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1 | /* SPDX-License-Identifier: LGPL-2.1+ */ | |
2 | ||
3 | #include "sd-messages.h" | |
4 | ||
5 | #include "alloc-util.h" | |
6 | #include "conf-files.h" | |
7 | #include "def.h" | |
8 | #include "dns-domain.h" | |
9 | #include "fd-util.h" | |
10 | #include "fileio.h" | |
11 | #include "hexdecoct.h" | |
12 | #include "nulstr-util.h" | |
13 | #include "parse-util.h" | |
14 | #include "resolved-dns-dnssec.h" | |
15 | #include "resolved-dns-trust-anchor.h" | |
16 | #include "set.h" | |
17 | #include "sort-util.h" | |
18 | #include "string-util.h" | |
19 | #include "strv.h" | |
20 | ||
21 | static const char trust_anchor_dirs[] = CONF_PATHS_NULSTR("dnssec-trust-anchors.d"); | |
22 | ||
23 | /* The first DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved December 2015 */ | |
24 | static const uint8_t root_digest1[] = | |
25 | { 0x49, 0xAA, 0xC1, 0x1D, 0x7B, 0x6F, 0x64, 0x46, 0x70, 0x2E, 0x54, 0xA1, 0x60, 0x73, 0x71, 0x60, | |
26 | 0x7A, 0x1A, 0x41, 0x85, 0x52, 0x00, 0xFD, 0x2C, 0xE1, 0xCD, 0xDE, 0x32, 0xF2, 0x4E, 0x8F, 0xB5 }; | |
27 | ||
28 | /* The second DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved February 2017 */ | |
29 | static const uint8_t root_digest2[] = | |
30 | { 0xE0, 0x6D, 0x44, 0xB8, 0x0B, 0x8F, 0x1D, 0x39, 0xA9, 0x5C, 0x0B, 0x0D, 0x7C, 0x65, 0xD0, 0x84, | |
31 | 0x58, 0xE8, 0x80, 0x40, 0x9B, 0xBC, 0x68, 0x34, 0x57, 0x10, 0x42, 0x37, 0xC7, 0xF8, 0xEC, 0x8D }; | |
32 | ||
33 | static bool dns_trust_anchor_knows_domain_positive(DnsTrustAnchor *d, const char *name) { | |
34 | assert(d); | |
35 | ||
36 | /* Returns true if there's an entry for the specified domain | |
37 | * name in our trust anchor */ | |
38 | ||
39 | return | |
40 | hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DNSKEY, name)) || | |
41 | hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name)); | |
42 | } | |
43 | ||
44 | static int add_root_ksk( | |
45 | DnsAnswer *answer, | |
46 | DnsResourceKey *key, | |
47 | uint16_t key_tag, | |
48 | uint8_t algorithm, | |
49 | uint8_t digest_type, | |
50 | const void *digest, | |
51 | size_t digest_size) { | |
52 | ||
53 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
54 | int r; | |
55 | ||
56 | rr = dns_resource_record_new(key); | |
57 | if (!rr) | |
58 | return -ENOMEM; | |
59 | ||
60 | rr->ds.key_tag = key_tag; | |
61 | rr->ds.algorithm = algorithm; | |
62 | rr->ds.digest_type = digest_type; | |
63 | rr->ds.digest_size = digest_size; | |
64 | rr->ds.digest = memdup(digest, rr->ds.digest_size); | |
65 | if (!rr->ds.digest) | |
66 | return -ENOMEM; | |
67 | ||
68 | r = dns_answer_add(answer, rr, 0, DNS_ANSWER_AUTHENTICATED); | |
69 | if (r < 0) | |
70 | return r; | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
75 | static int dns_trust_anchor_add_builtin_positive(DnsTrustAnchor *d) { | |
76 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
77 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
78 | int r; | |
79 | ||
80 | assert(d); | |
81 | ||
82 | r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); | |
83 | if (r < 0) | |
84 | return r; | |
85 | ||
86 | /* Only add the built-in trust anchor if there's neither a DS nor a DNSKEY defined for the root domain. That | |
87 | * way users have an easy way to override the root domain DS/DNSKEY data. */ | |
88 | if (dns_trust_anchor_knows_domain_positive(d, ".")) | |
89 | return 0; | |
90 | ||
91 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_DS, ""); | |
92 | if (!key) | |
93 | return -ENOMEM; | |
94 | ||
95 | answer = dns_answer_new(2); | |
96 | if (!answer) | |
97 | return -ENOMEM; | |
98 | ||
99 | /* Add the two RRs from https://data.iana.org/root-anchors/root-anchors.xml */ | |
100 | r = add_root_ksk(answer, key, 19036, DNSSEC_ALGORITHM_RSASHA256, DNSSEC_DIGEST_SHA256, root_digest1, sizeof(root_digest1)); | |
101 | if (r < 0) | |
102 | return r; | |
103 | ||
104 | r = add_root_ksk(answer, key, 20326, DNSSEC_ALGORITHM_RSASHA256, DNSSEC_DIGEST_SHA256, root_digest2, sizeof(root_digest2)); | |
105 | if (r < 0) | |
106 | return r; | |
107 | ||
108 | r = hashmap_put(d->positive_by_key, key, answer); | |
109 | if (r < 0) | |
110 | return r; | |
111 | ||
112 | answer = NULL; | |
113 | return 0; | |
114 | } | |
115 | ||
116 | static int dns_trust_anchor_add_builtin_negative(DnsTrustAnchor *d) { | |
117 | ||
118 | static const char private_domains[] = | |
119 | /* RFC 6761 says that .test is a special domain for | |
120 | * testing and not to be installed in the root zone */ | |
121 | "test\0" | |
122 | ||
123 | /* RFC 6761 says that these reverse IP lookup ranges | |
124 | * are for private addresses, and hence should not | |
125 | * show up in the root zone */ | |
126 | "10.in-addr.arpa\0" | |
127 | "16.172.in-addr.arpa\0" | |
128 | "17.172.in-addr.arpa\0" | |
129 | "18.172.in-addr.arpa\0" | |
130 | "19.172.in-addr.arpa\0" | |
131 | "20.172.in-addr.arpa\0" | |
132 | "21.172.in-addr.arpa\0" | |
133 | "22.172.in-addr.arpa\0" | |
134 | "23.172.in-addr.arpa\0" | |
135 | "24.172.in-addr.arpa\0" | |
136 | "25.172.in-addr.arpa\0" | |
137 | "26.172.in-addr.arpa\0" | |
138 | "27.172.in-addr.arpa\0" | |
139 | "28.172.in-addr.arpa\0" | |
140 | "29.172.in-addr.arpa\0" | |
141 | "30.172.in-addr.arpa\0" | |
142 | "31.172.in-addr.arpa\0" | |
143 | "168.192.in-addr.arpa\0" | |
144 | ||
145 | /* The same, but for IPv6. */ | |
146 | "d.f.ip6.arpa\0" | |
147 | ||
148 | /* RFC 6762 reserves the .local domain for Multicast | |
149 | * DNS, it hence cannot appear in the root zone. (Note | |
150 | * that we by default do not route .local traffic to | |
151 | * DNS anyway, except when a configured search domain | |
152 | * suggests so.) */ | |
153 | "local\0" | |
154 | ||
155 | /* These two are well known, popular private zone | |
156 | * TLDs, that are blocked from delegation, according | |
157 | * to: | |
158 | * http://icannwiki.com/Name_Collision#NGPC_Resolution | |
159 | * | |
160 | * There's also ongoing work on making this official | |
161 | * in an RRC: | |
162 | * https://www.ietf.org/archive/id/draft-chapin-additional-reserved-tlds-02.txt */ | |
163 | "home\0" | |
164 | "corp\0" | |
165 | ||
166 | /* The following four TLDs are suggested for private | |
167 | * zones in RFC 6762, Appendix G, and are hence very | |
168 | * unlikely to be made official TLDs any day soon */ | |
169 | "lan\0" | |
170 | "intranet\0" | |
171 | "internal\0" | |
172 | "private\0"; | |
173 | ||
174 | const char *name; | |
175 | int r; | |
176 | ||
177 | assert(d); | |
178 | ||
179 | /* Only add the built-in trust anchor if there's no negative | |
180 | * trust anchor defined at all. This enables easy overriding | |
181 | * of negative trust anchors. */ | |
182 | ||
183 | if (set_size(d->negative_by_name) > 0) | |
184 | return 0; | |
185 | ||
186 | r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); | |
187 | if (r < 0) | |
188 | return r; | |
189 | ||
190 | /* We add a couple of domains as default negative trust | |
191 | * anchors, where it's very unlikely they will be installed in | |
192 | * the root zone. If they exist they must be private, and thus | |
193 | * unsigned. */ | |
194 | ||
195 | NULSTR_FOREACH(name, private_domains) { | |
196 | ||
197 | if (dns_trust_anchor_knows_domain_positive(d, name)) | |
198 | continue; | |
199 | ||
200 | r = set_put_strdup(d->negative_by_name, name); | |
201 | if (r < 0) | |
202 | return r; | |
203 | } | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
208 | static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { | |
209 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
210 | _cleanup_free_ char *domain = NULL, *class = NULL, *type = NULL; | |
211 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
212 | DnsAnswer *old_answer = NULL; | |
213 | const char *p = s; | |
214 | int r; | |
215 | ||
216 | assert(d); | |
217 | assert(line); | |
218 | ||
219 | r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); | |
220 | if (r < 0) | |
221 | return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line); | |
222 | ||
223 | r = dns_name_is_valid(domain); | |
224 | if (r < 0) | |
225 | return log_warning_errno(r, "Failed to check validity of domain name '%s', at line %s:%u, ignoring line: %m", domain, path, line); | |
226 | if (r == 0) { | |
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 | r = dns_name_is_valid(domain); | |
394 | if (r < 0) | |
395 | return log_warning_errno(r, "Failed to check validity of domain name '%s', at line %s:%u, ignoring line: %m", domain, path, line); | |
396 | if (r == 0) { | |
397 | log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); | |
398 | return -EINVAL; | |
399 | } | |
400 | ||
401 | if (!isempty(p)) { | |
402 | log_warning("Trailing garbage at line %s:%u, ignoring line.", path, line); | |
403 | return -EINVAL; | |
404 | } | |
405 | ||
406 | r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); | |
407 | if (r < 0) | |
408 | return log_oom(); | |
409 | ||
410 | r = set_put(d->negative_by_name, domain); | |
411 | if (r < 0) | |
412 | return log_oom(); | |
413 | if (r > 0) | |
414 | domain = NULL; | |
415 | ||
416 | return 0; | |
417 | } | |
418 | ||
419 | static int dns_trust_anchor_load_files( | |
420 | DnsTrustAnchor *d, | |
421 | const char *suffix, | |
422 | int (*loader)(DnsTrustAnchor *d, const char *path, unsigned n, const char *line)) { | |
423 | ||
424 | _cleanup_strv_free_ char **files = NULL; | |
425 | char **f; | |
426 | int r; | |
427 | ||
428 | assert(d); | |
429 | assert(suffix); | |
430 | assert(loader); | |
431 | ||
432 | r = conf_files_list_nulstr(&files, suffix, NULL, 0, trust_anchor_dirs); | |
433 | if (r < 0) | |
434 | return log_error_errno(r, "Failed to enumerate %s trust anchor files: %m", suffix); | |
435 | ||
436 | STRV_FOREACH(f, files) { | |
437 | _cleanup_fclose_ FILE *g = NULL; | |
438 | unsigned n = 0; | |
439 | ||
440 | g = fopen(*f, "r"); | |
441 | if (!g) { | |
442 | if (errno == ENOENT) | |
443 | continue; | |
444 | ||
445 | log_warning_errno(errno, "Failed to open '%s', ignoring: %m", *f); | |
446 | continue; | |
447 | } | |
448 | ||
449 | for (;;) { | |
450 | _cleanup_free_ char *line = NULL; | |
451 | char *l; | |
452 | ||
453 | r = read_line(g, LONG_LINE_MAX, &line); | |
454 | if (r < 0) { | |
455 | log_warning_errno(r, "Failed to read '%s', ignoring: %m", *f); | |
456 | break; | |
457 | } | |
458 | if (r == 0) | |
459 | break; | |
460 | ||
461 | n++; | |
462 | ||
463 | l = strstrip(line); | |
464 | if (isempty(l)) | |
465 | continue; | |
466 | ||
467 | if (*l == ';') | |
468 | continue; | |
469 | ||
470 | (void) loader(d, *f, n, l); | |
471 | } | |
472 | } | |
473 | ||
474 | return 0; | |
475 | } | |
476 | ||
477 | static int domain_name_cmp(char * const *a, char * const *b) { | |
478 | return dns_name_compare_func(*a, *b); | |
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 | typesafe_qsort(l, set_size(d->negative_by_name), 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 | assert(d); | |
545 | ||
546 | d->positive_by_key = hashmap_free_with_destructor(d->positive_by_key, dns_answer_unref); | |
547 | d->revoked_by_rr = set_free_with_destructor(d->revoked_by_rr, dns_resource_record_unref); | |
548 | d->negative_by_name = set_free_free(d->negative_by_name); | |
549 | } | |
550 | ||
551 | int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey *key, DnsAnswer **ret) { | |
552 | DnsAnswer *a; | |
553 | ||
554 | assert(d); | |
555 | assert(key); | |
556 | assert(ret); | |
557 | ||
558 | /* We only serve DS and DNSKEY RRs. */ | |
559 | if (!IN_SET(key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) | |
560 | return 0; | |
561 | ||
562 | a = hashmap_get(d->positive_by_key, key); | |
563 | if (!a) | |
564 | return 0; | |
565 | ||
566 | *ret = dns_answer_ref(a); | |
567 | return 1; | |
568 | } | |
569 | ||
570 | int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name) { | |
571 | int r; | |
572 | ||
573 | assert(d); | |
574 | assert(name); | |
575 | ||
576 | for (;;) { | |
577 | /* If the domain is listed as-is in the NTA database, then that counts */ | |
578 | if (set_contains(d->negative_by_name, name)) | |
579 | return true; | |
580 | ||
581 | /* If the domain isn't listed as NTA, but is listed as positive trust anchor, then that counts. See RFC | |
582 | * 7646, section 1.1 */ | |
583 | if (hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name))) | |
584 | return false; | |
585 | ||
586 | if (hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_KEY, name))) | |
587 | return false; | |
588 | ||
589 | /* And now, let's look at the parent, and check that too */ | |
590 | r = dns_name_parent(&name); | |
591 | if (r < 0) | |
592 | return r; | |
593 | if (r == 0) | |
594 | break; | |
595 | } | |
596 | ||
597 | return false; | |
598 | } | |
599 | ||
600 | static int dns_trust_anchor_revoked_put(DnsTrustAnchor *d, DnsResourceRecord *rr) { | |
601 | int r; | |
602 | ||
603 | assert(d); | |
604 | ||
605 | r = set_ensure_allocated(&d->revoked_by_rr, &dns_resource_record_hash_ops); | |
606 | if (r < 0) | |
607 | return r; | |
608 | ||
609 | r = set_put(d->revoked_by_rr, rr); | |
610 | if (r < 0) | |
611 | return r; | |
612 | if (r > 0) | |
613 | dns_resource_record_ref(rr); | |
614 | ||
615 | return r; | |
616 | } | |
617 | ||
618 | static int dns_trust_anchor_remove_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { | |
619 | _cleanup_(dns_answer_unrefp) DnsAnswer *new_answer = NULL; | |
620 | DnsAnswer *old_answer; | |
621 | int r; | |
622 | ||
623 | /* Remember that this is a revoked trust anchor RR */ | |
624 | r = dns_trust_anchor_revoked_put(d, rr); | |
625 | if (r < 0) | |
626 | return r; | |
627 | ||
628 | /* Remove this from the positive trust anchor */ | |
629 | old_answer = hashmap_get(d->positive_by_key, rr->key); | |
630 | if (!old_answer) | |
631 | return 0; | |
632 | ||
633 | new_answer = dns_answer_ref(old_answer); | |
634 | ||
635 | r = dns_answer_remove_by_rr(&new_answer, rr); | |
636 | if (r <= 0) | |
637 | return r; | |
638 | ||
639 | /* We found the key! Warn the user */ | |
640 | log_struct(LOG_WARNING, | |
641 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_TRUST_ANCHOR_REVOKED_STR, | |
642 | LOG_MESSAGE("DNSSEC trust anchor %s has been revoked.\n" | |
643 | "Please update the trust anchor, or upgrade your operating system.", | |
644 | strna(dns_resource_record_to_string(rr))), | |
645 | "TRUST_ANCHOR=%s", dns_resource_record_to_string(rr)); | |
646 | ||
647 | if (dns_answer_size(new_answer) <= 0) { | |
648 | assert_se(hashmap_remove(d->positive_by_key, rr->key) == old_answer); | |
649 | dns_answer_unref(old_answer); | |
650 | return 1; | |
651 | } | |
652 | ||
653 | r = hashmap_replace(d->positive_by_key, new_answer->items[0].rr->key, new_answer); | |
654 | if (r < 0) | |
655 | return r; | |
656 | ||
657 | new_answer = NULL; | |
658 | dns_answer_unref(old_answer); | |
659 | return 1; | |
660 | } | |
661 | ||
662 | static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceRecord *revoked_dnskey) { | |
663 | DnsAnswer *a; | |
664 | int r; | |
665 | ||
666 | assert(d); | |
667 | assert(revoked_dnskey); | |
668 | assert(revoked_dnskey->key->type == DNS_TYPE_DNSKEY); | |
669 | assert(revoked_dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE); | |
670 | ||
671 | a = hashmap_get(d->positive_by_key, revoked_dnskey->key); | |
672 | if (a) { | |
673 | DnsResourceRecord *anchor; | |
674 | ||
675 | /* First, look for the precise DNSKEY in our trust anchor database */ | |
676 | ||
677 | DNS_ANSWER_FOREACH(anchor, a) { | |
678 | ||
679 | if (anchor->dnskey.protocol != revoked_dnskey->dnskey.protocol) | |
680 | continue; | |
681 | ||
682 | if (anchor->dnskey.algorithm != revoked_dnskey->dnskey.algorithm) | |
683 | continue; | |
684 | ||
685 | if (anchor->dnskey.key_size != revoked_dnskey->dnskey.key_size) | |
686 | continue; | |
687 | ||
688 | /* Note that we allow the REVOKE bit to be | |
689 | * different! It will be set in the revoked | |
690 | * key, but unset in our version of it */ | |
691 | if (((anchor->dnskey.flags ^ revoked_dnskey->dnskey.flags) | DNSKEY_FLAG_REVOKE) != DNSKEY_FLAG_REVOKE) | |
692 | continue; | |
693 | ||
694 | if (memcmp(anchor->dnskey.key, revoked_dnskey->dnskey.key, anchor->dnskey.key_size) != 0) | |
695 | continue; | |
696 | ||
697 | dns_trust_anchor_remove_revoked(d, anchor); | |
698 | break; | |
699 | } | |
700 | } | |
701 | ||
702 | 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))); | |
703 | if (a) { | |
704 | DnsResourceRecord *anchor; | |
705 | ||
706 | /* Second, look for DS RRs matching this DNSKEY in our trust anchor database */ | |
707 | ||
708 | DNS_ANSWER_FOREACH(anchor, a) { | |
709 | ||
710 | /* We set mask_revoke to true here, since our | |
711 | * DS fingerprint will be the one of the | |
712 | * unrevoked DNSKEY, but the one we got passed | |
713 | * here has the bit set. */ | |
714 | r = dnssec_verify_dnskey_by_ds(revoked_dnskey, anchor, true); | |
715 | if (r < 0) | |
716 | return r; | |
717 | if (r == 0) | |
718 | continue; | |
719 | ||
720 | dns_trust_anchor_remove_revoked(d, anchor); | |
721 | break; | |
722 | } | |
723 | } | |
724 | ||
725 | return 0; | |
726 | } | |
727 | ||
728 | int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) { | |
729 | DnsResourceRecord *rrsig; | |
730 | int r; | |
731 | ||
732 | assert(d); | |
733 | assert(dnskey); | |
734 | ||
735 | /* Looks if "dnskey" is a self-signed RR that has been revoked | |
736 | * and matches one of our trust anchor entries. If so, removes | |
737 | * it from the trust anchor and returns > 0. */ | |
738 | ||
739 | if (dnskey->key->type != DNS_TYPE_DNSKEY) | |
740 | return 0; | |
741 | ||
742 | /* Is this DNSKEY revoked? */ | |
743 | if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) | |
744 | return 0; | |
745 | ||
746 | /* Could this be interesting to us at all? If not, | |
747 | * there's no point in looking for and verifying a | |
748 | * self-signed RRSIG. */ | |
749 | if (!dns_trust_anchor_knows_domain_positive(d, dns_resource_key_name(dnskey->key))) | |
750 | return 0; | |
751 | ||
752 | /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */ | |
753 | DNS_ANSWER_FOREACH(rrsig, rrs) { | |
754 | DnssecResult result; | |
755 | ||
756 | if (rrsig->key->type != DNS_TYPE_RRSIG) | |
757 | continue; | |
758 | ||
759 | r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); | |
760 | if (r < 0) | |
761 | return r; | |
762 | if (r == 0) | |
763 | continue; | |
764 | ||
765 | r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result); | |
766 | if (r < 0) | |
767 | return r; | |
768 | if (result != DNSSEC_VALIDATED) | |
769 | continue; | |
770 | ||
771 | /* Bingo! This is a revoked self-signed DNSKEY. Let's | |
772 | * see if this precise one exists in our trust anchor | |
773 | * database, too. */ | |
774 | r = dns_trust_anchor_check_revoked_one(d, dnskey); | |
775 | if (r < 0) | |
776 | return r; | |
777 | ||
778 | return 1; | |
779 | } | |
780 | ||
781 | return 0; | |
782 | } | |
783 | ||
784 | int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { | |
785 | assert(d); | |
786 | ||
787 | if (!IN_SET(rr->key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) | |
788 | return 0; | |
789 | ||
790 | return set_contains(d->revoked_by_rr, rr); | |
791 | } |