crypto/x509/v3_asid.c

   1 /*
   2  * Copyright 2006-2021 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 /*
  11  * Implementation of RFC 3779 section 3.2.
  12  */
  13
  14 #include <assert.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include "internal/cryptlib.h"
  18 #include <openssl/conf.h>
  19 #include <openssl/asn1.h>
  20 #include <openssl/asn1t.h>
  21 #include <openssl/x509v3.h>
  22 #include <openssl/x509.h>
  23 #include "crypto/x509.h"
  24 #include <openssl/bn.h>
  25 #include "ext_dat.h"
  26 #include "x509_local.h"
  27
  28 #ifndef OPENSSL_NO_RFC3779
  29
  30 /*
  31  * OpenSSL ASN.1 template translation of RFC 3779 3.2.3.
  32  */
  33
  34 ASN1_SEQUENCE(ASRange) = {
  35   ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),
  36   ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)
  37 } ASN1_SEQUENCE_END(ASRange)
  38
  39 ASN1_CHOICE(ASIdOrRange) = {
  40   ASN1_SIMPLE(ASIdOrRange, u.id,    ASN1_INTEGER),
  41   ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)
  42 } ASN1_CHOICE_END(ASIdOrRange)
  43
  44 ASN1_CHOICE(ASIdentifierChoice) = {
  45   ASN1_SIMPLE(ASIdentifierChoice,      u.inherit,       ASN1_NULL),
  46   ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)
  47 } ASN1_CHOICE_END(ASIdentifierChoice)
  48
  49 ASN1_SEQUENCE(ASIdentifiers) = {
  50   ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),
  51   ASN1_EXP_OPT(ASIdentifiers, rdi,   ASIdentifierChoice, 1)
  52 } ASN1_SEQUENCE_END(ASIdentifiers)
  53
  54 IMPLEMENT_ASN1_FUNCTIONS(ASRange)
  55 IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)
  56 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)
  57 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)
  58
  59 /*
  60  * i2r method for an ASIdentifierChoice.
  61  */
  62 static int i2r_ASIdentifierChoice(BIO *out,
  63                                   ASIdentifierChoice *choice,
  64                                   int indent, const char *msg)
  65 {
  66     int i;
  67     char *s;
  68     if (choice == NULL)
  69         return 1;
  70     BIO_printf(out, "%*s%s:\n", indent, "", msg);
  71     switch (choice->type) {
  72     case ASIdentifierChoice_inherit:
  73         BIO_printf(out, "%*sinherit\n", indent + 2, "");
  74         break;
  75     case ASIdentifierChoice_asIdsOrRanges:
  76         for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {
  77             ASIdOrRange *aor =
  78                 sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
  79             switch (aor->type) {
  80             case ASIdOrRange_id:
  81                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)
  82                     return 0;
  83                 BIO_printf(out, "%*s%s\n", indent + 2, "", s);
  84                 OPENSSL_free(s);
  85                 break;
  86             case ASIdOrRange_range:
  87                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)
  88                     return 0;
  89                 BIO_printf(out, "%*s%s-", indent + 2, "", s);
  90                 OPENSSL_free(s);
  91                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)
  92                     return 0;
  93                 BIO_printf(out, "%s\n", s);
  94                 OPENSSL_free(s);
  95                 break;
  96             default:
  97                 return 0;
  98             }
  99         }
 100         break;
 101     default:
 102         return 0;
 103     }
 104     return 1;
 105 }
 106
 107 /*
 108  * i2r method for an ASIdentifier extension.
 109  */
 110 static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,
 111                              void *ext, BIO *out, int indent)
 112 {
 113     ASIdentifiers *asid = ext;
 114     return (i2r_ASIdentifierChoice(out, asid->asnum, indent,
 115                                    "Autonomous System Numbers") &&
 116             i2r_ASIdentifierChoice(out, asid->rdi, indent,
 117                                    "Routing Domain Identifiers"));
 118 }
 119
 120 /*
 121  * Sort comparison function for a sequence of ASIdOrRange elements.
 122  */
 123 static int ASIdOrRange_cmp(const ASIdOrRange *const *a_,
 124                            const ASIdOrRange *const *b_)
 125 {
 126     const ASIdOrRange *a = *a_, *b = *b_;
 127
 128     assert((a->type == ASIdOrRange_id && a->u.id != NULL) ||
 129            (a->type == ASIdOrRange_range && a->u.range != NULL &&
 130             a->u.range->min != NULL && a->u.range->max != NULL));
 131
 132     assert((b->type == ASIdOrRange_id && b->u.id != NULL) ||
 133            (b->type == ASIdOrRange_range && b->u.range != NULL &&
 134             b->u.range->min != NULL && b->u.range->max != NULL));
 135
 136     if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)
 137         return ASN1_INTEGER_cmp(a->u.id, b->u.id);
 138
 139     if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {
 140         int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);
 141         return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,
 142                                              b->u.range->max);
 143     }
 144
 145     if (a->type == ASIdOrRange_id)
 146         return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);
 147     else
 148         return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);
 149 }
 150
 151 /*
 152  * Add an inherit element.
 153  */
 154 int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)
 155 {
 156     ASIdentifierChoice **choice;
 157     if (asid == NULL)
 158         return 0;
 159     switch (which) {
 160     case V3_ASID_ASNUM:
 161         choice = &asid->asnum;
 162         break;
 163     case V3_ASID_RDI:
 164         choice = &asid->rdi;
 165         break;
 166     default:
 167         return 0;
 168     }
 169     if (*choice == NULL) {
 170         if ((*choice = ASIdentifierChoice_new()) == NULL)
 171             return 0;
 172         if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL)
 173             return 0;
 174         (*choice)->type = ASIdentifierChoice_inherit;
 175     }
 176     return (*choice)->type == ASIdentifierChoice_inherit;
 177 }
 178
 179 /*
 180  * Add an ID or range to an ASIdentifierChoice.
 181  */
 182 int X509v3_asid_add_id_or_range(ASIdentifiers *asid,
 183                                 int which, ASN1_INTEGER *min, ASN1_INTEGER *max)
 184 {
 185     ASIdentifierChoice **choice;
 186     ASIdOrRange *aor;
 187     if (asid == NULL)
 188         return 0;
 189     switch (which) {
 190     case V3_ASID_ASNUM:
 191         choice = &asid->asnum;
 192         break;
 193     case V3_ASID_RDI:
 194         choice = &asid->rdi;
 195         break;
 196     default:
 197         return 0;
 198     }
 199     if (*choice != NULL && (*choice)->type == ASIdentifierChoice_inherit)
 200         return 0;
 201     if (*choice == NULL) {
 202         if ((*choice = ASIdentifierChoice_new()) == NULL)
 203             return 0;
 204         (*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);
 205         if ((*choice)->u.asIdsOrRanges == NULL)
 206             return 0;
 207         (*choice)->type = ASIdentifierChoice_asIdsOrRanges;
 208     }
 209     if ((aor = ASIdOrRange_new()) == NULL)
 210         return 0;
 211     if (max == NULL) {
 212         aor->type = ASIdOrRange_id;
 213         aor->u.id = min;
 214     } else {
 215         aor->type = ASIdOrRange_range;
 216         if ((aor->u.range = ASRange_new()) == NULL)
 217             goto err;
 218         ASN1_INTEGER_free(aor->u.range->min);
 219         aor->u.range->min = min;
 220         ASN1_INTEGER_free(aor->u.range->max);
 221         aor->u.range->max = max;
 222     }
 223     if (!(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))
 224         goto err;
 225     return 1;
 226
 227  err:
 228     ASIdOrRange_free(aor);
 229     return 0;
 230 }
 231
 232 /*
 233  * Extract min and max values from an ASIdOrRange.
 234  */
 235 static int extract_min_max(ASIdOrRange *aor,
 236                            ASN1_INTEGER **min, ASN1_INTEGER **max)
 237 {
 238     if (!ossl_assert(aor != NULL))
 239         return 0;
 240     switch (aor->type) {
 241     case ASIdOrRange_id:
 242         *min = aor->u.id;
 243         *max = aor->u.id;
 244         return 1;
 245     case ASIdOrRange_range:
 246         *min = aor->u.range->min;
 247         *max = aor->u.range->max;
 248         return 1;
 249     }
 250
 251     return 0;
 252 }
 253
 254 /*
 255  * Check whether an ASIdentifierChoice is in canonical form.
 256  */
 257 static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)
 258 {
 259     ASN1_INTEGER *a_max_plus_one = NULL;
 260     ASN1_INTEGER *orig;
 261     BIGNUM *bn = NULL;
 262     int i, ret = 0;
 263
 264     /*
 265      * Empty element or inheritance is canonical.
 266      */
 267     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
 268         return 1;
 269
 270     /*
 271      * If not a list, or if empty list, it's broken.
 272      */
 273     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
 274         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)
 275         return 0;
 276
 277     /*
 278      * It's a list, check it.
 279      */
 280     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
 281         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
 282         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
 283         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
 284             NULL;
 285
 286         if (!extract_min_max(a, &a_min, &a_max)
 287                 || !extract_min_max(b, &b_min, &b_max))
 288             goto done;
 289
 290         /*
 291          * Punt misordered list, overlapping start, or inverted range.
 292          */
 293         if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 ||
 294             ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
 295             ASN1_INTEGER_cmp(b_min, b_max) > 0)
 296             goto done;
 297
 298         /*
 299          * Calculate a_max + 1 to check for adjacency.
 300          */
 301         if ((bn == NULL && (bn = BN_new()) == NULL) ||
 302             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
 303             !BN_add_word(bn, 1)) {
 304             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 305             goto done;
 306         }
 307
 308         if ((a_max_plus_one =
 309                 BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
 310             a_max_plus_one = orig;
 311             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 312             goto done;
 313         }
 314
 315         /*
 316          * Punt if adjacent or overlapping.
 317          */
 318         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)
 319             goto done;
 320     }
 321
 322     /*
 323      * Check for inverted range.
 324      */
 325     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
 326     {
 327         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
 328         ASN1_INTEGER *a_min, *a_max;
 329         if (a != NULL && a->type == ASIdOrRange_range) {
 330             if (!extract_min_max(a, &a_min, &a_max)
 331                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
 332                 goto done;
 333         }
 334     }
 335
 336     ret = 1;
 337
 338  done:
 339     ASN1_INTEGER_free(a_max_plus_one);
 340     BN_free(bn);
 341     return ret;
 342 }
 343
 344 /*
 345  * Check whether an ASIdentifier extension is in canonical form.
 346  */
 347 int X509v3_asid_is_canonical(ASIdentifiers *asid)
 348 {
 349     return (asid == NULL ||
 350             (ASIdentifierChoice_is_canonical(asid->asnum) &&
 351              ASIdentifierChoice_is_canonical(asid->rdi)));
 352 }
 353
 354 /*
 355  * Whack an ASIdentifierChoice into canonical form.
 356  */
 357 static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)
 358 {
 359     ASN1_INTEGER *a_max_plus_one = NULL;
 360     ASN1_INTEGER *orig;
 361     BIGNUM *bn = NULL;
 362     int i, ret = 0;
 363
 364     /*
 365      * Nothing to do for empty element or inheritance.
 366      */
 367     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
 368         return 1;
 369
 370     /*
 371      * If not a list, or if empty list, it's broken.
 372      */
 373     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
 374         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {
 375         ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
 376         return 0;
 377     }
 378
 379     /*
 380      * We have a non-empty list.  Sort it.
 381      */
 382     sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);
 383
 384     /*
 385      * Now check for errors and suboptimal encoding, rejecting the
 386      * former and fixing the latter.
 387      */
 388     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
 389         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
 390         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
 391         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
 392             NULL;
 393
 394         if (!extract_min_max(a, &a_min, &a_max)
 395                 || !extract_min_max(b, &b_min, &b_max))
 396             goto done;
 397
 398         /*
 399          * Make sure we're properly sorted (paranoia).
 400          */
 401         if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))
 402             goto done;
 403
 404         /*
 405          * Punt inverted ranges.
 406          */
 407         if (ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
 408             ASN1_INTEGER_cmp(b_min, b_max) > 0)
 409             goto done;
 410
 411         /*
 412          * Check for overlaps.
 413          */
 414         if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {
 415             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
 416             goto done;
 417         }
 418
 419         /*
 420          * Calculate a_max + 1 to check for adjacency.
 421          */
 422         if ((bn == NULL && (bn = BN_new()) == NULL) ||
 423             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
 424             !BN_add_word(bn, 1)) {
 425             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 426             goto done;
 427         }
 428
 429         if ((a_max_plus_one =
 430                  BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
 431             a_max_plus_one = orig;
 432             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 433             goto done;
 434         }
 435
 436         /*
 437          * If a and b are adjacent, merge them.
 438          */
 439         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {
 440             ASRange *r;
 441             switch (a->type) {
 442             case ASIdOrRange_id:
 443                 if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {
 444                     ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 445                     goto done;
 446                 }
 447                 r->min = a_min;
 448                 r->max = b_max;
 449                 a->type = ASIdOrRange_range;
 450                 a->u.range = r;
 451                 break;
 452             case ASIdOrRange_range:
 453                 ASN1_INTEGER_free(a->u.range->max);
 454                 a->u.range->max = b_max;
 455                 break;
 456             }
 457             switch (b->type) {
 458             case ASIdOrRange_id:
 459                 b->u.id = NULL;
 460                 break;
 461             case ASIdOrRange_range:
 462                 b->u.range->max = NULL;
 463                 break;
 464             }
 465             ASIdOrRange_free(b);
 466             (void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);
 467             i--;
 468             continue;
 469         }
 470     }
 471
 472     /*
 473      * Check for final inverted range.
 474      */
 475     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
 476     {
 477         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
 478         ASN1_INTEGER *a_min, *a_max;
 479         if (a != NULL && a->type == ASIdOrRange_range) {
 480             if (!extract_min_max(a, &a_min, &a_max)
 481                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
 482                 goto done;
 483         }
 484     }
 485
 486     /* Paranoia */
 487     if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))
 488         goto done;
 489
 490     ret = 1;
 491
 492  done:
 493     ASN1_INTEGER_free(a_max_plus_one);
 494     BN_free(bn);
 495     return ret;
 496 }
 497
 498 /*
 499  * Whack an ASIdentifier extension into canonical form.
 500  */
 501 int X509v3_asid_canonize(ASIdentifiers *asid)
 502 {
 503     return (asid == NULL ||
 504             (ASIdentifierChoice_canonize(asid->asnum) &&
 505              ASIdentifierChoice_canonize(asid->rdi)));
 506 }
 507
 508 /*
 509  * v2i method for an ASIdentifier extension.
 510  */
 511 static void *v2i_ASIdentifiers(const struct v3_ext_method *method,
 512                                struct v3_ext_ctx *ctx,
 513                                STACK_OF(CONF_VALUE) *values)
 514 {
 515     ASN1_INTEGER *min = NULL, *max = NULL;
 516     ASIdentifiers *asid = NULL;
 517     int i;
 518
 519     if ((asid = ASIdentifiers_new()) == NULL) {
 520         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 521         return NULL;
 522     }
 523
 524     for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
 525         CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
 526         int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;
 527
 528         /*
 529          * Figure out whether this is an AS or an RDI.
 530          */
 531         if (!ossl_v3_name_cmp(val->name, "AS")) {
 532             which = V3_ASID_ASNUM;
 533         } else if (!ossl_v3_name_cmp(val->name, "RDI")) {
 534             which = V3_ASID_RDI;
 535         } else {
 536             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NAME_ERROR);
 537             X509V3_conf_add_error_name_value(val);
 538             goto err;
 539         }
 540
 541         /*
 542          * Handle inheritance.
 543          */
 544         if (strcmp(val->value, "inherit") == 0) {
 545             if (X509v3_asid_add_inherit(asid, which))
 546                 continue;
 547             ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_INHERITANCE);
 548             X509V3_conf_add_error_name_value(val);
 549             goto err;
 550         }
 551
 552         /*
 553          * Number, range, or mistake, pick it apart and figure out which.
 554          */
 555         i1 = strspn(val->value, "0123456789");
 556         if (val->value[i1] == '\0') {
 557             is_range = 0;
 558         } else {
 559             is_range = 1;
 560             i2 = i1 + strspn(val->value + i1, " \t");
 561             if (val->value[i2] != '-') {
 562                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASNUMBER);
 563                 X509V3_conf_add_error_name_value(val);
 564                 goto err;
 565             }
 566             i2++;
 567             i2 = i2 + strspn(val->value + i2, " \t");
 568             i3 = i2 + strspn(val->value + i2, "0123456789");
 569             if (val->value[i3] != '\0') {
 570                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASRANGE);
 571                 X509V3_conf_add_error_name_value(val);
 572                 goto err;
 573             }
 574         }
 575
 576         /*
 577          * Syntax is ok, read and add it.
 578          */
 579         if (!is_range) {
 580             if (!X509V3_get_value_int(val, &min)) {
 581                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 582                 goto err;
 583             }
 584         } else {
 585             char *s = OPENSSL_strdup(val->value);
 586             if (s == NULL) {
 587                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 588                 goto err;
 589             }
 590             s[i1] = '\0';
 591             min = s2i_ASN1_INTEGER(NULL, s);
 592             max = s2i_ASN1_INTEGER(NULL, s + i2);
 593             OPENSSL_free(s);
 594             if (min == NULL || max == NULL) {
 595                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 596                 goto err;
 597             }
 598             if (ASN1_INTEGER_cmp(min, max) > 0) {
 599                 ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
 600                 goto err;
 601             }
 602         }
 603         if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {
 604             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 605             goto err;
 606         }
 607         min = max = NULL;
 608     }
 609
 610     /*
 611      * Canonize the result, then we're done.
 612      */
 613     if (!X509v3_asid_canonize(asid))
 614         goto err;
 615     return asid;
 616
 617  err:
 618     ASIdentifiers_free(asid);
 619     ASN1_INTEGER_free(min);
 620     ASN1_INTEGER_free(max);
 621     return NULL;
 622 }
 623
 624 /*
 625  * OpenSSL dispatch.
 626  */
 627 const X509V3_EXT_METHOD ossl_v3_asid = {
 628     NID_sbgp_autonomousSysNum,  /* nid */
 629     0,                          /* flags */
 630     ASN1_ITEM_ref(ASIdentifiers), /* template */
 631     0, 0, 0, 0,                 /* old functions, ignored */
 632     0,                          /* i2s */
 633     0,                          /* s2i */
 634     0,                          /* i2v */
 635     v2i_ASIdentifiers,          /* v2i */
 636     i2r_ASIdentifiers,          /* i2r */
 637     0,                          /* r2i */
 638     NULL                        /* extension-specific data */
 639 };
 640
 641 /*
 642  * Figure out whether extension uses inheritance.
 643  */
 644 int X509v3_asid_inherits(ASIdentifiers *asid)
 645 {
 646     return (asid != NULL &&
 647             ((asid->asnum != NULL &&
 648               asid->asnum->type == ASIdentifierChoice_inherit) ||
 649              (asid->rdi != NULL &&
 650               asid->rdi->type == ASIdentifierChoice_inherit)));
 651 }
 652
 653 /*
 654  * Figure out whether parent contains child.
 655  */
 656 static int asid_contains(ASIdOrRanges *parent, ASIdOrRanges *child)
 657 {
 658     ASN1_INTEGER *p_min = NULL, *p_max = NULL, *c_min = NULL, *c_max = NULL;
 659     int p, c;
 660
 661     if (child == NULL || parent == child)
 662         return 1;
 663     if (parent == NULL)
 664         return 0;
 665
 666     p = 0;
 667     for (c = 0; c < sk_ASIdOrRange_num(child); c++) {
 668         if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))
 669             return 0;
 670         for (;; p++) {
 671             if (p >= sk_ASIdOrRange_num(parent))
 672                 return 0;
 673             if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,
 674                                  &p_max))
 675                 return 0;
 676             if (ASN1_INTEGER_cmp(p_max, c_max) < 0)
 677                 continue;
 678             if (ASN1_INTEGER_cmp(p_min, c_min) > 0)
 679                 return 0;
 680             break;
 681         }
 682     }
 683
 684     return 1;
 685 }
 686
 687 /*
 688  * Test whether a is a subset of b.
 689  */
 690 int X509v3_asid_subset(ASIdentifiers *a, ASIdentifiers *b)
 691 {
 692     int subset;
 693
 694     if (a == NULL || a == b)
 695         return 1;
 696
 697     if (b == NULL)
 698         return 0;
 699
 700     if (X509v3_asid_inherits(a) || X509v3_asid_inherits(b))
 701         return 0;
 702
 703     subset = a->asnum == NULL
 704              || (b->asnum != NULL
 705                  && asid_contains(b->asnum->u.asIdsOrRanges,
 706                                   a->asnum->u.asIdsOrRanges));
 707     if (!subset)
 708         return 0;
 709
 710     return a->rdi == NULL
 711            || (b->rdi != NULL
 712                && asid_contains(b->rdi->u.asIdsOrRanges,
 713                                 a->rdi->u.asIdsOrRanges));
 714 }
 715
 716 /*
 717  * Validation error handling via callback.
 718  */
 719 #define validation_err(_err_)           \
 720   do {                                  \
 721     if (ctx != NULL) {                  \
 722       ctx->error = _err_;               \
 723       ctx->error_depth = i;             \
 724       ctx->current_cert = x;            \
 725       ret = ctx->verify_cb(0, ctx);     \
 726     } else {                            \
 727       ret = 0;                          \
 728     }                                   \
 729     if (!ret)                           \
 730       goto done;                        \
 731   } while (0)
 732
 733 /*
 734  * Core code for RFC 3779 3.3 path validation.
 735  */
 736 static int asid_validate_path_internal(X509_STORE_CTX *ctx,
 737                                        STACK_OF(X509) *chain,
 738                                        ASIdentifiers *ext)
 739 {
 740     ASIdOrRanges *child_as = NULL, *child_rdi = NULL;
 741     int i, ret = 1, inherit_as = 0, inherit_rdi = 0;
 742     X509 *x;
 743
 744     if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)
 745             || !ossl_assert(ctx != NULL || ext != NULL)
 746             || !ossl_assert(ctx == NULL || ctx->verify_cb != NULL)) {
 747         if (ctx != NULL)
 748             ctx->error = X509_V_ERR_UNSPECIFIED;
 749         return 0;
 750     }
 751
 752
 753     /*
 754      * Figure out where to start.  If we don't have an extension to
 755      * check, we're done.  Otherwise, check canonical form and
 756      * set up for walking up the chain.
 757      */
 758     if (ext != NULL) {
 759         i = -1;
 760         x = NULL;
 761     } else {
 762         i = 0;
 763         x = sk_X509_value(chain, i);
 764         if ((ext = x->rfc3779_asid) == NULL)
 765             goto done;
 766     }
 767     if (!X509v3_asid_is_canonical(ext))
 768         validation_err(X509_V_ERR_INVALID_EXTENSION);
 769     if (ext->asnum != NULL) {
 770         switch (ext->asnum->type) {
 771         case ASIdentifierChoice_inherit:
 772             inherit_as = 1;
 773             break;
 774         case ASIdentifierChoice_asIdsOrRanges:
 775             child_as = ext->asnum->u.asIdsOrRanges;
 776             break;
 777         }
 778     }
 779     if (ext->rdi != NULL) {
 780         switch (ext->rdi->type) {
 781         case ASIdentifierChoice_inherit:
 782             inherit_rdi = 1;
 783             break;
 784         case ASIdentifierChoice_asIdsOrRanges:
 785             child_rdi = ext->rdi->u.asIdsOrRanges;
 786             break;
 787         }
 788     }
 789
 790     /*
 791      * Now walk up the chain.  Extensions must be in canonical form, no
 792      * cert may list resources that its parent doesn't list.
 793      */
 794     for (i++; i < sk_X509_num(chain); i++) {
 795         x = sk_X509_value(chain, i);
 796         if (!ossl_assert(x != NULL)) {
 797             if (ctx != NULL)
 798                 ctx->error = X509_V_ERR_UNSPECIFIED;
 799             return 0;
 800         }
 801         if (x->rfc3779_asid == NULL) {
 802             if (child_as != NULL || child_rdi != NULL)
 803                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 804             continue;
 805         }
 806         if (!X509v3_asid_is_canonical(x->rfc3779_asid))
 807             validation_err(X509_V_ERR_INVALID_EXTENSION);
 808         if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {
 809             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 810             child_as = NULL;
 811             inherit_as = 0;
 812         }
 813         if (x->rfc3779_asid->asnum != NULL &&
 814             x->rfc3779_asid->asnum->type ==
 815             ASIdentifierChoice_asIdsOrRanges) {
 816             if (inherit_as
 817                 || asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,
 818                                  child_as)) {
 819                 child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;
 820                 inherit_as = 0;
 821             } else {
 822                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 823             }
 824         }
 825         if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {
 826             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 827             child_rdi = NULL;
 828             inherit_rdi = 0;
 829         }
 830         if (x->rfc3779_asid->rdi != NULL &&
 831             x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {
 832             if (inherit_rdi ||
 833                 asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,
 834                               child_rdi)) {
 835                 child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;
 836                 inherit_rdi = 0;
 837             } else {
 838                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 839             }
 840         }
 841     }
 842
 843     /*
 844      * Trust anchor can't inherit.
 845      */
 846     if (!ossl_assert(x != NULL)) {
 847         if (ctx != NULL)
 848             ctx->error = X509_V_ERR_UNSPECIFIED;
 849         return 0;
 850     }
 851     if (x->rfc3779_asid != NULL) {
 852         if (x->rfc3779_asid->asnum != NULL &&
 853             x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)
 854             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 855         if (x->rfc3779_asid->rdi != NULL &&
 856             x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)
 857             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
 858     }
 859
 860  done:
 861     return ret;
 862 }
 863
 864 #undef validation_err
 865
 866 /*
 867  * RFC 3779 3.3 path validation -- called from X509_verify_cert().
 868  */
 869 int X509v3_asid_validate_path(X509_STORE_CTX *ctx)
 870 {
 871     if (ctx->chain == NULL
 872             || sk_X509_num(ctx->chain) == 0
 873             || ctx->verify_cb == NULL) {
 874         ctx->error = X509_V_ERR_UNSPECIFIED;
 875         return 0;
 876     }
 877     return asid_validate_path_internal(ctx, ctx->chain, NULL);
 878 }
 879
 880 /*
 881  * RFC 3779 3.3 path validation of an extension.
 882  * Test whether chain covers extension.
 883  */
 884 int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
 885                                       ASIdentifiers *ext, int allow_inheritance)
 886 {
 887     if (ext == NULL)
 888         return 1;
 889     if (chain == NULL || sk_X509_num(chain) == 0)
 890         return 0;
 891     if (!allow_inheritance && X509v3_asid_inherits(ext))
 892         return 0;
 893     return asid_validate_path_internal(NULL, chain, ext);
 894 }
 895
 896 #endif                          /* OPENSSL_NO_RFC3779 */