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Commit | Line | Data |
---|---|---|
53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
2b442ac8 | 2 | |
349cc4a5 | 3 | #if HAVE_GCRYPT |
2fe21124 | 4 | # include <gcrypt.h> |
47091522 | 5 | #endif |
2b442ac8 LP |
6 | |
7 | #include "alloc-util.h" | |
8 | #include "dns-domain.h" | |
cb9eeb06 MCO |
9 | #include "fd-util.h" |
10 | #include "fileio.h" | |
91e023d8 | 11 | #include "gcrypt-util.h" |
72667f08 | 12 | #include "hexdecoct.h" |
0a970718 | 13 | #include "memory-util.h" |
2b442ac8 LP |
14 | #include "resolved-dns-dnssec.h" |
15 | #include "resolved-dns-packet.h" | |
760877e9 | 16 | #include "sort-util.h" |
24710c48 | 17 | #include "string-table.h" |
2b442ac8 | 18 | |
2b442ac8 LP |
19 | #define VERIFY_RRS_MAX 256 |
20 | #define MAX_KEY_SIZE (32*1024) | |
21 | ||
896c5672 LP |
22 | /* Permit a maximum clock skew of 1h 10min. This should be enough to deal with DST confusion */ |
23 | #define SKEW_MAX (1*USEC_PER_HOUR + 10*USEC_PER_MINUTE) | |
24 | ||
3a33c81b LP |
25 | /* Maximum number of NSEC3 iterations we'll do. RFC5155 says 2500 shall be the maximum useful value */ |
26 | #define NSEC3_ITERATIONS_MAX 2500 | |
a8f158b9 | 27 | |
2b442ac8 LP |
28 | /* |
29 | * The DNSSEC Chain of trust: | |
30 | * | |
31 | * Normal RRs are protected via RRSIG RRs in combination with DNSKEY RRs, all in the same zone | |
32 | * DNSKEY RRs are either protected like normal RRs, or via a DS from a zone "higher" up the tree | |
33 | * DS RRs are protected like normal RRs | |
34 | * | |
35 | * Example chain: | |
36 | * Normal RR → RRSIG/DNSKEY+ → DS → RRSIG/DNSKEY+ → DS → ... → DS → RRSIG/DNSKEY+ → DS | |
37 | */ | |
38 | ||
0c857028 | 39 | uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke) { |
2b442ac8 | 40 | const uint8_t *p; |
0c857028 | 41 | uint32_t sum, f; |
2b442ac8 LP |
42 | size_t i; |
43 | ||
44 | /* The algorithm from RFC 4034, Appendix B. */ | |
45 | ||
46 | assert(dnskey); | |
47 | assert(dnskey->key->type == DNS_TYPE_DNSKEY); | |
48 | ||
0c857028 LP |
49 | f = (uint32_t) dnskey->dnskey.flags; |
50 | ||
51 | if (mask_revoke) | |
52 | f &= ~DNSKEY_FLAG_REVOKE; | |
53 | ||
54 | sum = f + ((((uint32_t) dnskey->dnskey.protocol) << 8) + (uint32_t) dnskey->dnskey.algorithm); | |
2b442ac8 LP |
55 | |
56 | p = dnskey->dnskey.key; | |
57 | ||
58 | for (i = 0; i < dnskey->dnskey.key_size; i++) | |
59 | sum += (i & 1) == 0 ? (uint32_t) p[i] << 8 : (uint32_t) p[i]; | |
60 | ||
61 | sum += (sum >> 16) & UINT32_C(0xFFFF); | |
62 | ||
63 | return sum & UINT32_C(0xFFFF); | |
64 | } | |
65 | ||
dbf0b8a2 MO |
66 | int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) { |
67 | size_t c = 0; | |
68 | int r; | |
69 | ||
70 | /* Converts the specified hostname into DNSSEC canonicalized | |
71 | * form. */ | |
72 | ||
73 | if (buffer_max < 2) | |
74 | return -ENOBUFS; | |
75 | ||
76 | for (;;) { | |
7470cc4c | 77 | r = dns_label_unescape(&n, buffer, buffer_max, 0); |
dbf0b8a2 MO |
78 | if (r < 0) |
79 | return r; | |
80 | if (r == 0) | |
81 | break; | |
82 | ||
83 | if (buffer_max < (size_t) r + 2) | |
84 | return -ENOBUFS; | |
85 | ||
86 | /* The DNSSEC canonical form is not clear on what to | |
87 | * do with dots appearing in labels, the way DNS-SD | |
88 | * does it. Refuse it for now. */ | |
89 | ||
90 | if (memchr(buffer, '.', r)) | |
91 | return -EINVAL; | |
92 | ||
93 | ascii_strlower_n(buffer, (size_t) r); | |
94 | buffer[r] = '.'; | |
95 | ||
96 | buffer += r + 1; | |
97 | c += r + 1; | |
98 | ||
99 | buffer_max -= r + 1; | |
100 | } | |
101 | ||
102 | if (c <= 0) { | |
103 | /* Not even a single label: this is the root domain name */ | |
104 | ||
105 | assert(buffer_max > 2); | |
106 | buffer[0] = '.'; | |
107 | buffer[1] = 0; | |
108 | ||
109 | return 1; | |
110 | } | |
111 | ||
112 | return (int) c; | |
113 | } | |
114 | ||
349cc4a5 | 115 | #if HAVE_GCRYPT |
47091522 | 116 | |
93bab288 YW |
117 | static int rr_compare(DnsResourceRecord * const *a, DnsResourceRecord * const *b) { |
118 | const DnsResourceRecord *x = *a, *y = *b; | |
2b442ac8 LP |
119 | size_t m; |
120 | int r; | |
121 | ||
122 | /* Let's order the RRs according to RFC 4034, Section 6.3 */ | |
123 | ||
124 | assert(x); | |
93bab288 | 125 | assert(x->wire_format); |
2b442ac8 | 126 | assert(y); |
93bab288 | 127 | assert(y->wire_format); |
2b442ac8 | 128 | |
93bab288 | 129 | m = MIN(DNS_RESOURCE_RECORD_RDATA_SIZE(x), DNS_RESOURCE_RECORD_RDATA_SIZE(y)); |
2b442ac8 | 130 | |
93bab288 | 131 | r = memcmp(DNS_RESOURCE_RECORD_RDATA(x), DNS_RESOURCE_RECORD_RDATA(y), m); |
2b442ac8 LP |
132 | if (r != 0) |
133 | return r; | |
134 | ||
93bab288 | 135 | return CMP(DNS_RESOURCE_RECORD_RDATA_SIZE(x), DNS_RESOURCE_RECORD_RDATA_SIZE(y)); |
2b442ac8 LP |
136 | } |
137 | ||
ea3a892f | 138 | static int dnssec_rsa_verify_raw( |
2b442ac8 LP |
139 | const char *hash_algorithm, |
140 | const void *signature, size_t signature_size, | |
141 | const void *data, size_t data_size, | |
142 | const void *exponent, size_t exponent_size, | |
143 | const void *modulus, size_t modulus_size) { | |
144 | ||
145 | gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL; | |
146 | gcry_mpi_t n = NULL, e = NULL, s = NULL; | |
147 | gcry_error_t ge; | |
148 | int r; | |
149 | ||
150 | assert(hash_algorithm); | |
151 | ||
152 | ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature, signature_size, NULL); | |
153 | if (ge != 0) { | |
154 | r = -EIO; | |
155 | goto finish; | |
156 | } | |
157 | ||
158 | ge = gcry_mpi_scan(&e, GCRYMPI_FMT_USG, exponent, exponent_size, NULL); | |
159 | if (ge != 0) { | |
160 | r = -EIO; | |
161 | goto finish; | |
162 | } | |
163 | ||
164 | ge = gcry_mpi_scan(&n, GCRYMPI_FMT_USG, modulus, modulus_size, NULL); | |
165 | if (ge != 0) { | |
166 | r = -EIO; | |
167 | goto finish; | |
168 | } | |
169 | ||
170 | ge = gcry_sexp_build(&signature_sexp, | |
171 | NULL, | |
172 | "(sig-val (rsa (s %m)))", | |
173 | s); | |
174 | ||
175 | if (ge != 0) { | |
176 | r = -EIO; | |
177 | goto finish; | |
178 | } | |
179 | ||
180 | ge = gcry_sexp_build(&data_sexp, | |
181 | NULL, | |
182 | "(data (flags pkcs1) (hash %s %b))", | |
183 | hash_algorithm, | |
184 | (int) data_size, | |
185 | data); | |
186 | if (ge != 0) { | |
187 | r = -EIO; | |
188 | goto finish; | |
189 | } | |
190 | ||
191 | ge = gcry_sexp_build(&public_key_sexp, | |
192 | NULL, | |
193 | "(public-key (rsa (n %m) (e %m)))", | |
194 | n, | |
195 | e); | |
196 | if (ge != 0) { | |
197 | r = -EIO; | |
198 | goto finish; | |
199 | } | |
200 | ||
201 | ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp); | |
d12bf2bd | 202 | if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE) |
2b442ac8 | 203 | r = 0; |
d12bf2bd LP |
204 | else if (ge != 0) { |
205 | log_debug("RSA signature check failed: %s", gpg_strerror(ge)); | |
2b442ac8 | 206 | r = -EIO; |
d12bf2bd | 207 | } else |
2b442ac8 LP |
208 | r = 1; |
209 | ||
210 | finish: | |
211 | if (e) | |
212 | gcry_mpi_release(e); | |
213 | if (n) | |
214 | gcry_mpi_release(n); | |
215 | if (s) | |
216 | gcry_mpi_release(s); | |
217 | ||
218 | if (public_key_sexp) | |
219 | gcry_sexp_release(public_key_sexp); | |
220 | if (signature_sexp) | |
221 | gcry_sexp_release(signature_sexp); | |
222 | if (data_sexp) | |
223 | gcry_sexp_release(data_sexp); | |
224 | ||
225 | return r; | |
226 | } | |
227 | ||
ea3a892f LP |
228 | static int dnssec_rsa_verify( |
229 | const char *hash_algorithm, | |
230 | const void *hash, size_t hash_size, | |
231 | DnsResourceRecord *rrsig, | |
232 | DnsResourceRecord *dnskey) { | |
233 | ||
234 | size_t exponent_size, modulus_size; | |
235 | void *exponent, *modulus; | |
236 | ||
237 | assert(hash_algorithm); | |
238 | assert(hash); | |
239 | assert(hash_size > 0); | |
240 | assert(rrsig); | |
241 | assert(dnskey); | |
242 | ||
243 | if (*(uint8_t*) dnskey->dnskey.key == 0) { | |
244 | /* exponent is > 255 bytes long */ | |
245 | ||
246 | exponent = (uint8_t*) dnskey->dnskey.key + 3; | |
247 | exponent_size = | |
ac04adbe TG |
248 | ((size_t) (((uint8_t*) dnskey->dnskey.key)[1]) << 8) | |
249 | ((size_t) ((uint8_t*) dnskey->dnskey.key)[2]); | |
ea3a892f LP |
250 | |
251 | if (exponent_size < 256) | |
252 | return -EINVAL; | |
253 | ||
254 | if (3 + exponent_size >= dnskey->dnskey.key_size) | |
255 | return -EINVAL; | |
256 | ||
257 | modulus = (uint8_t*) dnskey->dnskey.key + 3 + exponent_size; | |
258 | modulus_size = dnskey->dnskey.key_size - 3 - exponent_size; | |
259 | ||
260 | } else { | |
261 | /* exponent is <= 255 bytes long */ | |
262 | ||
263 | exponent = (uint8_t*) dnskey->dnskey.key + 1; | |
264 | exponent_size = (size_t) ((uint8_t*) dnskey->dnskey.key)[0]; | |
265 | ||
266 | if (exponent_size <= 0) | |
267 | return -EINVAL; | |
268 | ||
269 | if (1 + exponent_size >= dnskey->dnskey.key_size) | |
270 | return -EINVAL; | |
271 | ||
272 | modulus = (uint8_t*) dnskey->dnskey.key + 1 + exponent_size; | |
273 | modulus_size = dnskey->dnskey.key_size - 1 - exponent_size; | |
274 | } | |
275 | ||
276 | return dnssec_rsa_verify_raw( | |
277 | hash_algorithm, | |
278 | rrsig->rrsig.signature, rrsig->rrsig.signature_size, | |
279 | hash, hash_size, | |
280 | exponent, exponent_size, | |
281 | modulus, modulus_size); | |
282 | } | |
283 | ||
e0240c64 LP |
284 | static int dnssec_ecdsa_verify_raw( |
285 | const char *hash_algorithm, | |
286 | const char *curve, | |
287 | const void *signature_r, size_t signature_r_size, | |
288 | const void *signature_s, size_t signature_s_size, | |
289 | const void *data, size_t data_size, | |
290 | const void *key, size_t key_size) { | |
291 | ||
292 | gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL; | |
293 | gcry_mpi_t q = NULL, r = NULL, s = NULL; | |
294 | gcry_error_t ge; | |
295 | int k; | |
296 | ||
297 | assert(hash_algorithm); | |
298 | ||
299 | ge = gcry_mpi_scan(&r, GCRYMPI_FMT_USG, signature_r, signature_r_size, NULL); | |
300 | if (ge != 0) { | |
301 | k = -EIO; | |
302 | goto finish; | |
303 | } | |
304 | ||
305 | ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature_s, signature_s_size, NULL); | |
306 | if (ge != 0) { | |
307 | k = -EIO; | |
308 | goto finish; | |
309 | } | |
310 | ||
311 | ge = gcry_mpi_scan(&q, GCRYMPI_FMT_USG, key, key_size, NULL); | |
312 | if (ge != 0) { | |
313 | k = -EIO; | |
314 | goto finish; | |
315 | } | |
316 | ||
317 | ge = gcry_sexp_build(&signature_sexp, | |
318 | NULL, | |
319 | "(sig-val (ecdsa (r %m) (s %m)))", | |
320 | r, | |
321 | s); | |
322 | if (ge != 0) { | |
323 | k = -EIO; | |
324 | goto finish; | |
325 | } | |
326 | ||
327 | ge = gcry_sexp_build(&data_sexp, | |
328 | NULL, | |
329 | "(data (flags rfc6979) (hash %s %b))", | |
330 | hash_algorithm, | |
331 | (int) data_size, | |
332 | data); | |
333 | if (ge != 0) { | |
334 | k = -EIO; | |
335 | goto finish; | |
336 | } | |
337 | ||
338 | ge = gcry_sexp_build(&public_key_sexp, | |
339 | NULL, | |
340 | "(public-key (ecc (curve %s) (q %m)))", | |
341 | curve, | |
342 | q); | |
343 | if (ge != 0) { | |
344 | k = -EIO; | |
345 | goto finish; | |
346 | } | |
347 | ||
348 | ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp); | |
349 | if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE) | |
350 | k = 0; | |
351 | else if (ge != 0) { | |
352 | log_debug("ECDSA signature check failed: %s", gpg_strerror(ge)); | |
353 | k = -EIO; | |
354 | } else | |
355 | k = 1; | |
356 | finish: | |
357 | if (r) | |
358 | gcry_mpi_release(r); | |
359 | if (s) | |
360 | gcry_mpi_release(s); | |
361 | if (q) | |
362 | gcry_mpi_release(q); | |
363 | ||
364 | if (public_key_sexp) | |
365 | gcry_sexp_release(public_key_sexp); | |
366 | if (signature_sexp) | |
367 | gcry_sexp_release(signature_sexp); | |
368 | if (data_sexp) | |
369 | gcry_sexp_release(data_sexp); | |
370 | ||
371 | return k; | |
372 | } | |
373 | ||
374 | static int dnssec_ecdsa_verify( | |
375 | const char *hash_algorithm, | |
376 | int algorithm, | |
377 | const void *hash, size_t hash_size, | |
378 | DnsResourceRecord *rrsig, | |
379 | DnsResourceRecord *dnskey) { | |
380 | ||
381 | const char *curve; | |
382 | size_t key_size; | |
383 | uint8_t *q; | |
384 | ||
385 | assert(hash); | |
386 | assert(hash_size); | |
387 | assert(rrsig); | |
388 | assert(dnskey); | |
389 | ||
390 | if (algorithm == DNSSEC_ALGORITHM_ECDSAP256SHA256) { | |
391 | key_size = 32; | |
392 | curve = "NIST P-256"; | |
393 | } else if (algorithm == DNSSEC_ALGORITHM_ECDSAP384SHA384) { | |
394 | key_size = 48; | |
395 | curve = "NIST P-384"; | |
396 | } else | |
397 | return -EOPNOTSUPP; | |
398 | ||
399 | if (dnskey->dnskey.key_size != key_size * 2) | |
400 | return -EINVAL; | |
401 | ||
402 | if (rrsig->rrsig.signature_size != key_size * 2) | |
403 | return -EINVAL; | |
404 | ||
6e9417f5 | 405 | q = newa(uint8_t, key_size*2 + 1); |
e0240c64 LP |
406 | q[0] = 0x04; /* Prepend 0x04 to indicate an uncompressed key */ |
407 | memcpy(q+1, dnskey->dnskey.key, key_size*2); | |
408 | ||
409 | return dnssec_ecdsa_verify_raw( | |
410 | hash_algorithm, | |
411 | curve, | |
412 | rrsig->rrsig.signature, key_size, | |
413 | (uint8_t*) rrsig->rrsig.signature + key_size, key_size, | |
414 | hash, hash_size, | |
415 | q, key_size*2+1); | |
416 | } | |
417 | ||
cb9eeb06 MCO |
418 | #if GCRYPT_VERSION_NUMBER >= 0x010600 |
419 | static int dnssec_eddsa_verify_raw( | |
420 | const char *curve, | |
421 | const void *signature_r, size_t signature_r_size, | |
422 | const void *signature_s, size_t signature_s_size, | |
423 | const void *data, size_t data_size, | |
424 | const void *key, size_t key_size) { | |
425 | ||
426 | gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL; | |
427 | gcry_error_t ge; | |
428 | int k; | |
429 | ||
430 | ge = gcry_sexp_build(&signature_sexp, | |
431 | NULL, | |
432 | "(sig-val (eddsa (r %b) (s %b)))", | |
433 | (int) signature_r_size, | |
434 | signature_r, | |
435 | (int) signature_s_size, | |
436 | signature_s); | |
437 | if (ge != 0) { | |
438 | k = -EIO; | |
439 | goto finish; | |
440 | } | |
441 | ||
442 | ge = gcry_sexp_build(&data_sexp, | |
443 | NULL, | |
444 | "(data (flags eddsa) (hash-algo sha512) (value %b))", | |
445 | (int) data_size, | |
446 | data); | |
447 | if (ge != 0) { | |
448 | k = -EIO; | |
449 | goto finish; | |
450 | } | |
451 | ||
452 | ge = gcry_sexp_build(&public_key_sexp, | |
453 | NULL, | |
454 | "(public-key (ecc (curve %s) (flags eddsa) (q %b)))", | |
455 | curve, | |
456 | (int) key_size, | |
457 | key); | |
458 | if (ge != 0) { | |
459 | k = -EIO; | |
460 | goto finish; | |
461 | } | |
462 | ||
463 | ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp); | |
464 | if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE) | |
465 | k = 0; | |
466 | else if (ge != 0) { | |
467 | log_debug("EdDSA signature check failed: %s", gpg_strerror(ge)); | |
468 | k = -EIO; | |
469 | } else | |
470 | k = 1; | |
471 | finish: | |
472 | if (public_key_sexp) | |
473 | gcry_sexp_release(public_key_sexp); | |
474 | if (signature_sexp) | |
475 | gcry_sexp_release(signature_sexp); | |
476 | if (data_sexp) | |
477 | gcry_sexp_release(data_sexp); | |
478 | ||
479 | return k; | |
480 | } | |
481 | ||
482 | static int dnssec_eddsa_verify( | |
483 | int algorithm, | |
484 | const void *data, size_t data_size, | |
485 | DnsResourceRecord *rrsig, | |
486 | DnsResourceRecord *dnskey) { | |
487 | const char *curve; | |
488 | size_t key_size; | |
489 | ||
490 | if (algorithm == DNSSEC_ALGORITHM_ED25519) { | |
491 | curve = "Ed25519"; | |
492 | key_size = 32; | |
493 | } else | |
494 | return -EOPNOTSUPP; | |
495 | ||
496 | if (dnskey->dnskey.key_size != key_size) | |
497 | return -EINVAL; | |
498 | ||
499 | if (rrsig->rrsig.signature_size != key_size * 2) | |
500 | return -EINVAL; | |
501 | ||
502 | return dnssec_eddsa_verify_raw( | |
503 | curve, | |
504 | rrsig->rrsig.signature, key_size, | |
505 | (uint8_t*) rrsig->rrsig.signature + key_size, key_size, | |
506 | data, data_size, | |
507 | dnskey->dnskey.key, key_size); | |
508 | } | |
509 | #endif | |
510 | ||
2b442ac8 LP |
511 | static void md_add_uint8(gcry_md_hd_t md, uint8_t v) { |
512 | gcry_md_write(md, &v, sizeof(v)); | |
513 | } | |
514 | ||
515 | static void md_add_uint16(gcry_md_hd_t md, uint16_t v) { | |
516 | v = htobe16(v); | |
517 | gcry_md_write(md, &v, sizeof(v)); | |
518 | } | |
519 | ||
cb9eeb06 MCO |
520 | static void fwrite_uint8(FILE *fp, uint8_t v) { |
521 | fwrite(&v, sizeof(v), 1, fp); | |
522 | } | |
523 | ||
524 | static void fwrite_uint16(FILE *fp, uint16_t v) { | |
525 | v = htobe16(v); | |
526 | fwrite(&v, sizeof(v), 1, fp); | |
527 | } | |
528 | ||
529 | static void fwrite_uint32(FILE *fp, uint32_t v) { | |
2b442ac8 | 530 | v = htobe32(v); |
cb9eeb06 | 531 | fwrite(&v, sizeof(v), 1, fp); |
2b442ac8 LP |
532 | } |
533 | ||
97c67192 LP |
534 | static int dnssec_rrsig_prepare(DnsResourceRecord *rrsig) { |
535 | int n_key_labels, n_signer_labels; | |
536 | const char *name; | |
537 | int r; | |
538 | ||
539 | /* Checks whether the specified RRSIG RR is somewhat valid, and initializes the .n_skip_labels_source and | |
540 | * .n_skip_labels_signer fields so that we can use them later on. */ | |
541 | ||
542 | assert(rrsig); | |
543 | assert(rrsig->key->type == DNS_TYPE_RRSIG); | |
544 | ||
545 | /* Check if this RRSIG RR is already prepared */ | |
546 | if (rrsig->n_skip_labels_source != (unsigned) -1) | |
547 | return 0; | |
548 | ||
549 | if (rrsig->rrsig.inception > rrsig->rrsig.expiration) | |
550 | return -EINVAL; | |
551 | ||
1c02e7ba | 552 | name = dns_resource_key_name(rrsig->key); |
97c67192 LP |
553 | |
554 | n_key_labels = dns_name_count_labels(name); | |
555 | if (n_key_labels < 0) | |
556 | return n_key_labels; | |
557 | if (rrsig->rrsig.labels > n_key_labels) | |
558 | return -EINVAL; | |
559 | ||
560 | n_signer_labels = dns_name_count_labels(rrsig->rrsig.signer); | |
561 | if (n_signer_labels < 0) | |
562 | return n_signer_labels; | |
563 | if (n_signer_labels > rrsig->rrsig.labels) | |
564 | return -EINVAL; | |
565 | ||
566 | r = dns_name_skip(name, n_key_labels - n_signer_labels, &name); | |
567 | if (r < 0) | |
568 | return r; | |
569 | if (r == 0) | |
570 | return -EINVAL; | |
571 | ||
572 | /* Check if the signer is really a suffix of us */ | |
573 | r = dns_name_equal(name, rrsig->rrsig.signer); | |
574 | if (r < 0) | |
575 | return r; | |
576 | if (r == 0) | |
577 | return -EINVAL; | |
578 | ||
579 | rrsig->n_skip_labels_source = n_key_labels - rrsig->rrsig.labels; | |
580 | rrsig->n_skip_labels_signer = n_key_labels - n_signer_labels; | |
581 | ||
582 | return 0; | |
583 | } | |
584 | ||
2a326321 LP |
585 | static int dnssec_rrsig_expired(DnsResourceRecord *rrsig, usec_t realtime) { |
586 | usec_t expiration, inception, skew; | |
587 | ||
588 | assert(rrsig); | |
589 | assert(rrsig->key->type == DNS_TYPE_RRSIG); | |
590 | ||
591 | if (realtime == USEC_INFINITY) | |
592 | realtime = now(CLOCK_REALTIME); | |
593 | ||
594 | expiration = rrsig->rrsig.expiration * USEC_PER_SEC; | |
595 | inception = rrsig->rrsig.inception * USEC_PER_SEC; | |
596 | ||
5ae5cd40 | 597 | /* Consider inverted validity intervals as expired */ |
2a326321 | 598 | if (inception > expiration) |
5ae5cd40 | 599 | return true; |
2a326321 | 600 | |
896c5672 LP |
601 | /* Permit a certain amount of clock skew of 10% of the valid |
602 | * time range. This takes inspiration from unbound's | |
603 | * resolver. */ | |
2a326321 | 604 | skew = (expiration - inception) / 10; |
896c5672 LP |
605 | if (skew > SKEW_MAX) |
606 | skew = SKEW_MAX; | |
2a326321 LP |
607 | |
608 | if (inception < skew) | |
609 | inception = 0; | |
610 | else | |
611 | inception -= skew; | |
612 | ||
613 | if (expiration + skew < expiration) | |
614 | expiration = USEC_INFINITY; | |
615 | else | |
616 | expiration += skew; | |
617 | ||
618 | return realtime < inception || realtime > expiration; | |
619 | } | |
620 | ||
ca994e85 | 621 | static int algorithm_to_gcrypt_md(uint8_t algorithm) { |
fbf1a66d | 622 | |
6af47493 LP |
623 | /* Translates a DNSSEC signature algorithm into a gcrypt |
624 | * digest identifier. | |
625 | * | |
626 | * Note that we implement all algorithms listed as "Must | |
627 | * implement" and "Recommended to Implement" in RFC6944. We | |
628 | * don't implement any algorithms that are listed as | |
629 | * "Optional" or "Must Not Implement". Specifically, we do not | |
630 | * implement RSAMD5, DSASHA1, DH, DSA-NSEC3-SHA1, and | |
631 | * GOST-ECC. */ | |
fbf1a66d LP |
632 | |
633 | switch (algorithm) { | |
634 | ||
635 | case DNSSEC_ALGORITHM_RSASHA1: | |
636 | case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1: | |
637 | return GCRY_MD_SHA1; | |
638 | ||
639 | case DNSSEC_ALGORITHM_RSASHA256: | |
e0240c64 | 640 | case DNSSEC_ALGORITHM_ECDSAP256SHA256: |
fbf1a66d LP |
641 | return GCRY_MD_SHA256; |
642 | ||
e0240c64 LP |
643 | case DNSSEC_ALGORITHM_ECDSAP384SHA384: |
644 | return GCRY_MD_SHA384; | |
645 | ||
fbf1a66d LP |
646 | case DNSSEC_ALGORITHM_RSASHA512: |
647 | return GCRY_MD_SHA512; | |
648 | ||
649 | default: | |
650 | return -EOPNOTSUPP; | |
651 | } | |
652 | } | |
653 | ||
97c67192 LP |
654 | static void dnssec_fix_rrset_ttl( |
655 | DnsResourceRecord *list[], | |
656 | unsigned n, | |
657 | DnsResourceRecord *rrsig, | |
658 | usec_t realtime) { | |
659 | ||
660 | unsigned k; | |
661 | ||
662 | assert(list); | |
663 | assert(n > 0); | |
664 | assert(rrsig); | |
665 | ||
666 | for (k = 0; k < n; k++) { | |
667 | DnsResourceRecord *rr = list[k]; | |
668 | ||
669 | /* Pick the TTL as the minimum of the RR's TTL, the | |
670 | * RR's original TTL according to the RRSIG and the | |
671 | * RRSIG's own TTL, see RFC 4035, Section 5.3.3 */ | |
672 | rr->ttl = MIN3(rr->ttl, rrsig->rrsig.original_ttl, rrsig->ttl); | |
673 | rr->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; | |
674 | ||
675 | /* Copy over information about the signer and wildcard source of synthesis */ | |
676 | rr->n_skip_labels_source = rrsig->n_skip_labels_source; | |
677 | rr->n_skip_labels_signer = rrsig->n_skip_labels_signer; | |
678 | } | |
679 | ||
680 | rrsig->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; | |
681 | } | |
682 | ||
2a326321 LP |
683 | int dnssec_verify_rrset( |
684 | DnsAnswer *a, | |
0c857028 | 685 | const DnsResourceKey *key, |
2a326321 LP |
686 | DnsResourceRecord *rrsig, |
687 | DnsResourceRecord *dnskey, | |
547973de LP |
688 | usec_t realtime, |
689 | DnssecResult *result) { | |
2a326321 | 690 | |
5e55cde9 | 691 | uint8_t wire_format_name[DNS_WIRE_FORMAT_HOSTNAME_MAX]; |
2b442ac8 | 692 | DnsResourceRecord **list, *rr; |
588c53d0 | 693 | const char *source, *name; |
8530efc1 | 694 | _cleanup_(gcry_md_closep) gcry_md_hd_t md = NULL; |
ca994e85 | 695 | int r, md_algorithm; |
2b442ac8 | 696 | size_t k, n = 0; |
cb9eeb06 MCO |
697 | size_t sig_size = 0; |
698 | _cleanup_free_ char *sig_data = NULL; | |
699 | _cleanup_fclose_ FILE *f = NULL; | |
588c53d0 LP |
700 | size_t hash_size; |
701 | void *hash; | |
7715f91d | 702 | bool wildcard; |
2b442ac8 LP |
703 | |
704 | assert(key); | |
705 | assert(rrsig); | |
706 | assert(dnskey); | |
547973de | 707 | assert(result); |
2a326321 LP |
708 | assert(rrsig->key->type == DNS_TYPE_RRSIG); |
709 | assert(dnskey->key->type == DNS_TYPE_DNSKEY); | |
2b442ac8 | 710 | |
c629ff58 | 711 | /* Verifies that the RRSet matches the specified "key" in "a", |
2b442ac8 | 712 | * using the signature "rrsig" and the key "dnskey". It's |
c629ff58 | 713 | * assumed that RRSIG and DNSKEY match. */ |
2b442ac8 | 714 | |
97c67192 LP |
715 | r = dnssec_rrsig_prepare(rrsig); |
716 | if (r == -EINVAL) { | |
717 | *result = DNSSEC_INVALID; | |
718 | return r; | |
719 | } | |
720 | if (r < 0) | |
721 | return r; | |
722 | ||
2a326321 LP |
723 | r = dnssec_rrsig_expired(rrsig, realtime); |
724 | if (r < 0) | |
725 | return r; | |
547973de LP |
726 | if (r > 0) { |
727 | *result = DNSSEC_SIGNATURE_EXPIRED; | |
728 | return 0; | |
729 | } | |
2a326321 | 730 | |
1c02e7ba | 731 | name = dns_resource_key_name(key); |
588c53d0 LP |
732 | |
733 | /* Some keys may only appear signed in the zone apex, and are invalid anywhere else. (SOA, NS...) */ | |
734 | if (dns_type_apex_only(rrsig->rrsig.type_covered)) { | |
735 | r = dns_name_equal(rrsig->rrsig.signer, name); | |
736 | if (r < 0) | |
737 | return r; | |
738 | if (r == 0) { | |
739 | *result = DNSSEC_INVALID; | |
740 | return 0; | |
741 | } | |
742 | } | |
743 | ||
744 | /* OTOH DS RRs may not appear in the zone apex, but are valid everywhere else. */ | |
745 | if (rrsig->rrsig.type_covered == DNS_TYPE_DS) { | |
746 | r = dns_name_equal(rrsig->rrsig.signer, name); | |
747 | if (r < 0) | |
748 | return r; | |
749 | if (r > 0) { | |
750 | *result = DNSSEC_INVALID; | |
751 | return 0; | |
752 | } | |
753 | } | |
754 | ||
7715f91d | 755 | /* Determine the "Source of Synthesis" and whether this is a wildcard RRSIG */ |
588c53d0 | 756 | r = dns_name_suffix(name, rrsig->rrsig.labels, &source); |
7715f91d LP |
757 | if (r < 0) |
758 | return r; | |
e8233bce LP |
759 | if (r > 0 && !dns_type_may_wildcard(rrsig->rrsig.type_covered)) { |
760 | /* We refuse to validate NSEC3 or SOA RRs that are synthesized from wildcards */ | |
761 | *result = DNSSEC_INVALID; | |
762 | return 0; | |
763 | } | |
7160eb1b LP |
764 | if (r == 1) { |
765 | /* If we stripped a single label, then let's see if that maybe was "*". If so, we are not really | |
766 | * synthesized from a wildcard, we are the wildcard itself. Treat that like a normal name. */ | |
588c53d0 | 767 | r = dns_name_startswith(name, "*"); |
7160eb1b LP |
768 | if (r < 0) |
769 | return r; | |
770 | if (r > 0) | |
588c53d0 | 771 | source = name; |
7160eb1b LP |
772 | |
773 | wildcard = r == 0; | |
774 | } else | |
775 | wildcard = r > 0; | |
7715f91d | 776 | |
2b442ac8 | 777 | /* Collect all relevant RRs in a single array, so that we can look at the RRset */ |
0f23174c | 778 | list = newa(DnsResourceRecord *, dns_answer_size(a)); |
2b442ac8 LP |
779 | |
780 | DNS_ANSWER_FOREACH(rr, a) { | |
781 | r = dns_resource_key_equal(key, rr->key); | |
782 | if (r < 0) | |
783 | return r; | |
784 | if (r == 0) | |
785 | continue; | |
786 | ||
787 | /* We need the wire format for ordering, and digest calculation */ | |
788 | r = dns_resource_record_to_wire_format(rr, true); | |
789 | if (r < 0) | |
790 | return r; | |
791 | ||
792 | list[n++] = rr; | |
935a999f TG |
793 | |
794 | if (n > VERIFY_RRS_MAX) | |
795 | return -E2BIG; | |
2b442ac8 LP |
796 | } |
797 | ||
798 | if (n <= 0) | |
799 | return -ENODATA; | |
800 | ||
801 | /* Bring the RRs into canonical order */ | |
93bab288 | 802 | typesafe_qsort(list, n, rr_compare); |
2b442ac8 | 803 | |
2fe21124 | 804 | f = open_memstream_unlocked(&sig_data, &sig_size); |
cb9eeb06 MCO |
805 | if (!f) |
806 | return -ENOMEM; | |
2b442ac8 | 807 | |
cb9eeb06 MCO |
808 | fwrite_uint16(f, rrsig->rrsig.type_covered); |
809 | fwrite_uint8(f, rrsig->rrsig.algorithm); | |
810 | fwrite_uint8(f, rrsig->rrsig.labels); | |
811 | fwrite_uint32(f, rrsig->rrsig.original_ttl); | |
812 | fwrite_uint32(f, rrsig->rrsig.expiration); | |
813 | fwrite_uint32(f, rrsig->rrsig.inception); | |
814 | fwrite_uint16(f, rrsig->rrsig.key_tag); | |
2b442ac8 LP |
815 | |
816 | r = dns_name_to_wire_format(rrsig->rrsig.signer, wire_format_name, sizeof(wire_format_name), true); | |
817 | if (r < 0) | |
8530efc1 | 818 | return r; |
cb9eeb06 | 819 | fwrite(wire_format_name, 1, r, f); |
2b442ac8 | 820 | |
7715f91d LP |
821 | /* Convert the source of synthesis into wire format */ |
822 | r = dns_name_to_wire_format(source, wire_format_name, sizeof(wire_format_name), true); | |
823 | if (r < 0) | |
8530efc1 | 824 | return r; |
7715f91d | 825 | |
2b442ac8 LP |
826 | for (k = 0; k < n; k++) { |
827 | size_t l; | |
7715f91d | 828 | |
2b442ac8 LP |
829 | rr = list[k]; |
830 | ||
7715f91d LP |
831 | /* Hash the source of synthesis. If this is a wildcard, then prefix it with the *. label */ |
832 | if (wildcard) | |
cb9eeb06 MCO |
833 | fwrite((uint8_t[]) { 1, '*'}, sizeof(uint8_t), 2, f); |
834 | fwrite(wire_format_name, 1, r, f); | |
2b442ac8 | 835 | |
cb9eeb06 MCO |
836 | fwrite_uint16(f, rr->key->type); |
837 | fwrite_uint16(f, rr->key->class); | |
838 | fwrite_uint32(f, rrsig->rrsig.original_ttl); | |
2b442ac8 | 839 | |
85aeaccc | 840 | l = DNS_RESOURCE_RECORD_RDATA_SIZE(rr); |
2b442ac8 LP |
841 | assert(l <= 0xFFFF); |
842 | ||
cb9eeb06 MCO |
843 | fwrite_uint16(f, (uint16_t) l); |
844 | fwrite(DNS_RESOURCE_RECORD_RDATA(rr), 1, l, f); | |
2b442ac8 LP |
845 | } |
846 | ||
cb9eeb06 MCO |
847 | r = fflush_and_check(f); |
848 | if (r < 0) | |
849 | return r; | |
850 | ||
851 | initialize_libgcrypt(false); | |
852 | ||
853 | switch (rrsig->rrsig.algorithm) { | |
854 | #if GCRYPT_VERSION_NUMBER >= 0x010600 | |
855 | case DNSSEC_ALGORITHM_ED25519: | |
856 | break; | |
857 | #else | |
858 | case DNSSEC_ALGORITHM_ED25519: | |
859 | #endif | |
860 | case DNSSEC_ALGORITHM_ED448: | |
861 | *result = DNSSEC_UNSUPPORTED_ALGORITHM; | |
8530efc1 | 862 | return 0; |
cb9eeb06 MCO |
863 | default: |
864 | /* OK, the RRs are now in canonical order. Let's calculate the digest */ | |
865 | md_algorithm = algorithm_to_gcrypt_md(rrsig->rrsig.algorithm); | |
866 | if (md_algorithm == -EOPNOTSUPP) { | |
867 | *result = DNSSEC_UNSUPPORTED_ALGORITHM; | |
8530efc1 | 868 | return 0; |
cb9eeb06 | 869 | } |
8530efc1 ZJS |
870 | if (md_algorithm < 0) |
871 | return md_algorithm; | |
cb9eeb06 MCO |
872 | |
873 | gcry_md_open(&md, md_algorithm, 0); | |
8530efc1 ZJS |
874 | if (!md) |
875 | return -EIO; | |
cb9eeb06 MCO |
876 | |
877 | hash_size = gcry_md_get_algo_dlen(md_algorithm); | |
878 | assert(hash_size > 0); | |
879 | ||
880 | gcry_md_write(md, sig_data, sig_size); | |
881 | ||
882 | hash = gcry_md_read(md, 0); | |
8530efc1 ZJS |
883 | if (!hash) |
884 | return -EIO; | |
2b442ac8 LP |
885 | } |
886 | ||
e0240c64 LP |
887 | switch (rrsig->rrsig.algorithm) { |
888 | ||
889 | case DNSSEC_ALGORITHM_RSASHA1: | |
890 | case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1: | |
891 | case DNSSEC_ALGORITHM_RSASHA256: | |
892 | case DNSSEC_ALGORITHM_RSASHA512: | |
893 | r = dnssec_rsa_verify( | |
ca994e85 | 894 | gcry_md_algo_name(md_algorithm), |
e0240c64 LP |
895 | hash, hash_size, |
896 | rrsig, | |
897 | dnskey); | |
898 | break; | |
899 | ||
900 | case DNSSEC_ALGORITHM_ECDSAP256SHA256: | |
901 | case DNSSEC_ALGORITHM_ECDSAP384SHA384: | |
902 | r = dnssec_ecdsa_verify( | |
ca994e85 | 903 | gcry_md_algo_name(md_algorithm), |
e0240c64 LP |
904 | rrsig->rrsig.algorithm, |
905 | hash, hash_size, | |
906 | rrsig, | |
907 | dnskey); | |
908 | break; | |
cb9eeb06 MCO |
909 | #if GCRYPT_VERSION_NUMBER >= 0x010600 |
910 | case DNSSEC_ALGORITHM_ED25519: | |
911 | r = dnssec_eddsa_verify( | |
912 | rrsig->rrsig.algorithm, | |
913 | sig_data, sig_size, | |
914 | rrsig, | |
915 | dnskey); | |
916 | break; | |
917 | #endif | |
e0240c64 | 918 | } |
2b442ac8 | 919 | if (r < 0) |
8530efc1 | 920 | return r; |
2b442ac8 | 921 | |
97c67192 LP |
922 | /* Now, fix the ttl, expiry, and remember the synthesizing source and the signer */ |
923 | if (r > 0) | |
924 | dnssec_fix_rrset_ttl(list, n, rrsig, realtime); | |
925 | ||
926 | if (r == 0) | |
0c7bff0a LP |
927 | *result = DNSSEC_INVALID; |
928 | else if (wildcard) | |
929 | *result = DNSSEC_VALIDATED_WILDCARD; | |
930 | else | |
931 | *result = DNSSEC_VALIDATED; | |
97c67192 | 932 | |
8530efc1 | 933 | return 0; |
2b442ac8 LP |
934 | } |
935 | ||
0c857028 | 936 | int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) { |
2b442ac8 LP |
937 | |
938 | assert(rrsig); | |
939 | assert(dnskey); | |
940 | ||
941 | /* Checks if the specified DNSKEY RR matches the key used for | |
942 | * the signature in the specified RRSIG RR */ | |
943 | ||
944 | if (rrsig->key->type != DNS_TYPE_RRSIG) | |
945 | return -EINVAL; | |
946 | ||
947 | if (dnskey->key->type != DNS_TYPE_DNSKEY) | |
948 | return 0; | |
949 | if (dnskey->key->class != rrsig->key->class) | |
950 | return 0; | |
951 | if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0) | |
952 | return 0; | |
0c857028 | 953 | if (!revoked_ok && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE)) |
28b8191e | 954 | return 0; |
2b442ac8 LP |
955 | if (dnskey->dnskey.protocol != 3) |
956 | return 0; | |
957 | if (dnskey->dnskey.algorithm != rrsig->rrsig.algorithm) | |
958 | return 0; | |
959 | ||
0c857028 | 960 | if (dnssec_keytag(dnskey, false) != rrsig->rrsig.key_tag) |
2b442ac8 LP |
961 | return 0; |
962 | ||
1c02e7ba | 963 | return dns_name_equal(dns_resource_key_name(dnskey->key), rrsig->rrsig.signer); |
2b442ac8 LP |
964 | } |
965 | ||
105e1512 | 966 | int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) { |
2b442ac8 LP |
967 | assert(key); |
968 | assert(rrsig); | |
969 | ||
970 | /* Checks if the specified RRSIG RR protects the RRSet of the specified RR key. */ | |
971 | ||
972 | if (rrsig->key->type != DNS_TYPE_RRSIG) | |
973 | return 0; | |
974 | if (rrsig->key->class != key->class) | |
975 | return 0; | |
976 | if (rrsig->rrsig.type_covered != key->type) | |
977 | return 0; | |
978 | ||
1c02e7ba | 979 | return dns_name_equal(dns_resource_key_name(rrsig->key), dns_resource_key_name(key)); |
2b442ac8 LP |
980 | } |
981 | ||
2a326321 LP |
982 | int dnssec_verify_rrset_search( |
983 | DnsAnswer *a, | |
0c857028 | 984 | const DnsResourceKey *key, |
2a326321 | 985 | DnsAnswer *validated_dnskeys, |
547973de | 986 | usec_t realtime, |
0c7bff0a LP |
987 | DnssecResult *result, |
988 | DnsResourceRecord **ret_rrsig) { | |
2a326321 | 989 | |
203f1b35 | 990 | bool found_rrsig = false, found_invalid = false, found_expired_rrsig = false, found_unsupported_algorithm = false; |
2b442ac8 LP |
991 | DnsResourceRecord *rrsig; |
992 | int r; | |
993 | ||
994 | assert(key); | |
547973de | 995 | assert(result); |
2b442ac8 | 996 | |
105e1512 | 997 | /* Verifies all RRs from "a" that match the key "key" against DNSKEYs in "validated_dnskeys" */ |
2b442ac8 LP |
998 | |
999 | if (!a || a->n_rrs <= 0) | |
1000 | return -ENODATA; | |
1001 | ||
1002 | /* Iterate through each RRSIG RR. */ | |
1003 | DNS_ANSWER_FOREACH(rrsig, a) { | |
1004 | DnsResourceRecord *dnskey; | |
105e1512 | 1005 | DnsAnswerFlags flags; |
2b442ac8 | 1006 | |
203f1b35 | 1007 | /* Is this an RRSIG RR that applies to RRs matching our key? */ |
2b442ac8 LP |
1008 | r = dnssec_key_match_rrsig(key, rrsig); |
1009 | if (r < 0) | |
1010 | return r; | |
1011 | if (r == 0) | |
1012 | continue; | |
1013 | ||
1014 | found_rrsig = true; | |
1015 | ||
547973de | 1016 | /* Look for a matching key */ |
105e1512 | 1017 | DNS_ANSWER_FOREACH_FLAGS(dnskey, flags, validated_dnskeys) { |
547973de | 1018 | DnssecResult one_result; |
2b442ac8 | 1019 | |
105e1512 LP |
1020 | if ((flags & DNS_ANSWER_AUTHENTICATED) == 0) |
1021 | continue; | |
1022 | ||
203f1b35 | 1023 | /* Is this a DNSKEY RR that matches they key of our RRSIG? */ |
0c857028 | 1024 | r = dnssec_rrsig_match_dnskey(rrsig, dnskey, false); |
2b442ac8 LP |
1025 | if (r < 0) |
1026 | return r; | |
1027 | if (r == 0) | |
1028 | continue; | |
1029 | ||
2a326321 LP |
1030 | /* Take the time here, if it isn't set yet, so |
1031 | * that we do all validations with the same | |
1032 | * time. */ | |
1033 | if (realtime == USEC_INFINITY) | |
1034 | realtime = now(CLOCK_REALTIME); | |
1035 | ||
2b442ac8 LP |
1036 | /* Yay, we found a matching RRSIG with a matching |
1037 | * DNSKEY, awesome. Now let's verify all entries of | |
1038 | * the RRSet against the RRSIG and DNSKEY | |
1039 | * combination. */ | |
1040 | ||
547973de | 1041 | r = dnssec_verify_rrset(a, key, rrsig, dnskey, realtime, &one_result); |
203f1b35 | 1042 | if (r < 0) |
2b442ac8 | 1043 | return r; |
203f1b35 LP |
1044 | |
1045 | switch (one_result) { | |
1046 | ||
1047 | case DNSSEC_VALIDATED: | |
0c7bff0a | 1048 | case DNSSEC_VALIDATED_WILDCARD: |
203f1b35 | 1049 | /* Yay, the RR has been validated, |
ee3d6aff | 1050 | * return immediately, but fix up the expiry */ |
0c7bff0a LP |
1051 | if (ret_rrsig) |
1052 | *ret_rrsig = rrsig; | |
1053 | ||
1054 | *result = one_result; | |
547973de | 1055 | return 0; |
2b442ac8 | 1056 | |
203f1b35 LP |
1057 | case DNSSEC_INVALID: |
1058 | /* If the signature is invalid, let's try another | |
1059 | key and/or signature. After all they | |
1060 | key_tags and stuff are not unique, and | |
1061 | might be shared by multiple keys. */ | |
1062 | found_invalid = true; | |
1063 | continue; | |
1064 | ||
1065 | case DNSSEC_UNSUPPORTED_ALGORITHM: | |
1066 | /* If the key algorithm is | |
1067 | unsupported, try another | |
1068 | RRSIG/DNSKEY pair, but remember we | |
1069 | encountered this, so that we can | |
1070 | return a proper error when we | |
1071 | encounter nothing better. */ | |
1072 | found_unsupported_algorithm = true; | |
1073 | continue; | |
1074 | ||
1075 | case DNSSEC_SIGNATURE_EXPIRED: | |
1076 | /* If the signature is expired, try | |
1077 | another one, but remember it, so | |
1078 | that we can return this */ | |
1079 | found_expired_rrsig = true; | |
1080 | continue; | |
1081 | ||
1082 | default: | |
1083 | assert_not_reached("Unexpected DNSSEC validation result"); | |
1084 | } | |
2b442ac8 LP |
1085 | } |
1086 | } | |
1087 | ||
203f1b35 LP |
1088 | if (found_expired_rrsig) |
1089 | *result = DNSSEC_SIGNATURE_EXPIRED; | |
1090 | else if (found_unsupported_algorithm) | |
1091 | *result = DNSSEC_UNSUPPORTED_ALGORITHM; | |
1092 | else if (found_invalid) | |
547973de LP |
1093 | *result = DNSSEC_INVALID; |
1094 | else if (found_rrsig) | |
1095 | *result = DNSSEC_MISSING_KEY; | |
1096 | else | |
1097 | *result = DNSSEC_NO_SIGNATURE; | |
2b442ac8 | 1098 | |
0c7bff0a LP |
1099 | if (ret_rrsig) |
1100 | *ret_rrsig = NULL; | |
1101 | ||
547973de | 1102 | return 0; |
2b442ac8 LP |
1103 | } |
1104 | ||
105e1512 LP |
1105 | int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) { |
1106 | DnsResourceRecord *rr; | |
1107 | int r; | |
1108 | ||
5238e957 | 1109 | /* Checks whether there's at least one RRSIG in 'a' that protects RRs of the specified key */ |
105e1512 LP |
1110 | |
1111 | DNS_ANSWER_FOREACH(rr, a) { | |
1112 | r = dnssec_key_match_rrsig(key, rr); | |
1113 | if (r < 0) | |
1114 | return r; | |
1115 | if (r > 0) | |
1116 | return 1; | |
1117 | } | |
1118 | ||
1119 | return 0; | |
1120 | } | |
1121 | ||
ca994e85 | 1122 | static int digest_to_gcrypt_md(uint8_t algorithm) { |
a1972a91 | 1123 | |
fbf1a66d | 1124 | /* Translates a DNSSEC digest algorithm into a gcrypt digest identifier */ |
a1972a91 LP |
1125 | |
1126 | switch (algorithm) { | |
1127 | ||
1128 | case DNSSEC_DIGEST_SHA1: | |
1129 | return GCRY_MD_SHA1; | |
1130 | ||
1131 | case DNSSEC_DIGEST_SHA256: | |
1132 | return GCRY_MD_SHA256; | |
1133 | ||
af22c65b LP |
1134 | case DNSSEC_DIGEST_SHA384: |
1135 | return GCRY_MD_SHA384; | |
1136 | ||
a1972a91 LP |
1137 | default: |
1138 | return -EOPNOTSUPP; | |
1139 | } | |
1140 | } | |
1141 | ||
96bb7673 | 1142 | int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) { |
5e55cde9 | 1143 | uint8_t wire_format[DNS_WIRE_FORMAT_HOSTNAME_MAX]; |
15c53310 | 1144 | _cleanup_(gcry_md_closep) gcry_md_hd_t md = NULL; |
a1972a91 | 1145 | size_t hash_size; |
ca994e85 | 1146 | int md_algorithm, r; |
2b442ac8 | 1147 | void *result; |
2b442ac8 LP |
1148 | |
1149 | assert(dnskey); | |
1150 | assert(ds); | |
1151 | ||
1152 | /* Implements DNSKEY verification by a DS, according to RFC 4035, section 5.2 */ | |
1153 | ||
1154 | if (dnskey->key->type != DNS_TYPE_DNSKEY) | |
1155 | return -EINVAL; | |
1156 | if (ds->key->type != DNS_TYPE_DS) | |
1157 | return -EINVAL; | |
1158 | if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0) | |
1159 | return -EKEYREJECTED; | |
0c857028 LP |
1160 | if (!mask_revoke && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE)) |
1161 | return -EKEYREJECTED; | |
2b442ac8 LP |
1162 | if (dnskey->dnskey.protocol != 3) |
1163 | return -EKEYREJECTED; | |
1164 | ||
2b442ac8 LP |
1165 | if (dnskey->dnskey.algorithm != ds->ds.algorithm) |
1166 | return 0; | |
0c857028 | 1167 | if (dnssec_keytag(dnskey, mask_revoke) != ds->ds.key_tag) |
2b442ac8 LP |
1168 | return 0; |
1169 | ||
91e023d8 | 1170 | initialize_libgcrypt(false); |
0638401a | 1171 | |
ca994e85 LP |
1172 | md_algorithm = digest_to_gcrypt_md(ds->ds.digest_type); |
1173 | if (md_algorithm < 0) | |
1174 | return md_algorithm; | |
2b442ac8 | 1175 | |
ca994e85 | 1176 | hash_size = gcry_md_get_algo_dlen(md_algorithm); |
a1972a91 | 1177 | assert(hash_size > 0); |
2b442ac8 | 1178 | |
a1972a91 LP |
1179 | if (ds->ds.digest_size != hash_size) |
1180 | return 0; | |
2b442ac8 | 1181 | |
c910c520 | 1182 | r = dns_name_to_wire_format(dns_resource_key_name(dnskey->key), wire_format, sizeof(wire_format), true); |
a1972a91 LP |
1183 | if (r < 0) |
1184 | return r; | |
2b442ac8 | 1185 | |
ca994e85 | 1186 | gcry_md_open(&md, md_algorithm, 0); |
2b442ac8 LP |
1187 | if (!md) |
1188 | return -EIO; | |
1189 | ||
c910c520 | 1190 | gcry_md_write(md, wire_format, r); |
0c857028 LP |
1191 | if (mask_revoke) |
1192 | md_add_uint16(md, dnskey->dnskey.flags & ~DNSKEY_FLAG_REVOKE); | |
1193 | else | |
1194 | md_add_uint16(md, dnskey->dnskey.flags); | |
2b442ac8 LP |
1195 | md_add_uint8(md, dnskey->dnskey.protocol); |
1196 | md_add_uint8(md, dnskey->dnskey.algorithm); | |
1197 | gcry_md_write(md, dnskey->dnskey.key, dnskey->dnskey.key_size); | |
1198 | ||
1199 | result = gcry_md_read(md, 0); | |
15c53310 ZJS |
1200 | if (!result) |
1201 | return -EIO; | |
2b442ac8 | 1202 | |
c910c520 | 1203 | return memcmp(result, ds->ds.digest, ds->ds.digest_size) == 0; |
2b442ac8 | 1204 | } |
24710c48 | 1205 | |
96bb7673 | 1206 | int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) { |
547973de | 1207 | DnsResourceRecord *ds; |
105e1512 | 1208 | DnsAnswerFlags flags; |
547973de LP |
1209 | int r; |
1210 | ||
1211 | assert(dnskey); | |
1212 | ||
1213 | if (dnskey->key->type != DNS_TYPE_DNSKEY) | |
1214 | return 0; | |
1215 | ||
105e1512 LP |
1216 | DNS_ANSWER_FOREACH_FLAGS(ds, flags, validated_ds) { |
1217 | ||
1218 | if ((flags & DNS_ANSWER_AUTHENTICATED) == 0) | |
1219 | continue; | |
547973de LP |
1220 | |
1221 | if (ds->key->type != DNS_TYPE_DS) | |
1222 | continue; | |
d1c4ee32 LP |
1223 | if (ds->key->class != dnskey->key->class) |
1224 | continue; | |
1225 | ||
1c02e7ba | 1226 | r = dns_name_equal(dns_resource_key_name(dnskey->key), dns_resource_key_name(ds->key)); |
d1c4ee32 LP |
1227 | if (r < 0) |
1228 | return r; | |
1229 | if (r == 0) | |
1230 | continue; | |
1231 | ||
96bb7673 | 1232 | r = dnssec_verify_dnskey_by_ds(dnskey, ds, false); |
54b778e7 LP |
1233 | if (IN_SET(r, -EKEYREJECTED, -EOPNOTSUPP)) |
1234 | return 0; /* The DNSKEY is revoked or otherwise invalid, or we don't support the digest algorithm */ | |
547973de LP |
1235 | if (r < 0) |
1236 | return r; | |
1237 | if (r > 0) | |
1238 | return 1; | |
1239 | } | |
1240 | ||
1241 | return 0; | |
1242 | } | |
1243 | ||
d15ad742 LP |
1244 | static int nsec3_hash_to_gcrypt_md(uint8_t algorithm) { |
1245 | ||
1246 | /* Translates a DNSSEC NSEC3 hash algorithm into a gcrypt digest identifier */ | |
1247 | ||
1248 | switch (algorithm) { | |
1249 | ||
1250 | case NSEC3_ALGORITHM_SHA1: | |
1251 | return GCRY_MD_SHA1; | |
1252 | ||
1253 | default: | |
1254 | return -EOPNOTSUPP; | |
1255 | } | |
1256 | } | |
1257 | ||
1d3db294 | 1258 | int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) { |
5e55cde9 | 1259 | uint8_t wire_format[DNS_WIRE_FORMAT_HOSTNAME_MAX]; |
72667f08 LP |
1260 | gcry_md_hd_t md = NULL; |
1261 | size_t hash_size; | |
1262 | int algorithm; | |
1263 | void *result; | |
1264 | unsigned k; | |
1265 | int r; | |
1266 | ||
1267 | assert(nsec3); | |
1268 | assert(name); | |
1269 | assert(ret); | |
1270 | ||
1271 | if (nsec3->key->type != DNS_TYPE_NSEC3) | |
1272 | return -EINVAL; | |
1273 | ||
baaa35ad ZJS |
1274 | if (nsec3->nsec3.iterations > NSEC3_ITERATIONS_MAX) |
1275 | return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), | |
1276 | "Ignoring NSEC3 RR %s with excessive number of iterations.", | |
1277 | dns_resource_record_to_string(nsec3)); | |
a8f158b9 | 1278 | |
d15ad742 | 1279 | algorithm = nsec3_hash_to_gcrypt_md(nsec3->nsec3.algorithm); |
72667f08 LP |
1280 | if (algorithm < 0) |
1281 | return algorithm; | |
1282 | ||
91e023d8 | 1283 | initialize_libgcrypt(false); |
72667f08 LP |
1284 | |
1285 | hash_size = gcry_md_get_algo_dlen(algorithm); | |
1286 | assert(hash_size > 0); | |
1287 | ||
1288 | if (nsec3->nsec3.next_hashed_name_size != hash_size) | |
1289 | return -EINVAL; | |
1290 | ||
1291 | r = dns_name_to_wire_format(name, wire_format, sizeof(wire_format), true); | |
1292 | if (r < 0) | |
1293 | return r; | |
1294 | ||
1295 | gcry_md_open(&md, algorithm, 0); | |
1296 | if (!md) | |
1297 | return -EIO; | |
1298 | ||
1299 | gcry_md_write(md, wire_format, r); | |
1300 | gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size); | |
1301 | ||
1302 | result = gcry_md_read(md, 0); | |
1303 | if (!result) { | |
1304 | r = -EIO; | |
1305 | goto finish; | |
1306 | } | |
1307 | ||
1308 | for (k = 0; k < nsec3->nsec3.iterations; k++) { | |
1309 | uint8_t tmp[hash_size]; | |
1310 | memcpy(tmp, result, hash_size); | |
1311 | ||
1312 | gcry_md_reset(md); | |
1313 | gcry_md_write(md, tmp, hash_size); | |
1314 | gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size); | |
1315 | ||
1316 | result = gcry_md_read(md, 0); | |
1317 | if (!result) { | |
1318 | r = -EIO; | |
1319 | goto finish; | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | memcpy(ret, result, hash_size); | |
1324 | r = (int) hash_size; | |
1325 | ||
1326 | finish: | |
1327 | gcry_md_close(md); | |
1328 | return r; | |
1329 | } | |
1330 | ||
3f5ecaad | 1331 | static int nsec3_is_good(DnsResourceRecord *rr, DnsResourceRecord *nsec3) { |
db5b0e92 LP |
1332 | const char *a, *b; |
1333 | int r; | |
1334 | ||
1335 | assert(rr); | |
1336 | ||
db5b0e92 LP |
1337 | if (rr->key->type != DNS_TYPE_NSEC3) |
1338 | return 0; | |
1339 | ||
1f133e0d | 1340 | /* RFC 5155, Section 8.2 says we MUST ignore NSEC3 RRs with flags != 0 or 1 */ |
db5b0e92 LP |
1341 | if (!IN_SET(rr->nsec3.flags, 0, 1)) |
1342 | return 0; | |
1343 | ||
d15ad742 LP |
1344 | /* Ignore NSEC3 RRs whose algorithm we don't know */ |
1345 | if (nsec3_hash_to_gcrypt_md(rr->nsec3.algorithm) < 0) | |
1346 | return 0; | |
a8f158b9 LP |
1347 | /* Ignore NSEC3 RRs with an excessive number of required iterations */ |
1348 | if (rr->nsec3.iterations > NSEC3_ITERATIONS_MAX) | |
1349 | return 0; | |
d15ad742 | 1350 | |
cbd100ac LP |
1351 | /* Ignore NSEC3 RRs generated from wildcards. If these NSEC3 RRs weren't correctly signed we can't make this |
1352 | * check (since rr->n_skip_labels_source is -1), but that's OK, as we won't trust them anyway in that case. */ | |
4c701096 | 1353 | if (!IN_SET(rr->n_skip_labels_source, 0, (unsigned) -1)) |
93a3b929 LP |
1354 | return 0; |
1355 | /* Ignore NSEC3 RRs that are located anywhere else than one label below the zone */ | |
4c701096 | 1356 | if (!IN_SET(rr->n_skip_labels_signer, 1, (unsigned) -1)) |
93a3b929 LP |
1357 | return 0; |
1358 | ||
db5b0e92 LP |
1359 | if (!nsec3) |
1360 | return 1; | |
1361 | ||
1362 | /* If a second NSEC3 RR is specified, also check if they are from the same zone. */ | |
1363 | ||
1364 | if (nsec3 == rr) /* Shortcut */ | |
1365 | return 1; | |
1366 | ||
1367 | if (rr->key->class != nsec3->key->class) | |
1368 | return 0; | |
1369 | if (rr->nsec3.algorithm != nsec3->nsec3.algorithm) | |
1370 | return 0; | |
1371 | if (rr->nsec3.iterations != nsec3->nsec3.iterations) | |
1372 | return 0; | |
1373 | if (rr->nsec3.salt_size != nsec3->nsec3.salt_size) | |
1374 | return 0; | |
1f66559c | 1375 | if (memcmp_safe(rr->nsec3.salt, nsec3->nsec3.salt, rr->nsec3.salt_size) != 0) |
db5b0e92 LP |
1376 | return 0; |
1377 | ||
1c02e7ba | 1378 | a = dns_resource_key_name(rr->key); |
db5b0e92 | 1379 | r = dns_name_parent(&a); /* strip off hash */ |
f20db199 | 1380 | if (r <= 0) |
db5b0e92 | 1381 | return r; |
db5b0e92 | 1382 | |
1c02e7ba | 1383 | b = dns_resource_key_name(nsec3->key); |
db5b0e92 | 1384 | r = dns_name_parent(&b); /* strip off hash */ |
f20db199 | 1385 | if (r <= 0) |
db5b0e92 | 1386 | return r; |
db5b0e92 | 1387 | |
93a3b929 | 1388 | /* Make sure both have the same parent */ |
db5b0e92 LP |
1389 | return dns_name_equal(a, b); |
1390 | } | |
1391 | ||
cdbffec0 LP |
1392 | static int nsec3_hashed_domain_format(const uint8_t *hashed, size_t hashed_size, const char *zone, char **ret) { |
1393 | _cleanup_free_ char *l = NULL; | |
1394 | char *j; | |
1395 | ||
1396 | assert(hashed); | |
1397 | assert(hashed_size > 0); | |
1398 | assert(zone); | |
1399 | assert(ret); | |
1400 | ||
1401 | l = base32hexmem(hashed, hashed_size, false); | |
1402 | if (!l) | |
1403 | return -ENOMEM; | |
1404 | ||
605405c6 | 1405 | j = strjoin(l, ".", zone); |
cdbffec0 LP |
1406 | if (!j) |
1407 | return -ENOMEM; | |
1408 | ||
1409 | *ret = j; | |
1410 | return (int) hashed_size; | |
1411 | } | |
1412 | ||
1413 | static int nsec3_hashed_domain_make(DnsResourceRecord *nsec3, const char *domain, const char *zone, char **ret) { | |
105e1512 | 1414 | uint8_t hashed[DNSSEC_HASH_SIZE_MAX]; |
6f76ec5a TG |
1415 | int hashed_size; |
1416 | ||
1417 | assert(nsec3); | |
1418 | assert(domain); | |
1419 | assert(zone); | |
1420 | assert(ret); | |
1421 | ||
1422 | hashed_size = dnssec_nsec3_hash(nsec3, domain, hashed); | |
1423 | if (hashed_size < 0) | |
1424 | return hashed_size; | |
1425 | ||
cdbffec0 | 1426 | return nsec3_hashed_domain_format(hashed, (size_t) hashed_size, zone, ret); |
6f76ec5a TG |
1427 | } |
1428 | ||
35ad41d3 TG |
1429 | /* See RFC 5155, Section 8 |
1430 | * First try to find a NSEC3 record that matches our query precisely, if that fails, find the closest | |
1431 | * enclosure. Secondly, find a proof that there is no closer enclosure and either a proof that there | |
1432 | * is no wildcard domain as a direct descendant of the closest enclosure, or find an NSEC3 record that | |
1433 | * matches the wildcard domain. | |
1434 | * | |
1435 | * Based on this we can prove either the existence of the record in @key, or NXDOMAIN or NODATA, or | |
1436 | * that there is no proof either way. The latter is the case if a the proof of non-existence of a given | |
1437 | * name uses an NSEC3 record with the opt-out bit set. Lastly, if we are given insufficient NSEC3 records | |
1438 | * to conclude anything we indicate this by returning NO_RR. */ | |
d3760be0 | 1439 | static int dnssec_test_nsec3(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { |
d41084a5 LP |
1440 | _cleanup_free_ char *next_closer_domain = NULL, *wildcard_domain = NULL; |
1441 | const char *zone, *p, *pp = NULL, *wildcard; | |
7e35195f | 1442 | DnsResourceRecord *rr, *enclosure_rr, *zone_rr, *wildcard_rr = NULL; |
105e1512 LP |
1443 | DnsAnswerFlags flags; |
1444 | int hashed_size, r; | |
35ad41d3 | 1445 | bool a, no_closer = false, no_wildcard = false, optout = false; |
72667f08 LP |
1446 | |
1447 | assert(key); | |
1448 | assert(result); | |
1449 | ||
d1511b33 TG |
1450 | /* First step, find the zone name and the NSEC3 parameters of the zone. |
1451 | * it is sufficient to look for the longest common suffix we find with | |
1452 | * any NSEC3 RR in the response. Any NSEC3 record will do as all NSEC3 | |
1453 | * records from a given zone in a response must use the same | |
1454 | * parameters. */ | |
1c02e7ba | 1455 | zone = dns_resource_key_name(key); |
13b78323 | 1456 | for (;;) { |
7e35195f | 1457 | DNS_ANSWER_FOREACH_FLAGS(zone_rr, flags, answer) { |
3f5ecaad | 1458 | r = nsec3_is_good(zone_rr, NULL); |
db5b0e92 LP |
1459 | if (r < 0) |
1460 | return r; | |
1461 | if (r == 0) | |
13b78323 LP |
1462 | continue; |
1463 | ||
1c02e7ba | 1464 | r = dns_name_equal_skip(dns_resource_key_name(zone_rr->key), 1, zone); |
13b78323 LP |
1465 | if (r < 0) |
1466 | return r; | |
1467 | if (r > 0) | |
d1511b33 | 1468 | goto found_zone; |
13b78323 LP |
1469 | } |
1470 | ||
1471 | /* Strip one label from the front */ | |
d1511b33 | 1472 | r = dns_name_parent(&zone); |
13b78323 LP |
1473 | if (r < 0) |
1474 | return r; | |
1475 | if (r == 0) | |
1476 | break; | |
1477 | } | |
1478 | ||
1479 | *result = DNSSEC_NSEC_NO_RR; | |
1480 | return 0; | |
1481 | ||
d1511b33 | 1482 | found_zone: |
13b78323 | 1483 | /* Second step, find the closest encloser NSEC3 RR in 'answer' that matches 'key' */ |
1c02e7ba | 1484 | p = dns_resource_key_name(key); |
105e1512 | 1485 | for (;;) { |
6f76ec5a | 1486 | _cleanup_free_ char *hashed_domain = NULL; |
72667f08 | 1487 | |
cdbffec0 | 1488 | hashed_size = nsec3_hashed_domain_make(zone_rr, p, zone, &hashed_domain); |
db5b0e92 LP |
1489 | if (hashed_size == -EOPNOTSUPP) { |
1490 | *result = DNSSEC_NSEC_UNSUPPORTED_ALGORITHM; | |
1491 | return 0; | |
1492 | } | |
1493 | if (hashed_size < 0) | |
1494 | return hashed_size; | |
72667f08 | 1495 | |
d1511b33 | 1496 | DNS_ANSWER_FOREACH_FLAGS(enclosure_rr, flags, answer) { |
db5b0e92 | 1497 | |
3f5ecaad | 1498 | r = nsec3_is_good(enclosure_rr, zone_rr); |
72667f08 LP |
1499 | if (r < 0) |
1500 | return r; | |
105e1512 LP |
1501 | if (r == 0) |
1502 | continue; | |
1503 | ||
d1511b33 | 1504 | if (enclosure_rr->nsec3.next_hashed_name_size != (size_t) hashed_size) |
db5b0e92 | 1505 | continue; |
105e1512 | 1506 | |
1c02e7ba | 1507 | r = dns_name_equal(dns_resource_key_name(enclosure_rr->key), hashed_domain); |
72667f08 LP |
1508 | if (r < 0) |
1509 | return r; | |
ed29bfdc LP |
1510 | if (r > 0) { |
1511 | a = flags & DNS_ANSWER_AUTHENTICATED; | |
13b78323 | 1512 | goto found_closest_encloser; |
ed29bfdc | 1513 | } |
105e1512 LP |
1514 | } |
1515 | ||
1516 | /* We didn't find the closest encloser with this name, | |
1517 | * but let's remember this domain name, it might be | |
1518 | * the next closer name */ | |
1519 | ||
1520 | pp = p; | |
1521 | ||
1522 | /* Strip one label from the front */ | |
1523 | r = dns_name_parent(&p); | |
1524 | if (r < 0) | |
1525 | return r; | |
1526 | if (r == 0) | |
72667f08 | 1527 | break; |
105e1512 | 1528 | } |
72667f08 | 1529 | |
105e1512 LP |
1530 | *result = DNSSEC_NSEC_NO_RR; |
1531 | return 0; | |
72667f08 | 1532 | |
13b78323 | 1533 | found_closest_encloser: |
105e1512 | 1534 | /* We found a closest encloser in 'p'; next closer is 'pp' */ |
72667f08 | 1535 | |
105e1512 | 1536 | if (!pp) { |
352af308 LP |
1537 | /* We have an exact match! If we area looking for a DS RR, then we must insist that we got the NSEC3 RR |
1538 | * from the parent. Otherwise the one from the child. Do so, by checking whether SOA and NS are | |
1539 | * appropriately set. */ | |
1540 | ||
1541 | if (key->type == DNS_TYPE_DS) { | |
1542 | if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) | |
1543 | return -EBADMSG; | |
1544 | } else { | |
1545 | if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_NS) && | |
1546 | !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) | |
1547 | return -EBADMSG; | |
1548 | } | |
1549 | ||
105e1512 | 1550 | /* No next closer NSEC3 RR. That means there's a direct NSEC3 RR for our key. */ |
146035b3 TG |
1551 | if (bitmap_isset(enclosure_rr->nsec3.types, key->type)) |
1552 | *result = DNSSEC_NSEC_FOUND; | |
1553 | else if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_CNAME)) | |
1554 | *result = DNSSEC_NSEC_CNAME; | |
1555 | else | |
1556 | *result = DNSSEC_NSEC_NODATA; | |
1557 | ||
d3760be0 LP |
1558 | if (authenticated) |
1559 | *authenticated = a; | |
1560 | if (ttl) | |
1561 | *ttl = enclosure_rr->ttl; | |
146035b3 | 1562 | |
105e1512 LP |
1563 | return 0; |
1564 | } | |
72667f08 | 1565 | |
352af308 LP |
1566 | /* Ensure this is not a DNAME domain, see RFC5155, section 8.3. */ |
1567 | if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_DNAME)) | |
1568 | return -EBADMSG; | |
1569 | ||
1570 | /* Ensure that this data is from the delegated domain | |
1571 | * (i.e. originates from the "lower" DNS server), and isn't | |
1572 | * just glue records (i.e. doesn't originate from the "upper" | |
1573 | * DNS server). */ | |
1574 | if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_NS) && | |
1575 | !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) | |
1576 | return -EBADMSG; | |
1577 | ||
35ad41d3 TG |
1578 | /* Prove that there is no next closer and whether or not there is a wildcard domain. */ |
1579 | ||
d41084a5 | 1580 | wildcard = strjoina("*.", p); |
cdbffec0 | 1581 | r = nsec3_hashed_domain_make(enclosure_rr, wildcard, zone, &wildcard_domain); |
105e1512 LP |
1582 | if (r < 0) |
1583 | return r; | |
1584 | if (r != hashed_size) | |
1585 | return -EBADMSG; | |
72667f08 | 1586 | |
cdbffec0 | 1587 | r = nsec3_hashed_domain_make(enclosure_rr, pp, zone, &next_closer_domain); |
105e1512 LP |
1588 | if (r < 0) |
1589 | return r; | |
1590 | if (r != hashed_size) | |
1591 | return -EBADMSG; | |
72667f08 | 1592 | |
105e1512 | 1593 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { |
cdbffec0 | 1594 | _cleanup_free_ char *next_hashed_domain = NULL; |
105e1512 | 1595 | |
3f5ecaad | 1596 | r = nsec3_is_good(rr, zone_rr); |
105e1512 LP |
1597 | if (r < 0) |
1598 | return r; | |
1599 | if (r == 0) | |
1600 | continue; | |
1601 | ||
cdbffec0 LP |
1602 | r = nsec3_hashed_domain_format(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, zone, &next_hashed_domain); |
1603 | if (r < 0) | |
1604 | return r; | |
105e1512 | 1605 | |
1c02e7ba | 1606 | r = dns_name_between(dns_resource_key_name(rr->key), next_closer_domain, next_hashed_domain); |
105e1512 LP |
1607 | if (r < 0) |
1608 | return r; | |
1609 | if (r > 0) { | |
1610 | if (rr->nsec3.flags & 1) | |
35ad41d3 | 1611 | optout = true; |
105e1512 | 1612 | |
35ad41d3 TG |
1613 | a = a && (flags & DNS_ANSWER_AUTHENTICATED); |
1614 | ||
1615 | no_closer = true; | |
1616 | } | |
1617 | ||
1c02e7ba | 1618 | r = dns_name_equal(dns_resource_key_name(rr->key), wildcard_domain); |
35ad41d3 TG |
1619 | if (r < 0) |
1620 | return r; | |
1621 | if (r > 0) { | |
1622 | a = a && (flags & DNS_ANSWER_AUTHENTICATED); | |
1623 | ||
1624 | wildcard_rr = rr; | |
1625 | } | |
1626 | ||
1c02e7ba | 1627 | r = dns_name_between(dns_resource_key_name(rr->key), wildcard_domain, next_hashed_domain); |
35ad41d3 TG |
1628 | if (r < 0) |
1629 | return r; | |
1630 | if (r > 0) { | |
1631 | if (rr->nsec3.flags & 1) | |
1632 | /* This only makes sense if we have a wildcard delegation, which is | |
1633 | * very unlikely, see RFC 4592, Section 4.2, but we cannot rely on | |
1634 | * this not happening, so hence cannot simply conclude NXDOMAIN as | |
1635 | * we would wish */ | |
1636 | optout = true; | |
1637 | ||
1638 | a = a && (flags & DNS_ANSWER_AUTHENTICATED); | |
1639 | ||
1640 | no_wildcard = true; | |
105e1512 LP |
1641 | } |
1642 | } | |
1643 | ||
35ad41d3 TG |
1644 | if (wildcard_rr && no_wildcard) |
1645 | return -EBADMSG; | |
1646 | ||
1647 | if (!no_closer) { | |
1648 | *result = DNSSEC_NSEC_NO_RR; | |
35ad41d3 TG |
1649 | return 0; |
1650 | } | |
1651 | ||
1652 | if (wildcard_rr) { | |
1653 | /* A wildcard exists that matches our query. */ | |
1654 | if (optout) | |
1655 | /* This is not specified in any RFC to the best of my knowledge, but | |
1656 | * if the next closer enclosure is covered by an opt-out NSEC3 RR | |
1657 | * it means that we cannot prove that the source of synthesis is | |
1658 | * correct, as there may be a closer match. */ | |
1659 | *result = DNSSEC_NSEC_OPTOUT; | |
1660 | else if (bitmap_isset(wildcard_rr->nsec3.types, key->type)) | |
1661 | *result = DNSSEC_NSEC_FOUND; | |
1662 | else if (bitmap_isset(wildcard_rr->nsec3.types, DNS_TYPE_CNAME)) | |
1663 | *result = DNSSEC_NSEC_CNAME; | |
1664 | else | |
1665 | *result = DNSSEC_NSEC_NODATA; | |
1666 | } else { | |
1667 | if (optout) | |
1668 | /* The RFC only specifies that we have to care for optout for NODATA for | |
1669 | * DS records. However, children of an insecure opt-out delegation should | |
1670 | * also be considered opt-out, rather than verified NXDOMAIN. | |
1671 | * Note that we do not require a proof of wildcard non-existence if the | |
1672 | * next closer domain is covered by an opt-out, as that would not provide | |
1673 | * any additional information. */ | |
1674 | *result = DNSSEC_NSEC_OPTOUT; | |
1675 | else if (no_wildcard) | |
1676 | *result = DNSSEC_NSEC_NXDOMAIN; | |
1677 | else { | |
1678 | *result = DNSSEC_NSEC_NO_RR; | |
1679 | ||
1680 | return 0; | |
1681 | } | |
1682 | } | |
1683 | ||
d3760be0 LP |
1684 | if (authenticated) |
1685 | *authenticated = a; | |
1686 | ||
1687 | if (ttl) | |
1688 | *ttl = enclosure_rr->ttl; | |
35ad41d3 | 1689 | |
105e1512 LP |
1690 | return 0; |
1691 | } | |
1692 | ||
ab481675 LP |
1693 | static int dnssec_nsec_wildcard_equal(DnsResourceRecord *rr, const char *name) { |
1694 | char label[DNS_LABEL_MAX]; | |
1695 | const char *n; | |
1696 | int r; | |
1697 | ||
1698 | assert(rr); | |
1699 | assert(rr->key->type == DNS_TYPE_NSEC); | |
1700 | ||
1701 | /* Checks whether the specified RR has a name beginning in "*.", and if the rest is a suffix of our name */ | |
1702 | ||
1703 | if (rr->n_skip_labels_source != 1) | |
1704 | return 0; | |
1705 | ||
1c02e7ba | 1706 | n = dns_resource_key_name(rr->key); |
7470cc4c | 1707 | r = dns_label_unescape(&n, label, sizeof label, 0); |
ab481675 LP |
1708 | if (r <= 0) |
1709 | return r; | |
1710 | if (r != 1 || label[0] != '*') | |
1711 | return 0; | |
1712 | ||
1713 | return dns_name_endswith(name, n); | |
1714 | } | |
1715 | ||
1716 | static int dnssec_nsec_in_path(DnsResourceRecord *rr, const char *name) { | |
b9282bc1 LP |
1717 | const char *nn, *common_suffix; |
1718 | int r; | |
1719 | ||
1720 | assert(rr); | |
1721 | assert(rr->key->type == DNS_TYPE_NSEC); | |
1722 | ||
1723 | /* Checks whether the specified nsec RR indicates that name is an empty non-terminal (ENT) | |
1724 | * | |
1725 | * A couple of examples: | |
1726 | * | |
1727 | * NSEC bar → waldo.foo.bar: indicates that foo.bar exists and is an ENT | |
1728 | * NSEC waldo.foo.bar → yyy.zzz.xoo.bar: indicates that xoo.bar and zzz.xoo.bar exist and are ENTs | |
1729 | * NSEC yyy.zzz.xoo.bar → bar: indicates pretty much nothing about ENTs | |
1730 | */ | |
1731 | ||
1732 | /* First, determine parent of next domain. */ | |
1733 | nn = rr->nsec.next_domain_name; | |
1734 | r = dns_name_parent(&nn); | |
1735 | if (r <= 0) | |
1736 | return r; | |
1737 | ||
1738 | /* If the name we just determined is not equal or child of the name we are interested in, then we can't say | |
1739 | * anything at all. */ | |
1740 | r = dns_name_endswith(nn, name); | |
1741 | if (r <= 0) | |
1742 | return r; | |
1743 | ||
61233823 | 1744 | /* If the name we are interested in is not a prefix of the common suffix of the NSEC RR's owner and next domain names, then we can't say anything either. */ |
1c02e7ba | 1745 | r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix); |
b9282bc1 LP |
1746 | if (r < 0) |
1747 | return r; | |
1748 | ||
1749 | return dns_name_endswith(name, common_suffix); | |
1750 | } | |
1751 | ||
ab481675 LP |
1752 | static int dnssec_nsec_from_parent_zone(DnsResourceRecord *rr, const char *name) { |
1753 | int r; | |
1754 | ||
1755 | assert(rr); | |
1756 | assert(rr->key->type == DNS_TYPE_NSEC); | |
1757 | ||
1758 | /* Checks whether this NSEC originates to the parent zone or the child zone. */ | |
1759 | ||
1760 | r = dns_name_parent(&name); | |
1761 | if (r <= 0) | |
1762 | return r; | |
1763 | ||
1c02e7ba | 1764 | r = dns_name_equal(name, dns_resource_key_name(rr->key)); |
ab481675 LP |
1765 | if (r <= 0) |
1766 | return r; | |
1767 | ||
1768 | /* DNAME, and NS without SOA is an indication for a delegation. */ | |
1769 | if (bitmap_isset(rr->nsec.types, DNS_TYPE_DNAME)) | |
1770 | return 1; | |
1771 | ||
1772 | if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) && !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) | |
1773 | return 1; | |
1774 | ||
1775 | return 0; | |
1776 | } | |
1777 | ||
1778 | static int dnssec_nsec_covers(DnsResourceRecord *rr, const char *name) { | |
0b491556 | 1779 | const char *signer; |
ab481675 LP |
1780 | int r; |
1781 | ||
1782 | assert(rr); | |
1783 | assert(rr->key->type == DNS_TYPE_NSEC); | |
1784 | ||
0b491556 LP |
1785 | /* Checks whether the name is covered by this NSEC RR. This means, that the name is somewhere below the NSEC's |
1786 | * signer name, and between the NSEC's two names. */ | |
ab481675 | 1787 | |
0b491556 | 1788 | r = dns_resource_record_signer(rr, &signer); |
ab481675 LP |
1789 | if (r < 0) |
1790 | return r; | |
1791 | ||
0b491556 LP |
1792 | r = dns_name_endswith(name, signer); /* this NSEC isn't suitable the name is not in the signer's domain */ |
1793 | if (r <= 0) | |
1794 | return r; | |
ab481675 | 1795 | |
0b491556 | 1796 | return dns_name_between(dns_resource_key_name(rr->key), name, rr->nsec.next_domain_name); |
ab481675 LP |
1797 | } |
1798 | ||
13e6f383 AT |
1799 | static int dnssec_nsec_generate_wildcard(DnsResourceRecord *rr, const char *name, char **wc) { |
1800 | const char *common_suffix1, *common_suffix2, *signer; | |
1801 | int r, labels1, labels2; | |
d86c982a LP |
1802 | |
1803 | assert(rr); | |
1804 | assert(rr->key->type == DNS_TYPE_NSEC); | |
1805 | ||
13e6f383 | 1806 | /* Generates "Wildcard at the Closest Encloser" for the given name and NSEC RR. */ |
d86c982a | 1807 | |
0b491556 | 1808 | r = dns_resource_record_signer(rr, &signer); |
d86c982a LP |
1809 | if (r < 0) |
1810 | return r; | |
1811 | ||
0b491556 | 1812 | r = dns_name_endswith(name, signer); /* this NSEC isn't suitable the name is not in the signer's domain */ |
d86c982a LP |
1813 | if (r <= 0) |
1814 | return r; | |
1815 | ||
13e6f383 | 1816 | r = dns_name_common_suffix(name, dns_resource_key_name(rr->key), &common_suffix1); |
0b491556 LP |
1817 | if (r < 0) |
1818 | return r; | |
0b491556 | 1819 | |
13e6f383 AT |
1820 | r = dns_name_common_suffix(name, rr->nsec.next_domain_name, &common_suffix2); |
1821 | if (r < 0) | |
1822 | return r; | |
1823 | ||
1824 | labels1 = dns_name_count_labels(common_suffix1); | |
1825 | if (labels1 < 0) | |
1826 | return labels1; | |
1827 | ||
1828 | labels2 = dns_name_count_labels(common_suffix2); | |
1829 | if (labels2 < 0) | |
1830 | return labels2; | |
1831 | ||
1832 | if (labels1 > labels2) | |
1833 | r = dns_name_concat("*", common_suffix1, 0, wc); | |
1834 | else | |
1835 | r = dns_name_concat("*", common_suffix2, 0, wc); | |
1836 | ||
97c2ea26 LP |
1837 | if (r < 0) |
1838 | return r; | |
1839 | ||
13e6f383 | 1840 | return 0; |
d86c982a LP |
1841 | } |
1842 | ||
0c7bff0a | 1843 | int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { |
d86c982a LP |
1844 | bool have_nsec3 = false, covering_rr_authenticated = false, wildcard_rr_authenticated = false; |
1845 | DnsResourceRecord *rr, *covering_rr = NULL, *wildcard_rr = NULL; | |
105e1512 | 1846 | DnsAnswerFlags flags; |
b9282bc1 | 1847 | const char *name; |
105e1512 LP |
1848 | int r; |
1849 | ||
1850 | assert(key); | |
1851 | assert(result); | |
1852 | ||
1853 | /* Look for any NSEC/NSEC3 RRs that say something about the specified key. */ | |
1854 | ||
1c02e7ba | 1855 | name = dns_resource_key_name(key); |
b9282bc1 | 1856 | |
105e1512 LP |
1857 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { |
1858 | ||
1859 | if (rr->key->class != key->class) | |
1860 | continue; | |
1861 | ||
ab481675 | 1862 | have_nsec3 = have_nsec3 || (rr->key->type == DNS_TYPE_NSEC3); |
105e1512 | 1863 | |
ab481675 LP |
1864 | if (rr->key->type != DNS_TYPE_NSEC) |
1865 | continue; | |
1866 | ||
1867 | /* The following checks only make sense for NSEC RRs that are not expanded from a wildcard */ | |
1868 | r = dns_resource_record_is_synthetic(rr); | |
1869 | if (r < 0) | |
1870 | return r; | |
1871 | if (r > 0) | |
1872 | continue; | |
105e1512 | 1873 | |
ab481675 | 1874 | /* Check if this is a direct match. If so, we have encountered a NODATA case */ |
1c02e7ba | 1875 | r = dns_name_equal(dns_resource_key_name(rr->key), name); |
ab481675 LP |
1876 | if (r < 0) |
1877 | return r; | |
1878 | if (r == 0) { | |
1879 | /* If it's not a direct match, maybe it's a wild card match? */ | |
1880 | r = dnssec_nsec_wildcard_equal(rr, name); | |
105e1512 LP |
1881 | if (r < 0) |
1882 | return r; | |
ab481675 LP |
1883 | } |
1884 | if (r > 0) { | |
1885 | if (key->type == DNS_TYPE_DS) { | |
1886 | /* If we look for a DS RR and the server sent us the NSEC RR of the child zone | |
1887 | * we have a problem. For DS RRs we want the NSEC RR from the parent */ | |
1888 | if (bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) | |
1889 | continue; | |
1890 | } else { | |
1891 | /* For all RR types, ensure that if NS is set SOA is set too, so that we know | |
1892 | * we got the child's NSEC. */ | |
1893 | if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) && | |
1894 | !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) | |
1895 | continue; | |
72667f08 LP |
1896 | } |
1897 | ||
ab481675 LP |
1898 | if (bitmap_isset(rr->nsec.types, key->type)) |
1899 | *result = DNSSEC_NSEC_FOUND; | |
1900 | else if (bitmap_isset(rr->nsec.types, DNS_TYPE_CNAME)) | |
1901 | *result = DNSSEC_NSEC_CNAME; | |
1902 | else | |
b9282bc1 | 1903 | *result = DNSSEC_NSEC_NODATA; |
d3760be0 | 1904 | |
ab481675 LP |
1905 | if (authenticated) |
1906 | *authenticated = flags & DNS_ANSWER_AUTHENTICATED; | |
1907 | if (ttl) | |
1908 | *ttl = rr->ttl; | |
d3760be0 | 1909 | |
ab481675 LP |
1910 | return 0; |
1911 | } | |
b9282bc1 | 1912 | |
ab481675 LP |
1913 | /* Check if the name we are looking for is an empty non-terminal within the owner or next name |
1914 | * of the NSEC RR. */ | |
1915 | r = dnssec_nsec_in_path(rr, name); | |
1916 | if (r < 0) | |
1917 | return r; | |
1918 | if (r > 0) { | |
1919 | *result = DNSSEC_NSEC_NODATA; | |
b9282bc1 | 1920 | |
ab481675 LP |
1921 | if (authenticated) |
1922 | *authenticated = flags & DNS_ANSWER_AUTHENTICATED; | |
1923 | if (ttl) | |
1924 | *ttl = rr->ttl; | |
b9282bc1 | 1925 | |
ab481675 LP |
1926 | return 0; |
1927 | } | |
72667f08 | 1928 | |
ab481675 LP |
1929 | /* The following two "covering" checks, are not useful if the NSEC is from the parent */ |
1930 | r = dnssec_nsec_from_parent_zone(rr, name); | |
1931 | if (r < 0) | |
1932 | return r; | |
1933 | if (r > 0) | |
1934 | continue; | |
1935 | ||
1936 | /* Check if this NSEC RR proves the absence of an explicit RR under this name */ | |
1937 | r = dnssec_nsec_covers(rr, name); | |
1938 | if (r < 0) | |
1939 | return r; | |
1940 | if (r > 0 && (!covering_rr || !covering_rr_authenticated)) { | |
1941 | covering_rr = rr; | |
1942 | covering_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED; | |
1943 | } | |
13e6f383 | 1944 | } |
ab481675 | 1945 | |
13e6f383 AT |
1946 | if (covering_rr) { |
1947 | _cleanup_free_ char *wc = NULL; | |
1948 | r = dnssec_nsec_generate_wildcard(covering_rr, name, &wc); | |
ab481675 LP |
1949 | if (r < 0) |
1950 | return r; | |
13e6f383 AT |
1951 | |
1952 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { | |
1953 | ||
1954 | if (rr->key->class != key->class) | |
1955 | continue; | |
1956 | ||
1957 | if (rr->key->type != DNS_TYPE_NSEC) | |
1958 | continue; | |
1959 | ||
1960 | /* Check if this NSEC RR proves the nonexistence of the wildcard */ | |
1961 | r = dnssec_nsec_covers(rr, wc); | |
1962 | if (r < 0) | |
1963 | return r; | |
1964 | if (r > 0 && (!wildcard_rr || !wildcard_rr_authenticated)) { | |
1965 | wildcard_rr = rr; | |
1966 | wildcard_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED; | |
1967 | } | |
72667f08 LP |
1968 | } |
1969 | } | |
1970 | ||
d86c982a LP |
1971 | if (covering_rr && wildcard_rr) { |
1972 | /* If we could prove that neither the name itself, nor the wildcard at the closest encloser exists, we | |
1973 | * proved the NXDOMAIN case. */ | |
1974 | *result = DNSSEC_NSEC_NXDOMAIN; | |
1975 | ||
1976 | if (authenticated) | |
1977 | *authenticated = covering_rr_authenticated && wildcard_rr_authenticated; | |
1978 | if (ttl) | |
1979 | *ttl = MIN(covering_rr->ttl, wildcard_rr->ttl); | |
1980 | ||
1981 | return 0; | |
1982 | } | |
1983 | ||
105e1512 LP |
1984 | /* OK, this was not sufficient. Let's see if NSEC3 can help. */ |
1985 | if (have_nsec3) | |
d3760be0 | 1986 | return dnssec_test_nsec3(answer, key, result, authenticated, ttl); |
105e1512 | 1987 | |
5238e957 | 1988 | /* No appropriate NSEC RR found, report this. */ |
72667f08 LP |
1989 | *result = DNSSEC_NSEC_NO_RR; |
1990 | return 0; | |
1991 | } | |
1992 | ||
421cc89d | 1993 | static int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, const char *name, const char *zone, bool *authenticated) { |
0c7bff0a LP |
1994 | DnsResourceRecord *rr; |
1995 | DnsAnswerFlags flags; | |
1996 | int r; | |
1997 | ||
1998 | assert(name); | |
1999 | assert(zone); | |
2000 | ||
2001 | /* Checks whether there's an NSEC/NSEC3 that proves that the specified 'name' is non-existing in the specified | |
2002 | * 'zone'. The 'zone' must be a suffix of the 'name'. */ | |
2003 | ||
2004 | DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { | |
2005 | bool found = false; | |
2006 | ||
e926785a LP |
2007 | if (rr->key->type != type && type != DNS_TYPE_ANY) |
2008 | continue; | |
2009 | ||
0c7bff0a LP |
2010 | switch (rr->key->type) { |
2011 | ||
2012 | case DNS_TYPE_NSEC: | |
97c67192 LP |
2013 | |
2014 | /* We only care for NSEC RRs from the indicated zone */ | |
2015 | r = dns_resource_record_is_signer(rr, zone); | |
2016 | if (r < 0) | |
2017 | return r; | |
2018 | if (r == 0) | |
2019 | continue; | |
2020 | ||
1c02e7ba | 2021 | r = dns_name_between(dns_resource_key_name(rr->key), name, rr->nsec.next_domain_name); |
0c7bff0a LP |
2022 | if (r < 0) |
2023 | return r; | |
2024 | ||
2025 | found = r > 0; | |
2026 | break; | |
2027 | ||
2028 | case DNS_TYPE_NSEC3: { | |
2029 | _cleanup_free_ char *hashed_domain = NULL, *next_hashed_domain = NULL; | |
2030 | ||
97c67192 LP |
2031 | /* We only care for NSEC3 RRs from the indicated zone */ |
2032 | r = dns_resource_record_is_signer(rr, zone); | |
2033 | if (r < 0) | |
2034 | return r; | |
2035 | if (r == 0) | |
2036 | continue; | |
2037 | ||
0c7bff0a LP |
2038 | r = nsec3_is_good(rr, NULL); |
2039 | if (r < 0) | |
2040 | return r; | |
2041 | if (r == 0) | |
2042 | break; | |
2043 | ||
2044 | /* Format the domain we are testing with the NSEC3 RR's hash function */ | |
2045 | r = nsec3_hashed_domain_make( | |
2046 | rr, | |
2047 | name, | |
2048 | zone, | |
2049 | &hashed_domain); | |
2050 | if (r < 0) | |
2051 | return r; | |
2052 | if ((size_t) r != rr->nsec3.next_hashed_name_size) | |
2053 | break; | |
2054 | ||
2055 | /* Format the NSEC3's next hashed name as proper domain name */ | |
2056 | r = nsec3_hashed_domain_format( | |
2057 | rr->nsec3.next_hashed_name, | |
2058 | rr->nsec3.next_hashed_name_size, | |
2059 | zone, | |
2060 | &next_hashed_domain); | |
2061 | if (r < 0) | |
2062 | return r; | |
2063 | ||
1c02e7ba | 2064 | r = dns_name_between(dns_resource_key_name(rr->key), hashed_domain, next_hashed_domain); |
0c7bff0a LP |
2065 | if (r < 0) |
2066 | return r; | |
2067 | ||
2068 | found = r > 0; | |
2069 | break; | |
2070 | } | |
2071 | ||
2072 | default: | |
2073 | continue; | |
2074 | } | |
2075 | ||
2076 | if (found) { | |
2077 | if (authenticated) | |
2078 | *authenticated = flags & DNS_ANSWER_AUTHENTICATED; | |
2079 | return 1; | |
2080 | } | |
2081 | } | |
2082 | ||
2083 | return 0; | |
2084 | } | |
2085 | ||
e926785a LP |
2086 | static int dnssec_test_positive_wildcard_nsec3( |
2087 | DnsAnswer *answer, | |
2088 | const char *name, | |
2089 | const char *source, | |
2090 | const char *zone, | |
2091 | bool *authenticated) { | |
2092 | ||
2093 | const char *next_closer = NULL; | |
2094 | int r; | |
2095 | ||
2096 | /* Run a positive NSEC3 wildcard proof. Specifically: | |
2097 | * | |
c629ff58 | 2098 | * A proof that the "next closer" of the generating wildcard does not exist. |
e926785a LP |
2099 | * |
2100 | * Note a key difference between the NSEC3 and NSEC versions of the proof. NSEC RRs don't have to exist for | |
2101 | * empty non-transients. NSEC3 RRs however have to. This means it's sufficient to check if the next closer name | |
2102 | * exists for the NSEC3 RR and we are done. | |
2103 | * | |
2104 | * To prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f all we have to check is that | |
2105 | * c.d.e.f does not exist. */ | |
2106 | ||
2107 | for (;;) { | |
2108 | next_closer = name; | |
2109 | r = dns_name_parent(&name); | |
f20db199 | 2110 | if (r <= 0) |
e926785a | 2111 | return r; |
e926785a LP |
2112 | |
2113 | r = dns_name_equal(name, source); | |
2114 | if (r < 0) | |
2115 | return r; | |
2116 | if (r > 0) | |
2117 | break; | |
2118 | } | |
2119 | ||
2120 | return dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC3, next_closer, zone, authenticated); | |
2121 | } | |
2122 | ||
2123 | static int dnssec_test_positive_wildcard_nsec( | |
2124 | DnsAnswer *answer, | |
2125 | const char *name, | |
2126 | const char *source, | |
2127 | const char *zone, | |
2128 | bool *_authenticated) { | |
2129 | ||
2130 | bool authenticated = true; | |
2131 | int r; | |
2132 | ||
2133 | /* Run a positive NSEC wildcard proof. Specifically: | |
2134 | * | |
2135 | * A proof that there's neither a wildcard name nor a non-wildcard name that is a suffix of the name "name" and | |
2136 | * a prefix of the synthesizing source "source" in the zone "zone". | |
2137 | * | |
2138 | * See RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4 | |
2139 | * | |
2140 | * Note that if we want to prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f, then we | |
2141 | * have to prove that none of the following exist: | |
2142 | * | |
2143 | * 1) a.b.c.d.e.f | |
2144 | * 2) *.b.c.d.e.f | |
2145 | * 3) b.c.d.e.f | |
2146 | * 4) *.c.d.e.f | |
2147 | * 5) c.d.e.f | |
e926785a LP |
2148 | */ |
2149 | ||
2150 | for (;;) { | |
2151 | _cleanup_free_ char *wc = NULL; | |
2152 | bool a = false; | |
2153 | ||
2154 | /* Check if there's an NSEC or NSEC3 RR that proves that the mame we determined is really non-existing, | |
2155 | * i.e between the owner name and the next name of an NSEC RR. */ | |
2156 | r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, name, zone, &a); | |
2157 | if (r <= 0) | |
2158 | return r; | |
2159 | ||
2160 | authenticated = authenticated && a; | |
2161 | ||
2162 | /* Strip one label off */ | |
2163 | r = dns_name_parent(&name); | |
2164 | if (r <= 0) | |
2165 | return r; | |
2166 | ||
2167 | /* Did we reach the source of synthesis? */ | |
2168 | r = dns_name_equal(name, source); | |
2169 | if (r < 0) | |
2170 | return r; | |
2171 | if (r > 0) { | |
2172 | /* Successful exit */ | |
2173 | *_authenticated = authenticated; | |
2174 | return 1; | |
2175 | } | |
2176 | ||
2177 | /* Safety check, that the source of synthesis is still our suffix */ | |
2178 | r = dns_name_endswith(name, source); | |
2179 | if (r < 0) | |
2180 | return r; | |
2181 | if (r == 0) | |
2182 | return -EBADMSG; | |
2183 | ||
2184 | /* Replace the label we stripped off with an asterisk */ | |
2185 | wc = strappend("*.", name); | |
2186 | if (!wc) | |
2187 | return -ENOMEM; | |
2188 | ||
2189 | /* And check if the proof holds for the asterisk name, too */ | |
2190 | r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, wc, zone, &a); | |
2191 | if (r <= 0) | |
2192 | return r; | |
2193 | ||
2194 | authenticated = authenticated && a; | |
2195 | /* In the next iteration we'll check the non-asterisk-prefixed version */ | |
2196 | } | |
2197 | } | |
2198 | ||
2199 | int dnssec_test_positive_wildcard( | |
2200 | DnsAnswer *answer, | |
2201 | const char *name, | |
2202 | const char *source, | |
2203 | const char *zone, | |
2204 | bool *authenticated) { | |
2205 | ||
2206 | int r; | |
2207 | ||
2208 | assert(name); | |
2209 | assert(source); | |
2210 | assert(zone); | |
2211 | assert(authenticated); | |
2212 | ||
2213 | r = dns_answer_contains_zone_nsec3(answer, zone); | |
2214 | if (r < 0) | |
2215 | return r; | |
2216 | if (r > 0) | |
2217 | return dnssec_test_positive_wildcard_nsec3(answer, name, source, zone, authenticated); | |
2218 | else | |
2219 | return dnssec_test_positive_wildcard_nsec(answer, name, source, zone, authenticated); | |
2220 | } | |
2221 | ||
47091522 MO |
2222 | #else |
2223 | ||
2224 | int dnssec_verify_rrset( | |
2225 | DnsAnswer *a, | |
2226 | const DnsResourceKey *key, | |
2227 | DnsResourceRecord *rrsig, | |
2228 | DnsResourceRecord *dnskey, | |
2229 | usec_t realtime, | |
2230 | DnssecResult *result) { | |
2231 | ||
2232 | return -EOPNOTSUPP; | |
2233 | } | |
2234 | ||
2235 | int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) { | |
2236 | ||
2237 | return -EOPNOTSUPP; | |
2238 | } | |
2239 | ||
2240 | int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) { | |
2241 | ||
2242 | return -EOPNOTSUPP; | |
2243 | } | |
2244 | ||
2245 | int dnssec_verify_rrset_search( | |
2246 | DnsAnswer *a, | |
2247 | const DnsResourceKey *key, | |
2248 | DnsAnswer *validated_dnskeys, | |
2249 | usec_t realtime, | |
2250 | DnssecResult *result, | |
2251 | DnsResourceRecord **ret_rrsig) { | |
2252 | ||
2253 | return -EOPNOTSUPP; | |
2254 | } | |
2255 | ||
2256 | int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) { | |
2257 | ||
2258 | return -EOPNOTSUPP; | |
2259 | } | |
2260 | ||
2261 | int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) { | |
2262 | ||
2263 | return -EOPNOTSUPP; | |
2264 | } | |
2265 | ||
2266 | int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) { | |
2267 | ||
2268 | return -EOPNOTSUPP; | |
2269 | } | |
2270 | ||
2271 | int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) { | |
2272 | ||
2273 | return -EOPNOTSUPP; | |
2274 | } | |
2275 | ||
2276 | int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { | |
2277 | ||
2278 | return -EOPNOTSUPP; | |
2279 | } | |
2280 | ||
2281 | int dnssec_test_positive_wildcard( | |
2282 | DnsAnswer *answer, | |
2283 | const char *name, | |
2284 | const char *source, | |
2285 | const char *zone, | |
2286 | bool *authenticated) { | |
2287 | ||
2288 | return -EOPNOTSUPP; | |
2289 | } | |
2290 | ||
2291 | #endif | |
2292 | ||
547973de LP |
2293 | static const char* const dnssec_result_table[_DNSSEC_RESULT_MAX] = { |
2294 | [DNSSEC_VALIDATED] = "validated", | |
0c7bff0a | 2295 | [DNSSEC_VALIDATED_WILDCARD] = "validated-wildcard", |
547973de | 2296 | [DNSSEC_INVALID] = "invalid", |
203f1b35 LP |
2297 | [DNSSEC_SIGNATURE_EXPIRED] = "signature-expired", |
2298 | [DNSSEC_UNSUPPORTED_ALGORITHM] = "unsupported-algorithm", | |
547973de LP |
2299 | [DNSSEC_NO_SIGNATURE] = "no-signature", |
2300 | [DNSSEC_MISSING_KEY] = "missing-key", | |
203f1b35 | 2301 | [DNSSEC_UNSIGNED] = "unsigned", |
547973de | 2302 | [DNSSEC_FAILED_AUXILIARY] = "failed-auxiliary", |
72667f08 | 2303 | [DNSSEC_NSEC_MISMATCH] = "nsec-mismatch", |
b652d4a2 | 2304 | [DNSSEC_INCOMPATIBLE_SERVER] = "incompatible-server", |
547973de LP |
2305 | }; |
2306 | DEFINE_STRING_TABLE_LOOKUP(dnssec_result, DnssecResult); | |
59c5b597 LP |
2307 | |
2308 | static const char* const dnssec_verdict_table[_DNSSEC_VERDICT_MAX] = { | |
2309 | [DNSSEC_SECURE] = "secure", | |
2310 | [DNSSEC_INSECURE] = "insecure", | |
2311 | [DNSSEC_BOGUS] = "bogus", | |
2312 | [DNSSEC_INDETERMINATE] = "indeterminate", | |
2313 | }; | |
2314 | DEFINE_STRING_TABLE_LOOKUP(dnssec_verdict, DnssecVerdict); |