crypto/asn1/tasn_dec.c

   1 /*
   2  * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 "internal/numbers.h"
  18 #include "asn1_locl.h"
  19
  20
  21 /*
  22  * Constructed types with a recursive definition (such as can be found in PKCS7)
  23  * could eventually exceed the stack given malicious input with excessive
  24  * recursion. Therefore we limit the stack depth. This is the maximum number of
  25  * recursive invocations of asn1_item_embed_d2i().
  26  */
  27 #define ASN1_MAX_CONSTRUCTED_NEST 30
  28
  29 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
  30                                long len, const ASN1_ITEM *it,
  31                                int tag, int aclass, char opt, ASN1_TLC *ctx,
  32                                int depth);
  33
  34 static int asn1_check_eoc(const unsigned char **in, long len);
  35 static int asn1_find_end(const unsigned char **in, long len, char inf);
  36
  37 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
  38                         char inf, int tag, int aclass, int depth);
  39
  40 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
  41
  42 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
  43                            char *inf, char *cst,
  44                            const unsigned char **in, long len,
  45                            int exptag, int expclass, char opt, ASN1_TLC *ctx);
  46
  47 static int asn1_template_ex_d2i(ASN1_VALUE **pval,
  48                                 const unsigned char **in, long len,
  49                                 const ASN1_TEMPLATE *tt, char opt,
  50                                 ASN1_TLC *ctx, int depth);
  51 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
  52                                    const unsigned char **in, long len,
  53                                    const ASN1_TEMPLATE *tt, char opt,
  54                                    ASN1_TLC *ctx, int depth);
  55 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
  56                                  const unsigned char **in, long len,
  57                                  const ASN1_ITEM *it,
  58                                  int tag, int aclass, char opt,
  59                                  ASN1_TLC *ctx);
  60 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
  61                        int utype, char *free_cont, const ASN1_ITEM *it);
  62
  63 /* Table to convert tags to bit values, used for MSTRING type */
  64 static const unsigned long tag2bit[32] = {
  65     /* tags  0 -  3 */
  66     0, 0, 0, B_ASN1_BIT_STRING,
  67     /* tags  4- 7 */
  68     B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
  69     /* tags  8-11 */
  70     B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
  71     /* tags 12-15 */
  72     B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
  73     /* tags 16-19 */
  74     B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
  75     /* tags 20-22 */
  76     B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
  77     /* tags 23-24 */
  78     B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
  79     /* tags 25-27 */
  80     B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
  81     /* tags 28-31 */
  82     B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
  83 };
  84
  85 unsigned long ASN1_tag2bit(int tag)
  86 {
  87     if ((tag < 0) || (tag > 30))
  88         return 0;
  89     return tag2bit[tag];
  90 }
  91
  92 /* Macro to initialize and invalidate the cache */
  93
  94 #define asn1_tlc_clear(c)       if (c) (c)->valid = 0
  95 /* Version to avoid compiler warning about 'c' always non-NULL */
  96 #define asn1_tlc_clear_nc(c)    (c)->valid = 0
  97
  98 /*
  99  * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
 100  * function. 'in' points to a buffer to read the data from, in future we
 101  * will have more advanced versions that can input data a piece at a time and
 102  * this will simply be a special case.
 103  */
 104
 105 ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
 106                           const unsigned char **in, long len,
 107                           const ASN1_ITEM *it)
 108 {
 109     ASN1_TLC c;
 110     ASN1_VALUE *ptmpval = NULL;
 111     if (!pval)
 112         pval = &ptmpval;
 113     asn1_tlc_clear_nc(&c);
 114     if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
 115         return *pval;
 116     return NULL;
 117 }
 118
 119 int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
 120                      const ASN1_ITEM *it,
 121                      int tag, int aclass, char opt, ASN1_TLC *ctx)
 122 {
 123     int rv;
 124     rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0);
 125     if (rv <= 0)
 126         ASN1_item_ex_free(pval, it);
 127     return rv;
 128 }
 129
 130 /*
 131  * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
 132  * tag mismatch return -1 to handle OPTIONAL
 133  */
 134
 135 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in,
 136                                long len, const ASN1_ITEM *it,
 137                                int tag, int aclass, char opt, ASN1_TLC *ctx,
 138                                int depth)
 139 {
 140     const ASN1_TEMPLATE *tt, *errtt = NULL;
 141     const ASN1_EXTERN_FUNCS *ef;
 142     const ASN1_AUX *aux = it->funcs;
 143     ASN1_aux_cb *asn1_cb;
 144     const unsigned char *p = NULL, *q;
 145     unsigned char oclass;
 146     char seq_eoc, seq_nolen, cst, isopt;
 147     long tmplen;
 148     int i;
 149     int otag;
 150     int ret = 0;
 151     ASN1_VALUE **pchptr;
 152     if (!pval)
 153         return 0;
 154     if (aux && aux->asn1_cb)
 155         asn1_cb = aux->asn1_cb;
 156     else
 157         asn1_cb = 0;
 158
 159     if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
 160         ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NESTED_TOO_DEEP);
 161         goto err;
 162     }
 163
 164     switch (it->itype) {
 165     case ASN1_ITYPE_PRIMITIVE:
 166         if (it->templates) {
 167             /*
 168              * tagging or OPTIONAL is currently illegal on an item template
 169              * because the flags can't get passed down. In practice this
 170              * isn't a problem: we include the relevant flags from the item
 171              * template in the template itself.
 172              */
 173             if ((tag != -1) || opt) {
 174                 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I,
 175                         ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
 176                 goto err;
 177             }
 178             return asn1_template_ex_d2i(pval, in, len,
 179                                         it->templates, opt, ctx, depth);
 180         }
 181         return asn1_d2i_ex_primitive(pval, in, len, it,
 182                                      tag, aclass, opt, ctx);
 183
 184     case ASN1_ITYPE_MSTRING:
 185         p = *in;
 186         /* Just read in tag and class */
 187         ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
 188                               &p, len, -1, 0, 1, ctx);
 189         if (!ret) {
 190             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 191             goto err;
 192         }
 193
 194         /* Must be UNIVERSAL class */
 195         if (oclass != V_ASN1_UNIVERSAL) {
 196             /* If OPTIONAL, assume this is OK */
 197             if (opt)
 198                 return -1;
 199             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
 200             goto err;
 201         }
 202         /* Check tag matches bit map */
 203         if (!(ASN1_tag2bit(otag) & it->utype)) {
 204             /* If OPTIONAL, assume this is OK */
 205             if (opt)
 206                 return -1;
 207             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG);
 208             goto err;
 209         }
 210         return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
 211
 212     case ASN1_ITYPE_EXTERN:
 213         /* Use new style d2i */
 214         ef = it->funcs;
 215         return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
 216
 217     case ASN1_ITYPE_CHOICE:
 218         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 219             goto auxerr;
 220         if (*pval) {
 221             /* Free up and zero CHOICE value if initialised */
 222             i = asn1_get_choice_selector(pval, it);
 223             if ((i >= 0) && (i < it->tcount)) {
 224                 tt = it->templates + i;
 225                 pchptr = asn1_get_field_ptr(pval, tt);
 226                 asn1_template_free(pchptr, tt);
 227                 asn1_set_choice_selector(pval, -1, it);
 228             }
 229         } else if (!ASN1_item_ex_new(pval, it)) {
 230             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 231             goto err;
 232         }
 233         /* CHOICE type, try each possibility in turn */
 234         p = *in;
 235         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 236             pchptr = asn1_get_field_ptr(pval, tt);
 237             /*
 238              * We mark field as OPTIONAL so its absence can be recognised.
 239              */
 240             ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth);
 241             /* If field not present, try the next one */
 242             if (ret == -1)
 243                 continue;
 244             /* If positive return, read OK, break loop */
 245             if (ret > 0)
 246                 break;
 247             /*
 248              * Must be an ASN1 parsing error.
 249              * Free up any partial choice value
 250              */
 251             asn1_template_free(pchptr, tt);
 252             errtt = tt;
 253             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 254             goto err;
 255         }
 256
 257         /* Did we fall off the end without reading anything? */
 258         if (i == it->tcount) {
 259             /* If OPTIONAL, this is OK */
 260             if (opt) {
 261                 /* Free and zero it */
 262                 ASN1_item_ex_free(pval, it);
 263                 return -1;
 264             }
 265             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
 266             goto err;
 267         }
 268
 269         asn1_set_choice_selector(pval, i, it);
 270
 271         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 272             goto auxerr;
 273         *in = p;
 274         return 1;
 275
 276     case ASN1_ITYPE_NDEF_SEQUENCE:
 277     case ASN1_ITYPE_SEQUENCE:
 278         p = *in;
 279         tmplen = len;
 280
 281         /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
 282         if (tag == -1) {
 283             tag = V_ASN1_SEQUENCE;
 284             aclass = V_ASN1_UNIVERSAL;
 285         }
 286         /* Get SEQUENCE length and update len, p */
 287         ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
 288                               &p, len, tag, aclass, opt, ctx);
 289         if (!ret) {
 290             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 291             goto err;
 292         } else if (ret == -1)
 293             return -1;
 294         if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
 295             len = tmplen - (p - *in);
 296             seq_nolen = 1;
 297         }
 298         /* If indefinite we don't do a length check */
 299         else
 300             seq_nolen = seq_eoc;
 301         if (!cst) {
 302             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
 303             goto err;
 304         }
 305
 306         if (!*pval && !ASN1_item_ex_new(pval, it)) {
 307             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR);
 308             goto err;
 309         }
 310
 311         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
 312             goto auxerr;
 313
 314         /* Free up and zero any ADB found */
 315         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 316             if (tt->flags & ASN1_TFLG_ADB_MASK) {
 317                 const ASN1_TEMPLATE *seqtt;
 318                 ASN1_VALUE **pseqval;
 319                 seqtt = asn1_do_adb(pval, tt, 0);
 320                 if (seqtt == NULL)
 321                     continue;
 322                 pseqval = asn1_get_field_ptr(pval, seqtt);
 323                 asn1_template_free(pseqval, seqtt);
 324             }
 325         }
 326
 327         /* Get each field entry */
 328         for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 329             const ASN1_TEMPLATE *seqtt;
 330             ASN1_VALUE **pseqval;
 331             seqtt = asn1_do_adb(pval, tt, 1);
 332             if (seqtt == NULL)
 333                 goto err;
 334             pseqval = asn1_get_field_ptr(pval, seqtt);
 335             /* Have we ran out of data? */
 336             if (!len)
 337                 break;
 338             q = p;
 339             if (asn1_check_eoc(&p, len)) {
 340                 if (!seq_eoc) {
 341                     ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC);
 342                     goto err;
 343                 }
 344                 len -= p - q;
 345                 seq_eoc = 0;
 346                 q = p;
 347                 break;
 348             }
 349             /*
 350              * This determines the OPTIONAL flag value. The field cannot be
 351              * omitted if it is the last of a SEQUENCE and there is still
 352              * data to be read. This isn't strictly necessary but it
 353              * increases efficiency in some cases.
 354              */
 355             if (i == (it->tcount - 1))
 356                 isopt = 0;
 357             else
 358                 isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
 359             /*
 360              * attempt to read in field, allowing each to be OPTIONAL
 361              */
 362
 363             ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx,
 364                                        depth);
 365             if (!ret) {
 366                 errtt = seqtt;
 367                 goto err;
 368             } else if (ret == -1) {
 369                 /*
 370                  * OPTIONAL component absent. Free and zero the field.
 371                  */
 372                 asn1_template_free(pseqval, seqtt);
 373                 continue;
 374             }
 375             /* Update length */
 376             len -= p - q;
 377         }
 378
 379         /* Check for EOC if expecting one */
 380         if (seq_eoc && !asn1_check_eoc(&p, len)) {
 381             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC);
 382             goto err;
 383         }
 384         /* Check all data read */
 385         if (!seq_nolen && len) {
 386             ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
 387             goto err;
 388         }
 389
 390         /*
 391          * If we get here we've got no more data in the SEQUENCE, however we
 392          * may not have read all fields so check all remaining are OPTIONAL
 393          * and clear any that are.
 394          */
 395         for (; i < it->tcount; tt++, i++) {
 396             const ASN1_TEMPLATE *seqtt;
 397             seqtt = asn1_do_adb(pval, tt, 1);
 398             if (seqtt == NULL)
 399                 goto err;
 400             if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
 401                 ASN1_VALUE **pseqval;
 402                 pseqval = asn1_get_field_ptr(pval, seqtt);
 403                 asn1_template_free(pseqval, seqtt);
 404             } else {
 405                 errtt = seqtt;
 406                 ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING);
 407                 goto err;
 408             }
 409         }
 410         /* Save encoding */
 411         if (!asn1_enc_save(pval, *in, p - *in, it))
 412             goto auxerr;
 413         if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 414             goto auxerr;
 415         *in = p;
 416         return 1;
 417
 418     default:
 419         return 0;
 420     }
 421  auxerr:
 422     ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR);
 423  err:
 424     if (errtt)
 425         ERR_add_error_data(4, "Field=", errtt->field_name,
 426                            ", Type=", it->sname);
 427     else
 428         ERR_add_error_data(2, "Type=", it->sname);
 429     return 0;
 430 }
 431
 432 /*
 433  * Templates are handled with two separate functions. One handles any
 434  * EXPLICIT tag and the other handles the rest.
 435  */
 436
 437 static int asn1_template_ex_d2i(ASN1_VALUE **val,
 438                                 const unsigned char **in, long inlen,
 439                                 const ASN1_TEMPLATE *tt, char opt,
 440                                 ASN1_TLC *ctx, int depth)
 441 {
 442     int flags, aclass;
 443     int ret;
 444     long len;
 445     const unsigned char *p, *q;
 446     char exp_eoc;
 447     if (!val)
 448         return 0;
 449     flags = tt->flags;
 450     aclass = flags & ASN1_TFLG_TAG_CLASS;
 451
 452     p = *in;
 453
 454     /* Check if EXPLICIT tag expected */
 455     if (flags & ASN1_TFLG_EXPTAG) {
 456         char cst;
 457         /*
 458          * Need to work out amount of data available to the inner content and
 459          * where it starts: so read in EXPLICIT header to get the info.
 460          */
 461         ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
 462                               &p, inlen, tt->tag, aclass, opt, ctx);
 463         q = p;
 464         if (!ret) {
 465             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 466             return 0;
 467         } else if (ret == -1)
 468             return -1;
 469         if (!cst) {
 470             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 471                     ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
 472             return 0;
 473         }
 474         /* We've found the field so it can't be OPTIONAL now */
 475         ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth);
 476         if (!ret) {
 477             ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
 478             return 0;
 479         }
 480         /* We read the field in OK so update length */
 481         len -= p - q;
 482         if (exp_eoc) {
 483             /* If NDEF we must have an EOC here */
 484             if (!asn1_check_eoc(&p, len)) {
 485                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
 486                 goto err;
 487             }
 488         } else {
 489             /*
 490              * Otherwise we must hit the EXPLICIT tag end or its an error
 491              */
 492             if (len) {
 493                 ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
 494                         ASN1_R_EXPLICIT_LENGTH_MISMATCH);
 495                 goto err;
 496             }
 497         }
 498     } else
 499         return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth);
 500
 501     *in = p;
 502     return 1;
 503
 504  err:
 505     return 0;
 506 }
 507
 508 static int asn1_template_noexp_d2i(ASN1_VALUE **val,
 509                                    const unsigned char **in, long len,
 510                                    const ASN1_TEMPLATE *tt, char opt,
 511                                    ASN1_TLC *ctx, int depth)
 512 {
 513     int flags, aclass;
 514     int ret;
 515     ASN1_VALUE *tval;
 516     const unsigned char *p, *q;
 517     if (!val)
 518         return 0;
 519     flags = tt->flags;
 520     aclass = flags & ASN1_TFLG_TAG_CLASS;
 521
 522     p = *in;
 523     q = p;
 524
 525     /*
 526      * If field is embedded then val needs fixing so it is a pointer to
 527      * a pointer to a field.
 528      */
 529     if (tt->flags & ASN1_TFLG_EMBED) {
 530         tval = (ASN1_VALUE *)val;
 531         val = &tval;
 532     }
 533
 534     if (flags & ASN1_TFLG_SK_MASK) {
 535         /* SET OF, SEQUENCE OF */
 536         int sktag, skaclass;
 537         char sk_eoc;
 538         /* First work out expected inner tag value */
 539         if (flags & ASN1_TFLG_IMPTAG) {
 540             sktag = tt->tag;
 541             skaclass = aclass;
 542         } else {
 543             skaclass = V_ASN1_UNIVERSAL;
 544             if (flags & ASN1_TFLG_SET_OF)
 545                 sktag = V_ASN1_SET;
 546             else
 547                 sktag = V_ASN1_SEQUENCE;
 548         }
 549         /* Get the tag */
 550         ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
 551                               &p, len, sktag, skaclass, opt, ctx);
 552         if (!ret) {
 553             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 554             return 0;
 555         } else if (ret == -1)
 556             return -1;
 557         if (!*val)
 558             *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null();
 559         else {
 560             /*
 561              * We've got a valid STACK: free up any items present
 562              */
 563             STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
 564             ASN1_VALUE *vtmp;
 565             while (sk_ASN1_VALUE_num(sktmp) > 0) {
 566                 vtmp = sk_ASN1_VALUE_pop(sktmp);
 567                 ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
 568             }
 569         }
 570
 571         if (!*val) {
 572             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
 573             goto err;
 574         }
 575
 576         /* Read as many items as we can */
 577         while (len > 0) {
 578             ASN1_VALUE *skfield;
 579             q = p;
 580             /* See if EOC found */
 581             if (asn1_check_eoc(&p, len)) {
 582                 if (!sk_eoc) {
 583                     ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 584                             ASN1_R_UNEXPECTED_EOC);
 585                     goto err;
 586                 }
 587                 len -= p - q;
 588                 sk_eoc = 0;
 589                 break;
 590             }
 591             skfield = NULL;
 592             if (!asn1_item_embed_d2i(&skfield, &p, len,
 593                                      ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx,
 594                                      depth)) {
 595                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
 596                         ERR_R_NESTED_ASN1_ERROR);
 597                 /* |skfield| may be partially allocated despite failure. */
 598                 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
 599                 goto err;
 600             }
 601             len -= p - q;
 602             if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
 603                 ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
 604                 ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item));
 605                 goto err;
 606             }
 607         }
 608         if (sk_eoc) {
 609             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
 610             goto err;
 611         }
 612     } else if (flags & ASN1_TFLG_IMPTAG) {
 613         /* IMPLICIT tagging */
 614         ret = asn1_item_embed_d2i(val, &p, len,
 615                                   ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
 616                                   ctx, depth);
 617         if (!ret) {
 618             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 619             goto err;
 620         } else if (ret == -1)
 621             return -1;
 622     } else {
 623         /* Nothing special */
 624         ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
 625                                   -1, 0, opt, ctx, depth);
 626         if (!ret) {
 627             ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
 628             goto err;
 629         } else if (ret == -1)
 630             return -1;
 631     }
 632
 633     *in = p;
 634     return 1;
 635
 636  err:
 637     return 0;
 638 }
 639
 640 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
 641                                  const unsigned char **in, long inlen,
 642                                  const ASN1_ITEM *it,
 643                                  int tag, int aclass, char opt, ASN1_TLC *ctx)
 644 {
 645     int ret = 0, utype;
 646     long plen;
 647     char cst, inf, free_cont = 0;
 648     const unsigned char *p;
 649     BUF_MEM buf = { 0, NULL, 0, 0 };
 650     const unsigned char *cont = NULL;
 651     long len;
 652     if (!pval) {
 653         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
 654         return 0;               /* Should never happen */
 655     }
 656
 657     if (it->itype == ASN1_ITYPE_MSTRING) {
 658         utype = tag;
 659         tag = -1;
 660     } else
 661         utype = it->utype;
 662
 663     if (utype == V_ASN1_ANY) {
 664         /* If type is ANY need to figure out type from tag */
 665         unsigned char oclass;
 666         if (tag >= 0) {
 667             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
 668             return 0;
 669         }
 670         if (opt) {
 671             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 672                     ASN1_R_ILLEGAL_OPTIONAL_ANY);
 673             return 0;
 674         }
 675         p = *in;
 676         ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
 677                               &p, inlen, -1, 0, 0, ctx);
 678         if (!ret) {
 679             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 680             return 0;
 681         }
 682         if (oclass != V_ASN1_UNIVERSAL)
 683             utype = V_ASN1_OTHER;
 684     }
 685     if (tag == -1) {
 686         tag = utype;
 687         aclass = V_ASN1_UNIVERSAL;
 688     }
 689     p = *in;
 690     /* Check header */
 691     ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
 692                           &p, inlen, tag, aclass, opt, ctx);
 693     if (!ret) {
 694         ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
 695         return 0;
 696     } else if (ret == -1)
 697         return -1;
 698     ret = 0;
 699     /* SEQUENCE, SET and "OTHER" are left in encoded form */
 700     if ((utype == V_ASN1_SEQUENCE)
 701         || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
 702         /*
 703          * Clear context cache for type OTHER because the auto clear when we
 704          * have a exact match won't work
 705          */
 706         if (utype == V_ASN1_OTHER) {
 707             asn1_tlc_clear(ctx);
 708         }
 709         /* SEQUENCE and SET must be constructed */
 710         else if (!cst) {
 711             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
 712                     ASN1_R_TYPE_NOT_CONSTRUCTED);
 713             return 0;
 714         }
 715
 716         cont = *in;
 717         /* If indefinite length constructed find the real end */
 718         if (inf) {
 719             if (!asn1_find_end(&p, plen, inf))
 720                 goto err;
 721             len = p - cont;
 722         } else {
 723             len = p - cont + plen;
 724             p += plen;
 725         }
 726     } else if (cst) {
 727         if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
 728             || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
 729             || utype == V_ASN1_ENUMERATED) {
 730             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
 731             return 0;
 732         }
 733
 734         /* Free any returned 'buf' content */
 735         free_cont = 1;
 736         /*
 737          * Should really check the internal tags are correct but some things
 738          * may get this wrong. The relevant specs say that constructed string
 739          * types should be OCTET STRINGs internally irrespective of the type.
 740          * So instead just check for UNIVERSAL class and ignore the tag.
 741          */
 742         if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
 743             goto err;
 744         }
 745         len = buf.length;
 746         /* Append a final null to string */
 747         if (!BUF_MEM_grow_clean(&buf, len + 1)) {
 748             ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
 749             goto err;
 750         }
 751         buf.data[len] = 0;
 752         cont = (const unsigned char *)buf.data;
 753     } else {
 754         cont = p;
 755         len = plen;
 756         p += plen;
 757     }
 758
 759     /* We now have content length and type: translate into a structure */
 760     /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */
 761     if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
 762         goto err;
 763
 764     *in = p;
 765     ret = 1;
 766  err:
 767     if (free_cont)
 768         OPENSSL_free(buf.data);
 769     return ret;
 770 }
 771
 772 /* Translate ASN1 content octets into a structure */
 773
 774 static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 775                        int utype, char *free_cont, const ASN1_ITEM *it)
 776 {
 777     ASN1_VALUE **opval = NULL;
 778     ASN1_STRING *stmp;
 779     ASN1_TYPE *typ = NULL;
 780     int ret = 0;
 781     const ASN1_PRIMITIVE_FUNCS *pf;
 782     ASN1_INTEGER **tint;
 783     pf = it->funcs;
 784
 785     if (pf && pf->prim_c2i)
 786         return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
 787     /* If ANY type clear type and set pointer to internal value */
 788     if (it->utype == V_ASN1_ANY) {
 789         if (!*pval) {
 790             typ = ASN1_TYPE_new();
 791             if (typ == NULL)
 792                 goto err;
 793             *pval = (ASN1_VALUE *)typ;
 794         } else
 795             typ = (ASN1_TYPE *)*pval;
 796
 797         if (utype != typ->type)
 798             ASN1_TYPE_set(typ, utype, NULL);
 799         opval = pval;
 800         pval = &typ->value.asn1_value;
 801     }
 802     switch (utype) {
 803     case V_ASN1_OBJECT:
 804         if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
 805             goto err;
 806         break;
 807
 808     case V_ASN1_NULL:
 809         if (len) {
 810             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
 811             goto err;
 812         }
 813         *pval = (ASN1_VALUE *)1;
 814         break;
 815
 816     case V_ASN1_BOOLEAN:
 817         if (len != 1) {
 818             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
 819             goto err;
 820         } else {
 821             ASN1_BOOLEAN *tbool;
 822             tbool = (ASN1_BOOLEAN *)pval;
 823             *tbool = *cont;
 824         }
 825         break;
 826
 827     case V_ASN1_BIT_STRING:
 828         if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
 829             goto err;
 830         break;
 831
 832     case V_ASN1_INTEGER:
 833     case V_ASN1_ENUMERATED:
 834         tint = (ASN1_INTEGER **)pval;
 835         if (!c2i_ASN1_INTEGER(tint, &cont, len))
 836             goto err;
 837         /* Fixup type to match the expected form */
 838         (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
 839         break;
 840
 841     case V_ASN1_OCTET_STRING:
 842     case V_ASN1_NUMERICSTRING:
 843     case V_ASN1_PRINTABLESTRING:
 844     case V_ASN1_T61STRING:
 845     case V_ASN1_VIDEOTEXSTRING:
 846     case V_ASN1_IA5STRING:
 847     case V_ASN1_UTCTIME:
 848     case V_ASN1_GENERALIZEDTIME:
 849     case V_ASN1_GRAPHICSTRING:
 850     case V_ASN1_VISIBLESTRING:
 851     case V_ASN1_GENERALSTRING:
 852     case V_ASN1_UNIVERSALSTRING:
 853     case V_ASN1_BMPSTRING:
 854     case V_ASN1_UTF8STRING:
 855     case V_ASN1_OTHER:
 856     case V_ASN1_SET:
 857     case V_ASN1_SEQUENCE:
 858     default:
 859         if (utype == V_ASN1_BMPSTRING && (len & 1)) {
 860             ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
 861             goto err;
 862         }
 863         if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
 864             ASN1err(ASN1_F_ASN1_EX_C2I,
 865                     ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
 866             goto err;
 867         }
 868         /* All based on ASN1_STRING and handled the same */
 869         if (!*pval) {
 870             stmp = ASN1_STRING_type_new(utype);
 871             if (stmp == NULL) {
 872                 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
 873                 goto err;
 874             }
 875             *pval = (ASN1_VALUE *)stmp;
 876         } else {
 877             stmp = (ASN1_STRING *)*pval;
 878             stmp->type = utype;
 879         }
 880         /* If we've already allocated a buffer use it */
 881         if (*free_cont) {
 882             OPENSSL_free(stmp->data);
 883             stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
 884             stmp->length = len;
 885             *free_cont = 0;
 886         } else {
 887             if (!ASN1_STRING_set(stmp, cont, len)) {
 888                 ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
 889                 ASN1_STRING_free(stmp);
 890                 *pval = NULL;
 891                 goto err;
 892             }
 893         }
 894         break;
 895     }
 896     /* If ASN1_ANY and NULL type fix up value */
 897     if (typ && (utype == V_ASN1_NULL))
 898         typ->value.ptr = NULL;
 899
 900     ret = 1;
 901  err:
 902     if (!ret) {
 903         ASN1_TYPE_free(typ);
 904         if (opval)
 905             *opval = NULL;
 906     }
 907     return ret;
 908 }
 909
 910 /*
 911  * This function finds the end of an ASN1 structure when passed its maximum
 912  * length, whether it is indefinite length and a pointer to the content. This
 913  * is more efficient than calling asn1_collect because it does not recurse on
 914  * each indefinite length header.
 915  */
 916
 917 static int asn1_find_end(const unsigned char **in, long len, char inf)
 918 {
 919     uint32_t expected_eoc;
 920     long plen;
 921     const unsigned char *p = *in, *q;
 922     /* If not indefinite length constructed just add length */
 923     if (inf == 0) {
 924         *in += len;
 925         return 1;
 926     }
 927     expected_eoc = 1;
 928     /*
 929      * Indefinite length constructed form. Find the end when enough EOCs are
 930      * found. If more indefinite length constructed headers are encountered
 931      * increment the expected eoc count otherwise just skip to the end of the
 932      * data.
 933      */
 934     while (len > 0) {
 935         if (asn1_check_eoc(&p, len)) {
 936             expected_eoc--;
 937             if (expected_eoc == 0)
 938                 break;
 939             len -= 2;
 940             continue;
 941         }
 942         q = p;
 943         /* Just read in a header: only care about the length */
 944         if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
 945                              -1, 0, 0, NULL)) {
 946             ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
 947             return 0;
 948         }
 949         if (inf) {
 950             if (expected_eoc == UINT32_MAX) {
 951                 ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
 952                 return 0;
 953             }
 954             expected_eoc++;
 955         } else {
 956             p += plen;
 957         }
 958         len -= p - q;
 959     }
 960     if (expected_eoc) {
 961         ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
 962         return 0;
 963     }
 964     *in = p;
 965     return 1;
 966 }
 967
 968 /*
 969  * This function collects the asn1 data from a constructed string type into
 970  * a buffer. The values of 'in' and 'len' should refer to the contents of the
 971  * constructed type and 'inf' should be set if it is indefinite length.
 972  */
 973
 974 #ifndef ASN1_MAX_STRING_NEST
 975 /*
 976  * This determines how many levels of recursion are permitted in ASN1 string
 977  * types. If it is not limited stack overflows can occur. If set to zero no
 978  * recursion is allowed at all. Although zero should be adequate examples
 979  * exist that require a value of 1. So 5 should be more than enough.
 980  */
 981 # define ASN1_MAX_STRING_NEST 5
 982 #endif
 983
 984 static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
 985                         char inf, int tag, int aclass, int depth)
 986 {
 987     const unsigned char *p, *q;
 988     long plen;
 989     char cst, ininf;
 990     p = *in;
 991     inf &= 1;
 992     /*
 993      * If no buffer and not indefinite length constructed just pass over the
 994      * encoded data
 995      */
 996     if (!buf && !inf) {
 997         *in += len;
 998         return 1;
 999     }
1000     while (len > 0) {
1001         q = p;
1002         /* Check for EOC */
1003         if (asn1_check_eoc(&p, len)) {
1004             /*
1005              * EOC is illegal outside indefinite length constructed form
1006              */
1007             if (!inf) {
1008                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
1009                 return 0;
1010             }
1011             inf = 0;
1012             break;
1013         }
1014
1015         if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1016                              len, tag, aclass, 0, NULL)) {
1017             ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1018             return 0;
1019         }
1020
1021         /* If indefinite length constructed update max length */
1022         if (cst) {
1023             if (depth >= ASN1_MAX_STRING_NEST) {
1024                 ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1025                 return 0;
1026             }
1027             if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1028                 return 0;
1029         } else if (plen && !collect_data(buf, &p, plen))
1030             return 0;
1031         len -= p - q;
1032     }
1033     if (inf) {
1034         ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1035         return 0;
1036     }
1037     *in = p;
1038     return 1;
1039 }
1040
1041 static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1042 {
1043     int len;
1044     if (buf) {
1045         len = buf->length;
1046         if (!BUF_MEM_grow_clean(buf, len + plen)) {
1047             ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1048             return 0;
1049         }
1050         memcpy(buf->data + len, *p, plen);
1051     }
1052     *p += plen;
1053     return 1;
1054 }
1055
1056 /* Check for ASN1 EOC and swallow it if found */
1057
1058 static int asn1_check_eoc(const unsigned char **in, long len)
1059 {
1060     const unsigned char *p;
1061     if (len < 2)
1062         return 0;
1063     p = *in;
1064     if (!p[0] && !p[1]) {
1065         *in += 2;
1066         return 1;
1067     }
1068     return 0;
1069 }
1070
1071 /*
1072  * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1073  * length for indefinite length constructed form, we don't know the exact
1074  * length but we can set an upper bound to the amount of data available minus
1075  * the header length just read.
1076  */
1077
1078 static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1079                            char *inf, char *cst,
1080                            const unsigned char **in, long len,
1081                            int exptag, int expclass, char opt, ASN1_TLC *ctx)
1082 {
1083     int i;
1084     int ptag, pclass;
1085     long plen;
1086     const unsigned char *p, *q;
1087     p = *in;
1088     q = p;
1089
1090     if (ctx && ctx->valid) {
1091         i = ctx->ret;
1092         plen = ctx->plen;
1093         pclass = ctx->pclass;
1094         ptag = ctx->ptag;
1095         p += ctx->hdrlen;
1096     } else {
1097         i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1098         if (ctx) {
1099             ctx->ret = i;
1100             ctx->plen = plen;
1101             ctx->pclass = pclass;
1102             ctx->ptag = ptag;
1103             ctx->hdrlen = p - q;
1104             ctx->valid = 1;
1105             /*
1106              * If definite length, and no error, length + header can't exceed
1107              * total amount of data available.
1108              */
1109             if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
1110                 ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
1111                 asn1_tlc_clear(ctx);
1112                 return 0;
1113             }
1114         }
1115     }
1116
1117     if (i & 0x80) {
1118         ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1119         asn1_tlc_clear(ctx);
1120         return 0;
1121     }
1122     if (exptag >= 0) {
1123         if ((exptag != ptag) || (expclass != pclass)) {
1124             /*
1125              * If type is OPTIONAL, not an error: indicate missing type.
1126              */
1127             if (opt)
1128                 return -1;
1129             asn1_tlc_clear(ctx);
1130             ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1131             return 0;
1132         }
1133         /*
1134          * We have a tag and class match: assume we are going to do something
1135          * with it
1136          */
1137         asn1_tlc_clear(ctx);
1138     }
1139
1140     if (i & 1)
1141         plen = len - (p - q);
1142
1143     if (inf)
1144         *inf = i & 1;
1145
1146     if (cst)
1147         *cst = i & V_ASN1_CONSTRUCTED;
1148
1149     if (olen)
1150         *olen = plen;
1151
1152     if (oclass)
1153         *oclass = pclass;
1154
1155     if (otag)
1156         *otag = ptag;
1157
1158     *in = p;
1159     return 1;
1160 }