899     long plen;
 900     const unsigned char *p = *in, *q;
 901     /* If not indefinite length constructed just add length */
 902     if (inf == 0) {
 903         *in += len;
 904         return 1;
 905     }
 906     expected_eoc = 1;
 907     /*
 908      * Indefinite length constructed form. Find the end when enough EOCs are
 909      * found. If more indefinite length constructed headers are encountered
 910      * increment the expected eoc count otherwise just skip to the end of the
 911      * data.
 912      */
 913     while (len > 0) {
 914         if (asn1_check_eoc(&p, len)) {
 915             expected_eoc--;
 916             if (expected_eoc == 0)
 917                 break;
 918             len -= 2;
 919             continue;
 920         }
 921         q = p;
 922         /* Just read in a header: only care about the length */
 923         if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
 924                              -1, 0, 0, NULL)) {
 925             ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
 926             return 0;
 927         }
 928         if (inf)
 929             expected_eoc++;
 930         else
 931             p += plen;
 932         len -= p - q;
 933     }
 934     if (expected_eoc) {
 935         ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
 936         return 0;
 937     }
 938     *in = p;
 939     return 1;
 940 }
 941
 942 /*
 943  * This function collects the asn1 data from a constructed string type into
 944  * a buffer. The values of 'in' and 'len' should refer to the contents of the
 945  * constructed type and 'inf' should be set if it is indefinite length.
 946  */
 947
 948 #ifndef ASN1_MAX_STRING_NEST
 949 /*
 950  * This determines how many levels of recursion are permitted in ASN1 string
 951  * types. If it is not limited stack overflows can occur. If set to zero no
 952  * recursion is allowed at all. Although zero should be adequate examples
 953  * exist that require a value of 1. So 5 should be more than enough.
 954  */
 955 # define ASN1_MAX_STRING_NEST 5
 956 #endif
 957
 958 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
 959                         char inf, int tag, int aclass, int depth)
 960 {
 961     const unsigned char *p, *q;
 962     long plen;
 963     char cst, ininf;
 964     p = *in;
 965     inf &= 1;
 966     /*
 967      * If no buffer and not indefinite length constructed just pass over the
 968      * encoded data
 969      */
 970     if (!buf && !inf) {
 971         *in += len;
 972         return 1;
 973     }
 974     while (len > 0) {
 975         q = p;
 976         /* Check for EOC */
 977         if (asn1_check_eoc(&p, len)) {
 978             /*
 979              * EOC is illegal outside indefinite length constructed form
 980              */
 981             if (!inf) {
 982                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
 983                 return 0;
 984             }
 985             inf = 0;
 986             break;
 987         }
 988
 989         if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
 990                              len, tag, aclass, 0, NULL)) {
 991             ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
 992             return 0;
 993         }
 994
 995         /* If indefinite length constructed update max length */
 996         if (cst) {
 997             if (depth >= ASN1_MAX_STRING_NEST) {
 998                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
 999                 return 0;
1000             }
1001             if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1002                 return 0;
1003         } else if (plen && !collect_data(buf, &p, plen))
1004             return 0;
1005         len -= p - q;
1006     }
1007     if (inf) {
1008         ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1009         return 0;
1010     }
1011     *in = p;
1012     return 1;
1013 }
1014
1015 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1016 {
1017     int len;
1018     if (buf) {
1019         len = buf->length;
1020         if (!BUF_MEM_grow_clean(buf, len + plen)) {
1021             ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1022             return 0;
1023         }
1024         memcpy(buf->data + len, *p, plen);
1025     }
1026     *p += plen;
1027     return 1;
1028 }
1029
1030 /* Check for ASN1 EOC and swallow it if found */
1031
1032 static int asn1_check_eoc(const unsigned char **in, long len)
1033 {
1034     const unsigned char *p;
1035     if (len < 2)
1036         return 0;
1037     p = *in;
1038     if (!p[0] && !p[1]) {
1039         *in += 2;
1040         return 1;
1041     }
1042     return 0;
1043 }
1044
1045 /*
1046  * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1047  * length for indefinite length constructed form, we don't know the exact
1048  * length but we can set an upper bound to the amount of data available minus
1049  * the header length just read.
1050  */
1051
1052 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1053                            char *inf, char *cst,
1054                            const unsigned char **in, long len,
1055                            int exptag, int expclass, char opt, ASN1_TLC *ctx)
1056 {
1057     int i;
1058     int ptag, pclass;
1059     long plen;
1060     const unsigned char *p, *q;
1061     p = *in;
1062     q = p;
1063
1064     if (ctx && ctx->valid) {
1065         i = ctx->ret;
1066         plen = ctx->plen;
1067         pclass = ctx->pclass;
1068         ptag = ctx->ptag;
1069         p += ctx->hdrlen;
1070     } else {
1071         i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1072         if (ctx) {
1073             ctx->ret = i;
1074             ctx->plen = plen;
1075             ctx->pclass = pclass;
1076             ctx->ptag = ptag;
1077             ctx->hdrlen = p - q;
1078             ctx->valid = 1;
1079             /*
1080              * If definite length, and no error, length + header can't exceed
1081              * total amount of data available.
1082              */
1083             if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
1084                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
1085                 asn1_tlc_clear(ctx);
1086                 return 0;
1087             }
1088         }
1089     }
1090
1091     if (i & 0x80) {
1092         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1093         asn1_tlc_clear(ctx);
1094         return 0;
1095     }
1096     if (exptag >= 0) {
1097         if ((exptag != ptag) || (expclass != pclass)) {
1098             /*
1099              * If type is OPTIONAL, not an error: indicate missing type.
1100              */
1101             if (opt)
1102                 return -1;
1103             asn1_tlc_clear(ctx);
1104             ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1105             return 0;
1106         }
1107         /*
1108          * We have a tag and class match: assume we are going to do something
1109          * with it
1110          */
1111         asn1_tlc_clear(ctx);
1112     }
1113
1114     if (i & 1)
1115         plen = len - (p - q);
1116
1117     if (inf)
1118         *inf = i & 1;
1119
1120     if (cst)
1121         *cst = i & V_ASN1_CONSTRUCTED;
1122
1123     if (olen)
1124         *olen = plen;
1125
1126     if (oclass)
1127         *oclass = pclass;
1128
1129     if (otag)
1130         *otag = ptag;
1131
1132     *in = p;
1133     return 1;
1134 }