src/resolve/resolved-dns-trust-anchor.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2015 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include "sd-messages.h"
  21
  22 #include "alloc-util.h"
  23 #include "conf-files.h"
  24 #include "def.h"
  25 #include "dns-domain.h"
  26 #include "fd-util.h"
  27 #include "fileio.h"
  28 #include "hexdecoct.h"
  29 #include "parse-util.h"
  30 #include "resolved-dns-trust-anchor.h"
  31 #include "resolved-dns-dnssec.h"
  32 #include "set.h"
  33 #include "string-util.h"
  34 #include "strv.h"
  35
  36 static const char trust_anchor_dirs[] = CONF_PATHS_NULSTR("dnssec-trust-anchors.d");
  37
  38 /* The first DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved December 2015 */
  39 static const uint8_t root_digest1[] =
  40         { 0x49, 0xAA, 0xC1, 0x1D, 0x7B, 0x6F, 0x64, 0x46, 0x70, 0x2E, 0x54, 0xA1, 0x60, 0x73, 0x71, 0x60,
  41           0x7A, 0x1A, 0x41, 0x85, 0x52, 0x00, 0xFD, 0x2C, 0xE1, 0xCD, 0xDE, 0x32, 0xF2, 0x4E, 0x8F, 0xB5 };
  42
  43 /* The second DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved February 2017 */
  44 static const uint8_t root_digest2[] =
  45         { 0xE0, 0x6D, 0x44, 0xB8, 0x0B, 0x8F, 0x1D, 0x39, 0xA9, 0x5C, 0x0B, 0x0D, 0x7C, 0x65, 0xD0, 0x84,
  46           0x58, 0xE8, 0x80, 0x40, 0x9B, 0xBC, 0x68, 0x34, 0x57, 0x10, 0x42, 0x37, 0xC7, 0xF8, 0xEC, 0x8D };
  47
  48 static bool dns_trust_anchor_knows_domain_positive(DnsTrustAnchor *d, const char *name) {
  49         assert(d);
  50
  51         /* Returns true if there's an entry for the specified domain
  52          * name in our trust anchor */
  53
  54         return
  55                 hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DNSKEY, name)) ||
  56                 hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name));
  57 }
  58
  59 static int add_root_ksk(
  60                 DnsAnswer *answer,
  61                 DnsResourceKey *key,
  62                 uint16_t key_tag,
  63                 uint8_t algorithm,
  64                 uint8_t digest_type,
  65                 const void *digest,
  66                 size_t digest_size) {
  67
  68         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
  69         int r;
  70
  71         rr = dns_resource_record_new(key);
  72         if (!rr)
  73                 return -ENOMEM;
  74
  75         rr->ds.key_tag = key_tag;
  76         rr->ds.algorithm = algorithm;
  77         rr->ds.digest_type = digest_type;
  78         rr->ds.digest_size = digest_size;
  79         rr->ds.digest = memdup(digest, rr->ds.digest_size);
  80         if (!rr->ds.digest)
  81                 return  -ENOMEM;
  82
  83         r = dns_answer_add(answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
  84         if (r < 0)
  85                 return r;
  86
  87         return 0;
  88 }
  89
  90 static int dns_trust_anchor_add_builtin_positive(DnsTrustAnchor *d) {
  91         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
  92         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
  93         int r;
  94
  95         assert(d);
  96
  97         r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops);
  98         if (r < 0)
  99                 return r;
 100
 101         /* Only add the built-in trust anchor if there's neither a DS nor a DNSKEY defined for the root domain. That
 102          * way users have an easy way to override the root domain DS/DNSKEY data. */
 103         if (dns_trust_anchor_knows_domain_positive(d, "."))
 104                 return 0;
 105
 106         key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_DS, "");
 107         if (!key)
 108                 return -ENOMEM;
 109
 110         answer = dns_answer_new(2);
 111         if (!answer)
 112                 return -ENOMEM;
 113
 114         /* Add the two RRs from https://data.iana.org/root-anchors/root-anchors.xml */
 115         r = add_root_ksk(answer, key, 19036, DNSSEC_ALGORITHM_RSASHA256, DNSSEC_DIGEST_SHA256, root_digest1, sizeof(root_digest1));
 116         if (r < 0)
 117                 return r;
 118
 119         r = add_root_ksk(answer, key, 20326, DNSSEC_ALGORITHM_RSASHA256, DNSSEC_DIGEST_SHA256, root_digest2, sizeof(root_digest2));
 120         if (r < 0)
 121                 return r;
 122
 123         r = hashmap_put(d->positive_by_key, key, answer);
 124         if (r < 0)
 125                 return r;
 126
 127         answer = NULL;
 128         return 0;
 129 }
 130
 131 static int dns_trust_anchor_add_builtin_negative(DnsTrustAnchor *d) {
 132
 133         static const char private_domains[] =
 134                 /* RFC 6761 says that .test is a special domain for
 135                  * testing and not to be installed in the root zone */
 136                 "test\0"
 137
 138                 /* RFC 6761 says that these reverse IP lookup ranges
 139                  * are for private addresses, and hence should not
 140                  * show up in the root zone */
 141                 "10.in-addr.arpa\0"
 142                 "16.172.in-addr.arpa\0"
 143                 "17.172.in-addr.arpa\0"
 144                 "18.172.in-addr.arpa\0"
 145                 "19.172.in-addr.arpa\0"
 146                 "20.172.in-addr.arpa\0"
 147                 "21.172.in-addr.arpa\0"
 148                 "22.172.in-addr.arpa\0"
 149                 "23.172.in-addr.arpa\0"
 150                 "24.172.in-addr.arpa\0"
 151                 "25.172.in-addr.arpa\0"
 152                 "26.172.in-addr.arpa\0"
 153                 "27.172.in-addr.arpa\0"
 154                 "28.172.in-addr.arpa\0"
 155                 "29.172.in-addr.arpa\0"
 156                 "30.172.in-addr.arpa\0"
 157                 "31.172.in-addr.arpa\0"
 158                 "168.192.in-addr.arpa\0"
 159
 160                 /* The same, but for IPv6. */
 161                 "d.f.ip6.arpa\0"
 162
 163                 /* RFC 6762 reserves the .local domain for Multicast
 164                  * DNS, it hence cannot appear in the root zone. (Note
 165                  * that we by default do not route .local traffic to
 166                  * DNS anyway, except when a configured search domain
 167                  * suggests so.) */
 168                 "local\0"
 169
 170                 /* These two are well known, popular private zone
 171                  * TLDs, that are blocked from delegation, according
 172                  * to:
 173                  * http://icannwiki.com/Name_Collision#NGPC_Resolution
 174                  *
 175                  * There's also ongoing work on making this official
 176                  * in an RRC:
 177                  * https://www.ietf.org/archive/id/draft-chapin-additional-reserved-tlds-02.txt */
 178                 "home\0"
 179                 "corp\0"
 180
 181                 /* The following four TLDs are suggested for private
 182                  * zones in RFC 6762, Appendix G, and are hence very
 183                  * unlikely to be made official TLDs any day soon */
 184                 "lan\0"
 185                 "intranet\0"
 186                 "internal\0"
 187                 "private\0";
 188
 189         const char *name;
 190         int r;
 191
 192         assert(d);
 193
 194         /* Only add the built-in trust anchor if there's no negative
 195          * trust anchor defined at all. This enables easy overriding
 196          * of negative trust anchors. */
 197
 198         if (set_size(d->negative_by_name) > 0)
 199                 return 0;
 200
 201         r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops);
 202         if (r < 0)
 203                 return r;
 204
 205         /* We add a couple of domains as default negative trust
 206          * anchors, where it's very unlikely they will be installed in
 207          * the root zone. If they exist they must be private, and thus
 208          * unsigned. */
 209
 210         NULSTR_FOREACH(name, private_domains) {
 211
 212                 if (dns_trust_anchor_knows_domain_positive(d, name))
 213                         continue;
 214
 215                 r = set_put_strdup(d->negative_by_name, name);
 216                 if (r < 0)
 217                         return r;
 218         }
 219
 220         return 0;
 221 }
 222
 223 static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) {
 224         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
 225         _cleanup_free_ char *domain = NULL, *class = NULL, *type = NULL;
 226         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
 227         DnsAnswer *old_answer = NULL;
 228         const char *p = s;
 229         int r;
 230
 231         assert(d);
 232         assert(line);
 233
 234         r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES);
 235         if (r < 0)
 236                 return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line);
 237
 238         if (!dns_name_is_valid(domain)) {
 239                 log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line);
 240                 return -EINVAL;
 241         }
 242
 243         r = extract_many_words(&p, NULL, 0, &class, &type, NULL);
 244         if (r < 0)
 245                 return log_warning_errno(r, "Unable to parse class and type in line %s:%u: %m", path, line);
 246         if (r != 2) {
 247                 log_warning("Missing class or type in line %s:%u", path, line);
 248                 return -EINVAL;
 249         }
 250
 251         if (!strcaseeq(class, "IN")) {
 252                 log_warning("RR class %s is not supported, ignoring line %s:%u.", class, path, line);
 253                 return -EINVAL;
 254         }
 255
 256         if (strcaseeq(type, "DS")) {
 257                 _cleanup_free_ char *key_tag = NULL, *algorithm = NULL, *digest_type = NULL, *digest = NULL;
 258                 _cleanup_free_ void *dd = NULL;
 259                 uint16_t kt;
 260                 int a, dt;
 261                 size_t l;
 262
 263                 r = extract_many_words(&p, NULL, 0, &key_tag, &algorithm, &digest_type, &digest, NULL);
 264                 if (r < 0) {
 265                         log_warning_errno(r, "Failed to parse DS parameters on line %s:%u: %m", path, line);
 266                         return -EINVAL;
 267                 }
 268                 if (r != 4) {
 269                         log_warning("Missing DS parameters on line %s:%u", path, line);
 270                         return -EINVAL;
 271                 }
 272
 273                 r = safe_atou16(key_tag, &kt);
 274                 if (r < 0)
 275                         return log_warning_errno(r, "Failed to parse DS key tag %s on line %s:%u: %m", key_tag, path, line);
 276
 277                 a = dnssec_algorithm_from_string(algorithm);
 278                 if (a < 0) {
 279                         log_warning("Failed to parse DS algorithm %s on line %s:%u", algorithm, path, line);
 280                         return -EINVAL;
 281                 }
 282
 283                 dt = dnssec_digest_from_string(digest_type);
 284                 if (dt < 0) {
 285                         log_warning("Failed to parse DS digest type %s on line %s:%u", digest_type, path, line);
 286                         return -EINVAL;
 287                 }
 288
 289                 r = unhexmem(digest, strlen(digest), &dd, &l);
 290                 if (r < 0) {
 291                         log_warning("Failed to parse DS digest %s on line %s:%u", digest, path, line);
 292                         return -EINVAL;
 293                 }
 294
 295                 rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, domain);
 296                 if (!rr)
 297                         return log_oom();
 298
 299                 rr->ds.key_tag = kt;
 300                 rr->ds.algorithm = a;
 301                 rr->ds.digest_type = dt;
 302                 rr->ds.digest_size = l;
 303                 rr->ds.digest = dd;
 304                 dd = NULL;
 305
 306         } else if (strcaseeq(type, "DNSKEY")) {
 307                 _cleanup_free_ char *flags = NULL, *protocol = NULL, *algorithm = NULL, *key = NULL;
 308                 _cleanup_free_ void *k = NULL;
 309                 uint16_t f;
 310                 size_t l;
 311                 int a;
 312
 313                 r = extract_many_words(&p, NULL, 0, &flags, &protocol, &algorithm, &key, NULL);
 314                 if (r < 0)
 315                         return log_warning_errno(r, "Failed to parse DNSKEY parameters on line %s:%u: %m", path, line);
 316                 if (r != 4) {
 317                         log_warning("Missing DNSKEY parameters on line %s:%u", path, line);
 318                         return -EINVAL;
 319                 }
 320
 321                 if (!streq(protocol, "3")) {
 322                         log_warning("DNSKEY Protocol is not 3 on line %s:%u", path, line);
 323                         return -EINVAL;
 324                 }
 325
 326                 r = safe_atou16(flags, &f);
 327                 if (r < 0)
 328                         return log_warning_errno(r, "Failed to parse DNSKEY flags field %s on line %s:%u", flags, path, line);
 329                 if ((f & DNSKEY_FLAG_ZONE_KEY) == 0) {
 330                         log_warning("DNSKEY lacks zone key bit set on line %s:%u", path, line);
 331                         return -EINVAL;
 332                 }
 333                 if ((f & DNSKEY_FLAG_REVOKE)) {
 334                         log_warning("DNSKEY is already revoked on line %s:%u", path, line);
 335                         return -EINVAL;
 336                 }
 337
 338                 a = dnssec_algorithm_from_string(algorithm);
 339                 if (a < 0) {
 340                         log_warning("Failed to parse DNSKEY algorithm %s on line %s:%u", algorithm, path, line);
 341                         return -EINVAL;
 342                 }
 343
 344                 r = unbase64mem(key, strlen(key), &k, &l);
 345                 if (r < 0)
 346                         return log_warning_errno(r, "Failed to parse DNSKEY key data %s on line %s:%u", key, path, line);
 347
 348                 rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, domain);
 349                 if (!rr)
 350                         return log_oom();
 351
 352                 rr->dnskey.flags = f;
 353                 rr->dnskey.protocol = 3;
 354                 rr->dnskey.algorithm = a;
 355                 rr->dnskey.key_size = l;
 356                 rr->dnskey.key = k;
 357                 k = NULL;
 358
 359         } else {
 360                 log_warning("RR type %s is not supported, ignoring line %s:%u.", type, path, line);
 361                 return -EINVAL;
 362         }
 363
 364         if (!isempty(p)) {
 365                 log_warning("Trailing garbage on line %s:%u, ignoring line.", path, line);
 366                 return -EINVAL;
 367         }
 368
 369         r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops);
 370         if (r < 0)
 371                 return log_oom();
 372
 373         old_answer = hashmap_get(d->positive_by_key, rr->key);
 374         answer = dns_answer_ref(old_answer);
 375
 376         r = dns_answer_add_extend(&answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
 377         if (r < 0)
 378                 return log_error_errno(r, "Failed to add trust anchor RR: %m");
 379
 380         r = hashmap_replace(d->positive_by_key, rr->key, answer);
 381         if (r < 0)
 382                 return log_error_errno(r, "Failed to add answer to trust anchor: %m");
 383
 384         old_answer = dns_answer_unref(old_answer);
 385         answer = NULL;
 386
 387         return 0;
 388 }
 389
 390 static int dns_trust_anchor_load_negative(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) {
 391         _cleanup_free_ char *domain = NULL;
 392         const char *p = s;
 393         int r;
 394
 395         assert(d);
 396         assert(line);
 397
 398         r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES);
 399         if (r < 0)
 400                 return log_warning_errno(r, "Unable to parse line %s:%u: %m", path, line);
 401
 402         if (!dns_name_is_valid(domain)) {
 403                 log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line);
 404                 return -EINVAL;
 405         }
 406
 407         if (!isempty(p)) {
 408                 log_warning("Trailing garbage at line %s:%u, ignoring line.", path, line);
 409                 return -EINVAL;
 410         }
 411
 412         r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops);
 413         if (r < 0)
 414                 return log_oom();
 415
 416         r = set_put(d->negative_by_name, domain);
 417         if (r < 0)
 418                 return log_oom();
 419         if (r > 0)
 420                 domain = NULL;
 421
 422         return 0;
 423 }
 424
 425 static int dns_trust_anchor_load_files(
 426                 DnsTrustAnchor *d,
 427                 const char *suffix,
 428                 int (*loader)(DnsTrustAnchor *d, const char *path, unsigned n, const char *line)) {
 429
 430         _cleanup_strv_free_ char **files = NULL;
 431         char **f;
 432         int r;
 433
 434         assert(d);
 435         assert(suffix);
 436         assert(loader);
 437
 438         r = conf_files_list_nulstr(&files, suffix, NULL, 0, trust_anchor_dirs);
 439         if (r < 0)
 440                 return log_error_errno(r, "Failed to enumerate %s trust anchor files: %m", suffix);
 441
 442         STRV_FOREACH(f, files) {
 443                 _cleanup_fclose_ FILE *g = NULL;
 444                 char line[LINE_MAX];
 445                 unsigned n = 0;
 446
 447                 g = fopen(*f, "r");
 448                 if (!g) {
 449                         if (errno == ENOENT)
 450                                 continue;
 451
 452                         log_warning_errno(errno, "Failed to open %s: %m", *f);
 453                         continue;
 454                 }
 455
 456                 FOREACH_LINE(line, g, log_warning_errno(errno, "Failed to read %s, ignoring: %m", *f)) {
 457                         char *l;
 458
 459                         n++;
 460
 461                         l = strstrip(line);
 462                         if (isempty(l))
 463                                 continue;
 464
 465                         if (*l == ';')
 466                                 continue;
 467
 468                         (void) loader(d, *f, n, l);
 469                 }
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int domain_name_cmp(const void *a, const void *b) {
 476         char **x = (char**) a, **y = (char**) b;
 477
 478         return dns_name_compare_func(*x, *y);
 479 }
 480
 481 static int dns_trust_anchor_dump(DnsTrustAnchor *d) {
 482         DnsAnswer *a;
 483         Iterator i;
 484
 485         assert(d);
 486
 487         if (hashmap_isempty(d->positive_by_key))
 488                 log_info("No positive trust anchors defined.");
 489         else {
 490                 log_info("Positive Trust Anchors:");
 491                 HASHMAP_FOREACH(a, d->positive_by_key, i) {
 492                         DnsResourceRecord *rr;
 493
 494                         DNS_ANSWER_FOREACH(rr, a)
 495                                 log_info("%s", dns_resource_record_to_string(rr));
 496                 }
 497         }
 498
 499         if (set_isempty(d->negative_by_name))
 500                 log_info("No negative trust anchors defined.");
 501         else {
 502                 _cleanup_free_ char **l = NULL, *j = NULL;
 503
 504                 l = set_get_strv(d->negative_by_name);
 505                 if (!l)
 506                         return log_oom();
 507
 508                 qsort_safe(l, set_size(d->negative_by_name), sizeof(char*), domain_name_cmp);
 509
 510                 j = strv_join(l, " ");
 511                 if (!j)
 512                         return log_oom();
 513
 514                 log_info("Negative trust anchors: %s", j);
 515         }
 516
 517         return 0;
 518 }
 519
 520 int dns_trust_anchor_load(DnsTrustAnchor *d) {
 521         int r;
 522
 523         assert(d);
 524
 525         /* If loading things from disk fails, we don't consider this fatal */
 526         (void) dns_trust_anchor_load_files(d, ".positive", dns_trust_anchor_load_positive);
 527         (void) dns_trust_anchor_load_files(d, ".negative", dns_trust_anchor_load_negative);
 528
 529         /* However, if the built-in DS fails, then we have a problem. */
 530         r = dns_trust_anchor_add_builtin_positive(d);
 531         if (r < 0)
 532                 return log_error_errno(r, "Failed to add built-in positive trust anchor: %m");
 533
 534         r = dns_trust_anchor_add_builtin_negative(d);
 535         if (r < 0)
 536                 return log_error_errno(r, "Failed to add built-in negative trust anchor: %m");
 537
 538         dns_trust_anchor_dump(d);
 539
 540         return 0;
 541 }
 542
 543 void dns_trust_anchor_flush(DnsTrustAnchor *d) {
 544         DnsAnswer *a;
 545         DnsResourceRecord *rr;
 546
 547         assert(d);
 548
 549         while ((a = hashmap_steal_first(d->positive_by_key)))
 550                 dns_answer_unref(a);
 551         d->positive_by_key = hashmap_free(d->positive_by_key);
 552
 553         while ((rr = set_steal_first(d->revoked_by_rr)))
 554                 dns_resource_record_unref(rr);
 555         d->revoked_by_rr = set_free(d->revoked_by_rr);
 556
 557         d->negative_by_name = set_free_free(d->negative_by_name);
 558 }
 559
 560 int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey *key, DnsAnswer **ret) {
 561         DnsAnswer *a;
 562
 563         assert(d);
 564         assert(key);
 565         assert(ret);
 566
 567         /* We only serve DS and DNSKEY RRs. */
 568         if (!IN_SET(key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY))
 569                 return 0;
 570
 571         a = hashmap_get(d->positive_by_key, key);
 572         if (!a)
 573                 return 0;
 574
 575         *ret = dns_answer_ref(a);
 576         return 1;
 577 }
 578
 579 int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name) {
 580         int r;
 581
 582         assert(d);
 583         assert(name);
 584
 585         for (;;) {
 586                 /* If the domain is listed as-is in the NTA database, then that counts */
 587                 if (set_contains(d->negative_by_name, name))
 588                         return true;
 589
 590                 /* If the domain isn't listed as NTA, but is listed as positive trust anchor, then that counts. See RFC
 591                  * 7646, section 1.1 */
 592                 if (hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name)))
 593                         return false;
 594
 595                 if (hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_KEY, name)))
 596                         return false;
 597
 598                 /* And now, let's look at the parent, and check that too */
 599                 r = dns_name_parent(&name);
 600                 if (r < 0)
 601                         return r;
 602                 if (r == 0)
 603                         break;
 604         }
 605
 606         return false;
 607 }
 608
 609 static int dns_trust_anchor_revoked_put(DnsTrustAnchor *d, DnsResourceRecord *rr) {
 610         int r;
 611
 612         assert(d);
 613
 614         r = set_ensure_allocated(&d->revoked_by_rr, &dns_resource_record_hash_ops);
 615         if (r < 0)
 616                 return r;
 617
 618         r = set_put(d->revoked_by_rr, rr);
 619         if (r < 0)
 620                 return r;
 621         if (r > 0)
 622                 dns_resource_record_ref(rr);
 623
 624         return r;
 625 }
 626
 627 static int dns_trust_anchor_remove_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) {
 628         _cleanup_(dns_answer_unrefp) DnsAnswer *new_answer = NULL;
 629         DnsAnswer *old_answer;
 630         int r;
 631
 632         /* Remember that this is a revoked trust anchor RR */
 633         r = dns_trust_anchor_revoked_put(d, rr);
 634         if (r < 0)
 635                 return r;
 636
 637         /* Remove this from the positive trust anchor */
 638         old_answer = hashmap_get(d->positive_by_key, rr->key);
 639         if (!old_answer)
 640                 return 0;
 641
 642         new_answer = dns_answer_ref(old_answer);
 643
 644         r = dns_answer_remove_by_rr(&new_answer, rr);
 645         if (r <= 0)
 646                 return r;
 647
 648         /* We found the key! Warn the user */
 649         log_struct(LOG_WARNING,
 650                    "MESSAGE_ID=" SD_MESSAGE_DNSSEC_TRUST_ANCHOR_REVOKED_STR,
 651                    LOG_MESSAGE("DNSSEC Trust anchor %s has been revoked. Please update the trust anchor, or upgrade your operating system."), strna(dns_resource_record_to_string(rr)),
 652                    "TRUST_ANCHOR=%s", dns_resource_record_to_string(rr),
 653                    NULL);
 654
 655         if (dns_answer_size(new_answer) <= 0) {
 656                 assert_se(hashmap_remove(d->positive_by_key, rr->key) == old_answer);
 657                 dns_answer_unref(old_answer);
 658                 return 1;
 659         }
 660
 661         r = hashmap_replace(d->positive_by_key, new_answer->items[0].rr->key, new_answer);
 662         if (r < 0)
 663                 return r;
 664
 665         new_answer = NULL;
 666         dns_answer_unref(old_answer);
 667         return 1;
 668 }
 669
 670 static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceRecord *revoked_dnskey) {
 671         DnsAnswer *a;
 672         int r;
 673
 674         assert(d);
 675         assert(revoked_dnskey);
 676         assert(revoked_dnskey->key->type == DNS_TYPE_DNSKEY);
 677         assert(revoked_dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE);
 678
 679         a = hashmap_get(d->positive_by_key, revoked_dnskey->key);
 680         if (a) {
 681                 DnsResourceRecord *anchor;
 682
 683                 /* First, look for the precise DNSKEY in our trust anchor database */
 684
 685                 DNS_ANSWER_FOREACH(anchor, a) {
 686
 687                         if (anchor->dnskey.protocol != revoked_dnskey->dnskey.protocol)
 688                                 continue;
 689
 690                         if (anchor->dnskey.algorithm != revoked_dnskey->dnskey.algorithm)
 691                                 continue;
 692
 693                         if (anchor->dnskey.key_size != revoked_dnskey->dnskey.key_size)
 694                                 continue;
 695
 696                         /* Note that we allow the REVOKE bit to be
 697                          * different! It will be set in the revoked
 698                          * key, but unset in our version of it */
 699                         if (((anchor->dnskey.flags ^ revoked_dnskey->dnskey.flags) | DNSKEY_FLAG_REVOKE) != DNSKEY_FLAG_REVOKE)
 700                                 continue;
 701
 702                         if (memcmp(anchor->dnskey.key, revoked_dnskey->dnskey.key, anchor->dnskey.key_size) != 0)
 703                                 continue;
 704
 705                         dns_trust_anchor_remove_revoked(d, anchor);
 706                         break;
 707                 }
 708         }
 709
 710         a = hashmap_get(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(revoked_dnskey->key->class, DNS_TYPE_DS, dns_resource_key_name(revoked_dnskey->key)));
 711         if (a) {
 712                 DnsResourceRecord *anchor;
 713
 714                 /* Second, look for DS RRs matching this DNSKEY in our trust anchor database */
 715
 716                 DNS_ANSWER_FOREACH(anchor, a) {
 717
 718                         /* We set mask_revoke to true here, since our
 719                          * DS fingerprint will be the one of the
 720                          * unrevoked DNSKEY, but the one we got passed
 721                          * here has the bit set. */
 722                         r = dnssec_verify_dnskey_by_ds(revoked_dnskey, anchor, true);
 723                         if (r < 0)
 724                                 return r;
 725                         if (r == 0)
 726                                 continue;
 727
 728                         dns_trust_anchor_remove_revoked(d, anchor);
 729                         break;
 730                 }
 731         }
 732
 733         return 0;
 734 }
 735
 736 int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) {
 737         DnsResourceRecord *rrsig;
 738         int r;
 739
 740         assert(d);
 741         assert(dnskey);
 742
 743         /* Looks if "dnskey" is a self-signed RR that has been revoked
 744          * and matches one of our trust anchor entries. If so, removes
 745          * it from the trust anchor and returns > 0. */
 746
 747         if (dnskey->key->type != DNS_TYPE_DNSKEY)
 748                 return 0;
 749
 750         /* Is this DNSKEY revoked? */
 751         if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0)
 752                 return 0;
 753
 754         /* Could this be interesting to us at all? If not,
 755          * there's no point in looking for and verifying a
 756          * self-signed RRSIG. */
 757         if (!dns_trust_anchor_knows_domain_positive(d, dns_resource_key_name(dnskey->key)))
 758                 return 0;
 759
 760         /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */
 761         DNS_ANSWER_FOREACH(rrsig, rrs) {
 762                 DnssecResult result;
 763
 764                 if (rrsig->key->type != DNS_TYPE_RRSIG)
 765                         continue;
 766
 767                 r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true);
 768                 if (r < 0)
 769                         return r;
 770                 if (r == 0)
 771                         continue;
 772
 773                 r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result);
 774                 if (r < 0)
 775                         return r;
 776                 if (result != DNSSEC_VALIDATED)
 777                         continue;
 778
 779                 /* Bingo! This is a revoked self-signed DNSKEY. Let's
 780                  * see if this precise one exists in our trust anchor
 781                  * database, too. */
 782                 r = dns_trust_anchor_check_revoked_one(d, dnskey);
 783                 if (r < 0)
 784                         return r;
 785
 786                 return 1;
 787         }
 788
 789         return 0;
 790 }
 791
 792 int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) {
 793         assert(d);
 794
 795         if (!IN_SET(rr->key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY))
 796                 return 0;
 797
 798         return set_contains(d->revoked_by_rr, rr);
 799 }