lib/asn1/template.c

   1 /*
   2  * Copyright (c) 2009 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Portions Copyright (c) 2009 Apple Inc. 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 the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "der_locl.h"
  37 #include <com_err.h>
  38
  39 #if 0
  40 #define ABORT_ON_ERROR() abort()
  41 #else
  42 #define ABORT_ON_ERROR() do { } while(0)
  43 #endif
  44
  45 #define DPOC(data,offset) ((const void *)(((const unsigned char *)data)  + offset))
  46 #define DPO(data,offset) ((void *)(((unsigned char *)data)  + offset))
  47
  48
  49 struct asn1_type_func prim[] = {
  50 #define el(name, type) {                                \
  51         (asn1_type_encode)der_put_##name,               \
  52         (asn1_type_decode)der_get_##name,               \
  53         (asn1_type_length)der_length_##name,            \
  54         (asn1_type_copy)der_copy_##name,                \
  55         (asn1_type_release)der_free_##name,             \
  56         sizeof(type)                                    \
  57     }
  58 #define elber(name, type) {                             \
  59         (asn1_type_encode)der_put_##name,               \
  60         (asn1_type_decode)der_get_##name##_ber,         \
  61         (asn1_type_length)der_length_##name,            \
  62         (asn1_type_copy)der_copy_##name,                \
  63         (asn1_type_release)der_free_##name,             \
  64         sizeof(type)                                    \
  65     }
  66     el(integer, int),
  67     el(heim_integer, heim_integer),
  68     el(integer, int),
  69     el(unsigned, unsigned),
  70     el(general_string, heim_general_string),
  71     el(octet_string, heim_octet_string),
  72     elber(octet_string, heim_octet_string),
  73     el(ia5_string, heim_ia5_string),
  74     el(bmp_string, heim_bmp_string),
  75     el(universal_string, heim_universal_string),
  76     el(printable_string, heim_printable_string),
  77     el(visible_string, heim_visible_string),
  78     el(utf8string, heim_utf8_string),
  79     el(generalized_time, time_t),
  80     el(utctime, time_t),
  81     el(bit_string, heim_bit_string),
  82     { (asn1_type_encode)der_put_boolean, (asn1_type_decode)der_get_boolean,
  83       (asn1_type_length)der_length_boolean, (asn1_type_copy)der_copy_integer,
  84       (asn1_type_release)der_free_integer, sizeof(int)
  85     },
  86     el(oid, heim_oid),
  87     el(general_string, heim_general_string),
  88 #undef el
  89 #undef elber
  90 };
  91
  92 static size_t
  93 sizeofType(const struct asn1_template *t)
  94 {
  95     return t->offset;
  96 }
  97
  98 /*
  99  * Here is abstraction to not so well evil fact of bit fields in C,
 100  * they are endian dependent, so when getting and setting bits in the
 101  * host local structure we need to know the endianness of the host.
 102  *
 103  * Its not the first time in Heimdal this have bitten us, and some day
 104  * we'll grow up and use #defined constant, but bit fields are still
 105  * so pretty and shiny.
 106  */
 107
 108 static void
 109 bmember_get_bit(const unsigned char *p, void *data,
 110                 unsigned int bit, size_t size)
 111 {
 112     unsigned int localbit = bit % 8;
 113     if ((*p >> (7 - localbit)) & 1) {
 114 #ifdef WORDS_BIGENDIAN
 115         *(unsigned int *)data |= (1 << ((size * 8) - bit - 1));
 116 #else
 117         *(unsigned int *)data |= (1 << bit);
 118 #endif
 119     }
 120 }
 121
 122 static int
 123 bmember_isset_bit(const void *data, unsigned int bit, size_t size)
 124 {
 125 #ifdef WORDS_BIGENDIAN
 126     if ((*(unsigned int *)data) & (1 << ((size * 8) - bit - 1)))
 127         return 1;
 128     return 0;
 129 #else
 130     if ((*(unsigned int *)data) & (1 << bit))
 131         return 1;
 132     return 0;
 133 #endif
 134 }
 135
 136 static void
 137 bmember_put_bit(unsigned char *p, const void *data, unsigned int bit,
 138                 size_t size, unsigned int *bitset)
 139 {
 140     unsigned int localbit = bit % 8;
 141
 142     if (bmember_isset_bit(data, bit, size)) {
 143         *p |= (1 << (7 - localbit));
 144         if (*bitset == 0)
 145             *bitset = (7 - localbit) + 1;
 146     }
 147 }
 148
 149 int
 150 _asn1_decode(const struct asn1_template *t, unsigned flags,
 151              const unsigned char *p, size_t len, void *data, size_t *size)
 152 {
 153     size_t elements = A1_HEADER_LEN(t);
 154     size_t oldlen = len;
 155     int ret = 0;
 156     const unsigned char *startp = NULL;
 157     unsigned int template_flags = t->tt;
 158
 159     /* skip over header */
 160     t++;
 161
 162     if (template_flags & A1_HF_PRESERVE)
 163         startp = p;
 164
 165     while (elements) {
 166         switch (t->tt & A1_OP_MASK) {
 167         case A1_OP_TYPE:
 168         case A1_OP_TYPE_EXTERN: {
 169             size_t newsize, size;
 170             void *el = DPO(data, t->offset);
 171             void **pel = (void **)el;
 172
 173             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 174                 size = sizeofType(t->ptr);
 175             } else {
 176                 const struct asn1_type_func *f = t->ptr;
 177                 size = f->size;
 178             }
 179
 180             if (t->tt & A1_FLAG_OPTIONAL) {
 181                 *pel = calloc(1, size);
 182                 if (*pel == NULL)
 183                     return ENOMEM;
 184                 el = *pel;
 185             }
 186             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 187                 ret = _asn1_decode(t->ptr, flags, p, len, el, &newsize);
 188             } else {
 189                 const struct asn1_type_func *f = t->ptr;
 190                 ret = (f->decode)(p, len, el, &newsize);
 191             }
 192             if (ret) {
 193                 if (t->tt & A1_FLAG_OPTIONAL) {
 194                     free(*pel);
 195                     *pel = NULL;
 196                     break;
 197                 }
 198                 return ret;
 199             }
 200             p += newsize; len -= newsize;
 201
 202             break;
 203         }
 204         case A1_OP_TAG: {
 205             Der_type dertype;
 206             size_t newsize;
 207             size_t datalen, l;
 208             void *olddata = data;
 209             int is_indefinite = 0;
 210             int subflags = flags;
 211
 212             ret = der_match_tag_and_length(p, len, A1_TAG_CLASS(t->tt),
 213                                            &dertype, A1_TAG_TAG(t->tt),
 214                                            &datalen, &l);
 215             if (ret) {
 216                 if (t->tt & A1_FLAG_OPTIONAL)
 217                     break;
 218                 return ret;
 219             }
 220
 221             p += l; len -= l;
 222
 223             /*
 224              * Only allow indefinite encoding for OCTET STRING and BER
 225              * for now. Should handle BIT STRING too.
 226              */
 227
 228             if (dertype != A1_TAG_TYPE(t->tt) && (flags & A1_PF_ALLOW_BER)) {
 229                 const struct asn1_template *subtype = t->ptr;
 230                 subtype++; /* skip header */
 231
 232                 if (((subtype->tt & A1_OP_MASK) == A1_OP_PARSE) &&
 233                     A1_PARSE_TYPE(subtype->tt) == A1T_OCTET_STRING)
 234                     subflags |= A1_PF_INDEFINTE;
 235             }
 236
 237             if (datalen == ASN1_INDEFINITE) {
 238                 if ((flags & A1_PF_ALLOW_BER) == 0)
 239                     return ASN1_GOT_BER;
 240                 is_indefinite = 1;
 241                 datalen = len;
 242                 if (datalen < 2)
 243                     return ASN1_OVERRUN;
 244                 /* hide EndOfContent for sub-decoder, catching it below */
 245                 datalen -= 2;
 246             } else if (datalen > len)
 247                 return ASN1_OVERRUN;
 248
 249             data = DPO(data, t->offset);
 250
 251             if (t->tt & A1_FLAG_OPTIONAL) {
 252                 void **el = (void **)data;
 253                 size_t ellen = sizeofType(t->ptr);
 254
 255                 *el = calloc(1, ellen);
 256                 if (*el == NULL)
 257                     return ENOMEM;
 258                 data = *el;
 259             }
 260
 261             ret = _asn1_decode(t->ptr, subflags, p, datalen, data, &newsize);
 262             if (ret)
 263                 return ret;
 264
 265             if (newsize != datalen)
 266                 return ASN1_EXTRA_DATA;
 267
 268             len -= datalen;
 269             p += datalen;
 270
 271             /*
 272              * Indefinite encoding needs a trailing EndOfContent,
 273              * check for that.
 274              */
 275             if (is_indefinite) {
 276                 ret = der_match_tag_and_length(p, len, ASN1_C_UNIV,
 277                                                &dertype, UT_EndOfContent,
 278                                                &datalen, &l);
 279                 if (ret)
 280                     return ret;
 281                 if (dertype != PRIM)
 282                     return ASN1_BAD_ID;
 283                 if (datalen != 0)
 284                     return ASN1_INDEF_EXTRA_DATA;
 285                 p += l; len -= l;
 286             }
 287             data = olddata;
 288
 289             break;
 290         }
 291         case A1_OP_PARSE: {
 292             unsigned int type = A1_PARSE_TYPE(t->tt);
 293             size_t newsize;
 294             void *el = DPO(data, t->offset);
 295
 296             /*
 297              * INDEFINITE primitive types are one element after the
 298              * same type but non-INDEFINITE version.
 299             */
 300             if (flags & A1_PF_INDEFINTE)
 301                 type++;
 302
 303             if (type >= sizeof(prim)/sizeof(prim[0])) {
 304                 ABORT_ON_ERROR();
 305                 return ASN1_PARSE_ERROR;
 306             }
 307
 308             ret = (prim[type].decode)(p, len, el, &newsize);
 309             if (ret)
 310                 return ret;
 311             p += newsize; len -= newsize;
 312
 313             break;
 314         }
 315         case A1_OP_SETOF:
 316         case A1_OP_SEQOF: {
 317             struct template_of *el = DPO(data, t->offset);
 318             size_t newsize;
 319             size_t ellen = sizeofType(t->ptr);
 320             size_t vallength = 0;
 321
 322             while (len > 0) {
 323                 void *tmp;
 324                 size_t newlen = vallength + ellen;
 325                 if (vallength > newlen)
 326                     return ASN1_OVERFLOW;
 327
 328                 tmp = realloc(el->val, newlen);
 329                 if (tmp == NULL)
 330                     return ENOMEM;
 331
 332                 memset(DPO(tmp, vallength), 0, ellen);
 333                 el->val = tmp;
 334
 335                 ret = _asn1_decode(t->ptr, flags & (~A1_PF_INDEFINTE), p, len,
 336                                    DPO(el->val, vallength), &newsize);
 337                 if (ret)
 338                     return ret;
 339                 vallength = newlen;
 340                 el->len++;
 341                 p += newsize; len -= newsize;
 342             }
 343
 344             break;
 345         }
 346         case A1_OP_BMEMBER: {
 347             const struct asn1_template *bmember = t->ptr;
 348             size_t size = bmember->offset;
 349             size_t elements = A1_HEADER_LEN(bmember);
 350             size_t pos = 0;
 351
 352             bmember++;
 353
 354             memset(data, 0, size);
 355
 356             if (len < 1)
 357                 return ASN1_OVERRUN;
 358             p++; len--;
 359
 360             while (elements && len) {
 361                 while (bmember->offset / 8 > pos / 8) {
 362                     if (len < 1)
 363                         break;
 364                     p++; len--;
 365                     pos += 8;
 366                 }
 367                 if (len) {
 368                     bmember_get_bit(p, data, bmember->offset, size);
 369                     elements--; bmember++;
 370                 }
 371             }
 372             len = 0;
 373             break;
 374         }
 375         case A1_OP_CHOICE: {
 376             const struct asn1_template *choice = t->ptr;
 377             unsigned int *element = DPO(data, choice->offset);
 378             size_t datalen;
 379             unsigned int i;
 380
 381             for (i = 1; i < A1_HEADER_LEN(choice) + 1; i++) {
 382                 /* should match first tag instead, store it in choice.tt */
 383                 ret = _asn1_decode(choice[i].ptr, 0, p, len,
 384                                    DPO(data, choice[i].offset), &datalen);
 385                 if (ret == 0) {
 386                     *element = i;
 387                     p += datalen; len -= datalen;
 388                     break;
 389                 } else if (ret != ASN1_BAD_ID && ret != ASN1_MISPLACED_FIELD && ret != ASN1_MISSING_FIELD) {
 390                     return ret;
 391                 }
 392             }
 393             if (i >= A1_HEADER_LEN(choice) + 1) {
 394                 if (choice->tt == 0)
 395                     return ASN1_BAD_ID;
 396
 397                 *element = 0;
 398                 ret = der_get_octet_string(p, len,
 399                                            DPO(data, choice->tt), &datalen);
 400                 if (ret)
 401                     return ret;
 402                 p += datalen; len -= datalen;
 403             }
 404
 405             break;
 406         }
 407         default:
 408             ABORT_ON_ERROR();
 409             return ASN1_PARSE_ERROR;
 410         }
 411         t++;
 412         elements--;
 413     }
 414     /* if we are using padding, eat up read of context */
 415     if (template_flags & A1_HF_ELLIPSIS)
 416         len = 0;
 417
 418     oldlen -= len;
 419
 420     if (size)
 421         *size = oldlen;
 422
 423     /*
 424      * saved the raw bits if asked for it, useful for signature
 425      * verification.
 426      */
 427     if (startp) {
 428         heim_octet_string *save = data;
 429
 430         save->data = malloc(oldlen);
 431         if (save->data == NULL)
 432             return ENOMEM;
 433         else {
 434             save->length = oldlen;
 435             memcpy(save->data, startp, oldlen);
 436         }
 437     }
 438     return 0;
 439 }
 440
 441 int
 442 _asn1_encode(const struct asn1_template *t, unsigned char *p, size_t len, const void *data, size_t *size)
 443 {
 444     size_t elements = A1_HEADER_LEN(t);
 445     int ret = 0;
 446     size_t oldlen = len;
 447
 448     t += A1_HEADER_LEN(t);
 449
 450     while (elements) {
 451         switch (t->tt & A1_OP_MASK) {
 452         case A1_OP_TYPE:
 453         case A1_OP_TYPE_EXTERN: {
 454             size_t newsize;
 455             const void *el = DPOC(data, t->offset);
 456
 457             if (t->tt & A1_FLAG_OPTIONAL) {
 458                 void **pel = (void **)el;
 459                 if (*pel == NULL)
 460                     break;
 461                 el = *pel;
 462             }
 463
 464             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 465                 ret = _asn1_encode(t->ptr, p, len, el, &newsize);
 466             } else {
 467                 const struct asn1_type_func *f = t->ptr;
 468                 ret = (f->encode)(p, len, el, &newsize);
 469             }
 470
 471             if (ret)
 472                 return ret;
 473             p -= newsize; len -= newsize;
 474
 475             break;
 476         }
 477         case A1_OP_TAG: {
 478             const void *olddata = data;
 479             size_t l, datalen;
 480
 481             data = DPOC(data, t->offset);
 482
 483             if (t->tt & A1_FLAG_OPTIONAL) {
 484                 void **el = (void **)data;
 485                 if (*el == NULL) {
 486                     data = olddata;
 487                     break;
 488                 }
 489                 data = *el;
 490             }
 491
 492             ret = _asn1_encode(t->ptr, p, len, data, &datalen);
 493             if (ret)
 494                 return ret;
 495
 496             len -= datalen; p -= datalen;
 497
 498             ret = der_put_length_and_tag(p, len, datalen,
 499                                          A1_TAG_CLASS(t->tt),
 500                                          A1_TAG_TYPE(t->tt),
 501                                          A1_TAG_TAG(t->tt), &l);
 502             if (ret)
 503                 return ret;
 504
 505             p -= l; len -= l;
 506
 507             data = olddata;
 508
 509             break;
 510         }
 511         case A1_OP_PARSE: {
 512             unsigned int type = A1_PARSE_TYPE(t->tt);
 513             size_t newsize;
 514             const void *el = DPOC(data, t->offset);
 515
 516             if (type > sizeof(prim)/sizeof(prim[0])) {
 517                 ABORT_ON_ERROR();
 518                 return ASN1_PARSE_ERROR;
 519             }
 520
 521             ret = (prim[type].encode)(p, len, el, &newsize);
 522             if (ret)
 523                 return ret;
 524             p -= newsize; len -= newsize;
 525
 526             break;
 527         }
 528         case A1_OP_SETOF: {
 529             const struct template_of *el = DPOC(data, t->offset);
 530             size_t ellen = sizeofType(t->ptr);
 531             struct heim_octet_string *val;
 532             unsigned char *elptr = el->val;
 533             size_t i, totallen;
 534
 535             if (el->len == 0)
 536                 break;
 537
 538             if (el->len > UINT_MAX/sizeof(val[0]))
 539                 return ERANGE;
 540
 541             val = malloc(sizeof(val[0]) * el->len);
 542             if (val == NULL)
 543                 return ENOMEM;
 544
 545             for(totallen = 0, i = 0; i < el->len; i++) {
 546                 unsigned char *next;
 547                 size_t l;
 548
 549                 val[i].length = _asn1_length(t->ptr, elptr);
 550                 val[i].data = malloc(val[i].length);
 551
 552                 ret = _asn1_encode(t->ptr, DPO(val[i].data, val[i].length - 1),
 553                                    val[i].length, elptr, &l);
 554                 if (ret)
 555                     break;
 556
 557                 next = elptr + ellen;
 558                 if (next < elptr) {
 559                     ret = ASN1_OVERFLOW;
 560                     break;
 561                 }
 562                 elptr = next;
 563                 totallen += val[i].length;
 564             }
 565             if (ret == 0 && totallen > len)
 566                 ret = ASN1_OVERFLOW;
 567             if (ret) {
 568                 do {
 569                     free(val[i].data);
 570                 } while(i-- > 0);
 571                 free(val);
 572                 return ret;
 573             }
 574
 575             len -= totallen;
 576
 577             qsort(val, el->len, sizeof(val[0]), _heim_der_set_sort);
 578
 579             i = el->len - 1;
 580             do {
 581                 p -= val[i].length;
 582                 memcpy(p + 1, val[i].data, val[i].length);
 583                 free(val[i].data);
 584             } while(i-- > 0);
 585             free(val);
 586
 587             break;
 588
 589         }
 590         case A1_OP_SEQOF: {
 591             struct template_of *el = DPO(data, t->offset);
 592             size_t ellen = sizeofType(t->ptr);
 593             size_t newsize;
 594             unsigned int i;
 595             unsigned char *elptr = el->val;
 596
 597             if (el->len == 0)
 598                 break;
 599
 600             elptr += ellen * (el->len - 1);
 601
 602             for (i = 0; i < el->len; i++) {
 603                 ret = _asn1_encode(t->ptr, p, len,
 604                                    elptr,
 605                                    &newsize);
 606                 if (ret)
 607                     return ret;
 608                 p -= newsize; len -= newsize;
 609                 elptr -= ellen;
 610             }
 611
 612             break;
 613         }
 614         case A1_OP_BMEMBER: {
 615             const struct asn1_template *bmember = t->ptr;
 616             size_t size = bmember->offset;
 617             size_t elements = A1_HEADER_LEN(bmember);
 618             size_t pos;
 619             unsigned char c = 0;
 620             unsigned int bitset = 0;
 621             int rfc1510 = (bmember->tt & A1_HBF_RFC1510);
 622
 623             bmember += elements;
 624
 625             if (rfc1510)
 626                 pos = 31;
 627             else
 628                 pos = bmember->offset;
 629
 630             while (elements && len) {
 631                 while (bmember->offset / 8 < pos / 8) {
 632                     if (rfc1510 || bitset || c) {
 633                         if (len < 1)
 634                             return ASN1_OVERFLOW;
 635                         *p-- = c; len--;
 636                     }
 637                     c = 0;
 638                     pos -= 8;
 639                 }
 640                 bmember_put_bit(&c, data, bmember->offset, size, &bitset);
 641                 elements--; bmember--;
 642             }
 643             if (rfc1510 || bitset) {
 644                 if (len < 1)
 645                     return ASN1_OVERFLOW;
 646                 *p-- = c; len--;
 647             }
 648
 649             if (len < 1)
 650                 return ASN1_OVERFLOW;
 651             if (rfc1510 || bitset == 0)
 652                 *p-- = 0;
 653             else
 654                 *p-- = bitset - 1;
 655
 656             len--;
 657
 658             break;
 659         }
 660         case A1_OP_CHOICE: {
 661             const struct asn1_template *choice = t->ptr;
 662             const unsigned int *element = DPOC(data, choice->offset);
 663             size_t datalen;
 664             const void *el;
 665
 666             if (*element > A1_HEADER_LEN(choice)) {
 667                 printf("element: %d\n", *element);
 668                 return ASN1_PARSE_ERROR;
 669             }
 670
 671             if (*element == 0) {
 672                 ret += der_put_octet_string(p, len,
 673                                             DPOC(data, choice->tt), &datalen);
 674             } else {
 675                 choice += *element;
 676                 el = DPOC(data, choice->offset);
 677                 ret = _asn1_encode(choice->ptr, p, len, el, &datalen);
 678                 if (ret)
 679                     return ret;
 680             }
 681             len -= datalen; p -= datalen;
 682
 683             break;
 684         }
 685         default:
 686             ABORT_ON_ERROR();
 687         }
 688         t--;
 689         elements--;
 690     }
 691     if (size)
 692         *size = oldlen - len;
 693
 694     return 0;
 695 }
 696
 697 size_t
 698 _asn1_length(const struct asn1_template *t, const void *data)
 699 {
 700     size_t elements = A1_HEADER_LEN(t);
 701     size_t ret = 0;
 702
 703     t += A1_HEADER_LEN(t);
 704
 705     while (elements) {
 706         switch (t->tt & A1_OP_MASK) {
 707         case A1_OP_TYPE:
 708         case A1_OP_TYPE_EXTERN: {
 709             const void *el = DPOC(data, t->offset);
 710
 711             if (t->tt & A1_FLAG_OPTIONAL) {
 712                 void **pel = (void **)el;
 713                 if (*pel == NULL)
 714                     break;
 715                 el = *pel;
 716             }
 717
 718             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 719                 ret += _asn1_length(t->ptr, el);
 720             } else {
 721                 const struct asn1_type_func *f = t->ptr;
 722                 ret += (f->length)(el);
 723             }
 724             break;
 725         }
 726         case A1_OP_TAG: {
 727             size_t datalen;
 728             const void *olddata = data;
 729
 730             data = DPO(data, t->offset);
 731
 732             if (t->tt & A1_FLAG_OPTIONAL) {
 733                 void **el = (void **)data;
 734                 if (*el == NULL) {
 735                     data = olddata;
 736                     break;
 737                 }
 738                 data = *el;
 739             }
 740             datalen = _asn1_length(t->ptr, data);
 741             ret += der_length_tag(A1_TAG_TAG(t->tt)) + der_length_len(datalen);
 742             ret += datalen;
 743             data = olddata;
 744             break;
 745         }
 746         case A1_OP_PARSE: {
 747             unsigned int type = A1_PARSE_TYPE(t->tt);
 748             const void *el = DPOC(data, t->offset);
 749
 750             if (type > sizeof(prim)/sizeof(prim[0])) {
 751                 ABORT_ON_ERROR();
 752                 break;
 753             }
 754             ret += (prim[type].length)(el);
 755             break;
 756         }
 757         case A1_OP_SETOF:
 758         case A1_OP_SEQOF: {
 759             const struct template_of *el = DPOC(data, t->offset);
 760             size_t ellen = sizeofType(t->ptr);
 761             const unsigned char *element = el->val;
 762             unsigned int i;
 763
 764             for (i = 0; i < el->len; i++) {
 765                 ret += _asn1_length(t->ptr, element);
 766                 element += ellen;
 767             }
 768
 769             break;
 770         }
 771         case A1_OP_BMEMBER: {
 772             const struct asn1_template *bmember = t->ptr;
 773             size_t size = bmember->offset;
 774             size_t elements = A1_HEADER_LEN(bmember);
 775             int rfc1510 = (bmember->tt & A1_HBF_RFC1510);
 776
 777             if (rfc1510) {
 778                 ret += 5;
 779             } else {
 780
 781                 ret += 1;
 782
 783                 bmember += elements;
 784
 785                 while (elements) {
 786                     if (bmember_isset_bit(data, bmember->offset, size)) {
 787                         ret += (bmember->offset / 8) + 1;
 788                         break;
 789                     }
 790                     elements--; bmember--;
 791                 }
 792             }
 793             break;
 794         }
 795         case A1_OP_CHOICE: {
 796             const struct asn1_template *choice = t->ptr;
 797             const unsigned int *element = DPOC(data, choice->offset);
 798
 799             if (*element > A1_HEADER_LEN(choice))
 800                 break;
 801
 802             if (*element == 0) {
 803                 ret += der_length_octet_string(DPOC(data, choice->tt));
 804             } else {
 805                 choice += *element;
 806                 ret += _asn1_length(choice->ptr, DPOC(data, choice->offset));
 807             }
 808             break;
 809         }
 810         default:
 811             ABORT_ON_ERROR();
 812             break;
 813         }
 814         elements--;
 815         t--;
 816     }
 817     return ret;
 818 }
 819
 820 void
 821 _asn1_free(const struct asn1_template *t, void *data)
 822 {
 823     size_t elements = A1_HEADER_LEN(t);
 824
 825     if (t->tt & A1_HF_PRESERVE)
 826         der_free_octet_string(data);
 827
 828     t++;
 829
 830     while (elements) {
 831         switch (t->tt & A1_OP_MASK) {
 832         case A1_OP_TYPE:
 833         case A1_OP_TYPE_EXTERN: {
 834             void *el = DPO(data, t->offset);
 835
 836             if (t->tt & A1_FLAG_OPTIONAL) {
 837                 void **pel = (void **)el;
 838                 if (*pel == NULL)
 839                     break;
 840                 el = *pel;
 841             }
 842
 843             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 844                 _asn1_free(t->ptr, el);
 845             } else {
 846                 const struct asn1_type_func *f = t->ptr;
 847                 (f->release)(el);
 848             }
 849             if (t->tt & A1_FLAG_OPTIONAL)
 850                 free(el);
 851
 852             break;
 853         }
 854         case A1_OP_PARSE: {
 855             unsigned int type = A1_PARSE_TYPE(t->tt);
 856             void *el = DPO(data, t->offset);
 857
 858             if (type > sizeof(prim)/sizeof(prim[0])) {
 859                 ABORT_ON_ERROR();
 860                 break;
 861             }
 862             (prim[type].release)(el);
 863             break;
 864         }
 865         case A1_OP_TAG: {
 866             void *el = DPO(data, t->offset);
 867
 868             if (t->tt & A1_FLAG_OPTIONAL) {
 869                 void **pel = (void **)el;
 870                 if (*pel == NULL)
 871                     break;
 872                 el = *pel;
 873             }
 874
 875             _asn1_free(t->ptr, el);
 876
 877             if (t->tt & A1_FLAG_OPTIONAL)
 878                 free(el);
 879
 880             break;
 881         }
 882         case A1_OP_SETOF:
 883         case A1_OP_SEQOF: {
 884             struct template_of *el = DPO(data, t->offset);
 885             size_t ellen = sizeofType(t->ptr);
 886             unsigned char *element = el->val;
 887             unsigned int i;
 888
 889             for (i = 0; i < el->len; i++) {
 890                 _asn1_free(t->ptr, element);
 891                 element += ellen;
 892             }
 893             free(el->val);
 894             el->val = NULL;
 895             el->len = 0;
 896
 897             break;
 898         }
 899         case A1_OP_BMEMBER:
 900             break;
 901         case A1_OP_CHOICE: {
 902             const struct asn1_template *choice = t->ptr;
 903             const unsigned int *element = DPOC(data, choice->offset);
 904
 905             if (*element > A1_HEADER_LEN(choice))
 906                 break;
 907
 908             if (*element == 0) {
 909                 der_free_octet_string(DPO(data, choice->tt));
 910             } else {
 911                 choice += *element;
 912                 _asn1_free(choice->ptr, DPO(data, choice->offset));
 913             }
 914             break;
 915         }
 916         default:
 917             ABORT_ON_ERROR();
 918             break;
 919         }
 920         t++;
 921         elements--;
 922     }
 923 }
 924
 925 int
 926 _asn1_copy(const struct asn1_template *t, const void *from, void *to)
 927 {
 928     size_t elements = A1_HEADER_LEN(t);
 929     int ret = 0;
 930     int preserve = (t->tt & A1_HF_PRESERVE);
 931
 932     t++;
 933
 934     if (preserve) {
 935         ret = der_copy_octet_string(from, to);
 936         if (ret)
 937             return ret;
 938     }
 939
 940     while (elements) {
 941         switch (t->tt & A1_OP_MASK) {
 942         case A1_OP_TYPE:
 943         case A1_OP_TYPE_EXTERN: {
 944             const void *fel = DPOC(from, t->offset);
 945             void *tel = DPO(to, t->offset);
 946             void **ptel = (void **)tel;
 947             size_t size;
 948
 949             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 950                 size = sizeofType(t->ptr);
 951             } else {
 952                 const struct asn1_type_func *f = t->ptr;
 953                 size = f->size;
 954             }
 955
 956             if (t->tt & A1_FLAG_OPTIONAL) {
 957                 void **pfel = (void **)fel;
 958                 if (*pfel == NULL)
 959                     break;
 960                 fel = *pfel;
 961
 962                 tel = *ptel = calloc(1, size);
 963                 if (tel == NULL)
 964                     return ENOMEM;
 965             }
 966
 967             if ((t->tt & A1_OP_MASK) == A1_OP_TYPE) {
 968                 ret = _asn1_copy(t->ptr, fel, tel);
 969             } else {
 970                 const struct asn1_type_func *f = t->ptr;
 971                 ret = (f->copy)(fel, tel);
 972             }
 973
 974             if (ret) {
 975                 if (t->tt & A1_FLAG_OPTIONAL) {
 976                     free(*ptel);
 977                     *ptel = NULL;
 978                 }
 979                 return ret;
 980             }
 981             break;
 982         }
 983         case A1_OP_PARSE: {
 984             unsigned int type = A1_PARSE_TYPE(t->tt);
 985             const void *fel = DPOC(from, t->offset);
 986             void *tel = DPO(to, t->offset);
 987
 988             if (type > sizeof(prim)/sizeof(prim[0])) {
 989                 ABORT_ON_ERROR();
 990                 return ASN1_PARSE_ERROR;
 991             }
 992             ret = (prim[type].copy)(fel, tel);
 993             if (ret)
 994                 return ret;
 995             break;
 996         }
 997         case A1_OP_TAG: {
 998             const void *oldfrom = from;
 999             void *oldto = to;
1000             void **tel = NULL;
1001
1002             from = DPOC(from, t->offset);
1003             to = DPO(to, t->offset);
1004
1005             if (t->tt & A1_FLAG_OPTIONAL) {
1006                 void **fel = (void **)from;
1007                 tel = (void **)to;
1008                 if (*fel == NULL) {
1009                     from = oldfrom;
1010                     to = oldto;
1011                     break;
1012                 }
1013                 from = *fel;
1014
1015                 to = *tel = calloc(1, sizeofType(t->ptr));
1016                 if (to == NULL)
1017                     return ENOMEM;
1018             }
1019
1020             ret = _asn1_copy(t->ptr, from, to);
1021             if (ret) {
1022                 if (t->tt & A1_FLAG_OPTIONAL) {
1023                     free(*tel);
1024                     *tel = NULL;
1025                 }
1026                 return ret;
1027             }
1028
1029             from = oldfrom;
1030             to = oldto;
1031
1032             break;
1033         }
1034         case A1_OP_SETOF:
1035         case A1_OP_SEQOF: {
1036             const struct template_of *fel = DPOC(from, t->offset);
1037             struct template_of *tel = DPO(to, t->offset);
1038             size_t ellen = sizeofType(t->ptr);
1039             unsigned int i;
1040
1041             tel->val = calloc(fel->len, ellen);
1042             if (tel->val == NULL)
1043                 return ENOMEM;
1044
1045             tel->len = fel->len;
1046
1047             for (i = 0; i < fel->len; i++) {
1048                 ret = _asn1_copy(t->ptr,
1049                                  DPOC(fel->val, (i * ellen)),
1050                                  DPO(tel->val, (i *ellen)));
1051                 if (ret)
1052                     return ret;
1053             }
1054             break;
1055         }
1056         case A1_OP_BMEMBER: {
1057             const struct asn1_template *bmember = t->ptr;
1058             size_t size = bmember->offset;
1059             memcpy(to, from, size);
1060             break;
1061         }
1062         case A1_OP_CHOICE: {
1063             const struct asn1_template *choice = t->ptr;
1064             const unsigned int *felement = DPOC(from, choice->offset);
1065             unsigned int *telement = DPO(to, choice->offset);
1066
1067             if (*felement > A1_HEADER_LEN(choice))
1068                 return ASN1_PARSE_ERROR;
1069
1070             *telement = *felement;
1071
1072             if (*felement == 0) {
1073                 ret = der_copy_octet_string(DPOC(from, choice->tt), DPO(to, choice->tt));
1074             } else {
1075                 choice += *felement;
1076                 ret = _asn1_copy(choice->ptr,
1077                                  DPOC(from, choice->offset),
1078                                  DPO(to, choice->offset));
1079             }
1080             if (ret)
1081                 return ret;
1082             break;
1083         }
1084         default:
1085             ABORT_ON_ERROR();
1086             break;
1087         }
1088         t++;
1089         elements--;
1090     }
1091     return 0;
1092 }
1093
1094 int
1095 _asn1_decode_top(const struct asn1_template *t, unsigned flags, const unsigned char *p, size_t len, void *data, size_t *size)
1096 {
1097     int ret;
1098     memset(data, 0, t->offset);
1099     ret = _asn1_decode(t, flags, p, len, data, size);
1100     if (ret) {
1101         _asn1_free(t, data);
1102         memset(data, 0, t->offset);
1103     }
1104
1105     return ret;
1106 }
1107
1108 int
1109 _asn1_copy_top(const struct asn1_template *t, const void *from, void *to)
1110 {
1111     int ret;
1112     memset(to, 0, t->offset);
1113     ret = _asn1_copy(t, from, to);
1114     if (ret) {
1115         _asn1_free(t, to);
1116         memset(to, 0, t->offset);
1117     }
1118     return ret;
1119 }