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8d41ebd8 | 1 | /* dnssec.c is Copyright (c) 2012 Giovanni Bajo <rasky@develer.com> |
aff33962 | 2 | and Copyright (c) 2012-2015 Simon Kelley |
8d41ebd8 GB |
3 | |
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; version 2 dated June, 1991, or | |
7 | (at your option) version 3 dated 29 June, 2007. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
e292e93d GB |
17 | |
18 | #include "dnsmasq.h" | |
0fc2f313 SK |
19 | |
20 | #ifdef HAVE_DNSSEC | |
21 | ||
86bec2d3 SK |
22 | #include <nettle/rsa.h> |
23 | #include <nettle/dsa.h> | |
c152dc84 SK |
24 | #ifndef NO_NETTLE_ECC |
25 | # include <nettle/ecdsa.h> | |
26 | # include <nettle/ecc-curve.h> | |
27 | #endif | |
86bec2d3 | 28 | #include <nettle/nettle-meta.h> |
063efb33 SK |
29 | #include <nettle/bignum.h> |
30 | ||
cdb755c5 SK |
31 | /* Nettle-3.0 moved to a new API for DSA. We use a name that's defined in the new API |
32 | to detect Nettle-3, and invoke the backwards compatibility mode. */ | |
33 | #ifdef dsa_params_init | |
34 | #include <nettle/dsa-compat.h> | |
35 | #endif | |
36 | ||
f6e62e2a | 37 | #include <utime.h> |
c3e0b9b6 | 38 | |
e292e93d GB |
39 | #define SERIAL_UNDEF -100 |
40 | #define SERIAL_EQ 0 | |
41 | #define SERIAL_LT -1 | |
42 | #define SERIAL_GT 1 | |
43 | ||
86bec2d3 SK |
44 | /* http://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ |
45 | static char *ds_digest_name(int digest) | |
46 | { | |
47 | switch (digest) | |
48 | { | |
49 | case 1: return "sha1"; | |
50 | case 2: return "sha256"; | |
51 | case 3: return "gosthash94"; | |
52 | case 4: return "sha384"; | |
53 | default: return NULL; | |
54 | } | |
55 | } | |
56 | ||
57 | /* http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ | |
58 | static char *algo_digest_name(int algo) | |
59 | { | |
60 | switch (algo) | |
61 | { | |
62 | case 1: return "md5"; | |
63 | case 3: return "sha1"; | |
64 | case 5: return "sha1"; | |
65 | case 6: return "sha1"; | |
66 | case 7: return "sha1"; | |
67 | case 8: return "sha256"; | |
68 | case 10: return "sha512"; | |
69 | case 12: return "gosthash94"; | |
70 | case 13: return "sha256"; | |
71 | case 14: return "sha384"; | |
72 | default: return NULL; | |
73 | } | |
74 | } | |
75 | ||
76 | /* Find pointer to correct hash function in nettle library */ | |
77 | static const struct nettle_hash *hash_find(char *name) | |
78 | { | |
79 | int i; | |
80 | ||
81 | if (!name) | |
82 | return NULL; | |
83 | ||
84 | for (i = 0; nettle_hashes[i]; i++) | |
85 | { | |
86 | if (strcmp(nettle_hashes[i]->name, name) == 0) | |
87 | return nettle_hashes[i]; | |
88 | } | |
89 | ||
90 | return NULL; | |
91 | } | |
92 | ||
93 | /* expand ctx and digest memory allocations if necessary and init hash function */ | |
94 | static int hash_init(const struct nettle_hash *hash, void **ctxp, unsigned char **digestp) | |
95 | { | |
96 | static void *ctx = NULL; | |
97 | static unsigned char *digest = NULL; | |
98 | static unsigned int ctx_sz = 0; | |
99 | static unsigned int digest_sz = 0; | |
100 | ||
101 | void *new; | |
102 | ||
103 | if (ctx_sz < hash->context_size) | |
104 | { | |
105 | if (!(new = whine_malloc(hash->context_size))) | |
106 | return 0; | |
107 | if (ctx) | |
108 | free(ctx); | |
109 | ctx = new; | |
110 | ctx_sz = hash->context_size; | |
111 | } | |
112 | ||
113 | if (digest_sz < hash->digest_size) | |
114 | { | |
115 | if (!(new = whine_malloc(hash->digest_size))) | |
116 | return 0; | |
117 | if (digest) | |
118 | free(digest); | |
119 | digest = new; | |
120 | digest_sz = hash->digest_size; | |
121 | } | |
122 | ||
123 | *ctxp = ctx; | |
124 | *digestp = digest; | |
125 | ||
126 | hash->init(ctx); | |
127 | ||
128 | return 1; | |
129 | } | |
130 | ||
cdb755c5 SK |
131 | static int dnsmasq_rsa_verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
132 | unsigned char *digest, int algo) | |
86bec2d3 SK |
133 | { |
134 | unsigned char *p; | |
135 | size_t exp_len; | |
136 | ||
137 | static struct rsa_public_key *key = NULL; | |
138 | static mpz_t sig_mpz; | |
139 | ||
140 | if (key == NULL) | |
141 | { | |
142 | if (!(key = whine_malloc(sizeof(struct rsa_public_key)))) | |
143 | return 0; | |
144 | ||
145 | nettle_rsa_public_key_init(key); | |
146 | mpz_init(sig_mpz); | |
147 | } | |
148 | ||
149 | if ((key_len < 3) || !(p = blockdata_retrieve(key_data, key_len, NULL))) | |
150 | return 0; | |
151 | ||
152 | key_len--; | |
153 | if ((exp_len = *p++) == 0) | |
154 | { | |
155 | GETSHORT(exp_len, p); | |
156 | key_len -= 2; | |
157 | } | |
158 | ||
159 | if (exp_len >= key_len) | |
160 | return 0; | |
161 | ||
162 | key->size = key_len - exp_len; | |
163 | mpz_import(key->e, exp_len, 1, 1, 0, 0, p); | |
164 | mpz_import(key->n, key->size, 1, 1, 0, 0, p + exp_len); | |
165 | ||
166 | mpz_import(sig_mpz, sig_len, 1, 1, 0, 0, sig); | |
167 | ||
168 | switch (algo) | |
169 | { | |
170 | case 1: | |
171 | return nettle_rsa_md5_verify_digest(key, digest, sig_mpz); | |
172 | case 5: case 7: | |
173 | return nettle_rsa_sha1_verify_digest(key, digest, sig_mpz); | |
174 | case 8: | |
175 | return nettle_rsa_sha256_verify_digest(key, digest, sig_mpz); | |
176 | case 10: | |
177 | return nettle_rsa_sha512_verify_digest(key, digest, sig_mpz); | |
178 | } | |
179 | ||
180 | return 0; | |
181 | } | |
182 | ||
cdb755c5 SK |
183 | static int dnsmasq_dsa_verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
184 | unsigned char *digest, int algo) | |
86bec2d3 SK |
185 | { |
186 | unsigned char *p; | |
187 | unsigned int t; | |
188 | ||
189 | static struct dsa_public_key *key = NULL; | |
190 | static struct dsa_signature *sig_struct; | |
191 | ||
192 | if (key == NULL) | |
193 | { | |
194 | if (!(sig_struct = whine_malloc(sizeof(struct dsa_signature))) || | |
195 | !(key = whine_malloc(sizeof(struct dsa_public_key)))) | |
196 | return 0; | |
197 | ||
198 | nettle_dsa_public_key_init(key); | |
199 | nettle_dsa_signature_init(sig_struct); | |
200 | } | |
201 | ||
202 | if ((sig_len < 41) || !(p = blockdata_retrieve(key_data, key_len, NULL))) | |
203 | return 0; | |
204 | ||
205 | t = *p++; | |
206 | ||
207 | if (key_len < (213 + (t * 24))) | |
208 | return 0; | |
ebe95a83 | 209 | |
86bec2d3 SK |
210 | mpz_import(key->q, 20, 1, 1, 0, 0, p); p += 20; |
211 | mpz_import(key->p, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); | |
212 | mpz_import(key->g, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); | |
213 | mpz_import(key->y, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); | |
214 | ||
215 | mpz_import(sig_struct->r, 20, 1, 1, 0, 0, sig+1); | |
216 | mpz_import(sig_struct->s, 20, 1, 1, 0, 0, sig+21); | |
217 | ||
218 | (void)algo; | |
ebe95a83 | 219 | |
86bec2d3 SK |
220 | return nettle_dsa_sha1_verify_digest(key, digest, sig_struct); |
221 | } | |
222 | ||
c152dc84 SK |
223 | #ifndef NO_NETTLE_ECC |
224 | static int dnsmasq_ecdsa_verify(struct blockdata *key_data, unsigned int key_len, | |
225 | unsigned char *sig, size_t sig_len, | |
ebe95a83 SK |
226 | unsigned char *digest, size_t digest_len, int algo) |
227 | { | |
228 | unsigned char *p; | |
229 | unsigned int t; | |
230 | struct ecc_point *key; | |
231 | ||
232 | static struct ecc_point *key_256 = NULL, *key_384 = NULL; | |
233 | static mpz_t x, y; | |
234 | static struct dsa_signature *sig_struct; | |
235 | ||
236 | if (!sig_struct) | |
237 | { | |
238 | if (!(sig_struct = whine_malloc(sizeof(struct dsa_signature)))) | |
239 | return 0; | |
240 | ||
241 | nettle_dsa_signature_init(sig_struct); | |
242 | mpz_init(x); | |
243 | mpz_init(y); | |
244 | } | |
245 | ||
246 | switch (algo) | |
247 | { | |
248 | case 13: | |
249 | if (!key_256) | |
250 | { | |
251 | if (!(key_256 = whine_malloc(sizeof(struct ecc_point)))) | |
252 | return 0; | |
253 | ||
254 | nettle_ecc_point_init(key_256, &nettle_secp_256r1); | |
255 | } | |
256 | ||
257 | key = key_256; | |
258 | t = 32; | |
259 | break; | |
260 | ||
261 | case 14: | |
262 | if (!key_384) | |
263 | { | |
264 | if (!(key_384 = whine_malloc(sizeof(struct ecc_point)))) | |
265 | return 0; | |
266 | ||
267 | nettle_ecc_point_init(key_384, &nettle_secp_384r1); | |
268 | } | |
269 | ||
270 | key = key_384; | |
271 | t = 48; | |
272 | break; | |
273 | ||
274 | default: | |
275 | return 0; | |
276 | } | |
277 | ||
278 | if (sig_len != 2*t || key_len != 2*t || | |
6ef15b34 | 279 | !(p = blockdata_retrieve(key_data, key_len, NULL))) |
ebe95a83 SK |
280 | return 0; |
281 | ||
282 | mpz_import(x, t , 1, 1, 0, 0, p); | |
283 | mpz_import(y, t , 1, 1, 0, 0, p + t); | |
284 | ||
285 | if (!ecc_point_set(key, x, y)) | |
286 | return 0; | |
287 | ||
288 | mpz_import(sig_struct->r, t, 1, 1, 0, 0, sig); | |
289 | mpz_import(sig_struct->s, t, 1, 1, 0, 0, sig + t); | |
290 | ||
291 | return nettle_ecdsa_verify(key, digest_len, digest, sig_struct); | |
292 | } | |
c152dc84 SK |
293 | #endif |
294 | ||
86bec2d3 | 295 | static int verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
ebe95a83 | 296 | unsigned char *digest, size_t digest_len, int algo) |
86bec2d3 | 297 | { |
7b1eae4f SK |
298 | (void)digest_len; |
299 | ||
86bec2d3 SK |
300 | switch (algo) |
301 | { | |
302 | case 1: case 5: case 7: case 8: case 10: | |
cdb755c5 | 303 | return dnsmasq_rsa_verify(key_data, key_len, sig, sig_len, digest, algo); |
86bec2d3 SK |
304 | |
305 | case 3: case 6: | |
cdb755c5 | 306 | return dnsmasq_dsa_verify(key_data, key_len, sig, sig_len, digest, algo); |
c152dc84 SK |
307 | |
308 | #ifndef NO_NETTLE_ECC | |
ebe95a83 SK |
309 | case 13: case 14: |
310 | return dnsmasq_ecdsa_verify(key_data, key_len, sig, sig_len, digest, digest_len, algo); | |
c152dc84 SK |
311 | #endif |
312 | } | |
86bec2d3 SK |
313 | |
314 | return 0; | |
315 | } | |
316 | ||
0fc2f313 SK |
317 | /* Convert from presentation format to wire format, in place. |
318 | Also map UC -> LC. | |
319 | Note that using extract_name to get presentation format | |
320 | then calling to_wire() removes compression and maps case, | |
321 | thus generating names in canonical form. | |
322 | Calling to_wire followed by from_wire is almost an identity, | |
323 | except that the UC remains mapped to LC. | |
324 | */ | |
325 | static int to_wire(char *name) | |
7f0485cf | 326 | { |
0fc2f313 SK |
327 | unsigned char *l, *p, term; |
328 | int len; | |
329 | ||
330 | for (l = (unsigned char*)name; *l != 0; l = p) | |
331 | { | |
332 | for (p = l; *p != '.' && *p != 0; p++) | |
333 | if (*p >= 'A' && *p <= 'Z') | |
334 | *p = *p - 'A' + 'a'; | |
335 | ||
336 | term = *p; | |
337 | ||
338 | if ((len = p - l) != 0) | |
339 | memmove(l+1, l, len); | |
340 | *l = len; | |
341 | ||
342 | p++; | |
343 | ||
344 | if (term == 0) | |
345 | *p = 0; | |
346 | } | |
347 | ||
348 | return l + 1 - (unsigned char *)name; | |
7f0485cf GB |
349 | } |
350 | ||
0fc2f313 SK |
351 | /* Note: no compression allowed in input. */ |
352 | static void from_wire(char *name) | |
13e435eb | 353 | { |
0fc2f313 SK |
354 | unsigned char *l; |
355 | int len; | |
13e435eb | 356 | |
0fc2f313 | 357 | for (l = (unsigned char *)name; *l != 0; l += len+1) |
13e435eb | 358 | { |
0fc2f313 SK |
359 | len = *l; |
360 | memmove(l, l+1, len); | |
361 | l[len] = '.'; | |
13e435eb | 362 | } |
7f0485cf | 363 | |
e3f14558 | 364 | if ((char *)l != name) |
bd9b3cf5 | 365 | *(l-1) = 0; |
13e435eb GB |
366 | } |
367 | ||
5ada8885 SK |
368 | /* Input in presentation format */ |
369 | static int count_labels(char *name) | |
370 | { | |
371 | int i; | |
372 | ||
373 | if (*name == 0) | |
374 | return 0; | |
375 | ||
376 | for (i = 0; *name; name++) | |
377 | if (*name == '.') | |
378 | i++; | |
379 | ||
380 | return i+1; | |
381 | } | |
382 | ||
5f8e58f4 SK |
383 | /* Implement RFC1982 wrapped compare for 32-bit numbers */ |
384 | static int serial_compare_32(unsigned long s1, unsigned long s2) | |
385 | { | |
386 | if (s1 == s2) | |
387 | return SERIAL_EQ; | |
0ca895f5 | 388 | |
5f8e58f4 SK |
389 | if ((s1 < s2 && (s2 - s1) < (1UL<<31)) || |
390 | (s1 > s2 && (s1 - s2) > (1UL<<31))) | |
391 | return SERIAL_LT; | |
392 | if ((s1 < s2 && (s2 - s1) > (1UL<<31)) || | |
393 | (s1 > s2 && (s1 - s2) < (1UL<<31))) | |
394 | return SERIAL_GT; | |
395 | return SERIAL_UNDEF; | |
396 | } | |
0852d76b | 397 | |
f6e62e2a SK |
398 | /* Called at startup. If the timestamp file is configured and exists, put its mtime on |
399 | timestamp_time. If it doesn't exist, create it, and set the mtime to 1-1-2015. | |
360f2513 SK |
400 | return -1 -> Cannot create file. |
401 | 0 -> not using timestamp, or timestamp exists and is in past. | |
402 | 1 -> timestamp exists and is in future. | |
f6e62e2a | 403 | */ |
360f2513 | 404 | |
f6e62e2a SK |
405 | static time_t timestamp_time; |
406 | static int back_to_the_future; | |
407 | ||
360f2513 | 408 | int setup_timestamp(void) |
f6e62e2a SK |
409 | { |
410 | struct stat statbuf; | |
411 | ||
412 | back_to_the_future = 0; | |
413 | ||
360f2513 | 414 | if (!daemon->timestamp_file) |
f6e62e2a SK |
415 | return 0; |
416 | ||
417 | if (stat(daemon->timestamp_file, &statbuf) != -1) | |
418 | { | |
419 | timestamp_time = statbuf.st_mtime; | |
420 | check_and_exit: | |
421 | if (difftime(timestamp_time, time(0)) <= 0) | |
422 | { | |
423 | /* time already OK, update timestamp, and do key checking from the start. */ | |
424 | if (utime(daemon->timestamp_file, NULL) == -1) | |
425 | my_syslog(LOG_ERR, _("failed to update mtime on %s: %s"), daemon->timestamp_file, strerror(errno)); | |
426 | back_to_the_future = 1; | |
427 | return 0; | |
428 | } | |
429 | return 1; | |
430 | } | |
431 | ||
432 | if (errno == ENOENT) | |
433 | { | |
360f2513 SK |
434 | /* NB. for explanation of O_EXCL flag, see comment on pidfile in dnsmasq.c */ |
435 | int fd = open(daemon->timestamp_file, O_WRONLY | O_CREAT | O_NONBLOCK | O_EXCL, 0666); | |
f6e62e2a SK |
436 | if (fd != -1) |
437 | { | |
438 | struct utimbuf timbuf; | |
439 | ||
440 | close(fd); | |
441 | ||
442 | timestamp_time = timbuf.actime = timbuf.modtime = 1420070400; /* 1-1-2015 */ | |
360f2513 | 443 | if (utime(daemon->timestamp_file, &timbuf) == 0) |
f6e62e2a SK |
444 | goto check_and_exit; |
445 | } | |
446 | } | |
447 | ||
360f2513 | 448 | return -1; |
f6e62e2a SK |
449 | } |
450 | ||
5f8e58f4 SK |
451 | /* Check whether today/now is between date_start and date_end */ |
452 | static int check_date_range(unsigned long date_start, unsigned long date_end) | |
0852d76b | 453 | { |
f6e62e2a SK |
454 | unsigned long curtime = time(0); |
455 | ||
e98bd52e | 456 | /* Checking timestamps may be temporarily disabled */ |
f6e62e2a SK |
457 | |
458 | /* If the current time if _before_ the timestamp | |
459 | on our persistent timestamp file, then assume the | |
460 | time if not yet correct, and don't check the | |
461 | key timestamps. As soon as the current time is | |
462 | later then the timestamp, update the timestamp | |
463 | and start checking keys */ | |
464 | if (daemon->timestamp_file) | |
465 | { | |
466 | if (back_to_the_future == 0 && difftime(timestamp_time, curtime) <= 0) | |
467 | { | |
468 | if (utime(daemon->timestamp_file, NULL) != 0) | |
469 | my_syslog(LOG_ERR, _("failed to update mtime on %s: %s"), daemon->timestamp_file, strerror(errno)); | |
470 | ||
471 | back_to_the_future = 1; | |
472 | set_option_bool(OPT_DNSSEC_TIME); | |
473 | queue_event(EVENT_RELOAD); /* purge cache */ | |
474 | } | |
475 | ||
476 | if (back_to_the_future == 0) | |
477 | return 1; | |
478 | } | |
479 | else if (option_bool(OPT_DNSSEC_TIME)) | |
e98bd52e SK |
480 | return 1; |
481 | ||
5f8e58f4 SK |
482 | /* We must explicitly check against wanted values, because of SERIAL_UNDEF */ |
483 | return serial_compare_32(curtime, date_start) == SERIAL_GT | |
484 | && serial_compare_32(curtime, date_end) == SERIAL_LT; | |
485 | } | |
f119ed38 | 486 | |
5f8e58f4 SK |
487 | static u16 *get_desc(int type) |
488 | { | |
489 | /* List of RRtypes which include domains in the data. | |
490 | 0 -> domain | |
491 | integer -> no of plain bytes | |
492 | -1 -> end | |
493 | ||
494 | zero is not a valid RRtype, so the final entry is returned for | |
495 | anything which needs no mangling. | |
496 | */ | |
497 | ||
498 | static u16 rr_desc[] = | |
499 | { | |
500 | T_NS, 0, -1, | |
501 | T_MD, 0, -1, | |
502 | T_MF, 0, -1, | |
503 | T_CNAME, 0, -1, | |
504 | T_SOA, 0, 0, -1, | |
505 | T_MB, 0, -1, | |
506 | T_MG, 0, -1, | |
507 | T_MR, 0, -1, | |
508 | T_PTR, 0, -1, | |
509 | T_MINFO, 0, 0, -1, | |
510 | T_MX, 2, 0, -1, | |
511 | T_RP, 0, 0, -1, | |
512 | T_AFSDB, 2, 0, -1, | |
513 | T_RT, 2, 0, -1, | |
514 | T_SIG, 18, 0, -1, | |
515 | T_PX, 2, 0, 0, -1, | |
516 | T_NXT, 0, -1, | |
517 | T_KX, 2, 0, -1, | |
518 | T_SRV, 6, 0, -1, | |
519 | T_DNAME, 0, -1, | |
5f8e58f4 SK |
520 | 0, -1 /* wildcard/catchall */ |
521 | }; | |
522 | ||
523 | u16 *p = rr_desc; | |
524 | ||
525 | while (*p != type && *p != 0) | |
526 | while (*p++ != (u16)-1); | |
f119ed38 | 527 | |
5f8e58f4 SK |
528 | return p+1; |
529 | } | |
0852d76b | 530 | |
5f8e58f4 SK |
531 | /* Return bytes of canonicalised rdata, when the return value is zero, the remaining |
532 | data, pointed to by *p, should be used raw. */ | |
094b5c3d | 533 | static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff, int bufflen, |
5f8e58f4 SK |
534 | unsigned char **p, u16 **desc) |
535 | { | |
536 | int d = **desc; | |
537 | ||
5f8e58f4 SK |
538 | /* No more data needs mangling */ |
539 | if (d == (u16)-1) | |
094b5c3d SK |
540 | { |
541 | /* If there's more data than we have space for, just return what fits, | |
542 | we'll get called again for more chunks */ | |
543 | if (end - *p > bufflen) | |
544 | { | |
545 | memcpy(buff, *p, bufflen); | |
546 | *p += bufflen; | |
547 | return bufflen; | |
548 | } | |
549 | ||
550 | return 0; | |
551 | } | |
552 | ||
553 | (*desc)++; | |
5f8e58f4 | 554 | |
394ff492 | 555 | if (d == 0 && extract_name(header, plen, p, buff, 1, 0)) |
5f8e58f4 SK |
556 | /* domain-name, canonicalise */ |
557 | return to_wire(buff); | |
558 | else | |
559 | { | |
560 | /* plain data preceding a domain-name, don't run off the end of the data */ | |
561 | if ((end - *p) < d) | |
562 | d = end - *p; | |
563 | ||
564 | if (d != 0) | |
565 | { | |
566 | memcpy(buff, *p, d); | |
567 | *p += d; | |
568 | } | |
569 | ||
570 | return d; | |
571 | } | |
0852d76b GB |
572 | } |
573 | ||
613ad15d SK |
574 | static int expand_workspace(unsigned char ***wkspc, int *sz, int new) |
575 | { | |
576 | unsigned char **p; | |
577 | int new_sz = *sz; | |
578 | ||
579 | if (new_sz > new) | |
580 | return 1; | |
581 | ||
582 | if (new >= 100) | |
583 | return 0; | |
584 | ||
585 | new_sz += 5; | |
586 | ||
587 | if (!(p = whine_malloc((new_sz) * sizeof(unsigned char **)))) | |
588 | return 0; | |
589 | ||
590 | if (*wkspc) | |
591 | { | |
592 | memcpy(p, *wkspc, *sz * sizeof(unsigned char **)); | |
593 | free(*wkspc); | |
594 | } | |
595 | ||
596 | *wkspc = p; | |
597 | *sz = new_sz; | |
00a5b5d4 SK |
598 | |
599 | return 1; | |
613ad15d SK |
600 | } |
601 | ||
5f8e58f4 SK |
602 | /* Bubble sort the RRset into the canonical order. |
603 | Note that the byte-streams from two RRs may get unsynced: consider | |
604 | RRs which have two domain-names at the start and then other data. | |
605 | The domain-names may have different lengths in each RR, but sort equal | |
606 | ||
607 | ------------ | |
608 | |abcde|fghi| | |
609 | ------------ | |
610 | |abcd|efghi| | |
611 | ------------ | |
612 | ||
613 | leaving the following bytes as deciding the order. Hence the nasty left1 and left2 variables. | |
614 | */ | |
615 | ||
616 | static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int rrsetidx, | |
617 | unsigned char **rrset, char *buff1, char *buff2) | |
c3e0b9b6 | 618 | { |
5f8e58f4 | 619 | int swap, quit, i; |
0fc2f313 | 620 | |
5f8e58f4 SK |
621 | do |
622 | { | |
623 | for (swap = 0, i = 0; i < rrsetidx-1; i++) | |
624 | { | |
625 | int rdlen1, rdlen2, left1, left2, len1, len2, len, rc; | |
626 | u16 *dp1, *dp2; | |
627 | unsigned char *end1, *end2; | |
5107ace1 SK |
628 | /* Note that these have been determined to be OK previously, |
629 | so we don't need to check for NULL return here. */ | |
5f8e58f4 SK |
630 | unsigned char *p1 = skip_name(rrset[i], header, plen, 10); |
631 | unsigned char *p2 = skip_name(rrset[i+1], header, plen, 10); | |
632 | ||
633 | p1 += 8; /* skip class, type, ttl */ | |
634 | GETSHORT(rdlen1, p1); | |
635 | end1 = p1 + rdlen1; | |
636 | ||
637 | p2 += 8; /* skip class, type, ttl */ | |
638 | GETSHORT(rdlen2, p2); | |
639 | end2 = p2 + rdlen2; | |
640 | ||
641 | dp1 = dp2 = rr_desc; | |
642 | ||
1486a9c7 | 643 | for (quit = 0, left1 = 0, left2 = 0, len1 = 0, len2 = 0; !quit;) |
5f8e58f4 | 644 | { |
1486a9c7 SK |
645 | if (left1 != 0) |
646 | memmove(buff1, buff1 + len1 - left1, left1); | |
647 | ||
094b5c3d | 648 | if ((len1 = get_rdata(header, plen, end1, buff1 + left1, MAXDNAME - left1, &p1, &dp1)) == 0) |
5f8e58f4 SK |
649 | { |
650 | quit = 1; | |
651 | len1 = end1 - p1; | |
652 | memcpy(buff1 + left1, p1, len1); | |
653 | } | |
654 | len1 += left1; | |
655 | ||
1486a9c7 SK |
656 | if (left2 != 0) |
657 | memmove(buff2, buff2 + len2 - left2, left2); | |
658 | ||
094b5c3d | 659 | if ((len2 = get_rdata(header, plen, end2, buff2 + left2, MAXDNAME - left2, &p2, &dp2)) == 0) |
5f8e58f4 SK |
660 | { |
661 | quit = 1; | |
662 | len2 = end2 - p2; | |
663 | memcpy(buff2 + left2, p2, len2); | |
664 | } | |
665 | len2 += left2; | |
666 | ||
667 | if (len1 > len2) | |
1486a9c7 | 668 | left1 = len1 - len2, left2 = 0, len = len2; |
5f8e58f4 | 669 | else |
1486a9c7 | 670 | left2 = len2 - len1, left1 = 0, len = len1; |
5f8e58f4 | 671 | |
6fd6dacb | 672 | rc = (len == 0) ? 0 : memcmp(buff1, buff2, len); |
5f8e58f4 | 673 | |
4619d946 | 674 | if (rc > 0 || (rc == 0 && quit && len1 > len2)) |
5f8e58f4 SK |
675 | { |
676 | unsigned char *tmp = rrset[i+1]; | |
677 | rrset[i+1] = rrset[i]; | |
678 | rrset[i] = tmp; | |
679 | swap = quit = 1; | |
680 | } | |
6fd6dacb SK |
681 | else if (rc < 0) |
682 | quit = 1; | |
5f8e58f4 SK |
683 | } |
684 | } | |
685 | } while (swap); | |
686 | } | |
c3e0b9b6 | 687 | |
5f8e58f4 SK |
688 | /* Validate a single RRset (class, type, name) in the supplied DNS reply |
689 | Return code: | |
690 | STAT_SECURE if it validates. | |
5107ace1 | 691 | STAT_SECURE_WILDCARD if it validates and is the result of wildcard expansion. |
fbc52057 | 692 | (In this case *wildcard_out points to the "body" of the wildcard within name.) |
00a5b5d4 | 693 | STAT_NO_SIG no RRsigs found. |
87070192 SK |
694 | STAT_INSECURE RRset empty. |
695 | STAT_BOGUS signature is wrong, bad packet. | |
5f8e58f4 SK |
696 | STAT_NEED_KEY need DNSKEY to complete validation (name is returned in keyname) |
697 | ||
698 | if key is non-NULL, use that key, which has the algo and tag given in the params of those names, | |
699 | otherwise find the key in the cache. | |
5107ace1 SK |
700 | |
701 | name is unchanged on exit. keyname is used as workspace and trashed. | |
5f8e58f4 | 702 | */ |
fbc52057 SK |
703 | static int validate_rrset(time_t now, struct dns_header *header, size_t plen, int class, int type, |
704 | char *name, char *keyname, char **wildcard_out, struct blockdata *key, int keylen, int algo_in, int keytag_in) | |
5f8e58f4 SK |
705 | { |
706 | static unsigned char **rrset = NULL, **sigs = NULL; | |
707 | static int rrset_sz = 0, sig_sz = 0; | |
0fc2f313 | 708 | |
5f8e58f4 | 709 | unsigned char *p; |
5ada8885 | 710 | int rrsetidx, sigidx, res, rdlen, j, name_labels; |
5f8e58f4 SK |
711 | struct crec *crecp = NULL; |
712 | int type_covered, algo, labels, orig_ttl, sig_expiration, sig_inception, key_tag; | |
713 | u16 *rr_desc = get_desc(type); | |
83d2ed09 SK |
714 | |
715 | if (wildcard_out) | |
716 | *wildcard_out = NULL; | |
717 | ||
5f8e58f4 | 718 | if (!(p = skip_questions(header, plen))) |
87070192 | 719 | return STAT_BOGUS; |
83d2ed09 | 720 | |
5ada8885 SK |
721 | name_labels = count_labels(name); /* For 4035 5.3.2 check */ |
722 | ||
723 | /* look for RRSIGs for this RRset and get pointers to each RR in the set. */ | |
5f8e58f4 SK |
724 | for (rrsetidx = 0, sigidx = 0, j = ntohs(header->ancount) + ntohs(header->nscount); |
725 | j != 0; j--) | |
726 | { | |
727 | unsigned char *pstart, *pdata; | |
b98d22c1 | 728 | int stype, sclass; |
c3e0b9b6 | 729 | |
5f8e58f4 SK |
730 | pstart = p; |
731 | ||
732 | if (!(res = extract_name(header, plen, &p, name, 0, 10))) | |
87070192 | 733 | return STAT_BOGUS; /* bad packet */ |
5f8e58f4 SK |
734 | |
735 | GETSHORT(stype, p); | |
736 | GETSHORT(sclass, p); | |
b98d22c1 | 737 | p += 4; /* TTL */ |
5f8e58f4 SK |
738 | |
739 | pdata = p; | |
c3e0b9b6 | 740 | |
5f8e58f4 SK |
741 | GETSHORT(rdlen, p); |
742 | ||
e7829aef | 743 | if (!CHECK_LEN(header, p, plen, rdlen)) |
87070192 | 744 | return STAT_BOGUS; |
e7829aef | 745 | |
5f8e58f4 SK |
746 | if (res == 1 && sclass == class) |
747 | { | |
748 | if (stype == type) | |
749 | { | |
613ad15d | 750 | if (!expand_workspace(&rrset, &rrset_sz, rrsetidx)) |
87070192 | 751 | return STAT_BOGUS; |
613ad15d | 752 | |
5f8e58f4 SK |
753 | rrset[rrsetidx++] = pstart; |
754 | } | |
755 | ||
756 | if (stype == T_RRSIG) | |
757 | { | |
613ad15d | 758 | if (rdlen < 18) |
87070192 | 759 | return STAT_BOGUS; /* bad packet */ |
613ad15d SK |
760 | |
761 | GETSHORT(type_covered, p); | |
762 | ||
763 | if (type_covered == type) | |
764 | { | |
765 | if (!expand_workspace(&sigs, &sig_sz, sigidx)) | |
87070192 | 766 | return STAT_BOGUS; |
613ad15d SK |
767 | |
768 | sigs[sigidx++] = pdata; | |
769 | } | |
770 | ||
771 | p = pdata + 2; /* restore for ADD_RDLEN */ | |
5f8e58f4 SK |
772 | } |
773 | } | |
613ad15d | 774 | |
5f8e58f4 | 775 | if (!ADD_RDLEN(header, p, plen, rdlen)) |
87070192 | 776 | return STAT_BOGUS; |
5f8e58f4 | 777 | } |
c3e0b9b6 | 778 | |
00a5b5d4 SK |
779 | /* RRset empty */ |
780 | if (rrsetidx == 0) | |
5f8e58f4 | 781 | return STAT_INSECURE; |
00a5b5d4 SK |
782 | |
783 | /* no RRSIGs */ | |
784 | if (sigidx == 0) | |
785 | return STAT_NO_SIG; | |
5f8e58f4 SK |
786 | |
787 | /* Sort RRset records into canonical order. | |
d387380a | 788 | Note that at this point keyname and daemon->workspacename buffs are |
5f8e58f4 | 789 | unused, and used as workspace by the sort. */ |
d387380a | 790 | sort_rrset(header, plen, rr_desc, rrsetidx, rrset, daemon->workspacename, keyname); |
5f8e58f4 SK |
791 | |
792 | /* Now try all the sigs to try and find one which validates */ | |
793 | for (j = 0; j <sigidx; j++) | |
794 | { | |
d387380a | 795 | unsigned char *psav, *sig, *digest; |
86bec2d3 SK |
796 | int i, wire_len, sig_len; |
797 | const struct nettle_hash *hash; | |
798 | void *ctx; | |
d387380a | 799 | char *name_start; |
5f8e58f4 SK |
800 | u32 nsigttl; |
801 | ||
802 | p = sigs[j]; | |
5ada8885 | 803 | GETSHORT(rdlen, p); /* rdlen >= 18 checked previously */ |
5f8e58f4 SK |
804 | psav = p; |
805 | ||
5ada8885 | 806 | p += 2; /* type_covered - already checked */ |
5f8e58f4 SK |
807 | algo = *p++; |
808 | labels = *p++; | |
809 | GETLONG(orig_ttl, p); | |
e7829aef SK |
810 | GETLONG(sig_expiration, p); |
811 | GETLONG(sig_inception, p); | |
5f8e58f4 SK |
812 | GETSHORT(key_tag, p); |
813 | ||
394ff492 | 814 | if (!extract_name(header, plen, &p, keyname, 1, 0)) |
87070192 | 815 | return STAT_BOGUS; |
d387380a SK |
816 | |
817 | /* RFC 4035 5.3.1 says that the Signer's Name field MUST equal | |
818 | the name of the zone containing the RRset. We can't tell that | |
819 | for certain, but we can check that the RRset name is equal to | |
820 | or encloses the signers name, which should be enough to stop | |
821 | an attacker using signatures made with the key of an unrelated | |
822 | zone he controls. Note that the root key is always allowed. */ | |
823 | if (*keyname != 0) | |
824 | { | |
825 | int failed = 0; | |
826 | ||
827 | for (name_start = name; !hostname_isequal(name_start, keyname); ) | |
828 | if ((name_start = strchr(name_start, '.'))) | |
829 | name_start++; /* chop a label off and try again */ | |
830 | else | |
831 | { | |
832 | failed = 1; | |
833 | break; | |
834 | } | |
835 | ||
836 | /* Bad sig, try another */ | |
837 | if (failed) | |
838 | continue; | |
839 | } | |
5f8e58f4 | 840 | |
d387380a | 841 | /* Other 5.3.1 checks */ |
e7829aef SK |
842 | if (!check_date_range(sig_inception, sig_expiration) || |
843 | labels > name_labels || | |
844 | !(hash = hash_find(algo_digest_name(algo))) || | |
845 | !hash_init(hash, &ctx, &digest)) | |
846 | continue; | |
847 | ||
5f8e58f4 SK |
848 | /* OK, we have the signature record, see if the relevant DNSKEY is in the cache. */ |
849 | if (!key && !(crecp = cache_find_by_name(NULL, keyname, now, F_DNSKEY))) | |
850 | return STAT_NEED_KEY; | |
851 | ||
86bec2d3 SK |
852 | sig = p; |
853 | sig_len = rdlen - (p - psav); | |
e7829aef | 854 | |
5f8e58f4 SK |
855 | nsigttl = htonl(orig_ttl); |
856 | ||
86bec2d3 | 857 | hash->update(ctx, 18, psav); |
5f8e58f4 | 858 | wire_len = to_wire(keyname); |
86bec2d3 | 859 | hash->update(ctx, (unsigned int)wire_len, (unsigned char*)keyname); |
5f8e58f4 SK |
860 | from_wire(keyname); |
861 | ||
5f8e58f4 SK |
862 | for (i = 0; i < rrsetidx; ++i) |
863 | { | |
864 | int seg; | |
865 | unsigned char *end, *cp; | |
866 | u16 len, *dp; | |
d387380a | 867 | |
5f8e58f4 | 868 | p = rrset[i]; |
394ff492 | 869 | if (!extract_name(header, plen, &p, name, 1, 10)) |
87070192 | 870 | return STAT_BOGUS; |
5ada8885 | 871 | |
d387380a SK |
872 | name_start = name; |
873 | ||
5ada8885 SK |
874 | /* if more labels than in RRsig name, hash *.<no labels in rrsig labels field> 4035 5.3.2 */ |
875 | if (labels < name_labels) | |
876 | { | |
877 | int k; | |
878 | for (k = name_labels - labels; k != 0; k--) | |
fbc52057 SK |
879 | { |
880 | while (*name_start != '.' && *name_start != 0) | |
881 | name_start++; | |
0b1008d3 | 882 | if (k != 1 && *name_start == '.') |
fbc52057 SK |
883 | name_start++; |
884 | } | |
885 | ||
886 | if (wildcard_out) | |
887 | *wildcard_out = name_start+1; | |
888 | ||
5ada8885 SK |
889 | name_start--; |
890 | *name_start = '*'; | |
891 | } | |
892 | ||
893 | wire_len = to_wire(name_start); | |
86bec2d3 SK |
894 | hash->update(ctx, (unsigned int)wire_len, (unsigned char *)name_start); |
895 | hash->update(ctx, 4, p); /* class and type */ | |
896 | hash->update(ctx, 4, (unsigned char *)&nsigttl); | |
5f8e58f4 SK |
897 | |
898 | p += 8; /* skip class, type, ttl */ | |
899 | GETSHORT(rdlen, p); | |
5ada8885 | 900 | if (!CHECK_LEN(header, p, plen, rdlen)) |
87070192 | 901 | return STAT_BOGUS; |
5ada8885 | 902 | |
5f8e58f4 SK |
903 | end = p + rdlen; |
904 | ||
905 | /* canonicalise rdata and calculate length of same, use name buffer as workspace */ | |
906 | cp = p; | |
907 | dp = rr_desc; | |
094b5c3d | 908 | for (len = 0; (seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)) != 0; len += seg); |
5f8e58f4 SK |
909 | len += end - cp; |
910 | len = htons(len); | |
86bec2d3 | 911 | hash->update(ctx, 2, (unsigned char *)&len); |
5f8e58f4 SK |
912 | |
913 | /* Now canonicalise again and digest. */ | |
914 | cp = p; | |
915 | dp = rr_desc; | |
094b5c3d | 916 | while ((seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp))) |
86bec2d3 | 917 | hash->update(ctx, seg, (unsigned char *)name); |
5f8e58f4 | 918 | if (cp != end) |
86bec2d3 | 919 | hash->update(ctx, end - cp, cp); |
5f8e58f4 | 920 | } |
86bec2d3 SK |
921 | |
922 | hash->digest(ctx, hash->digest_size, digest); | |
923 | ||
5ada8885 SK |
924 | /* namebuff used for workspace above, restore to leave unchanged on exit */ |
925 | p = (unsigned char*)(rrset[0]); | |
394ff492 | 926 | extract_name(header, plen, &p, name, 1, 0); |
5ada8885 | 927 | |
5f8e58f4 SK |
928 | if (key) |
929 | { | |
930 | if (algo_in == algo && keytag_in == key_tag && | |
ebe95a83 | 931 | verify(key, keylen, sig, sig_len, digest, hash->digest_size, algo)) |
5f8e58f4 SK |
932 | return STAT_SECURE; |
933 | } | |
934 | else | |
935 | { | |
936 | /* iterate through all possible keys 4035 5.3.1 */ | |
937 | for (; crecp; crecp = cache_find_by_name(crecp, keyname, now, F_DNSKEY)) | |
51ea3ca2 SK |
938 | if (crecp->addr.key.algo == algo && |
939 | crecp->addr.key.keytag == key_tag && | |
3f7483e8 | 940 | crecp->uid == (unsigned int)class && |
ebe95a83 | 941 | verify(crecp->addr.key.keydata, crecp->addr.key.keylen, sig, sig_len, digest, hash->digest_size, algo)) |
5107ace1 | 942 | return (labels < name_labels) ? STAT_SECURE_WILDCARD : STAT_SECURE; |
5f8e58f4 SK |
943 | } |
944 | } | |
945 | ||
946 | return STAT_BOGUS; | |
947 | } | |
948 | ||
0fc2f313 | 949 | /* The DNS packet is expected to contain the answer to a DNSKEY query. |
c3e0b9b6 SK |
950 | Put all DNSKEYs in the answer which are valid into the cache. |
951 | return codes: | |
97e618a0 | 952 | STAT_SECURE At least one valid DNSKEY found and in cache. |
0fc2f313 | 953 | STAT_BOGUS No DNSKEYs found, which can be validated with DS, |
87070192 | 954 | or self-sign for DNSKEY RRset is not valid, bad packet. |
0fc2f313 | 955 | STAT_NEED_DS DS records to validate a key not found, name in keyname |
c3e0b9b6 SK |
956 | */ |
957 | int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) | |
958 | { | |
0fc2f313 | 959 | unsigned char *psave, *p = (unsigned char *)(header+1); |
c3e0b9b6 | 960 | struct crec *crecp, *recp1; |
8d718cbb | 961 | int rc, j, qtype, qclass, ttl, rdlen, flags, algo, valid, keytag, type_covered; |
c3e0b9b6 | 962 | struct blockdata *key; |
51ea3ca2 | 963 | struct all_addr a; |
c3e0b9b6 | 964 | |
5f8e58f4 | 965 | if (ntohs(header->qdcount) != 1 || |
394ff492 | 966 | !extract_name(header, plen, &p, name, 1, 4)) |
87070192 | 967 | return STAT_BOGUS; |
5f8e58f4 | 968 | |
c3e0b9b6 SK |
969 | GETSHORT(qtype, p); |
970 | GETSHORT(qclass, p); | |
971 | ||
97e618a0 | 972 | if (qtype != T_DNSKEY || qclass != class || ntohs(header->ancount) == 0) |
f01d7be6 | 973 | return STAT_BOGUS; |
c3e0b9b6 | 974 | |
b8eac191 | 975 | /* See if we have cached a DS record which validates this key */ |
0fc2f313 SK |
976 | if (!(crecp = cache_find_by_name(NULL, name, now, F_DS))) |
977 | { | |
978 | strcpy(keyname, name); | |
979 | return STAT_NEED_DS; | |
980 | } | |
b8eac191 SK |
981 | |
982 | /* If we've cached that DS provably doesn't exist, result must be INSECURE */ | |
983 | if (crecp->flags & F_NEG) | |
984 | return STAT_INSECURE; | |
985 | ||
0fc2f313 | 986 | /* NOTE, we need to find ONE DNSKEY which matches the DS */ |
e7829aef | 987 | for (valid = 0, j = ntohs(header->ancount); j != 0 && !valid; j--) |
c3e0b9b6 SK |
988 | { |
989 | /* Ensure we have type, class TTL and length */ | |
0fc2f313 | 990 | if (!(rc = extract_name(header, plen, &p, name, 0, 10))) |
87070192 | 991 | return STAT_BOGUS; /* bad packet */ |
c3e0b9b6 SK |
992 | |
993 | GETSHORT(qtype, p); | |
994 | GETSHORT(qclass, p); | |
995 | GETLONG(ttl, p); | |
996 | GETSHORT(rdlen, p); | |
6f468103 | 997 | |
0fc2f313 | 998 | if (!CHECK_LEN(header, p, plen, rdlen) || rdlen < 4) |
87070192 | 999 | return STAT_BOGUS; /* bad packet */ |
0fc2f313 | 1000 | |
6f468103 SK |
1001 | if (qclass != class || qtype != T_DNSKEY || rc == 2) |
1002 | { | |
1003 | p += rdlen; | |
1004 | continue; | |
1005 | } | |
1006 | ||
0fc2f313 | 1007 | psave = p; |
c3e0b9b6 | 1008 | |
c3e0b9b6 | 1009 | GETSHORT(flags, p); |
0fc2f313 | 1010 | if (*p++ != 3) |
f01d7be6 | 1011 | return STAT_BOGUS; |
c3e0b9b6 | 1012 | algo = *p++; |
0fc2f313 | 1013 | keytag = dnskey_keytag(algo, flags, p, rdlen - 4); |
e7829aef | 1014 | key = NULL; |
c3e0b9b6 | 1015 | |
e7829aef SK |
1016 | /* key must have zone key flag set */ |
1017 | if (flags & 0x100) | |
1018 | key = blockdata_alloc((char*)p, rdlen - 4); | |
c3e0b9b6 | 1019 | |
0fc2f313 | 1020 | p = psave; |
e7829aef | 1021 | |
0fc2f313 | 1022 | if (!ADD_RDLEN(header, p, plen, rdlen)) |
8d718cbb SK |
1023 | { |
1024 | if (key) | |
1025 | blockdata_free(key); | |
87070192 | 1026 | return STAT_BOGUS; /* bad packet */ |
8d718cbb SK |
1027 | } |
1028 | ||
e7829aef SK |
1029 | /* No zone key flag or malloc failure */ |
1030 | if (!key) | |
0fc2f313 SK |
1031 | continue; |
1032 | ||
1033 | for (recp1 = crecp; recp1; recp1 = cache_find_by_name(recp1, name, now, F_DS)) | |
86bec2d3 SK |
1034 | { |
1035 | void *ctx; | |
1036 | unsigned char *digest, *ds_digest; | |
1037 | const struct nettle_hash *hash; | |
1038 | ||
51ea3ca2 SK |
1039 | if (recp1->addr.ds.algo == algo && |
1040 | recp1->addr.ds.keytag == keytag && | |
3f7483e8 | 1041 | recp1->uid == (unsigned int)class && |
51ea3ca2 | 1042 | (hash = hash_find(ds_digest_name(recp1->addr.ds.digest))) && |
86bec2d3 | 1043 | hash_init(hash, &ctx, &digest)) |
0fc2f313 | 1044 | |
86bec2d3 SK |
1045 | { |
1046 | int wire_len = to_wire(name); | |
1047 | ||
1048 | /* Note that digest may be different between DSs, so | |
1049 | we can't move this outside the loop. */ | |
1050 | hash->update(ctx, (unsigned int)wire_len, (unsigned char *)name); | |
1051 | hash->update(ctx, (unsigned int)rdlen, psave); | |
1052 | hash->digest(ctx, hash->digest_size, digest); | |
1053 | ||
1054 | from_wire(name); | |
1055 | ||
824202ef SK |
1056 | if (recp1->addr.ds.keylen == (int)hash->digest_size && |
1057 | (ds_digest = blockdata_retrieve(recp1->addr.key.keydata, recp1->addr.ds.keylen, NULL)) && | |
1058 | memcmp(ds_digest, digest, recp1->addr.ds.keylen) == 0 && | |
fbc52057 | 1059 | validate_rrset(now, header, plen, class, T_DNSKEY, name, keyname, NULL, key, rdlen - 4, algo, keytag) == STAT_SECURE) |
86bec2d3 | 1060 | { |
86bec2d3 | 1061 | valid = 1; |
86bec2d3 SK |
1062 | break; |
1063 | } | |
1064 | } | |
1065 | } | |
e7829aef | 1066 | blockdata_free(key); |
c3e0b9b6 | 1067 | } |
c3e0b9b6 | 1068 | |
0fc2f313 SK |
1069 | if (valid) |
1070 | { | |
8d718cbb | 1071 | /* DNSKEY RRset determined to be OK, now cache it and the RRsigs that sign it. */ |
e7829aef SK |
1072 | cache_start_insert(); |
1073 | ||
1074 | p = skip_questions(header, plen); | |
1075 | ||
1076 | for (j = ntohs(header->ancount); j != 0; j--) | |
1077 | { | |
1078 | /* Ensure we have type, class TTL and length */ | |
1079 | if (!(rc = extract_name(header, plen, &p, name, 0, 10))) | |
1080 | return STAT_INSECURE; /* bad packet */ | |
1081 | ||
1082 | GETSHORT(qtype, p); | |
1083 | GETSHORT(qclass, p); | |
1084 | GETLONG(ttl, p); | |
1085 | GETSHORT(rdlen, p); | |
8d718cbb SK |
1086 | |
1087 | if (!CHECK_LEN(header, p, plen, rdlen)) | |
87070192 | 1088 | return STAT_BOGUS; /* bad packet */ |
e7829aef | 1089 | |
8d718cbb | 1090 | if (qclass == class && rc == 1) |
e7829aef | 1091 | { |
8d718cbb | 1092 | psave = p; |
e7829aef | 1093 | |
8d718cbb SK |
1094 | if (qtype == T_DNSKEY) |
1095 | { | |
1096 | if (rdlen < 4) | |
87070192 | 1097 | return STAT_BOGUS; /* bad packet */ |
8d718cbb SK |
1098 | |
1099 | GETSHORT(flags, p); | |
1100 | if (*p++ != 3) | |
f01d7be6 | 1101 | return STAT_BOGUS; |
8d718cbb SK |
1102 | algo = *p++; |
1103 | keytag = dnskey_keytag(algo, flags, p, rdlen - 4); | |
1104 | ||
1105 | /* Cache needs to known class for DNSSEC stuff */ | |
1106 | a.addr.dnssec.class = class; | |
1107 | ||
1108 | if ((key = blockdata_alloc((char*)p, rdlen - 4))) | |
1109 | { | |
1110 | if (!(recp1 = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DNSSECOK))) | |
1111 | blockdata_free(key); | |
1112 | else | |
1113 | { | |
1114 | a.addr.keytag = keytag; | |
25cf5e37 | 1115 | log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DNSKEY keytag %u"); |
8d718cbb SK |
1116 | |
1117 | recp1->addr.key.keylen = rdlen - 4; | |
1118 | recp1->addr.key.keydata = key; | |
1119 | recp1->addr.key.algo = algo; | |
1120 | recp1->addr.key.keytag = keytag; | |
1121 | recp1->addr.key.flags = flags; | |
8d718cbb SK |
1122 | } |
1123 | } | |
1124 | } | |
1125 | else if (qtype == T_RRSIG) | |
1126 | { | |
1127 | /* RRSIG, cache if covers DNSKEY RRset */ | |
1128 | if (rdlen < 18) | |
87070192 | 1129 | return STAT_BOGUS; /* bad packet */ |
8d718cbb SK |
1130 | |
1131 | GETSHORT(type_covered, p); | |
1132 | ||
1133 | if (type_covered == T_DNSKEY) | |
1134 | { | |
1135 | a.addr.dnssec.class = class; | |
1136 | a.addr.dnssec.type = type_covered; | |
1137 | ||
1138 | algo = *p++; | |
1139 | p += 13; /* labels, orig_ttl, expiration, inception */ | |
1140 | GETSHORT(keytag, p); | |
1141 | if ((key = blockdata_alloc((char*)psave, rdlen))) | |
1142 | { | |
1143 | if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DS))) | |
1144 | blockdata_free(key); | |
1145 | else | |
1146 | { | |
8d718cbb SK |
1147 | crecp->addr.sig.keydata = key; |
1148 | crecp->addr.sig.keylen = rdlen; | |
1149 | crecp->addr.sig.keytag = keytag; | |
1150 | crecp->addr.sig.type_covered = type_covered; | |
1151 | crecp->addr.sig.algo = algo; | |
1152 | } | |
1153 | } | |
1154 | } | |
1155 | } | |
e7829aef | 1156 | |
8d718cbb | 1157 | p = psave; |
e7829aef | 1158 | } |
8d718cbb | 1159 | |
e7829aef | 1160 | if (!ADD_RDLEN(header, p, plen, rdlen)) |
87070192 | 1161 | return STAT_BOGUS; /* bad packet */ |
e7829aef SK |
1162 | } |
1163 | ||
0fc2f313 SK |
1164 | /* commit cache insert. */ |
1165 | cache_end_insert(); | |
1166 | return STAT_SECURE; | |
1167 | } | |
1168 | ||
25cf5e37 | 1169 | log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, "BOGUS DNSKEY"); |
0fc2f313 | 1170 | return STAT_BOGUS; |
c3e0b9b6 | 1171 | } |
0fc2f313 | 1172 | |
c3e0b9b6 SK |
1173 | /* The DNS packet is expected to contain the answer to a DS query |
1174 | Put all DSs in the answer which are valid into the cache. | |
1175 | return codes: | |
c3e0b9b6 | 1176 | STAT_SECURE At least one valid DS found and in cache. |
00a5b5d4 | 1177 | STAT_NO_DS It's proved there's no DS here. |
97e618a0 SK |
1178 | STAT_NO_NS It's proved there's no DS _or_ NS here. |
1179 | STAT_BOGUS no DS in reply or not signed, fails validation, bad packet. | |
0b8a5a30 | 1180 | STAT_NEED_KEY DNSKEY records to validate a DS not found, name in keyname |
c3e0b9b6 SK |
1181 | */ |
1182 | ||
1183 | int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) | |
1184 | { | |
51ea3ca2 | 1185 | unsigned char *p = (unsigned char *)(header+1); |
97e618a0 | 1186 | int qtype, qclass, val, i, neganswer, nons; |
c3e0b9b6 | 1187 | |
5f8e58f4 | 1188 | if (ntohs(header->qdcount) != 1 || |
b8eac191 | 1189 | !(p = skip_name(p, header, plen, 4))) |
87070192 | 1190 | return STAT_BOGUS; |
8d718cbb | 1191 | |
c3e0b9b6 SK |
1192 | GETSHORT(qtype, p); |
1193 | GETSHORT(qclass, p); | |
1194 | ||
b47b04c8 SK |
1195 | if (qtype != T_DS || qclass != class) |
1196 | val = STAT_BOGUS; | |
1197 | else | |
97e618a0 SK |
1198 | val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer, &nons); |
1199 | /* Note dnssec_validate_reply() will have cached positive answers */ | |
1200 | ||
1201 | if (val == STAT_NO_SIG || val == STAT_INSECURE) | |
1202 | val = STAT_BOGUS; | |
51ea3ca2 | 1203 | |
b8eac191 | 1204 | p = (unsigned char *)(header+1); |
394ff492 | 1205 | extract_name(header, plen, &p, name, 1, 4); |
b8eac191 SK |
1206 | p += 4; /* qtype, qclass */ |
1207 | ||
00a5b5d4 | 1208 | if (!(p = skip_section(p, ntohs(header->ancount), header, plen))) |
97e618a0 | 1209 | val = STAT_BOGUS; |
00a5b5d4 | 1210 | |
0b8a5a30 SK |
1211 | /* If the key needed to validate the DS is on the same domain as the DS, we'll |
1212 | loop getting nowhere. Stop that now. This can happen of the DS answer comes | |
1213 | from the DS's zone, and not the parent zone. */ | |
1214 | if (val == STAT_BOGUS || (val == STAT_NEED_KEY && hostname_isequal(name, keyname))) | |
b8eac191 | 1215 | { |
25cf5e37 | 1216 | log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, "BOGUS DS"); |
97e618a0 SK |
1217 | return STAT_BOGUS; |
1218 | } | |
1219 | ||
1220 | /* By here, the answer is proved secure, and a positive answer has been cached. */ | |
1221 | if (val == STAT_SECURE && neganswer) | |
1222 | { | |
1223 | int rdlen, flags = F_FORWARD | F_DS | F_NEG | F_DNSSECOK; | |
b8eac191 SK |
1224 | unsigned long ttl, minttl = ULONG_MAX; |
1225 | struct all_addr a; | |
00a5b5d4 SK |
1226 | |
1227 | if (RCODE(header) == NXDOMAIN) | |
1228 | flags |= F_NXDOMAIN; | |
1229 | ||
97e618a0 SK |
1230 | /* We only cache validated DS records, DNSSECOK flag hijacked |
1231 | to store presence/absence of NS. */ | |
1232 | if (nons) | |
1233 | flags &= ~F_DNSSECOK; | |
b8eac191 SK |
1234 | |
1235 | for (i = ntohs(header->nscount); i != 0; i--) | |
1236 | { | |
00a5b5d4 | 1237 | if (!(p = skip_name(p, header, plen, 0))) |
87070192 | 1238 | return STAT_BOGUS; |
b8eac191 SK |
1239 | |
1240 | GETSHORT(qtype, p); | |
1241 | GETSHORT(qclass, p); | |
1242 | GETLONG(ttl, p); | |
1243 | GETSHORT(rdlen, p); | |
1244 | ||
00a5b5d4 | 1245 | if (!CHECK_LEN(header, p, plen, rdlen)) |
87070192 | 1246 | return STAT_BOGUS; /* bad packet */ |
00a5b5d4 SK |
1247 | |
1248 | if (qclass != class || qtype != T_SOA) | |
b8eac191 SK |
1249 | { |
1250 | p += rdlen; | |
1251 | continue; | |
1252 | } | |
1253 | ||
1254 | if (ttl < minttl) | |
1255 | minttl = ttl; | |
1256 | ||
1257 | /* MNAME */ | |
1258 | if (!(p = skip_name(p, header, plen, 0))) | |
87070192 | 1259 | return STAT_BOGUS; |
b8eac191 SK |
1260 | /* RNAME */ |
1261 | if (!(p = skip_name(p, header, plen, 20))) | |
87070192 | 1262 | return STAT_BOGUS; |
b8eac191 SK |
1263 | p += 16; /* SERIAL REFRESH RETRY EXPIRE */ |
1264 | ||
1265 | GETLONG(ttl, p); /* minTTL */ | |
1266 | if (ttl < minttl) | |
1267 | minttl = ttl; | |
00a5b5d4 SK |
1268 | |
1269 | break; | |
b8eac191 SK |
1270 | } |
1271 | ||
00a5b5d4 SK |
1272 | if (i != 0) |
1273 | { | |
1274 | cache_start_insert(); | |
1275 | ||
1276 | a.addr.dnssec.class = class; | |
1277 | cache_insert(name, &a, now, ttl, flags); | |
1278 | ||
97e618a0 SK |
1279 | cache_end_insert(); |
1280 | ||
25cf5e37 | 1281 | log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, nons ? "no delegation" : "no DS"); |
00a5b5d4 | 1282 | } |
b8eac191 | 1283 | |
97e618a0 | 1284 | return nons ? STAT_NO_NS : STAT_NO_DS; |
b8eac191 SK |
1285 | } |
1286 | ||
51ea3ca2 | 1287 | return val; |
c3e0b9b6 SK |
1288 | } |
1289 | ||
c5f4ec7d SK |
1290 | /* 4034 6.1 */ |
1291 | static int hostname_cmp(const char *a, const char *b) | |
1292 | { | |
dbf72123 SK |
1293 | char *sa, *ea, *ca, *sb, *eb, *cb; |
1294 | unsigned char ac, bc; | |
1295 | ||
1296 | sa = ea = (char *)a + strlen(a); | |
1297 | sb = eb = (char *)b + strlen(b); | |
1298 | ||
c5f4ec7d SK |
1299 | while (1) |
1300 | { | |
dbf72123 SK |
1301 | while (sa != a && *(sa-1) != '.') |
1302 | sa--; | |
c5f4ec7d | 1303 | |
dbf72123 SK |
1304 | while (sb != b && *(sb-1) != '.') |
1305 | sb--; | |
1306 | ||
1307 | ca = sa; | |
1308 | cb = sb; | |
1309 | ||
1310 | while (1) | |
1311 | { | |
1312 | if (ca == ea) | |
1313 | { | |
1314 | if (cb == eb) | |
1315 | break; | |
1316 | ||
1317 | return -1; | |
1318 | } | |
c5f4ec7d | 1319 | |
dbf72123 SK |
1320 | if (cb == eb) |
1321 | return 1; | |
1322 | ||
1323 | ac = (unsigned char) *ca++; | |
1324 | bc = (unsigned char) *cb++; | |
1325 | ||
1326 | if (ac >= 'A' && ac <= 'Z') | |
1327 | ac += 'a' - 'A'; | |
1328 | if (bc >= 'A' && bc <= 'Z') | |
1329 | bc += 'a' - 'A'; | |
1330 | ||
979cdf9b | 1331 | if (ac < bc) |
dbf72123 SK |
1332 | return -1; |
1333 | else if (ac != bc) | |
1334 | return 1; | |
1335 | } | |
c5f4ec7d | 1336 | |
dbf72123 SK |
1337 | |
1338 | if (sa == a) | |
c5f4ec7d | 1339 | { |
dbf72123 SK |
1340 | if (sb == b) |
1341 | return 0; | |
c5f4ec7d | 1342 | |
dbf72123 | 1343 | return -1; |
c5f4ec7d SK |
1344 | } |
1345 | ||
dbf72123 SK |
1346 | if (sb == b) |
1347 | return 1; | |
c5f4ec7d | 1348 | |
dbf72123 SK |
1349 | ea = sa--; |
1350 | eb = sb--; | |
c5f4ec7d SK |
1351 | } |
1352 | } | |
1353 | ||
5107ace1 SK |
1354 | /* Find all the NSEC or NSEC3 records in a reply. |
1355 | return an array of pointers to them. */ | |
1356 | static int find_nsec_records(struct dns_header *header, size_t plen, unsigned char ***nsecsetp, int *nsecsetl, int class_reqd) | |
1357 | { | |
1358 | static unsigned char **nsecset = NULL; | |
1359 | static int nsecset_sz = 0; | |
1360 | ||
87070192 | 1361 | int type_found = 0; |
5107ace1 SK |
1362 | unsigned char *p = skip_questions(header, plen); |
1363 | int type, class, rdlen, i, nsecs_found; | |
1364 | ||
1365 | /* Move to NS section */ | |
1366 | if (!p || !(p = skip_section(p, ntohs(header->ancount), header, plen))) | |
1367 | return 0; | |
1368 | ||
1369 | for (nsecs_found = 0, i = ntohs(header->nscount); i != 0; i--) | |
1370 | { | |
1371 | unsigned char *pstart = p; | |
1372 | ||
1373 | if (!(p = skip_name(p, header, plen, 10))) | |
1374 | return 0; | |
1375 | ||
1376 | GETSHORT(type, p); | |
1377 | GETSHORT(class, p); | |
1378 | p += 4; /* TTL */ | |
1379 | GETSHORT(rdlen, p); | |
1380 | ||
1381 | if (class == class_reqd && (type == T_NSEC || type == T_NSEC3)) | |
1382 | { | |
1383 | /* No mixed NSECing 'round here, thankyouverymuch */ | |
1384 | if (type_found == T_NSEC && type == T_NSEC3) | |
1385 | return 0; | |
1386 | if (type_found == T_NSEC3 && type == T_NSEC) | |
1387 | return 0; | |
1388 | ||
1389 | type_found = type; | |
1390 | ||
613ad15d SK |
1391 | if (!expand_workspace(&nsecset, &nsecset_sz, nsecs_found)) |
1392 | return 0; | |
1393 | ||
5107ace1 SK |
1394 | nsecset[nsecs_found++] = pstart; |
1395 | } | |
613ad15d | 1396 | |
5107ace1 SK |
1397 | if (!ADD_RDLEN(header, p, plen, rdlen)) |
1398 | return 0; | |
1399 | } | |
1400 | ||
1401 | *nsecsetp = nsecset; | |
1402 | *nsecsetl = nsecs_found; | |
1403 | ||
1404 | return type_found; | |
1405 | } | |
1406 | ||
24187530 | 1407 | static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count, |
97e618a0 | 1408 | char *workspace1, char *workspace2, char *name, int type, int *nons) |
5107ace1 SK |
1409 | { |
1410 | int i, rc, rdlen; | |
1411 | unsigned char *p, *psave; | |
1412 | int offset = (type & 0xff) >> 3; | |
1413 | int mask = 0x80 >> (type & 0x07); | |
97e618a0 SK |
1414 | |
1415 | if (nons) | |
1416 | *nons = 0; | |
5107ace1 SK |
1417 | |
1418 | /* Find NSEC record that proves name doesn't exist */ | |
1419 | for (i = 0; i < nsec_count; i++) | |
1420 | { | |
1421 | p = nsecs[i]; | |
394ff492 | 1422 | if (!extract_name(header, plen, &p, workspace1, 1, 10)) |
87070192 | 1423 | return STAT_BOGUS; |
5107ace1 SK |
1424 | p += 8; /* class, type, TTL */ |
1425 | GETSHORT(rdlen, p); | |
1426 | psave = p; | |
394ff492 | 1427 | if (!extract_name(header, plen, &p, workspace2, 1, 10)) |
87070192 | 1428 | return STAT_BOGUS; |
5107ace1 SK |
1429 | |
1430 | rc = hostname_cmp(workspace1, name); | |
1431 | ||
1432 | if (rc == 0) | |
1433 | { | |
f01d7be6 SK |
1434 | /* 4035 para 5.4. Last sentence */ |
1435 | if (type == T_NSEC || type == T_RRSIG) | |
1436 | return STAT_SECURE; | |
1437 | ||
5107ace1 SK |
1438 | /* NSEC with the same name as the RR we're testing, check |
1439 | that the type in question doesn't appear in the type map */ | |
1440 | rdlen -= p - psave; | |
1441 | /* rdlen is now length of type map, and p points to it */ | |
1442 | ||
97e618a0 SK |
1443 | /* If we can prove that there's no NS record, return that information. */ |
1444 | if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0) | |
1445 | *nons = 1; | |
1446 | ||
5107ace1 SK |
1447 | while (rdlen >= 2) |
1448 | { | |
1449 | if (!CHECK_LEN(header, p, plen, rdlen)) | |
87070192 | 1450 | return STAT_BOGUS; |
5107ace1 SK |
1451 | |
1452 | if (p[0] == type >> 8) | |
1453 | { | |
1454 | /* Does the NSEC say our type exists? */ | |
a857daa3 | 1455 | if (offset < p[1] && (p[offset+2] & mask) != 0) |
5107ace1 SK |
1456 | return STAT_BOGUS; |
1457 | ||
1458 | break; /* finshed checking */ | |
1459 | } | |
1460 | ||
1461 | rdlen -= p[1]; | |
1462 | p += p[1]; | |
1463 | } | |
1464 | ||
1465 | return STAT_SECURE; | |
1466 | } | |
1467 | else if (rc == -1) | |
1468 | { | |
1469 | /* Normal case, name falls between NSEC name and next domain name, | |
1470 | wrap around case, name falls between NSEC name (rc == -1) and end */ | |
1471 | if (hostname_cmp(workspace2, name) == 1 || hostname_cmp(workspace1, workspace2) == 1) | |
1472 | return STAT_SECURE; | |
1473 | } | |
1474 | else | |
1475 | { | |
1476 | /* wrap around case, name falls between start and next domain name */ | |
1477 | if (hostname_cmp(workspace1, workspace2) == 1 && hostname_cmp(workspace2, name) == 1) | |
1478 | return STAT_SECURE; | |
1479 | } | |
1480 | } | |
1481 | ||
1482 | return STAT_BOGUS; | |
1483 | } | |
1484 | ||
1485 | /* return digest length, or zero on error */ | |
1486 | static int hash_name(char *in, unsigned char **out, struct nettle_hash const *hash, | |
1487 | unsigned char *salt, int salt_len, int iterations) | |
1488 | { | |
1489 | void *ctx; | |
1490 | unsigned char *digest; | |
1491 | int i; | |
1492 | ||
1493 | if (!hash_init(hash, &ctx, &digest)) | |
1494 | return 0; | |
1495 | ||
1496 | hash->update(ctx, to_wire(in), (unsigned char *)in); | |
1497 | hash->update(ctx, salt_len, salt); | |
1498 | hash->digest(ctx, hash->digest_size, digest); | |
1499 | ||
1500 | for(i = 0; i < iterations; i++) | |
1501 | { | |
1502 | hash->update(ctx, hash->digest_size, digest); | |
1503 | hash->update(ctx, salt_len, salt); | |
1504 | hash->digest(ctx, hash->digest_size, digest); | |
1505 | } | |
1506 | ||
1507 | from_wire(in); | |
1508 | ||
1509 | *out = digest; | |
1510 | return hash->digest_size; | |
1511 | } | |
1512 | ||
1513 | /* Decode base32 to first "." or end of string */ | |
1514 | static int base32_decode(char *in, unsigned char *out) | |
1515 | { | |
a857daa3 | 1516 | int oc, on, c, mask, i; |
5107ace1 SK |
1517 | unsigned char *p = out; |
1518 | ||
a857daa3 | 1519 | for (c = *in, oc = 0, on = 0; c != 0 && c != '.'; c = *++in) |
5107ace1 | 1520 | { |
5107ace1 SK |
1521 | if (c >= '0' && c <= '9') |
1522 | c -= '0'; | |
1523 | else if (c >= 'a' && c <= 'v') | |
1524 | c -= 'a', c += 10; | |
1525 | else if (c >= 'A' && c <= 'V') | |
1526 | c -= 'A', c += 10; | |
1527 | else | |
1528 | return 0; | |
1529 | ||
1530 | for (mask = 0x10, i = 0; i < 5; i++) | |
1531 | { | |
a857daa3 SK |
1532 | if (c & mask) |
1533 | oc |= 1; | |
1534 | mask = mask >> 1; | |
1535 | if (((++on) & 7) == 0) | |
1536 | *p++ = oc; | |
1537 | oc = oc << 1; | |
5107ace1 SK |
1538 | } |
1539 | } | |
1540 | ||
1541 | if ((on & 7) != 0) | |
1542 | return 0; | |
1543 | ||
1544 | return p - out; | |
1545 | } | |
1546 | ||
fbc52057 | 1547 | static int check_nsec3_coverage(struct dns_header *header, size_t plen, int digest_len, unsigned char *digest, int type, |
97e618a0 | 1548 | char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count, int *nons) |
fbc52057 SK |
1549 | { |
1550 | int i, hash_len, salt_len, base32_len, rdlen; | |
1551 | unsigned char *p, *psave; | |
1552 | ||
1553 | for (i = 0; i < nsec_count; i++) | |
1554 | if ((p = nsecs[i])) | |
1555 | { | |
394ff492 | 1556 | if (!extract_name(header, plen, &p, workspace1, 1, 0) || |
fbc52057 SK |
1557 | !(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) |
1558 | return 0; | |
1559 | ||
1560 | p += 8; /* class, type, TTL */ | |
1561 | GETSHORT(rdlen, p); | |
1562 | psave = p; | |
1563 | p += 4; /* algo, flags, iterations */ | |
1564 | salt_len = *p++; /* salt_len */ | |
1565 | p += salt_len; /* salt */ | |
1566 | hash_len = *p++; /* p now points to next hashed name */ | |
1567 | ||
1568 | if (!CHECK_LEN(header, p, plen, hash_len)) | |
1569 | return 0; | |
1570 | ||
1571 | if (digest_len == base32_len && hash_len == base32_len) | |
1572 | { | |
1573 | int rc = memcmp(workspace2, digest, digest_len); | |
1574 | ||
1575 | if (rc == 0) | |
1576 | { | |
1577 | /* We found an NSEC3 whose hashed name exactly matches the query, so | |
1578 | we just need to check the type map. p points to the RR data for the record. */ | |
1579 | ||
1580 | int offset = (type & 0xff) >> 3; | |
1581 | int mask = 0x80 >> (type & 0x07); | |
1582 | ||
1583 | p += hash_len; /* skip next-domain hash */ | |
1584 | rdlen -= p - psave; | |
1585 | ||
1586 | if (!CHECK_LEN(header, p, plen, rdlen)) | |
1587 | return 0; | |
1588 | ||
97e618a0 SK |
1589 | /* If we can prove that there's no NS record, return that information. */ |
1590 | if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0) | |
1591 | *nons = 1; | |
1592 | ||
fbc52057 SK |
1593 | while (rdlen >= 2) |
1594 | { | |
1595 | if (p[0] == type >> 8) | |
1596 | { | |
1597 | /* Does the NSEC3 say our type exists? */ | |
1598 | if (offset < p[1] && (p[offset+2] & mask) != 0) | |
1599 | return STAT_BOGUS; | |
1600 | ||
1601 | break; /* finshed checking */ | |
1602 | } | |
1603 | ||
1604 | rdlen -= p[1]; | |
1605 | p += p[1]; | |
1606 | } | |
1607 | ||
1608 | return 1; | |
1609 | } | |
1610 | else if (rc <= 0) | |
1611 | { | |
1612 | /* Normal case, hash falls between NSEC3 name-hash and next domain name-hash, | |
1613 | wrap around case, name-hash falls between NSEC3 name-hash and end */ | |
1614 | if (memcmp(p, digest, digest_len) > 0 || memcmp(workspace2, p, digest_len) > 0) | |
1615 | return 1; | |
1616 | } | |
1617 | else | |
1618 | { | |
1619 | /* wrap around case, name falls between start and next domain name */ | |
1620 | if (memcmp(workspace2, p, digest_len) > 0 && memcmp(p, digest, digest_len) > 0) | |
1621 | return 1; | |
1622 | } | |
1623 | } | |
1624 | } | |
1625 | return 0; | |
1626 | } | |
1627 | ||
24187530 | 1628 | static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count, |
97e618a0 | 1629 | char *workspace1, char *workspace2, char *name, int type, char *wildname, int *nons) |
5107ace1 | 1630 | { |
a857daa3 | 1631 | unsigned char *salt, *p, *digest; |
fbc52057 | 1632 | int digest_len, i, iterations, salt_len, base32_len, algo = 0; |
5107ace1 SK |
1633 | struct nettle_hash const *hash; |
1634 | char *closest_encloser, *next_closest, *wildcard; | |
97e618a0 SK |
1635 | |
1636 | if (nons) | |
1637 | *nons = 0; | |
1638 | ||
5107ace1 SK |
1639 | /* Look though the NSEC3 records to find the first one with |
1640 | an algorithm we support (currently only algo == 1). | |
1641 | ||
1642 | Take the algo, iterations, and salt of that record | |
1643 | as the ones we're going to use, and prune any | |
1644 | that don't match. */ | |
1645 | ||
1646 | for (i = 0; i < nsec_count; i++) | |
1647 | { | |
1648 | if (!(p = skip_name(nsecs[i], header, plen, 15))) | |
87070192 | 1649 | return STAT_BOGUS; /* bad packet */ |
5107ace1 SK |
1650 | |
1651 | p += 10; /* type, class, TTL, rdlen */ | |
1652 | algo = *p++; | |
1653 | ||
1654 | if (algo == 1) | |
1655 | break; /* known algo */ | |
1656 | } | |
1657 | ||
1658 | /* No usable NSEC3s */ | |
1659 | if (i == nsec_count) | |
1660 | return STAT_BOGUS; | |
1661 | ||
1662 | p++; /* flags */ | |
1663 | GETSHORT (iterations, p); | |
1664 | salt_len = *p++; | |
1665 | salt = p; | |
1666 | if (!CHECK_LEN(header, salt, plen, salt_len)) | |
87070192 | 1667 | return STAT_BOGUS; /* bad packet */ |
5107ace1 SK |
1668 | |
1669 | /* Now prune so we only have NSEC3 records with same iterations, salt and algo */ | |
1670 | for (i = 0; i < nsec_count; i++) | |
1671 | { | |
1672 | unsigned char *nsec3p = nsecs[i]; | |
1673 | int this_iter; | |
1674 | ||
1675 | nsecs[i] = NULL; /* Speculative, will be restored if OK. */ | |
1676 | ||
1677 | if (!(p = skip_name(nsec3p, header, plen, 15))) | |
87070192 | 1678 | return STAT_BOGUS; /* bad packet */ |
5107ace1 SK |
1679 | |
1680 | p += 10; /* type, class, TTL, rdlen */ | |
1681 | ||
1682 | if (*p++ != algo) | |
1683 | continue; | |
1684 | ||
1685 | p++; /* flags */ | |
1686 | ||
a857daa3 | 1687 | GETSHORT(this_iter, p); |
5107ace1 SK |
1688 | if (this_iter != iterations) |
1689 | continue; | |
1690 | ||
1691 | if (salt_len != *p++) | |
1692 | continue; | |
1693 | ||
1694 | if (!CHECK_LEN(header, p, plen, salt_len)) | |
87070192 | 1695 | return STAT_BOGUS; /* bad packet */ |
5107ace1 SK |
1696 | |
1697 | if (memcmp(p, salt, salt_len) != 0) | |
1698 | continue; | |
1699 | ||
1700 | /* All match, put the pointer back */ | |
1701 | nsecs[i] = nsec3p; | |
1702 | } | |
1703 | ||
1704 | /* Algo is checked as 1 above */ | |
1705 | if (!(hash = hash_find("sha1"))) | |
87070192 | 1706 | return STAT_BOGUS; |
5107ace1 | 1707 | |
fbc52057 SK |
1708 | if ((digest_len = hash_name(name, &digest, hash, salt, salt_len, iterations)) == 0) |
1709 | return STAT_BOGUS; | |
1710 | ||
97e618a0 | 1711 | if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, nons)) |
fbc52057 SK |
1712 | return STAT_SECURE; |
1713 | ||
1714 | /* Can't find an NSEC3 which covers the name directly, we need the "closest encloser NSEC3" | |
1715 | or an answer inferred from a wildcard record. */ | |
5107ace1 SK |
1716 | closest_encloser = name; |
1717 | next_closest = NULL; | |
1718 | ||
1719 | do | |
1720 | { | |
1721 | if (*closest_encloser == '.') | |
1722 | closest_encloser++; | |
c5f4ec7d | 1723 | |
fbc52057 SK |
1724 | if (wildname && hostname_isequal(closest_encloser, wildname)) |
1725 | break; | |
1726 | ||
a857daa3 | 1727 | if ((digest_len = hash_name(closest_encloser, &digest, hash, salt, salt_len, iterations)) == 0) |
87070192 | 1728 | return STAT_BOGUS; |
5107ace1 SK |
1729 | |
1730 | for (i = 0; i < nsec_count; i++) | |
1731 | if ((p = nsecs[i])) | |
1732 | { | |
394ff492 | 1733 | if (!extract_name(header, plen, &p, workspace1, 1, 0) || |
a857daa3 | 1734 | !(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) |
87070192 | 1735 | return STAT_BOGUS; |
5107ace1 | 1736 | |
a857daa3 SK |
1737 | if (digest_len == base32_len && |
1738 | memcmp(digest, workspace2, digest_len) == 0) | |
5107ace1 SK |
1739 | break; /* Gotit */ |
1740 | } | |
1741 | ||
1742 | if (i != nsec_count) | |
1743 | break; | |
1744 | ||
1745 | next_closest = closest_encloser; | |
1746 | } | |
1747 | while ((closest_encloser = strchr(closest_encloser, '.'))); | |
1748 | ||
fbc52057 | 1749 | if (!closest_encloser) |
5107ace1 SK |
1750 | return STAT_BOGUS; |
1751 | ||
24187530 | 1752 | /* Look for NSEC3 that proves the non-existence of the next-closest encloser */ |
a857daa3 | 1753 | if ((digest_len = hash_name(next_closest, &digest, hash, salt, salt_len, iterations)) == 0) |
87070192 | 1754 | return STAT_BOGUS; |
5107ace1 | 1755 | |
97e618a0 | 1756 | if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL)) |
87070192 | 1757 | return STAT_BOGUS; |
5107ace1 | 1758 | |
fbc52057 SK |
1759 | /* Finally, check that there's no seat of wildcard synthesis */ |
1760 | if (!wildname) | |
1761 | { | |
1762 | if (!(wildcard = strchr(next_closest, '.')) || wildcard == next_closest) | |
1763 | return STAT_BOGUS; | |
1764 | ||
1765 | wildcard--; | |
1766 | *wildcard = '*'; | |
1767 | ||
1768 | if ((digest_len = hash_name(wildcard, &digest, hash, salt, salt_len, iterations)) == 0) | |
1769 | return STAT_BOGUS; | |
1770 | ||
97e618a0 | 1771 | if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL)) |
fbc52057 SK |
1772 | return STAT_BOGUS; |
1773 | } | |
5107ace1 | 1774 | |
fbc52057 | 1775 | return STAT_SECURE; |
5107ace1 SK |
1776 | } |
1777 | ||
0fc2f313 | 1778 | /* Validate all the RRsets in the answer and authority sections of the reply (4035:3.2.3) */ |
51ea3ca2 | 1779 | /* Returns are the same as validate_rrset, plus the class if the missing key is in *class */ |
97e618a0 SK |
1780 | int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, |
1781 | int *class, int *neganswer, int *nons) | |
adca3e9c | 1782 | { |
00a5b5d4 SK |
1783 | unsigned char *ans_start, *qname, *p1, *p2, **nsecs; |
1784 | int type1, class1, rdlen1, type2, class2, rdlen2, qclass, qtype; | |
1fbe4d2f | 1785 | int i, j, rc, nsec_count, cname_count = CNAME_CHAIN; |
00a5b5d4 | 1786 | int nsec_type = 0, have_answer = 0; |
adca3e9c | 1787 | |
00a5b5d4 SK |
1788 | if (neganswer) |
1789 | *neganswer = 0; | |
1790 | ||
87070192 | 1791 | if (RCODE(header) == SERVFAIL || ntohs(header->qdcount) != 1) |
e3ec15af SK |
1792 | return STAT_BOGUS; |
1793 | ||
87070192 | 1794 | if (RCODE(header) != NXDOMAIN && RCODE(header) != NOERROR) |
72ae2f3d | 1795 | return STAT_INSECURE; |
00a5b5d4 SK |
1796 | |
1797 | qname = p1 = (unsigned char *)(header+1); | |
c5f4ec7d | 1798 | |
394ff492 | 1799 | if (!extract_name(header, plen, &p1, name, 1, 4)) |
87070192 | 1800 | return STAT_BOGUS; |
00a5b5d4 SK |
1801 | |
1802 | GETSHORT(qtype, p1); | |
1803 | GETSHORT(qclass, p1); | |
1804 | ans_start = p1; | |
9d1b22aa SK |
1805 | |
1806 | if (qtype == T_ANY) | |
1807 | have_answer = 1; | |
00a5b5d4 SK |
1808 | |
1809 | /* Can't validate an RRISG query */ | |
1810 | if (qtype == T_RRSIG) | |
0fc2f313 | 1811 | return STAT_INSECURE; |
00a5b5d4 SK |
1812 | |
1813 | cname_loop: | |
1814 | for (j = ntohs(header->ancount); j != 0; j--) | |
1815 | { | |
1816 | /* leave pointer to missing name in qname */ | |
1817 | ||
1818 | if (!(rc = extract_name(header, plen, &p1, name, 0, 10))) | |
87070192 | 1819 | return STAT_BOGUS; /* bad packet */ |
00a5b5d4 SK |
1820 | |
1821 | GETSHORT(type2, p1); | |
1822 | GETSHORT(class2, p1); | |
1823 | p1 += 4; /* TTL */ | |
1824 | GETSHORT(rdlen2, p1); | |
1825 | ||
1826 | if (rc == 1 && qclass == class2) | |
1827 | { | |
1828 | /* Do we have an answer for the question? */ | |
1829 | if (type2 == qtype) | |
1830 | { | |
1831 | have_answer = 1; | |
1832 | break; | |
1833 | } | |
1834 | else if (type2 == T_CNAME) | |
1835 | { | |
1836 | qname = p1; | |
1837 | ||
1838 | /* looped CNAMES */ | |
394ff492 | 1839 | if (!cname_count-- || !extract_name(header, plen, &p1, name, 1, 0)) |
87070192 | 1840 | return STAT_BOGUS; |
00a5b5d4 SK |
1841 | |
1842 | p1 = ans_start; | |
1843 | goto cname_loop; | |
1844 | } | |
1845 | } | |
1846 | ||
1847 | if (!ADD_RDLEN(header, p1, plen, rdlen2)) | |
87070192 | 1848 | return STAT_BOGUS; |
00a5b5d4 | 1849 | } |
0fc2f313 | 1850 | |
00a5b5d4 SK |
1851 | if (neganswer && !have_answer) |
1852 | *neganswer = 1; | |
0575610f SK |
1853 | |
1854 | /* No data, therefore no sigs */ | |
1855 | if (ntohs(header->ancount) + ntohs(header->nscount) == 0) | |
1856 | return STAT_NO_SIG; | |
00a5b5d4 | 1857 | |
0fc2f313 | 1858 | for (p1 = ans_start, i = 0; i < ntohs(header->ancount) + ntohs(header->nscount); i++) |
adca3e9c | 1859 | { |
394ff492 | 1860 | if (!extract_name(header, plen, &p1, name, 1, 10)) |
87070192 | 1861 | return STAT_BOGUS; /* bad packet */ |
0fc2f313 SK |
1862 | |
1863 | GETSHORT(type1, p1); | |
1864 | GETSHORT(class1, p1); | |
1865 | p1 += 4; /* TTL */ | |
1866 | GETSHORT(rdlen1, p1); | |
1867 | ||
1868 | /* Don't try and validate RRSIGs! */ | |
1869 | if (type1 != T_RRSIG) | |
1870 | { | |
1871 | /* Check if we've done this RRset already */ | |
1872 | for (p2 = ans_start, j = 0; j < i; j++) | |
1873 | { | |
1874 | if (!(rc = extract_name(header, plen, &p2, name, 0, 10))) | |
87070192 | 1875 | return STAT_BOGUS; /* bad packet */ |
0fc2f313 SK |
1876 | |
1877 | GETSHORT(type2, p2); | |
1878 | GETSHORT(class2, p2); | |
1879 | p2 += 4; /* TTL */ | |
1880 | GETSHORT(rdlen2, p2); | |
1881 | ||
1882 | if (type2 == type1 && class2 == class1 && rc == 1) | |
1883 | break; /* Done it before: name, type, class all match. */ | |
1884 | ||
1885 | if (!ADD_RDLEN(header, p2, plen, rdlen2)) | |
87070192 | 1886 | return STAT_BOGUS; |
0fc2f313 SK |
1887 | } |
1888 | ||
1889 | /* Not done, validate now */ | |
51ea3ca2 | 1890 | if (j == i) |
0fc2f313 | 1891 | { |
8d718cbb SK |
1892 | int ttl, keytag, algo, digest, type_covered; |
1893 | unsigned char *psave; | |
1894 | struct all_addr a; | |
1895 | struct blockdata *key; | |
1896 | struct crec *crecp; | |
fbc52057 | 1897 | char *wildname; |
5e321739 | 1898 | int have_wildcard = 0; |
fbc52057 SK |
1899 | |
1900 | rc = validate_rrset(now, header, plen, class1, type1, name, keyname, &wildname, NULL, 0, 0, 0); | |
5107ace1 SK |
1901 | |
1902 | if (rc == STAT_SECURE_WILDCARD) | |
1903 | { | |
5e321739 SK |
1904 | have_wildcard = 1; |
1905 | ||
5107ace1 | 1906 | /* An attacker replay a wildcard answer with a different |
a857daa3 | 1907 | answer and overlay a genuine RR. To prove this |
5107ace1 | 1908 | hasn't happened, the answer must prove that |
a857daa3 | 1909 | the gennuine record doesn't exist. Check that here. */ |
87070192 SK |
1910 | if (!nsec_type && !(nsec_type = find_nsec_records(header, plen, &nsecs, &nsec_count, class1))) |
1911 | return STAT_BOGUS; /* No NSECs or bad packet */ | |
5107ace1 SK |
1912 | |
1913 | if (nsec_type == T_NSEC) | |
97e618a0 | 1914 | rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1, NULL); |
5107ace1 | 1915 | else |
97e618a0 SK |
1916 | rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, |
1917 | keyname, name, type1, wildname, NULL); | |
1918 | ||
5107ace1 SK |
1919 | if (rc != STAT_SECURE) |
1920 | return rc; | |
1921 | } | |
1922 | else if (rc != STAT_SECURE) | |
51ea3ca2 SK |
1923 | { |
1924 | if (class) | |
1925 | *class = class1; /* Class for DS or DNSKEY */ | |
1926 | return rc; | |
1927 | } | |
5107ace1 | 1928 | |
8d718cbb SK |
1929 | /* Cache RRsigs in answer section, and if we just validated a DS RRset, cache it */ |
1930 | cache_start_insert(); | |
1931 | ||
1932 | for (p2 = ans_start, j = 0; j < ntohs(header->ancount); j++) | |
51ea3ca2 | 1933 | { |
8d718cbb | 1934 | if (!(rc = extract_name(header, plen, &p2, name, 0, 10))) |
87070192 | 1935 | return STAT_BOGUS; /* bad packet */ |
51ea3ca2 | 1936 | |
8d718cbb SK |
1937 | GETSHORT(type2, p2); |
1938 | GETSHORT(class2, p2); | |
1939 | GETLONG(ttl, p2); | |
1940 | GETSHORT(rdlen2, p2); | |
1941 | ||
1942 | if (!CHECK_LEN(header, p2, plen, rdlen2)) | |
87070192 | 1943 | return STAT_BOGUS; /* bad packet */ |
8d718cbb SK |
1944 | |
1945 | if (class2 == class1 && rc == 1) | |
1946 | { | |
1947 | psave = p2; | |
1948 | ||
1949 | if (type1 == T_DS && type2 == T_DS) | |
51ea3ca2 | 1950 | { |
8d718cbb | 1951 | if (rdlen2 < 4) |
87070192 | 1952 | return STAT_BOGUS; /* bad packet */ |
8d718cbb | 1953 | |
51ea3ca2 SK |
1954 | GETSHORT(keytag, p2); |
1955 | algo = *p2++; | |
1956 | digest = *p2++; | |
1957 | ||
1958 | /* Cache needs to known class for DNSSEC stuff */ | |
1959 | a.addr.dnssec.class = class2; | |
1960 | ||
8d718cbb | 1961 | if ((key = blockdata_alloc((char*)p2, rdlen2 - 4))) |
51ea3ca2 | 1962 | { |
8d718cbb SK |
1963 | if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DS | F_DNSSECOK))) |
1964 | blockdata_free(key); | |
1965 | else | |
1966 | { | |
1967 | a.addr.keytag = keytag; | |
25cf5e37 | 1968 | log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DS keytag %u"); |
8d718cbb SK |
1969 | crecp->addr.ds.digest = digest; |
1970 | crecp->addr.ds.keydata = key; | |
1971 | crecp->addr.ds.algo = algo; | |
1972 | crecp->addr.ds.keytag = keytag; | |
8d718cbb SK |
1973 | crecp->addr.ds.keylen = rdlen2 - 4; |
1974 | } | |
1975 | } | |
1976 | } | |
1977 | else if (type2 == T_RRSIG) | |
1978 | { | |
1979 | if (rdlen2 < 18) | |
87070192 | 1980 | return STAT_BOGUS; /* bad packet */ |
51ea3ca2 | 1981 | |
8d718cbb SK |
1982 | GETSHORT(type_covered, p2); |
1983 | ||
1984 | if (type_covered == type1 && | |
1985 | (type_covered == T_A || type_covered == T_AAAA || | |
1986 | type_covered == T_CNAME || type_covered == T_DS || | |
1987 | type_covered == T_DNSKEY || type_covered == T_PTR)) | |
1988 | { | |
1989 | a.addr.dnssec.type = type_covered; | |
c8ca33f8 | 1990 | a.addr.dnssec.class = class1; |
8d718cbb SK |
1991 | |
1992 | algo = *p2++; | |
1993 | p2 += 13; /* labels, orig_ttl, expiration, inception */ | |
1994 | GETSHORT(keytag, p2); | |
1995 | ||
5e321739 SK |
1996 | /* We don't cache sigs for wildcard answers, because to reproduce the |
1997 | answer from the cache will require one or more NSEC/NSEC3 records | |
1998 | which we don't cache. The lack of the RRSIG ensures that a query for | |
1999 | this RRset asking for a secure answer will always be forwarded. */ | |
2000 | if (!have_wildcard && (key = blockdata_alloc((char*)psave, rdlen2))) | |
8d718cbb SK |
2001 | { |
2002 | if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DS))) | |
2003 | blockdata_free(key); | |
2004 | else | |
2005 | { | |
8d718cbb SK |
2006 | crecp->addr.sig.keydata = key; |
2007 | crecp->addr.sig.keylen = rdlen2; | |
2008 | crecp->addr.sig.keytag = keytag; | |
2009 | crecp->addr.sig.type_covered = type_covered; | |
2010 | crecp->addr.sig.algo = algo; | |
2011 | } | |
2012 | } | |
2013 | } | |
51ea3ca2 SK |
2014 | } |
2015 | ||
8d718cbb | 2016 | p2 = psave; |
51ea3ca2 SK |
2017 | } |
2018 | ||
8d718cbb | 2019 | if (!ADD_RDLEN(header, p2, plen, rdlen2)) |
87070192 | 2020 | return STAT_BOGUS; /* bad packet */ |
51ea3ca2 | 2021 | } |
8d718cbb SK |
2022 | |
2023 | cache_end_insert(); | |
0fc2f313 SK |
2024 | } |
2025 | } | |
adca3e9c | 2026 | |
0fc2f313 | 2027 | if (!ADD_RDLEN(header, p1, plen, rdlen1)) |
87070192 | 2028 | return STAT_BOGUS; |
adca3e9c GB |
2029 | } |
2030 | ||
c5f4ec7d | 2031 | /* OK, all the RRsets validate, now see if we have a NODATA or NXDOMAIN reply */ |
00a5b5d4 SK |
2032 | if (have_answer) |
2033 | return STAT_SECURE; | |
2034 | ||
5107ace1 | 2035 | /* NXDOMAIN or NODATA reply, prove that (name, class1, type1) can't exist */ |
5107ace1 | 2036 | /* First marshall the NSEC records, if we've not done it previously */ |
87070192 | 2037 | if (!nsec_type && !(nsec_type = find_nsec_records(header, plen, &nsecs, &nsec_count, qclass))) |
88052830 SK |
2038 | return STAT_NO_SIG; /* No NSECs, this is probably a dangling CNAME pointing into |
2039 | an unsigned zone. Return STAT_NO_SIG to cause this to be proved. */ | |
00a5b5d4 SK |
2040 | |
2041 | /* Get name of missing answer */ | |
394ff492 | 2042 | if (!extract_name(header, plen, &qname, name, 1, 0)) |
87070192 | 2043 | return STAT_BOGUS; |
5107ace1 SK |
2044 | |
2045 | if (nsec_type == T_NSEC) | |
97e618a0 | 2046 | return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, nons); |
5107ace1 | 2047 | else |
97e618a0 | 2048 | return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, NULL, nons); |
e292e93d GB |
2049 | } |
2050 | ||
00a5b5d4 SK |
2051 | /* Chase the CNAME chain in the packet until the first record which _doesn't validate. |
2052 | Needed for proving answer in unsigned space. | |
2053 | Return STAT_NEED_* | |
2054 | STAT_BOGUS - error | |
2055 | STAT_INSECURE - name of first non-secure record in name | |
2056 | */ | |
2057 | int dnssec_chase_cname(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname) | |
2058 | { | |
2059 | unsigned char *p = (unsigned char *)(header+1); | |
c07d30dc | 2060 | int type, class, qclass, rdlen, j, rc; |
1fbe4d2f | 2061 | int cname_count = CNAME_CHAIN; |
00a5b5d4 SK |
2062 | |
2063 | /* Get question */ | |
394ff492 | 2064 | if (!extract_name(header, plen, &p, name, 1, 4)) |
00a5b5d4 SK |
2065 | return STAT_BOGUS; |
2066 | ||
c07d30dc | 2067 | p +=2; /* type */ |
00a5b5d4 SK |
2068 | GETSHORT(qclass, p); |
2069 | ||
2070 | while (1) | |
2071 | { | |
2072 | for (j = ntohs(header->ancount); j != 0; j--) | |
2073 | { | |
2074 | if (!(rc = extract_name(header, plen, &p, name, 0, 10))) | |
2075 | return STAT_BOGUS; /* bad packet */ | |
2076 | ||
2077 | GETSHORT(type, p); | |
2078 | GETSHORT(class, p); | |
2079 | p += 4; /* TTL */ | |
2080 | GETSHORT(rdlen, p); | |
2081 | ||
2082 | /* Not target, loop */ | |
2083 | if (rc == 2 || qclass != class) | |
2084 | { | |
2085 | if (!ADD_RDLEN(header, p, plen, rdlen)) | |
2086 | return STAT_BOGUS; | |
2087 | continue; | |
2088 | } | |
2089 | ||
2090 | /* Got to end of CNAME chain. */ | |
2091 | if (type != T_CNAME) | |
2092 | return STAT_INSECURE; | |
2093 | ||
2094 | /* validate CNAME chain, return if insecure or need more data */ | |
fbc52057 | 2095 | rc = validate_rrset(now, header, plen, class, type, name, keyname, NULL, NULL, 0, 0, 0); |
00a5b5d4 SK |
2096 | if (rc != STAT_SECURE) |
2097 | { | |
2098 | if (rc == STAT_NO_SIG) | |
2099 | rc = STAT_INSECURE; | |
2100 | return rc; | |
2101 | } | |
2102 | ||
2103 | /* Loop down CNAME chain/ */ | |
2104 | if (!cname_count-- || | |
394ff492 | 2105 | !extract_name(header, plen, &p, name, 1, 0) || |
00a5b5d4 SK |
2106 | !(p = skip_questions(header, plen))) |
2107 | return STAT_BOGUS; | |
2108 | ||
2109 | break; | |
2110 | } | |
2111 | ||
2112 | /* End of CNAME chain */ | |
2113 | return STAT_INSECURE; | |
2114 | } | |
2115 | } | |
2116 | ||
2117 | ||
3471f181 | 2118 | /* Compute keytag (checksum to quickly index a key). See RFC4034 */ |
0fc2f313 | 2119 | int dnskey_keytag(int alg, int flags, unsigned char *key, int keylen) |
3471f181 | 2120 | { |
75ffc9bf GB |
2121 | if (alg == 1) |
2122 | { | |
2123 | /* Algorithm 1 (RSAMD5) has a different (older) keytag calculation algorithm. | |
2124 | See RFC4034, Appendix B.1 */ | |
0fc2f313 | 2125 | return key[keylen-4] * 256 + key[keylen-3]; |
75ffc9bf GB |
2126 | } |
2127 | else | |
2128 | { | |
1633e308 | 2129 | unsigned long ac = flags + 0x300 + alg; |
75ffc9bf GB |
2130 | int i; |
2131 | ||
0fc2f313 SK |
2132 | for (i = 0; i < keylen; ++i) |
2133 | ac += (i & 1) ? key[i] : key[i] << 8; | |
1633e308 | 2134 | |
0fc2f313 SK |
2135 | ac += (ac >> 16) & 0xffff; |
2136 | return ac & 0xffff; | |
0304d28f | 2137 | } |
3471f181 | 2138 | } |
e292e93d | 2139 | |
5f8e58f4 SK |
2140 | size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr) |
2141 | { | |
2142 | unsigned char *p; | |
610e782a | 2143 | char *types = querystr("dnssec-query", type); |
5f8e58f4 SK |
2144 | |
2145 | if (addr->sa.sa_family == AF_INET) | |
25cf5e37 | 2146 | log_query(F_NOEXTRA | F_DNSSEC | F_IPV4, name, (struct all_addr *)&addr->in.sin_addr, types); |
5f8e58f4 SK |
2147 | #ifdef HAVE_IPV6 |
2148 | else | |
25cf5e37 | 2149 | log_query(F_NOEXTRA | F_DNSSEC | F_IPV6, name, (struct all_addr *)&addr->in6.sin6_addr, types); |
5f8e58f4 SK |
2150 | #endif |
2151 | ||
2152 | header->qdcount = htons(1); | |
2153 | header->ancount = htons(0); | |
2154 | header->nscount = htons(0); | |
2155 | header->arcount = htons(0); | |
e292e93d | 2156 | |
5f8e58f4 SK |
2157 | header->hb3 = HB3_RD; |
2158 | SET_OPCODE(header, QUERY); | |
5b3bf921 SK |
2159 | /* For debugging, set Checking Disabled, otherwise, have the upstream check too, |
2160 | this allows it to select auth servers when one is returning bad data. */ | |
2161 | header->hb4 = option_bool(OPT_DNSSEC_DEBUG) ? HB4_CD : 0; | |
5f8e58f4 SK |
2162 | |
2163 | /* ID filled in later */ | |
2164 | ||
2165 | p = (unsigned char *)(header+1); | |
2166 | ||
2167 | p = do_rfc1035_name(p, name); | |
2168 | *p++ = 0; | |
2169 | PUTSHORT(type, p); | |
2170 | PUTSHORT(class, p); | |
2171 | ||
2172 | return add_do_bit(header, p - (unsigned char *)header, end); | |
2173 | } | |
8a9be9e4 | 2174 | |
613ad15d SK |
2175 | /* Go through a domain name, find "pointers" and fix them up based on how many bytes |
2176 | we've chopped out of the packet, or check they don't point into an elided part. */ | |
2177 | static int check_name(unsigned char **namep, struct dns_header *header, size_t plen, int fixup, unsigned char **rrs, int rr_count) | |
2178 | { | |
2179 | unsigned char *ansp = *namep; | |
2180 | ||
2181 | while(1) | |
2182 | { | |
2183 | unsigned int label_type; | |
2184 | ||
2185 | if (!CHECK_LEN(header, ansp, plen, 1)) | |
2186 | return 0; | |
2187 | ||
2188 | label_type = (*ansp) & 0xc0; | |
2189 | ||
2190 | if (label_type == 0xc0) | |
2191 | { | |
2192 | /* pointer for compression. */ | |
00a5b5d4 SK |
2193 | unsigned int offset; |
2194 | int i; | |
613ad15d SK |
2195 | unsigned char *p; |
2196 | ||
2197 | if (!CHECK_LEN(header, ansp, plen, 2)) | |
2198 | return 0; | |
2199 | ||
2200 | offset = ((*ansp++) & 0x3f) << 8; | |
2201 | offset |= *ansp++; | |
2202 | ||
2203 | p = offset + (unsigned char *)header; | |
2204 | ||
2205 | for (i = 0; i < rr_count; i++) | |
2206 | if (p < rrs[i]) | |
2207 | break; | |
2208 | else | |
2209 | if (i & 1) | |
2210 | offset -= rrs[i] - rrs[i-1]; | |
2211 | ||
2212 | /* does the pointer end up in an elided RR? */ | |
2213 | if (i & 1) | |
00a5b5d4 | 2214 | return 0; |
613ad15d SK |
2215 | |
2216 | /* No, scale the pointer */ | |
2217 | if (fixup) | |
2218 | { | |
2219 | ansp -= 2; | |
2220 | *ansp++ = (offset >> 8) | 0xc0; | |
2221 | *ansp++ = offset & 0xff; | |
2222 | } | |
2223 | break; | |
2224 | } | |
2225 | else if (label_type == 0x80) | |
2226 | return 0; /* reserved */ | |
2227 | else if (label_type == 0x40) | |
2228 | { | |
2229 | /* Extended label type */ | |
2230 | unsigned int count; | |
2231 | ||
2232 | if (!CHECK_LEN(header, ansp, plen, 2)) | |
2233 | return 0; | |
2234 | ||
2235 | if (((*ansp++) & 0x3f) != 1) | |
2236 | return 0; /* we only understand bitstrings */ | |
2237 | ||
2238 | count = *(ansp++); /* Bits in bitstring */ | |
2239 | ||
2240 | if (count == 0) /* count == 0 means 256 bits */ | |
2241 | ansp += 32; | |
2242 | else | |
2243 | ansp += ((count-1)>>3)+1; | |
2244 | } | |
2245 | else | |
2246 | { /* label type == 0 Bottom six bits is length */ | |
2247 | unsigned int len = (*ansp++) & 0x3f; | |
2248 | ||
2249 | if (!ADD_RDLEN(header, ansp, plen, len)) | |
2250 | return 0; | |
2251 | ||
2252 | if (len == 0) | |
2253 | break; /* zero length label marks the end. */ | |
2254 | } | |
2255 | } | |
2256 | ||
2257 | *namep = ansp; | |
2258 | ||
2259 | return 1; | |
2260 | } | |
2261 | ||
2262 | /* Go through RRs and check or fixup the domain names contained within */ | |
2263 | static int check_rrs(unsigned char *p, struct dns_header *header, size_t plen, int fixup, unsigned char **rrs, int rr_count) | |
2264 | { | |
2265 | int i, type, class, rdlen; | |
00a5b5d4 | 2266 | unsigned char *pp; |
613ad15d | 2267 | |
50f86ce8 | 2268 | for (i = 0; i < ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount); i++) |
613ad15d | 2269 | { |
00a5b5d4 SK |
2270 | pp = p; |
2271 | ||
2272 | if (!(p = skip_name(p, header, plen, 10))) | |
2273 | return 0; | |
613ad15d SK |
2274 | |
2275 | GETSHORT(type, p); | |
2276 | GETSHORT(class, p); | |
2277 | p += 4; /* TTL */ | |
2278 | GETSHORT(rdlen, p); | |
00a5b5d4 | 2279 | |
613ad15d SK |
2280 | if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG) |
2281 | { | |
00a5b5d4 SK |
2282 | /* fixup name of RR */ |
2283 | if (!check_name(&pp, header, plen, fixup, rrs, rr_count)) | |
2284 | return 0; | |
2285 | ||
613ad15d SK |
2286 | if (class == C_IN) |
2287 | { | |
2288 | u16 *d; | |
14db4212 SK |
2289 | |
2290 | for (pp = p, d = get_desc(type); *d != (u16)-1; d++) | |
613ad15d SK |
2291 | { |
2292 | if (*d != 0) | |
2293 | pp += *d; | |
2294 | else if (!check_name(&pp, header, plen, fixup, rrs, rr_count)) | |
2295 | return 0; | |
2296 | } | |
2297 | } | |
2298 | } | |
2299 | ||
2300 | if (!ADD_RDLEN(header, p, plen, rdlen)) | |
2301 | return 0; | |
2302 | } | |
2303 | ||
2304 | return 1; | |
2305 | } | |
2306 | ||
2307 | ||
2308 | size_t filter_rrsigs(struct dns_header *header, size_t plen) | |
2309 | { | |
2310 | static unsigned char **rrs; | |
2311 | static int rr_sz = 0; | |
2312 | ||
2313 | unsigned char *p = (unsigned char *)(header+1); | |
50f86ce8 | 2314 | int i, rdlen, qtype, qclass, rr_found, chop_an, chop_ns, chop_ar; |
613ad15d SK |
2315 | |
2316 | if (ntohs(header->qdcount) != 1 || | |
2317 | !(p = skip_name(p, header, plen, 4))) | |
2318 | return plen; | |
2319 | ||
2320 | GETSHORT(qtype, p); | |
2321 | GETSHORT(qclass, p); | |
2322 | ||
2323 | /* First pass, find pointers to start and end of all the records we wish to elide: | |
2324 | records added for DNSSEC, unless explicity queried for */ | |
50f86ce8 SK |
2325 | for (rr_found = 0, chop_ns = 0, chop_an = 0, chop_ar = 0, i = 0; |
2326 | i < ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount); | |
2327 | i++) | |
613ad15d SK |
2328 | { |
2329 | unsigned char *pstart = p; | |
2330 | int type, class; | |
2331 | ||
2332 | if (!(p = skip_name(p, header, plen, 10))) | |
2333 | return plen; | |
2334 | ||
2335 | GETSHORT(type, p); | |
2336 | GETSHORT(class, p); | |
2337 | p += 4; /* TTL */ | |
2338 | GETSHORT(rdlen, p); | |
2339 | ||
2340 | if ((type == T_NSEC || type == T_NSEC3 || type == T_RRSIG) && | |
2341 | (type != qtype || class != qclass)) | |
2342 | { | |
2343 | if (!expand_workspace(&rrs, &rr_sz, rr_found + 1)) | |
2344 | return plen; | |
2345 | ||
2346 | rrs[rr_found++] = pstart; | |
2347 | ||
2348 | if (!ADD_RDLEN(header, p, plen, rdlen)) | |
2349 | return plen; | |
2350 | ||
2351 | rrs[rr_found++] = p; | |
2352 | ||
2353 | if (i < ntohs(header->ancount)) | |
2354 | chop_an++; | |
e6096e64 | 2355 | else if (i < (ntohs(header->nscount) + ntohs(header->ancount))) |
613ad15d | 2356 | chop_ns++; |
50f86ce8 SK |
2357 | else |
2358 | chop_ar++; | |
613ad15d SK |
2359 | } |
2360 | else if (!ADD_RDLEN(header, p, plen, rdlen)) | |
2361 | return plen; | |
2362 | } | |
2363 | ||
2364 | /* Nothing to do. */ | |
2365 | if (rr_found == 0) | |
2366 | return plen; | |
2367 | ||
2368 | /* Second pass, look for pointers in names in the records we're keeping and make sure they don't | |
2369 | point to records we're going to elide. This is theoretically possible, but unlikely. If | |
2370 | it happens, we give up and leave the answer unchanged. */ | |
2371 | p = (unsigned char *)(header+1); | |
2372 | ||
2373 | /* question first */ | |
2374 | if (!check_name(&p, header, plen, 0, rrs, rr_found)) | |
2375 | return plen; | |
2376 | p += 4; /* qclass, qtype */ | |
2377 | ||
2378 | /* Now answers and NS */ | |
2379 | if (!check_rrs(p, header, plen, 0, rrs, rr_found)) | |
2380 | return plen; | |
2381 | ||
2382 | /* Third pass, elide records */ | |
2383 | for (p = rrs[0], i = 1; i < rr_found; i += 2) | |
2384 | { | |
2385 | unsigned char *start = rrs[i]; | |
2386 | unsigned char *end = (i != rr_found - 1) ? rrs[i+1] : ((unsigned char *)(header+1)) + plen; | |
2387 | ||
2388 | memmove(p, start, end-start); | |
2389 | p += end-start; | |
2390 | } | |
2391 | ||
2392 | plen = p - (unsigned char *)header; | |
2393 | header->ancount = htons(ntohs(header->ancount) - chop_an); | |
2394 | header->nscount = htons(ntohs(header->nscount) - chop_ns); | |
50f86ce8 SK |
2395 | header->arcount = htons(ntohs(header->arcount) - chop_ar); |
2396 | ||
613ad15d SK |
2397 | /* Fourth pass, fix up pointers in the remaining records */ |
2398 | p = (unsigned char *)(header+1); | |
2399 | ||
2400 | check_name(&p, header, plen, 1, rrs, rr_found); | |
2401 | p += 4; /* qclass, qtype */ | |
2402 | ||
2403 | check_rrs(p, header, plen, 1, rrs, rr_found); | |
2404 | ||
2405 | return plen; | |
2406 | } | |
2407 | ||
8a9be9e4 SK |
2408 | unsigned char* hash_questions(struct dns_header *header, size_t plen, char *name) |
2409 | { | |
2410 | int q; | |
2411 | unsigned int len; | |
2412 | unsigned char *p = (unsigned char *)(header+1); | |
2413 | const struct nettle_hash *hash; | |
2414 | void *ctx; | |
2415 | unsigned char *digest; | |
5f8e58f4 | 2416 | |
8a9be9e4 SK |
2417 | if (!(hash = hash_find("sha1")) || !hash_init(hash, &ctx, &digest)) |
2418 | return NULL; | |
2419 | ||
2420 | for (q = ntohs(header->qdcount); q != 0; q--) | |
2421 | { | |
394ff492 | 2422 | if (!extract_name(header, plen, &p, name, 1, 4)) |
7d23a66f | 2423 | break; /* bad packet */ |
8a9be9e4 SK |
2424 | |
2425 | len = to_wire(name); | |
2426 | hash->update(ctx, len, (unsigned char *)name); | |
2427 | /* CRC the class and type as well */ | |
2428 | hash->update(ctx, 4, p); | |
2429 | ||
2430 | p += 4; | |
2431 | if (!CHECK_LEN(header, p, plen, 0)) | |
7d23a66f | 2432 | break; /* bad packet */ |
8a9be9e4 | 2433 | } |
703c7ff4 SK |
2434 | |
2435 | hash->digest(ctx, hash->digest_size, digest); | |
8a9be9e4 SK |
2436 | return digest; |
2437 | } | |
2438 | ||
0fc2f313 | 2439 | #endif /* HAVE_DNSSEC */ |