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

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