1 /*
2 * validator/validator.c - secure validator DNS query response module
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /**
37 * \file
38 *
39 * This file contains a module that performs validation of DNS queries.
40 * According to RFC 4034.
41 */
42 #include "config.h"
43 #include <ctype.h>
44 #include "validator/validator.h"
45 #include "validator/val_anchor.h"
46 #include "validator/val_kcache.h"
47 #include "validator/val_kentry.h"
48 #include "validator/val_utils.h"
49 #include "validator/val_nsec.h"
50 #include "validator/val_nsec3.h"
51 #include "validator/val_neg.h"
52 #include "validator/val_sigcrypt.h"
53 #include "validator/autotrust.h"
54 #include "services/cache/dns.h"
55 #include "services/cache/rrset.h"
56 #include "util/data/dname.h"
57 #include "util/module.h"
58 #include "util/log.h"
59 #include "util/net_help.h"
60 #include "util/regional.h"
61 #include "util/config_file.h"
62 #include "util/fptr_wlist.h"
63 #include "sldns/rrdef.h"
64 #include "sldns/wire2str.h"
65 #include "sldns/str2wire.h"
66
67 /** Max number of RRSIGs to validate at once, suspend query for later. */
68 #define MAX_VALIDATE_AT_ONCE 8
69 /** Max number of validation suspends allowed, error out otherwise. */
70 #define MAX_VALIDATION_SUSPENDS 16
71 /** Max answer RRsets for qtype ANY that are validated. The lists is
72 * shortened to fit this limit. */
73 #define MAX_RRSETS_ANY_VALIDATED 24
74
75 /* forward decl for cache response and normal super inform calls of a DS */
76 static void process_ds_response(struct module_qstate* qstate,
77 struct val_qstate* vq, int id, int rcode, struct dns_msg* msg,
78 struct query_info* qinfo, struct sock_list* origin, int* suspend,
79 struct module_qstate* sub_qstate);
80
81
82 /* Updates the supplied EDE (RFC8914) code selectively so we don't lose
83 * a more specific code */
84 static void
update_reason_bogus(struct reply_info * rep,sldns_ede_code reason_bogus)85 update_reason_bogus(struct reply_info* rep, sldns_ede_code reason_bogus)
86 {
87 if(reason_bogus == LDNS_EDE_NONE) return;
88 if(reason_bogus == LDNS_EDE_DNSSEC_BOGUS
89 && rep->reason_bogus != LDNS_EDE_NONE
90 && rep->reason_bogus != LDNS_EDE_DNSSEC_BOGUS) return;
91 rep->reason_bogus = reason_bogus;
92 }
93
94
95 /** fill up nsec3 key iterations config entry */
96 static int
fill_nsec3_iter(size_t ** keysize,size_t ** maxiter,char * s,int c)97 fill_nsec3_iter(size_t** keysize, size_t** maxiter, char* s, int c)
98 {
99 char* e;
100 int i;
101 *keysize = (size_t*)calloc((size_t)c, sizeof(size_t));
102 *maxiter = (size_t*)calloc((size_t)c, sizeof(size_t));
103 if(!*keysize || !*maxiter) {
104 free(*keysize);
105 *keysize = NULL;
106 free(*maxiter);
107 *maxiter = NULL;
108 log_err("out of memory");
109 return 0;
110 }
111 for(i=0; i<c; i++) {
112 (*keysize)[i] = (size_t)strtol(s, &e, 10);
113 if(s == e) {
114 log_err("cannot parse: %s", s);
115 free(*keysize);
116 *keysize = NULL;
117 free(*maxiter);
118 *maxiter = NULL;
119 return 0;
120 }
121 s = e;
122 (*maxiter)[i] = (size_t)strtol(s, &e, 10);
123 if(s == e) {
124 log_err("cannot parse: %s", s);
125 free(*keysize);
126 *keysize = NULL;
127 free(*maxiter);
128 *maxiter = NULL;
129 return 0;
130 }
131 s = e;
132 if(i>0 && (*keysize)[i-1] >= (*keysize)[i]) {
133 log_err("nsec3 key iterations not ascending: %d %d",
134 (int)(*keysize)[i-1], (int)(*keysize)[i]);
135 free(*keysize);
136 *keysize = NULL;
137 free(*maxiter);
138 *maxiter = NULL;
139 return 0;
140 }
141 verbose(VERB_ALGO, "validator nsec3cfg keysz %d mxiter %d",
142 (int)(*keysize)[i], (int)(*maxiter)[i]);
143 }
144 return 1;
145 }
146
147 int
val_env_parse_key_iter(char * val_nsec3_key_iterations,size_t ** keysize,size_t ** maxiter,int * keyiter_count)148 val_env_parse_key_iter(char* val_nsec3_key_iterations, size_t** keysize,
149 size_t** maxiter, int* keyiter_count)
150 {
151 int c;
152 c = cfg_count_numbers(val_nsec3_key_iterations);
153 if(c < 1 || (c&1)) {
154 log_err("validator: unparsable or odd nsec3 key "
155 "iterations: %s", val_nsec3_key_iterations);
156 return 0;
157 }
158 *keyiter_count = c/2;
159 if(!fill_nsec3_iter(keysize, maxiter, val_nsec3_key_iterations, c/2)) {
160 log_err("validator: cannot apply nsec3 key iterations");
161 return 0;
162 }
163 return 1;
164 }
165
166 void
val_env_apply_cfg(struct val_env * val_env,struct config_file * cfg,size_t * keysize,size_t * maxiter,int keyiter_count)167 val_env_apply_cfg(struct val_env* val_env, struct config_file* cfg,
168 size_t* keysize, size_t* maxiter, int keyiter_count)
169 {
170 free(val_env->nsec3_keysize);
171 free(val_env->nsec3_maxiter);
172 val_env->nsec3_keysize = keysize;
173 val_env->nsec3_maxiter = maxiter;
174 val_env->nsec3_keyiter_count = keyiter_count;
175 val_env->bogus_ttl = (uint32_t)cfg->bogus_ttl;
176 val_env->date_override = cfg->val_date_override;
177 val_env->skew_min = cfg->val_sig_skew_min;
178 val_env->skew_max = cfg->val_sig_skew_max;
179 val_env->max_restart = cfg->val_max_restart;
180 }
181
182 /** apply config settings to validator */
183 static int
val_apply_cfg(struct module_env * env,struct val_env * val_env,struct config_file * cfg)184 val_apply_cfg(struct module_env* env, struct val_env* val_env,
185 struct config_file* cfg)
186 {
187 size_t* keysize=NULL, *maxiter=NULL;
188 int keyiter_count = 0;
189 if(!env->anchors)
190 env->anchors = anchors_create();
191 if(!env->anchors) {
192 log_err("out of memory");
193 return 0;
194 }
195 if (env->key_cache)
196 val_env->kcache = env->key_cache;
197 if(!val_env->kcache)
198 val_env->kcache = key_cache_create(cfg);
199 if(!val_env->kcache) {
200 log_err("out of memory");
201 return 0;
202 }
203 env->key_cache = val_env->kcache;
204 if(!anchors_apply_cfg(env->anchors, cfg)) {
205 log_err("validator: error in trustanchors config");
206 return 0;
207 }
208 if(!val_env_parse_key_iter(cfg->val_nsec3_key_iterations,
209 &keysize, &maxiter, &keyiter_count)) {
210 return 0;
211 }
212 val_env_apply_cfg(val_env, cfg, keysize, maxiter, keyiter_count);
213 if (env->neg_cache)
214 val_env->neg_cache = env->neg_cache;
215 if(!val_env->neg_cache)
216 val_env->neg_cache = val_neg_create(cfg,
217 val_env->nsec3_maxiter[val_env->nsec3_keyiter_count-1]);
218 if(!val_env->neg_cache) {
219 log_err("out of memory");
220 return 0;
221 }
222 env->neg_cache = val_env->neg_cache;
223 return 1;
224 }
225
226 #ifdef USE_ECDSA_EVP_WORKAROUND
227 void ecdsa_evp_workaround_init(void);
228 #endif
229 int
val_init(struct module_env * env,int id)230 val_init(struct module_env* env, int id)
231 {
232 struct val_env* val_env = (struct val_env*)calloc(1,
233 sizeof(struct val_env));
234 if(!val_env) {
235 log_err("malloc failure");
236 return 0;
237 }
238 env->modinfo[id] = (void*)val_env;
239 env->need_to_validate = 1;
240 lock_basic_init(&val_env->bogus_lock);
241 lock_protect(&val_env->bogus_lock, &val_env->num_rrset_bogus,
242 sizeof(val_env->num_rrset_bogus));
243 #ifdef USE_ECDSA_EVP_WORKAROUND
244 ecdsa_evp_workaround_init();
245 #endif
246 if(!val_apply_cfg(env, val_env, env->cfg)) {
247 log_err("validator: could not apply configuration settings.");
248 return 0;
249 }
250 if(env->cfg->disable_edns_do) {
251 struct trust_anchor* anchor = anchors_find_any_noninsecure(
252 env->anchors);
253 if(anchor) {
254 char b[LDNS_MAX_DOMAINLEN];
255 dname_str(anchor->name, b);
256 log_warn("validator: disable-edns-do is enabled, but there is a trust anchor for '%s'. Since DNSSEC could not work, the disable-edns-do setting is turned off. Continuing without it.", b);
257 lock_basic_unlock(&anchor->lock);
258 env->cfg->disable_edns_do = 0;
259 }
260 }
261
262 return 1;
263 }
264
265 void
val_deinit(struct module_env * env,int id)266 val_deinit(struct module_env* env, int id)
267 {
268 struct val_env* val_env;
269 if(!env || !env->modinfo[id])
270 return;
271 val_env = (struct val_env*)env->modinfo[id];
272 lock_basic_destroy(&val_env->bogus_lock);
273 anchors_delete(env->anchors);
274 env->anchors = NULL;
275 key_cache_delete(val_env->kcache);
276 env->key_cache = NULL;
277 neg_cache_delete(val_env->neg_cache);
278 env->neg_cache = NULL;
279 free(val_env->nsec3_keysize);
280 free(val_env->nsec3_maxiter);
281 free(val_env);
282 env->modinfo[id] = NULL;
283 }
284
285 /** fill in message structure */
286 static struct val_qstate*
val_new_getmsg(struct module_qstate * qstate,struct val_qstate * vq)287 val_new_getmsg(struct module_qstate* qstate, struct val_qstate* vq)
288 {
289 if(!qstate->return_msg || qstate->return_rcode != LDNS_RCODE_NOERROR) {
290 /* create a message to verify */
291 verbose(VERB_ALGO, "constructing reply for validation");
292 vq->orig_msg = (struct dns_msg*)regional_alloc(qstate->region,
293 sizeof(struct dns_msg));
294 if(!vq->orig_msg)
295 return NULL;
296 vq->orig_msg->qinfo = qstate->qinfo;
297 vq->orig_msg->rep = (struct reply_info*)regional_alloc(
298 qstate->region, sizeof(struct reply_info));
299 if(!vq->orig_msg->rep)
300 return NULL;
301 memset(vq->orig_msg->rep, 0, sizeof(struct reply_info));
302 vq->orig_msg->rep->flags = (uint16_t)(qstate->return_rcode&0xf)
303 |BIT_QR|BIT_RA|(qstate->query_flags|(BIT_CD|BIT_RD));
304 vq->orig_msg->rep->qdcount = 1;
305 vq->orig_msg->rep->reason_bogus = LDNS_EDE_NONE;
306 } else {
307 vq->orig_msg = qstate->return_msg;
308 }
309 vq->qchase = qstate->qinfo;
310 /* chase reply will be an edited (sub)set of the orig msg rrset ptrs */
311 vq->chase_reply = regional_alloc_init(qstate->region,
312 vq->orig_msg->rep,
313 sizeof(struct reply_info) - sizeof(struct rrset_ref));
314 if(!vq->chase_reply)
315 return NULL;
316 if(vq->orig_msg->rep->rrset_count > RR_COUNT_MAX)
317 return NULL; /* protect against integer overflow */
318 /* Over allocate (+an_numrrsets) in case we need to put extra DNAME
319 * records for unsigned CNAME repetitions */
320 vq->chase_reply->rrsets = regional_alloc(qstate->region,
321 sizeof(struct ub_packed_rrset_key*) *
322 (vq->orig_msg->rep->rrset_count
323 + vq->orig_msg->rep->an_numrrsets));
324 if(!vq->chase_reply->rrsets)
325 return NULL;
326 memmove(vq->chase_reply->rrsets, vq->orig_msg->rep->rrsets,
327 sizeof(struct ub_packed_rrset_key*) *
328 vq->orig_msg->rep->rrset_count);
329 vq->rrset_skip = 0;
330 return vq;
331 }
332
333 /** allocate new validator query state */
334 static struct val_qstate*
val_new(struct module_qstate * qstate,int id)335 val_new(struct module_qstate* qstate, int id)
336 {
337 struct val_qstate* vq = (struct val_qstate*)regional_alloc(
338 qstate->region, sizeof(*vq));
339 log_assert(!qstate->minfo[id]);
340 if(!vq)
341 return NULL;
342 memset(vq, 0, sizeof(*vq));
343 qstate->minfo[id] = vq;
344 vq->state = VAL_INIT_STATE;
345 return val_new_getmsg(qstate, vq);
346 }
347
348 /** reset validator query state for query restart */
349 static void
val_restart(struct val_qstate * vq)350 val_restart(struct val_qstate* vq)
351 {
352 struct comm_timer* temp_timer;
353 int restart_count, num_validation_attempts, num_hash_attempts;
354 if(!vq) return;
355 temp_timer = vq->suspend_timer;
356 restart_count = vq->restart_count+1;
357 num_validation_attempts = vq->num_validation_attempts;
358 num_hash_attempts = vq->num_hash_attempts;
359 memset(vq, 0, sizeof(*vq));
360 vq->suspend_timer = temp_timer;
361 vq->restart_count = restart_count;
362 vq->num_validation_attempts = num_validation_attempts;
363 vq->num_hash_attempts = num_hash_attempts;
364 vq->state = VAL_INIT_STATE;
365 }
366
367 /**
368 * Exit validation with an error status
369 *
370 * @param qstate: query state
371 * @param id: validator id.
372 * @return false, for use by caller to return to stop processing.
373 */
374 static int
val_error(struct module_qstate * qstate,int id)375 val_error(struct module_qstate* qstate, int id)
376 {
377 qstate->ext_state[id] = module_error;
378 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
379 return 0;
380 }
381
382 /**
383 * Check to see if a given response needs to go through the validation
384 * process. Typical reasons for this routine to return false are: CD bit was
385 * on in the original request, or the response is a kind of message that
386 * is unvalidatable (i.e., SERVFAIL, REFUSED, etc.)
387 *
388 * @param qstate: query state.
389 * @param ret_rc: rcode for this message (if noerror - examine ret_msg).
390 * @param ret_msg: return msg, can be NULL; look at rcode instead.
391 * @return true if the response could use validation (although this does not
392 * mean we can actually validate this response).
393 */
394 static int
needs_validation(struct module_qstate * qstate,int ret_rc,struct dns_msg * ret_msg)395 needs_validation(struct module_qstate* qstate, int ret_rc,
396 struct dns_msg* ret_msg)
397 {
398 int rcode;
399
400 /* If the CD bit is on in the original request, then you could think
401 * that we don't bother to validate anything.
402 * But this is signalled internally with the valrec flag.
403 * User queries are validated with BIT_CD to make our cache clean
404 * so that bogus messages get retried by the upstream also for
405 * downstream validators that set BIT_CD.
406 * For DNS64 bit_cd signals no dns64 processing, but we want to
407 * provide validation there too */
408 /*
409 if((qstate->query_flags & BIT_CD)) {
410 verbose(VERB_ALGO, "not validating response due to CD bit");
411 return 0;
412 }
413 */
414 if(qstate->is_valrec) {
415 verbose(VERB_ALGO, "not validating response, is valrec"
416 "(validation recursion lookup)");
417 return 0;
418 }
419
420 if(ret_rc != LDNS_RCODE_NOERROR || !ret_msg)
421 rcode = ret_rc;
422 else rcode = (int)FLAGS_GET_RCODE(ret_msg->rep->flags);
423
424 if(rcode != LDNS_RCODE_NOERROR && rcode != LDNS_RCODE_NXDOMAIN) {
425 if(verbosity >= VERB_ALGO) {
426 char rc[16];
427 rc[0]=0;
428 (void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
429 verbose(VERB_ALGO, "cannot validate non-answer, rcode %s", rc);
430 }
431 return 0;
432 }
433
434 /* cannot validate positive RRSIG response. (negatives can) */
435 if(qstate->qinfo.qtype == LDNS_RR_TYPE_RRSIG &&
436 rcode == LDNS_RCODE_NOERROR && ret_msg &&
437 ret_msg->rep->an_numrrsets > 0) {
438 verbose(VERB_ALGO, "cannot validate RRSIG, no sigs on sigs.");
439 return 0;
440 }
441 return 1;
442 }
443
444 /**
445 * Check to see if the response has already been validated.
446 * @param ret_msg: return msg, can be NULL
447 * @return true if the response has already been validated
448 */
449 static int
already_validated(struct dns_msg * ret_msg)450 already_validated(struct dns_msg* ret_msg)
451 {
452 /* validate unchecked, and re-validate bogus messages */
453 if (ret_msg && ret_msg->rep->security > sec_status_bogus)
454 {
455 verbose(VERB_ALGO, "response has already been validated: %s",
456 sec_status_to_string(ret_msg->rep->security));
457 return 1;
458 }
459 return 0;
460 }
461
462 /** If it is possible to restart the validation state */
463 static int
val_can_restart(struct module_qstate * qstate,struct val_qstate * vq,struct val_env * ve)464 val_can_restart(struct module_qstate* qstate, struct val_qstate* vq,
465 struct val_env* ve)
466 {
467 /* For validation failures that are limits exceeded on the amount
468 * of work that the DNSSEC validator is willing to do, the restart
469 * is not allowed. A restart would increase the amount of effort
470 * spent even further. */
471 if(vq->restart_count < ve->max_restart &&
472 vq->num_validation_attempts <= qstate->env->cfg->val_validation_attempts &&
473 vq->num_hash_attempts <= qstate->env->cfg->val_hash_attempts &&
474 !vq->num_nsec_attempts_exceeded)
475 return 1;
476 (void)qstate;
477 return 0;
478 }
479
480 /**
481 * Generate a request for DNS data.
482 *
483 * @param qstate: query state that is the parent.
484 * @param id: module id.
485 * @param name: what name to query for.
486 * @param namelen: length of name.
487 * @param qtype: query type.
488 * @param qclass: query class.
489 * @param flags: additional flags, such as the CD bit (BIT_CD), or 0.
490 * @param newq: If the subquery is newly created, it is returned,
491 * otherwise NULL is returned
492 * @param detached: true if this qstate should not attach to the subquery
493 * @return false on alloc failure.
494 */
495 static int
generate_request(struct module_qstate * qstate,int id,uint8_t * name,size_t namelen,uint16_t qtype,uint16_t qclass,uint16_t flags,struct module_qstate ** newq,int detached)496 generate_request(struct module_qstate* qstate, int id, uint8_t* name,
497 size_t namelen, uint16_t qtype, uint16_t qclass, uint16_t flags,
498 struct module_qstate** newq, int detached)
499 {
500 struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
501 struct query_info ask;
502 int valrec;
503 ask.qname = name;
504 ask.qname_len = namelen;
505 ask.qtype = qtype;
506 ask.qclass = qclass;
507 ask.local_alias = NULL;
508 log_query_info(VERB_ALGO, "generate request", &ask);
509 /* enable valrec flag to avoid recursion to the same validation
510 * routine, this lookup is simply a lookup. */
511 valrec = 1;
512
513 fptr_ok(fptr_whitelist_modenv_detect_cycle(qstate->env->detect_cycle));
514 if((*qstate->env->detect_cycle)(qstate, &ask,
515 (uint16_t)(BIT_RD|flags), 0, valrec)) {
516 verbose(VERB_ALGO, "Could not generate request: cycle detected");
517 return 0;
518 }
519
520 if(detached) {
521 struct mesh_state* sub = NULL;
522 fptr_ok(fptr_whitelist_modenv_add_sub(
523 qstate->env->add_sub));
524 if(!(*qstate->env->add_sub)(qstate, &ask, NULL,
525 (uint16_t)(BIT_RD|flags), 0, valrec, newq, &sub)){
526 log_err("Could not generate request: out of memory");
527 return 0;
528 }
529 }
530 else {
531 fptr_ok(fptr_whitelist_modenv_attach_sub(
532 qstate->env->attach_sub));
533 if(!(*qstate->env->attach_sub)(qstate, &ask, NULL,
534 (uint16_t)(BIT_RD|flags), 0, valrec, newq)){
535 log_err("Could not generate request: out of memory");
536 return 0;
537 }
538 }
539 /* newq; validator does not need state created for that
540 * query, and its a 'normal' for iterator as well */
541 if(*newq) {
542 /* add our blacklist to the query blacklist */
543 sock_list_merge(&(*newq)->blacklist, (*newq)->region,
544 vq->chain_blacklist);
545 /* start its global quota counter where this one is. */
546 if(qstate->global_quota_reached >
547 (*newq)->global_quota_reached) {
548 (*newq)->global_quota_started =
549 qstate->global_quota_reached;
550 (*newq)->global_quota_reached =
551 qstate->global_quota_reached;
552 }
553 }
554 qstate->ext_state[id] = module_wait_subquery;
555 return 1;
556 }
557
558 /**
559 * Generate, send and detach key tag signaling query.
560 *
561 * @param qstate: query state.
562 * @param id: module id.
563 * @param ta: trust anchor, locked.
564 * @return false on a processing error.
565 */
566 static int
generate_keytag_query(struct module_qstate * qstate,int id,struct trust_anchor * ta)567 generate_keytag_query(struct module_qstate* qstate, int id,
568 struct trust_anchor* ta)
569 {
570 /* 3 bytes for "_ta", 5 bytes per tag (4 bytes + "-") */
571 #define MAX_LABEL_TAGS (LDNS_MAX_LABELLEN-3)/5
572 size_t i, numtag;
573 uint16_t tags[MAX_LABEL_TAGS];
574 char tagstr[LDNS_MAX_LABELLEN+1] = "_ta"; /* +1 for NULL byte */
575 size_t tagstr_left = sizeof(tagstr) - strlen(tagstr);
576 char* tagstr_pos = tagstr + strlen(tagstr);
577 uint8_t dnamebuf[LDNS_MAX_DOMAINLEN+1]; /* +1 for label length byte */
578 size_t dnamebuf_len = sizeof(dnamebuf);
579 uint8_t* keytagdname;
580 struct module_qstate* newq = NULL;
581 enum module_ext_state ext_state = qstate->ext_state[id];
582
583 numtag = anchor_list_keytags(ta, tags, MAX_LABEL_TAGS);
584 if(numtag == 0)
585 return 0;
586
587 for(i=0; i<numtag; i++) {
588 /* Buffer can't overflow; numtag is limited to tags that fit in
589 * the buffer. */
590 snprintf(tagstr_pos, tagstr_left, "-%04x", (unsigned)tags[i]);
591 tagstr_left -= strlen(tagstr_pos);
592 tagstr_pos += strlen(tagstr_pos);
593 }
594
595 sldns_str2wire_dname_buf_origin(tagstr, dnamebuf, &dnamebuf_len,
596 ta->name, ta->namelen);
597 if(!(keytagdname = (uint8_t*)regional_alloc_init(qstate->region,
598 dnamebuf, dnamebuf_len))) {
599 log_err("could not generate key tag query: out of memory");
600 return 0;
601 }
602
603 log_nametypeclass(VERB_OPS, "generate keytag query", keytagdname,
604 LDNS_RR_TYPE_NULL, ta->dclass);
605 if(!generate_request(qstate, id, keytagdname, dnamebuf_len,
606 LDNS_RR_TYPE_NULL, ta->dclass, 0, &newq, 1)) {
607 verbose(VERB_ALGO, "failed to generate key tag signaling request");
608 return 0;
609 }
610
611 /* Not interested in subquery response. Restore the ext_state,
612 * that might be changed by generate_request() */
613 qstate->ext_state[id] = ext_state;
614
615 return 1;
616 }
617
618 /**
619 * Get keytag as uint16_t from string
620 *
621 * @param start: start of string containing keytag
622 * @param keytag: pointer where to store the extracted keytag
623 * @return: 1 if keytag was extracted, else 0.
624 */
625 static int
sentinel_get_keytag(char * start,uint16_t * keytag)626 sentinel_get_keytag(char* start, uint16_t* keytag) {
627 char* keytag_str;
628 char* e = NULL;
629 keytag_str = calloc(1, SENTINEL_KEYTAG_LEN + 1 /* null byte */);
630 if(!keytag_str)
631 return 0;
632 memmove(keytag_str, start, SENTINEL_KEYTAG_LEN);
633 keytag_str[SENTINEL_KEYTAG_LEN] = '\0';
634 *keytag = (uint16_t)strtol(keytag_str, &e, 10);
635 if(!e || *e != '\0') {
636 free(keytag_str);
637 return 0;
638 }
639 free(keytag_str);
640 return 1;
641 }
642
643 /**
644 * Prime trust anchor for use.
645 * Generate and dispatch a priming query for the given trust anchor.
646 * The trust anchor can be DNSKEY or DS and does not have to be signed.
647 *
648 * @param qstate: query state.
649 * @param vq: validator query state.
650 * @param id: module id.
651 * @param toprime: what to prime.
652 * @return false on a processing error.
653 */
654 static int
prime_trust_anchor(struct module_qstate * qstate,struct val_qstate * vq,int id,struct trust_anchor * toprime)655 prime_trust_anchor(struct module_qstate* qstate, struct val_qstate* vq,
656 int id, struct trust_anchor* toprime)
657 {
658 struct module_qstate* newq = NULL;
659 int ret = generate_request(qstate, id, toprime->name, toprime->namelen,
660 LDNS_RR_TYPE_DNSKEY, toprime->dclass, BIT_CD, &newq, 0);
661
662 if(newq && qstate->env->cfg->trust_anchor_signaling &&
663 !generate_keytag_query(qstate, id, toprime)) {
664 verbose(VERB_ALGO, "keytag signaling query failed");
665 return 0;
666 }
667
668 if(!ret) {
669 verbose(VERB_ALGO, "Could not prime trust anchor");
670 return 0;
671 }
672 /* ignore newq; validator does not need state created for that
673 * query, and its a 'normal' for iterator as well */
674 vq->wait_prime_ta = 1; /* to elicit PRIME_RESP_STATE processing
675 from the validator inform_super() routine */
676 /* store trust anchor name for later lookup when prime returns */
677 vq->trust_anchor_name = regional_alloc_init(qstate->region,
678 toprime->name, toprime->namelen);
679 vq->trust_anchor_len = toprime->namelen;
680 vq->trust_anchor_labs = toprime->namelabs;
681 if(!vq->trust_anchor_name) {
682 log_err("Could not prime trust anchor: out of memory");
683 return 0;
684 }
685 return 1;
686 }
687
688 /**
689 * Validate if the ANSWER and AUTHORITY sections contain valid rrsets.
690 * They must be validly signed with the given key.
691 * Tries to validate ADDITIONAL rrsets as well, but only to check them.
692 * Allows unsigned CNAME after a DNAME that expands the DNAME.
693 *
694 * Note that by the time this method is called, the process of finding the
695 * trusted DNSKEY rrset that signs this response must already have been
696 * completed.
697 *
698 * @param qstate: query state.
699 * @param vq: validator query state.
700 * @param env: module env for verify.
701 * @param ve: validator env for verify.
702 * @param chase_reply: answer to validate.
703 * @param key_entry: the key entry, which is trusted, and which matches
704 * the signer of the answer. The key entry isgood().
705 * @param suspend: returned true if the task takes too long and needs to
706 * suspend to continue the effort later.
707 * @return false if any of the rrsets in the an or ns sections of the message
708 * fail to verify. The message is then set to bogus.
709 */
710 static int
validate_msg_signatures(struct module_qstate * qstate,struct val_qstate * vq,struct module_env * env,struct val_env * ve,struct reply_info * chase_reply,struct key_entry_key * key_entry,int * suspend)711 validate_msg_signatures(struct module_qstate* qstate, struct val_qstate* vq,
712 struct module_env* env, struct val_env* ve,
713 struct reply_info* chase_reply, struct key_entry_key* key_entry,
714 int* suspend)
715 {
716 uint8_t* sname;
717 size_t i, slen;
718 struct ub_packed_rrset_key* s;
719 enum sec_status sec;
720 int num_verifies = 0, verified, have_state = 0;
721 char reasonbuf[256];
722 char* reason = NULL;
723 sldns_ede_code reason_bogus = LDNS_EDE_DNSSEC_BOGUS;
724 *suspend = 0;
725 if(vq->msg_signatures_state) {
726 /* Pick up the state, and reset it, may not be needed now. */
727 vq->msg_signatures_state = 0;
728 have_state = 1;
729 }
730
731 /* validate the ANSWER section */
732 for(i=0; i<chase_reply->an_numrrsets; i++) {
733 if(have_state && i <= vq->msg_signatures_index)
734 continue;
735 s = chase_reply->rrsets[i];
736 /* Skip the CNAME following a (validated) DNAME.
737 * Because of the normalization routines in the iterator,
738 * there will always be an unsigned CNAME following a DNAME
739 * (unless qtype=DNAME in the answer part). */
740 if(i>0 && ntohs(chase_reply->rrsets[i-1]->rk.type) ==
741 LDNS_RR_TYPE_DNAME &&
742 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
743 ((struct packed_rrset_data*)chase_reply->rrsets[i-1]->entry.data)->security == sec_status_secure &&
744 dname_strict_subdomain_c(s->rk.dname, chase_reply->rrsets[i-1]->rk.dname)
745 ) {
746 /* Check that the CNAME target matches the DNAME
747 * derivation. Zone changes during the redirection
748 * lookups or looped DNAMEs can have such a CNAME. */
749 uint8_t expected_target[LDNS_MAX_DOMAINLEN];
750 uint8_t* cname_target = NULL;
751 size_t cname_target_len = 0;
752 get_cname_target(s, &cname_target, &cname_target_len);
753 if(!cname_target ||
754 !derive_cname_from_dname(s, /* CNAME RRset */
755 chase_reply->rrsets[i-1], /* DNAME RRset */
756 expected_target, /* Output buffer */
757 sizeof(expected_target))) {
758 verbose(VERB_ALGO, "DNAME CNAME derivation failed");
759 errinf_ede(qstate, "DNAME CNAME derivation failed", reason_bogus);
760 errinf_origin(qstate, qstate->reply_origin);
761 chase_reply->security = sec_status_bogus;
762 update_reason_bogus(chase_reply, reason_bogus);
763 return 0;
764 }
765 if(query_dname_compare(cname_target, expected_target) != 0) {
766 verbose(VERB_ALGO, "CNAME target mismatch: not synthesized from DNAME");
767 errinf_ede(qstate, "CNAME target mismatch: not synthesized from DNAME", reason_bogus);
768 errinf_dname(qstate, ", for", s->rk.dname);
769 errinf_dname(qstate, "CNAME", cname_target);
770 errinf(qstate, ",");
771 errinf_origin(qstate, qstate->reply_origin);
772 chase_reply->security = sec_status_bogus;
773 update_reason_bogus(chase_reply, reason_bogus);
774 return 0;
775 }
776
777 /* CNAME was synthesized by our own iterator */
778 /* since the DNAME verified, mark the CNAME as secure */
779 ((struct packed_rrset_data*)s->entry.data)->security =
780 sec_status_secure;
781 ((struct packed_rrset_data*)s->entry.data)->trust =
782 rrset_trust_validated;
783 continue;
784 }
785
786 /* Verify the answer rrset */
787 sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason,
788 &reason_bogus, LDNS_SECTION_ANSWER, qstate, vq,
789 &verified, reasonbuf, sizeof(reasonbuf));
790 /* If the (answer) rrset failed to validate, then this
791 * message is BAD. */
792 if(sec != sec_status_secure) {
793 log_nametypeclass(VERB_QUERY, "validator: response "
794 "has failed ANSWER rrset:", s->rk.dname,
795 ntohs(s->rk.type), ntohs(s->rk.rrset_class));
796 errinf_ede(qstate, reason, reason_bogus);
797 if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME)
798 errinf(qstate, "for CNAME");
799 else if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME)
800 errinf(qstate, "for DNAME");
801 errinf_origin(qstate, qstate->reply_origin);
802 chase_reply->security = sec_status_bogus;
803 update_reason_bogus(chase_reply, reason_bogus);
804
805 return 0;
806 }
807
808 num_verifies += verified;
809 if(num_verifies > MAX_VALIDATE_AT_ONCE &&
810 i+1 < (env->cfg->val_clean_additional?
811 chase_reply->an_numrrsets+chase_reply->ns_numrrsets:
812 chase_reply->rrset_count)) {
813 /* If the number of RRSIGs exceeds the maximum in
814 * one go, suspend. Only suspend if there is a next
815 * rrset to verify, i+1<loopmax. Store where to
816 * continue later. */
817 *suspend = 1;
818 vq->msg_signatures_state = 1;
819 vq->msg_signatures_index = i;
820 verbose(VERB_ALGO, "msg signature validation "
821 "suspended");
822 return 0;
823 }
824 }
825
826 /* validate the AUTHORITY section */
827 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
828 chase_reply->ns_numrrsets; i++) {
829 if(have_state && i <= vq->msg_signatures_index)
830 continue;
831 s = chase_reply->rrsets[i];
832 sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason,
833 &reason_bogus, LDNS_SECTION_AUTHORITY, qstate, vq,
834 &verified, reasonbuf, sizeof(reasonbuf));
835 /* If anything in the authority section fails to be secure,
836 * we have a bad message. */
837 if(sec != sec_status_secure) {
838 log_nametypeclass(VERB_QUERY, "validator: response "
839 "has failed AUTHORITY rrset:", s->rk.dname,
840 ntohs(s->rk.type), ntohs(s->rk.rrset_class));
841 errinf_ede(qstate, reason, reason_bogus);
842 errinf_origin(qstate, qstate->reply_origin);
843 errinf_rrset(qstate, s);
844 chase_reply->security = sec_status_bogus;
845 update_reason_bogus(chase_reply, reason_bogus);
846 return 0;
847 }
848 num_verifies += verified;
849 if(num_verifies > MAX_VALIDATE_AT_ONCE &&
850 i+1 < (env->cfg->val_clean_additional?
851 chase_reply->an_numrrsets+chase_reply->ns_numrrsets:
852 chase_reply->rrset_count)) {
853 *suspend = 1;
854 vq->msg_signatures_state = 1;
855 vq->msg_signatures_index = i;
856 verbose(VERB_ALGO, "msg signature validation "
857 "suspended");
858 return 0;
859 }
860 }
861
862 /* If set, the validator should clean the additional section of
863 * secure messages. */
864 if(!env->cfg->val_clean_additional)
865 return 1;
866 /* attempt to validate the ADDITIONAL section rrsets */
867 for(i=chase_reply->an_numrrsets+chase_reply->ns_numrrsets;
868 i<chase_reply->rrset_count; i++) {
869 if(have_state && i <= vq->msg_signatures_index)
870 continue;
871 s = chase_reply->rrsets[i];
872 /* only validate rrs that have signatures with the key */
873 /* leave others unchecked, those get removed later on too */
874 val_find_rrset_signer(s, &sname, &slen);
875
876 verified = 0;
877 if(sname && query_dname_compare(sname, key_entry->name)==0)
878 (void)val_verify_rrset_entry(env, ve, s, key_entry,
879 &reason, NULL, LDNS_SECTION_ADDITIONAL, qstate,
880 vq, &verified, reasonbuf, sizeof(reasonbuf));
881 /* the additional section can fail to be secure,
882 * it is optional, check signature in case we need
883 * to clean the additional section later. */
884 num_verifies += verified;
885 if(num_verifies > MAX_VALIDATE_AT_ONCE &&
886 i+1 < chase_reply->rrset_count) {
887 *suspend = 1;
888 vq->msg_signatures_state = 1;
889 vq->msg_signatures_index = i;
890 verbose(VERB_ALGO, "msg signature validation "
891 "suspended");
892 return 0;
893 }
894 }
895
896 return 1;
897 }
898
899 void
validate_suspend_timer_cb(void * arg)900 validate_suspend_timer_cb(void* arg)
901 {
902 struct module_qstate* qstate = (struct module_qstate*)arg;
903 verbose(VERB_ALGO, "validate_suspend timer, continue");
904 mesh_run(qstate->env->mesh, qstate->mesh_info, module_event_pass,
905 NULL);
906 }
907
908 /** Setup timer to continue validation of msg signatures later */
909 static int
validate_suspend_setup_timer(struct module_qstate * qstate,struct val_qstate * vq,int id,enum val_state resume_state)910 validate_suspend_setup_timer(struct module_qstate* qstate,
911 struct val_qstate* vq, int id, enum val_state resume_state)
912 {
913 struct timeval tv;
914 int usec, slack, base;
915 if(vq->suspend_count >= MAX_VALIDATION_SUSPENDS) {
916 verbose(VERB_ALGO, "validate_suspend timer: "
917 "reached MAX_VALIDATION_SUSPENDS (%d); error out",
918 MAX_VALIDATION_SUSPENDS);
919 errinf(qstate, "max validation suspends reached, "
920 "too many RRSIG validations");
921 return 0;
922 }
923 verbose(VERB_ALGO, "validate_suspend timer, set for suspend");
924 vq->state = resume_state;
925 qstate->ext_state[id] = module_wait_reply;
926 if(!vq->suspend_timer) {
927 vq->suspend_timer = comm_timer_create(
928 qstate->env->worker_base,
929 validate_suspend_timer_cb, qstate);
930 if(!vq->suspend_timer) {
931 log_err("validate_suspend_setup_timer: "
932 "out of memory for comm_timer_create");
933 return 0;
934 }
935 }
936 /* The timer is activated later, after other events in the event
937 * loop have been processed. The query state can also be deleted,
938 * when the list is full and query states are dropped. */
939 /* Extend wait time if there are a lot of queries or if this one
940 * is taking long, to keep around cpu time for ordinary queries. */
941 usec = 50000; /* 50 msec */
942 slack = 0;
943 if(qstate->env->mesh->all.count >= qstate->env->mesh->max_reply_states)
944 slack += 3;
945 else if(qstate->env->mesh->all.count >= qstate->env->mesh->max_reply_states/2)
946 slack += 2;
947 else if(qstate->env->mesh->all.count >= qstate->env->mesh->max_reply_states/4)
948 slack += 1;
949 /* One step of back-off after the first suspend so a single bad
950 * message still yields, but does not grow exponentially on its own. */
951 if(vq->suspend_count > 0)
952 slack += 1;
953 if(slack != 0 && slack <= 12 /* No numeric overflow. */) {
954 usec = usec << slack;
955 }
956 /* Spread such timeouts within 90%-100% of the original timer. */
957 base = usec * 9/10;
958 usec = base + ub_random_max(qstate->env->rnd, usec-base);
959 tv.tv_usec = (usec % 1000000);
960 tv.tv_sec = (usec / 1000000);
961 vq->suspend_count ++;
962 comm_timer_set(vq->suspend_timer, &tv);
963 return 1;
964 }
965
966 /**
967 * Detect wrong truncated response (say from BIND 9.6.1 that is forwarding
968 * and saw the NS record without signatures from a referral).
969 * The positive response has a mangled authority section.
970 * Remove that authority section and the additional section.
971 * @param rep: reply
972 * @return true if a wrongly truncated response.
973 */
974 static int
detect_wrongly_truncated(struct reply_info * rep)975 detect_wrongly_truncated(struct reply_info* rep)
976 {
977 size_t i;
978 /* only NS in authority, and it is bogus */
979 if(rep->ns_numrrsets != 1 || rep->an_numrrsets == 0)
980 return 0;
981 if(ntohs(rep->rrsets[ rep->an_numrrsets ]->rk.type) != LDNS_RR_TYPE_NS)
982 return 0;
983 if(((struct packed_rrset_data*)rep->rrsets[ rep->an_numrrsets ]
984 ->entry.data)->security == sec_status_secure)
985 return 0;
986 /* answer section is present and secure */
987 for(i=0; i<rep->an_numrrsets; i++) {
988 if(((struct packed_rrset_data*)rep->rrsets[ i ]
989 ->entry.data)->security != sec_status_secure)
990 return 0;
991 }
992 verbose(VERB_ALGO, "truncating to minimal response");
993 return 1;
994 }
995
996 /**
997 * For messages that are not referrals, if the chase reply contains an
998 * unsigned NS record in the authority section it could have been
999 * inserted by a (BIND) forwarder that thinks the zone is insecure, and
1000 * that has an NS record without signatures in cache. Remove the NS
1001 * record since the reply does not hinge on that record (in the authority
1002 * section), but do not remove it if it removes the last record from the
1003 * answer+authority sections.
1004 * @param chase_reply: the chased reply, we have a key for this contents,
1005 * so we should have signatures for these rrsets and not having
1006 * signatures means it will be bogus.
1007 * @param orig_reply: original reply, remove NS from there as well because
1008 * we cannot mark the NS record as DNSSEC valid because it is not
1009 * validated by signatures.
1010 */
1011 static void
remove_spurious_authority(struct reply_info * chase_reply,struct reply_info * orig_reply)1012 remove_spurious_authority(struct reply_info* chase_reply,
1013 struct reply_info* orig_reply)
1014 {
1015 size_t i, found = 0;
1016 int remove = 0;
1017 /* if no answer and only 1 auth RRset, do not remove that one */
1018 if(chase_reply->an_numrrsets == 0 && chase_reply->ns_numrrsets == 1)
1019 return;
1020 /* search authority section for unsigned NS records */
1021 for(i = chase_reply->an_numrrsets;
1022 i < chase_reply->an_numrrsets+chase_reply->ns_numrrsets; i++) {
1023 struct packed_rrset_data* d = (struct packed_rrset_data*)
1024 chase_reply->rrsets[i]->entry.data;
1025 if(ntohs(chase_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
1026 && d->rrsig_count == 0) {
1027 found = i;
1028 remove = 1;
1029 break;
1030 }
1031 }
1032 /* see if we found the entry */
1033 if(!remove) return;
1034 log_rrset_key(VERB_ALGO, "Removing spurious unsigned NS record "
1035 "(likely inserted by forwarder)", chase_reply->rrsets[found]);
1036
1037 /* find rrset in orig_reply */
1038 for(i = orig_reply->an_numrrsets;
1039 i < orig_reply->an_numrrsets+orig_reply->ns_numrrsets; i++) {
1040 if(ntohs(orig_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
1041 && query_dname_compare(orig_reply->rrsets[i]->rk.dname,
1042 chase_reply->rrsets[found]->rk.dname) == 0) {
1043 /* remove from orig_msg */
1044 val_reply_remove_auth(orig_reply, i);
1045 break;
1046 }
1047 }
1048 /* remove rrset from chase_reply */
1049 val_reply_remove_auth(chase_reply, found);
1050 }
1051
1052 /**
1053 * Cap the number of answer RRsets for validation of type ANY.
1054 * This limits the number of RRSIG validations performed.
1055 * It is allowed to return a subset of available RRsets when processing
1056 * ANY query.
1057 * @param chase_reply: the chased reply, shorten if if too long.
1058 * @param orig_reply: original reply, remove the records here as well,
1059 * so it can be marked as DNSSEC valid.
1060 * @param skip: the number of rrsets skipped in the answer section due to
1061 * CNAME chain that is followed.
1062 * @param max_rrsets: the number allowed.
1063 */
1064 static void
shorten_answer_any(struct reply_info * chase_reply,struct reply_info * orig_reply,size_t skip,size_t max_rrsets)1065 shorten_answer_any(struct reply_info* chase_reply,
1066 struct reply_info* orig_reply, size_t skip, size_t max_rrsets)
1067 {
1068 if(chase_reply->an_numrrsets > max_rrsets) {
1069 size_t to_rem = chase_reply->an_numrrsets - max_rrsets;
1070 val_reply_remove_answers(chase_reply, max_rrsets, to_rem);
1071 val_reply_remove_answers(orig_reply, skip+max_rrsets, to_rem);
1072 }
1073 }
1074
1075 /**
1076 * Given a "positive" response -- a response that contains an answer to the
1077 * question, and no CNAME chain, validate this response.
1078 *
1079 * The answer and authority RRsets must already be verified as secure.
1080 *
1081 * @param env: module env for verify.
1082 * @param ve: validator env for verify.
1083 * @param qchase: query that was made.
1084 * @param chase_reply: answer to that query to validate.
1085 * @param kkey: the key entry, which is trusted, and which matches
1086 * the signer of the answer. The key entry isgood().
1087 * @param qstate: query state for the region.
1088 * @param vq: validator state for the nsec3 cache table.
1089 * @param nsec3_calculations: current nsec3 hash calculations.
1090 * @param suspend: returned true if the task takes too long and needs to
1091 * suspend to continue the effort later.
1092 */
1093 static void
validate_positive_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1094 validate_positive_response(struct module_env* env, struct val_env* ve,
1095 struct query_info* qchase, struct reply_info* chase_reply,
1096 struct key_entry_key* kkey, struct module_qstate* qstate,
1097 struct val_qstate* vq, int* nsec3_calculations, int* suspend)
1098 {
1099 uint8_t* wc = NULL;
1100 size_t wl;
1101 int wc_cached = 0;
1102 int wc_to_cache = 0;
1103 uint8_t* cache_wc = NULL;
1104 size_t cache_wl = 0;
1105 struct ub_packed_rrset_key* cache_s = NULL;
1106 int wc_NSEC_ok = 0;
1107 /* This is used to update the RRset cache, with the combination
1108 * of the dname expansion and this wildcard, for security status. */
1109 struct ub_packed_rrset_key* wc_rrset = NULL;
1110 int nsec3s_seen = 0;
1111 size_t i;
1112 struct ub_packed_rrset_key* s;
1113 *suspend = 0;
1114
1115 /* validate the ANSWER section - this will be the answer itself */
1116 for(i=0; i<chase_reply->an_numrrsets; i++) {
1117 s = chase_reply->rrsets[i];
1118
1119 /* Check to see if the rrset is the result of a wildcard
1120 * expansion. If so, an additional check will need to be
1121 * made in the authority section. */
1122 if(!val_rrset_wildcard(s, &wc, &wl)) {
1123 log_nametypeclass(VERB_QUERY, "Positive response has "
1124 "inconsistent wildcard sigs:", s->rk.dname,
1125 ntohs(s->rk.type), ntohs(s->rk.rrset_class));
1126 chase_reply->security = sec_status_bogus;
1127 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1128 if(wc_rrset)
1129 ((struct packed_rrset_data*)wc_rrset->
1130 entry.data)->security = sec_status_bogus;
1131 return;
1132 }
1133 if(wc && !wc_cached && env->cfg->aggressive_nsec) {
1134 /* Postpone cache adjust until proof has succeeded. */
1135 wc_to_cache = 1;
1136 cache_wc = wc;
1137 cache_wl = wl;
1138 cache_s = s;
1139 wc_cached = 1;
1140 }
1141 if(wc) wc_rrset = s;
1142 }
1143
1144 /* validate the AUTHORITY section as well - this will generally be
1145 * the NS rrset (which could be missing, no problem) */
1146 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
1147 chase_reply->ns_numrrsets; i++) {
1148 s = chase_reply->rrsets[i];
1149
1150 /* If this is a positive wildcard response, and we have a
1151 * (just verified) NSEC record, try to use it to 1) prove
1152 * that qname doesn't exist and 2) that the correct wildcard
1153 * was used. */
1154 if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1155 if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
1156 wc_NSEC_ok = 1;
1157 }
1158 /* if not, continue looking for proof */
1159 }
1160
1161 /* Otherwise, if this is a positive wildcard response and
1162 * we have NSEC3 records */
1163 if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1164 nsec3s_seen = 1;
1165 }
1166 }
1167
1168 /* If this was a positive wildcard response that we haven't already
1169 * proven, and we have NSEC3 records, try to prove it using the NSEC3
1170 * records. */
1171 if(wc != NULL && !wc_NSEC_ok && nsec3s_seen &&
1172 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1173 enum sec_status sec = nsec3_prove_wildcard(env, ve,
1174 chase_reply->rrsets+chase_reply->an_numrrsets,
1175 chase_reply->ns_numrrsets, qchase, kkey, wc,
1176 &vq->nsec3_cache_table, nsec3_calculations);
1177 if(sec == sec_status_insecure) {
1178 verbose(VERB_ALGO, "Positive wildcard response is "
1179 "insecure");
1180 chase_reply->security = sec_status_insecure;
1181 return;
1182 } else if(sec == sec_status_secure) {
1183 wc_NSEC_ok = 1;
1184 } else if(sec == sec_status_unchecked) {
1185 *suspend = 1;
1186 return;
1187 }
1188 }
1189
1190 /* If after all this, we still haven't proven the positive wildcard
1191 * response, fail. */
1192 if(wc != NULL && !wc_NSEC_ok) {
1193 verbose(VERB_QUERY, "positive response was wildcard "
1194 "expansion and did not prove original data "
1195 "did not exist");
1196 chase_reply->security = sec_status_bogus;
1197 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1198 if(wc_rrset)
1199 ((struct packed_rrset_data*)wc_rrset->
1200 entry.data)->security = sec_status_bogus;
1201 return;
1202 }
1203 if(wc_to_cache) {
1204 rrset_cache_update_wildcard(env->rrset_cache, cache_s,
1205 cache_wc, cache_wl, env->alloc, *env->now);
1206 }
1207
1208 verbose(VERB_ALGO, "Successfully validated positive response");
1209 chase_reply->security = sec_status_secure;
1210 }
1211
1212 /**
1213 * Validate a NOERROR/NODATA signed response -- a response that has a
1214 * NOERROR Rcode but no ANSWER section RRsets. This consists of making
1215 * certain that the authority section NSEC/NSEC3s proves that the qname
1216 * does exist and the qtype doesn't.
1217 *
1218 * The answer and authority RRsets must already be verified as secure.
1219 *
1220 * @param env: module env for verify.
1221 * @param ve: validator env for verify.
1222 * @param qchase: query that was made.
1223 * @param chase_reply: answer to that query to validate.
1224 * @param kkey: the key entry, which is trusted, and which matches
1225 * the signer of the answer. The key entry isgood().
1226 * @param qstate: query state for the region.
1227 * @param vq: validator state for the nsec3 cache table.
1228 * @param nsec3_calculations: current nsec3 hash calculations.
1229 * @param suspend: returned true if the task takes too long and needs to
1230 * suspend to continue the effort later.
1231 */
1232 static void
validate_nodata_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1233 validate_nodata_response(struct module_env* env, struct val_env* ve,
1234 struct query_info* qchase, struct reply_info* chase_reply,
1235 struct key_entry_key* kkey, struct module_qstate* qstate,
1236 struct val_qstate* vq, int* nsec3_calculations, int* suspend)
1237 {
1238 /* Since we are here, there must be nothing in the ANSWER section to
1239 * validate. */
1240 /* (Note: CNAME/DNAME responses will not directly get here --
1241 * instead, they are chased down into individual CNAME validations,
1242 * and at the end of the cname chain a POSITIVE, or CNAME_NOANSWER
1243 * validation.) */
1244
1245 /* validate the AUTHORITY section */
1246 int has_valid_nsec = 0; /* If true, then the NODATA has been proven.*/
1247 uint8_t* ce = NULL; /* for wildcard nodata responses. This is the
1248 proven closest encloser. */
1249 uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
1250 int nsec3s_seen = 0; /* nsec3s seen */
1251 struct ub_packed_rrset_key* s;
1252 size_t i;
1253 *suspend = 0;
1254
1255 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
1256 chase_reply->ns_numrrsets; i++) {
1257 s = chase_reply->rrsets[i];
1258 /* If we encounter an NSEC record, try to use it to prove
1259 * NODATA.
1260 * This needs to handle the ENT NODATA case. */
1261 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1262 if(nsec_proves_nodata(s, qchase, &wc)) {
1263 has_valid_nsec = 1;
1264 /* sets wc-encloser if wildcard applicable */
1265 }
1266 if(val_nsec_proves_name_error(s, qchase->qname)) {
1267 ce = nsec_closest_encloser(qchase->qname, s);
1268 }
1269 if(val_nsec_proves_insecuredelegation(s, qchase)) {
1270 verbose(VERB_ALGO, "delegation is insecure");
1271 chase_reply->security = sec_status_insecure;
1272 return;
1273 }
1274 } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1275 nsec3s_seen = 1;
1276 }
1277 }
1278
1279 /* check to see if we have a wildcard NODATA proof. */
1280
1281 /* The wildcard NODATA is 1 NSEC proving that qname does not exist
1282 * (and also proving what the closest encloser is), and 1 NSEC
1283 * showing the matching wildcard, which must be *.closest_encloser. */
1284 if(wc && !ce)
1285 has_valid_nsec = 0;
1286 else if(wc && ce) {
1287 if(query_dname_compare(wc, ce) != 0) {
1288 has_valid_nsec = 0;
1289 }
1290 }
1291
1292 if(!has_valid_nsec && nsec3s_seen &&
1293 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1294 enum sec_status sec = nsec3_prove_nodata(env, ve,
1295 chase_reply->rrsets+chase_reply->an_numrrsets,
1296 chase_reply->ns_numrrsets, qchase, kkey,
1297 &vq->nsec3_cache_table, nsec3_calculations);
1298 if(sec == sec_status_insecure) {
1299 verbose(VERB_ALGO, "NODATA response is insecure");
1300 chase_reply->security = sec_status_insecure;
1301 return;
1302 } else if(sec == sec_status_secure) {
1303 has_valid_nsec = 1;
1304 } else if(sec == sec_status_unchecked) {
1305 /* check is incomplete; suspend */
1306 *suspend = 1;
1307 return;
1308 }
1309 }
1310
1311 if(!has_valid_nsec) {
1312 verbose(VERB_QUERY, "NODATA response failed to prove NODATA "
1313 "status with NSEC/NSEC3");
1314 if(verbosity >= VERB_ALGO)
1315 log_dns_msg("Failed NODATA", qchase, chase_reply);
1316 chase_reply->security = sec_status_bogus;
1317 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1318 return;
1319 }
1320
1321 verbose(VERB_ALGO, "successfully validated NODATA response.");
1322 chase_reply->security = sec_status_secure;
1323 }
1324
1325 /**
1326 * Validate a NAMEERROR signed response -- a response that has a NXDOMAIN
1327 * Rcode.
1328 * This consists of making certain that the authority section NSEC proves
1329 * that the qname doesn't exist and the covering wildcard also doesn't exist..
1330 *
1331 * The answer and authority RRsets must have already been verified as secure.
1332 *
1333 * @param env: module env for verify.
1334 * @param ve: validator env for verify.
1335 * @param qchase: query that was made.
1336 * @param chase_reply: answer to that query to validate.
1337 * @param kkey: the key entry, which is trusted, and which matches
1338 * the signer of the answer. The key entry isgood().
1339 * @param rcode: adjusted RCODE, in case of RCODE/proof mismatch leniency.
1340 * @param qstate: query state for the region.
1341 * @param vq: validator state for the nsec3 cache table.
1342 * @param nsec3_calculations: current nsec3 hash calculations.
1343 * @param suspend: returned true if the task takes too long and needs to
1344 * suspend to continue the effort later.
1345 */
1346 static void
validate_nameerror_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,int * rcode,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1347 validate_nameerror_response(struct module_env* env, struct val_env* ve,
1348 struct query_info* qchase, struct reply_info* chase_reply,
1349 struct key_entry_key* kkey, int* rcode,
1350 struct module_qstate* qstate, struct val_qstate* vq,
1351 int* nsec3_calculations, int* suspend)
1352 {
1353 int has_valid_nsec = 0;
1354 int has_valid_wnsec = 0;
1355 int nsec3s_seen = 0;
1356 struct ub_packed_rrset_key* s;
1357 size_t i;
1358 uint8_t* ce;
1359 int ce_labs = 0;
1360 int prev_ce_labs = 0;
1361 *suspend = 0;
1362
1363 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
1364 chase_reply->ns_numrrsets; i++) {
1365 s = chase_reply->rrsets[i];
1366 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1367 if(val_nsec_proves_name_error(s, qchase->qname))
1368 has_valid_nsec = 1;
1369 ce = nsec_closest_encloser(qchase->qname, s);
1370 ce_labs = dname_count_labels(ce);
1371 /* Use longest closest encloser to prove wildcard. */
1372 if(ce_labs > prev_ce_labs ||
1373 (ce_labs == prev_ce_labs &&
1374 has_valid_wnsec == 0)) {
1375 if(val_nsec_proves_no_wc(s, qchase->qname,
1376 qchase->qname_len))
1377 has_valid_wnsec = 1;
1378 else
1379 has_valid_wnsec = 0;
1380 }
1381 prev_ce_labs = ce_labs;
1382 if(val_nsec_proves_insecuredelegation(s, qchase)) {
1383 verbose(VERB_ALGO, "delegation is insecure");
1384 chase_reply->security = sec_status_insecure;
1385 return;
1386 }
1387 } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3)
1388 nsec3s_seen = 1;
1389 }
1390
1391 if((!has_valid_nsec || !has_valid_wnsec) && nsec3s_seen &&
1392 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1393 /* use NSEC3 proof, both answer and auth rrsets, in case
1394 * NSEC3s end up in the answer (due to qtype=NSEC3 or so) */
1395 chase_reply->security = nsec3_prove_nameerror(env, ve,
1396 chase_reply->rrsets, chase_reply->an_numrrsets+
1397 chase_reply->ns_numrrsets, qchase, kkey,
1398 &vq->nsec3_cache_table, nsec3_calculations);
1399 if(chase_reply->security == sec_status_unchecked) {
1400 *suspend = 1;
1401 return;
1402 } else if(chase_reply->security != sec_status_secure) {
1403 verbose(VERB_QUERY, "NameError response failed nsec, "
1404 "nsec3 proof was %s", sec_status_to_string(
1405 chase_reply->security));
1406 return;
1407 }
1408 has_valid_nsec = 1;
1409 has_valid_wnsec = 1;
1410 }
1411
1412 /* If the message fails to prove either condition, it is bogus. */
1413 if(!has_valid_nsec) {
1414 validate_nodata_response(env, ve, qchase, chase_reply, kkey,
1415 qstate, vq, nsec3_calculations, suspend);
1416 if(*suspend) return;
1417 verbose(VERB_QUERY, "NameError response has failed to prove: "
1418 "qname does not exist");
1419 /* Be lenient with RCODE in NSEC NameError responses */
1420 if(chase_reply->security == sec_status_secure) {
1421 *rcode = LDNS_RCODE_NOERROR;
1422 } else {
1423 chase_reply->security = sec_status_bogus;
1424 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1425 }
1426 return;
1427 }
1428
1429 if(!has_valid_wnsec) {
1430 validate_nodata_response(env, ve, qchase, chase_reply, kkey,
1431 qstate, vq, nsec3_calculations, suspend);
1432 if(*suspend) return;
1433 verbose(VERB_QUERY, "NameError response has failed to prove: "
1434 "covering wildcard does not exist");
1435 /* Be lenient with RCODE in NSEC NameError responses */
1436 if (chase_reply->security == sec_status_secure) {
1437 *rcode = LDNS_RCODE_NOERROR;
1438 } else {
1439 chase_reply->security = sec_status_bogus;
1440 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1441 }
1442 return;
1443 }
1444
1445 /* Otherwise, we consider the message secure. */
1446 verbose(VERB_ALGO, "successfully validated NAME ERROR response.");
1447 chase_reply->security = sec_status_secure;
1448 }
1449
1450 /**
1451 * Given a referral response, validate rrsets and take least trusted rrset
1452 * as the current validation status.
1453 *
1454 * Note that by the time this method is called, the process of finding the
1455 * trusted DNSKEY rrset that signs this response must already have been
1456 * completed.
1457 *
1458 * @param env: module env.
1459 * @param chase_reply: answer to validate.
1460 */
1461 static void
validate_referral_response(struct module_env * env,struct reply_info * chase_reply)1462 validate_referral_response(struct module_env* env, struct reply_info* chase_reply)
1463 {
1464 size_t i, count;
1465 enum sec_status s;
1466 /* message security equals lowest rrset security */
1467 chase_reply->security = sec_status_secure;
1468 if(env->cfg->val_clean_additional)
1469 count = chase_reply->rrset_count;
1470 else count = chase_reply->an_numrrsets+chase_reply->ns_numrrsets;
1471 for(i=0; i<count; i++) {
1472 s = ((struct packed_rrset_data*)chase_reply->rrsets[i]
1473 ->entry.data)->security;
1474 if(s < chase_reply->security)
1475 chase_reply->security = s;
1476 }
1477 verbose(VERB_ALGO, "validated part of referral response as %s",
1478 sec_status_to_string(chase_reply->security));
1479 }
1480
1481 /**
1482 * Given an "ANY" response -- a response that contains an answer to a
1483 * qtype==ANY question, with answers. This does no checking that all
1484 * types are present.
1485 *
1486 * NOTE: it may be possible to get parent-side delegation point records
1487 * here, which won't all be signed. Right now, this routine relies on the
1488 * upstream iterative resolver to not return these responses -- instead
1489 * treating them as referrals.
1490 *
1491 * NOTE: RFC 4035 is silent on this issue, so this may change upon
1492 * clarification. Clarification draft -05 says to not check all types are
1493 * present.
1494 *
1495 * Note that by the time this method is called, the process of finding the
1496 * trusted DNSKEY rrset that signs this response must already have been
1497 * completed.
1498 *
1499 * @param env: module env for verify.
1500 * @param ve: validator env for verify.
1501 * @param qchase: query that was made.
1502 * @param chase_reply: answer to that query to validate.
1503 * @param kkey: the key entry, which is trusted, and which matches
1504 * the signer of the answer. The key entry isgood().
1505 * @param qstate: query state for the region.
1506 * @param vq: validator state for the nsec3 cache table.
1507 * @param nsec3_calculations: current nsec3 hash calculations.
1508 * @param suspend: returned true if the task takes too long and needs to
1509 * suspend to continue the effort later.
1510 */
1511 static void
validate_any_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1512 validate_any_response(struct module_env* env, struct val_env* ve,
1513 struct query_info* qchase, struct reply_info* chase_reply,
1514 struct key_entry_key* kkey, struct module_qstate* qstate,
1515 struct val_qstate* vq, int* nsec3_calculations, int* suspend)
1516 {
1517 /* all answer and auth rrsets already verified */
1518 /* but check if a wildcard response is given, then check NSEC/NSEC3
1519 * for qname denial to see if wildcard is applicable */
1520 uint8_t* wc = NULL;
1521 size_t wl;
1522 int wc_NSEC_ok = 0;
1523 int nsec3s_seen = 0;
1524 size_t i;
1525 struct ub_packed_rrset_key* s;
1526 *suspend = 0;
1527
1528 if(qchase->qtype != LDNS_RR_TYPE_ANY) {
1529 log_err("internal error: ANY validation called for non-ANY");
1530 chase_reply->security = sec_status_bogus;
1531 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1532 return;
1533 }
1534
1535 /* validate the ANSWER section - this will be the answer itself */
1536 for(i=0; i<chase_reply->an_numrrsets; i++) {
1537 s = chase_reply->rrsets[i];
1538
1539 /* Check to see if the rrset is the result of a wildcard
1540 * expansion. If so, an additional check will need to be
1541 * made in the authority section. */
1542 if(!val_rrset_wildcard(s, &wc, &wl)) {
1543 log_nametypeclass(VERB_QUERY, "Positive ANY response"
1544 " has inconsistent wildcard sigs:",
1545 s->rk.dname, ntohs(s->rk.type),
1546 ntohs(s->rk.rrset_class));
1547 chase_reply->security = sec_status_bogus;
1548 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1549 return;
1550 }
1551 }
1552
1553 /* if it was a wildcard, check for NSEC/NSEC3s in both answer
1554 * and authority sections (NSEC may be moved to the ANSWER section) */
1555 if(wc != NULL)
1556 for(i=0; i<chase_reply->an_numrrsets+chase_reply->ns_numrrsets;
1557 i++) {
1558 s = chase_reply->rrsets[i];
1559
1560 /* If this is a positive wildcard response, and we have a
1561 * (just verified) NSEC record, try to use it to 1) prove
1562 * that qname doesn't exist and 2) that the correct wildcard
1563 * was used. */
1564 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1565 if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
1566 wc_NSEC_ok = 1;
1567 }
1568 /* if not, continue looking for proof */
1569 }
1570
1571 /* Otherwise, if this is a positive wildcard response and
1572 * we have NSEC3 records */
1573 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1574 nsec3s_seen = 1;
1575 }
1576 }
1577
1578 /* If this was a positive wildcard response that we haven't already
1579 * proven, and we have NSEC3 records, try to prove it using the NSEC3
1580 * records. */
1581 if(wc != NULL && !wc_NSEC_ok && nsec3s_seen &&
1582 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1583 /* look both in answer and auth section for NSEC3s */
1584 enum sec_status sec = nsec3_prove_wildcard(env, ve,
1585 chase_reply->rrsets,
1586 chase_reply->an_numrrsets+chase_reply->ns_numrrsets,
1587 qchase, kkey, wc, &vq->nsec3_cache_table,
1588 nsec3_calculations);
1589 if(sec == sec_status_insecure) {
1590 verbose(VERB_ALGO, "Positive ANY wildcard response is "
1591 "insecure");
1592 chase_reply->security = sec_status_insecure;
1593 return;
1594 } else if(sec == sec_status_secure) {
1595 wc_NSEC_ok = 1;
1596 } else if(sec == sec_status_unchecked) {
1597 *suspend = 1;
1598 return;
1599 }
1600 }
1601
1602 /* If after all this, we still haven't proven the positive wildcard
1603 * response, fail. */
1604 if(wc != NULL && !wc_NSEC_ok) {
1605 verbose(VERB_QUERY, "positive ANY response was wildcard "
1606 "expansion and did not prove original data "
1607 "did not exist");
1608 chase_reply->security = sec_status_bogus;
1609 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1610 /* Make the expanded name and wildcard RRSIG rrsets bogus */
1611 for(i=0; i<chase_reply->an_numrrsets; i++) {
1612 uint8_t* cwc = NULL;
1613 size_t cwl = 0;
1614 s = chase_reply->rrsets[i];
1615 if(val_rrset_wildcard(s, &cwc, &cwl) && cwc) {
1616 ((struct packed_rrset_data*)s->
1617 entry.data)->security = sec_status_bogus;
1618 }
1619 }
1620 return;
1621 }
1622
1623 verbose(VERB_ALGO, "Successfully validated positive ANY response");
1624 chase_reply->security = sec_status_secure;
1625 }
1626
1627 /**
1628 * Validate CNAME response, or DNAME+CNAME.
1629 * This is just like a positive proof, except that this is about a
1630 * DNAME+CNAME. Possible wildcard proof.
1631 * Difference with positive proof is that this routine refuses
1632 * wildcarded DNAMEs.
1633 *
1634 * The answer and authority rrsets must already be verified as secure.
1635 *
1636 * @param env: module env for verify.
1637 * @param ve: validator env for verify.
1638 * @param qchase: query that was made.
1639 * @param chase_reply: answer to that query to validate.
1640 * @param kkey: the key entry, which is trusted, and which matches
1641 * the signer of the answer. The key entry isgood().
1642 * @param qstate: query state for the region.
1643 * @param vq: validator state for the nsec3 cache table.
1644 * @param nsec3_calculations: current nsec3 hash calculations.
1645 * @param suspend: returned true if the task takes too long and needs to
1646 * suspend to continue the effort later.
1647 */
1648 static void
validate_cname_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1649 validate_cname_response(struct module_env* env, struct val_env* ve,
1650 struct query_info* qchase, struct reply_info* chase_reply,
1651 struct key_entry_key* kkey, struct module_qstate* qstate,
1652 struct val_qstate* vq, int* nsec3_calculations, int* suspend)
1653 {
1654 uint8_t* wc = NULL;
1655 size_t wl;
1656 int wc_NSEC_ok = 0;
1657 /* This is used to update the RRset cache, with the combination
1658 * of the dname expansion and this wildcard, for security status. */
1659 struct ub_packed_rrset_key* wc_rrset = NULL;
1660 int nsec3s_seen = 0;
1661 size_t i;
1662 struct ub_packed_rrset_key* s;
1663 *suspend = 0;
1664
1665 /* validate the ANSWER section - this will be the CNAME (+DNAME) */
1666 for(i=0; i<chase_reply->an_numrrsets; i++) {
1667 s = chase_reply->rrsets[i];
1668
1669 /* Check to see if the rrset is the result of a wildcard
1670 * expansion. If so, an additional check will need to be
1671 * made in the authority section. */
1672 if(!val_rrset_wildcard(s, &wc, &wl)) {
1673 log_nametypeclass(VERB_QUERY, "Cname response has "
1674 "inconsistent wildcard sigs:", s->rk.dname,
1675 ntohs(s->rk.type), ntohs(s->rk.rrset_class));
1676 chase_reply->security = sec_status_bogus;
1677 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1678 return;
1679 }
1680 if(wc) wc_rrset = s;
1681
1682 /* Refuse wildcarded DNAMEs rfc 4597.
1683 * Do not follow a wildcarded DNAME because
1684 * its synthesized CNAME expansion is underdefined */
1685 if(qchase->qtype != LDNS_RR_TYPE_DNAME &&
1686 ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME && wc) {
1687 log_nametypeclass(VERB_QUERY, "cannot validate a "
1688 "wildcarded DNAME:", s->rk.dname,
1689 ntohs(s->rk.type), ntohs(s->rk.rrset_class));
1690 chase_reply->security = sec_status_bogus;
1691 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1692 if(wc_rrset)
1693 ((struct packed_rrset_data*)wc_rrset->
1694 entry.data)->security = sec_status_bogus;
1695 return;
1696 }
1697
1698 /* If we have found a CNAME, stop looking for one.
1699 * The iterator has placed the CNAME chain in correct
1700 * order. */
1701 if (ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
1702 break;
1703 }
1704 }
1705
1706 /* AUTHORITY section */
1707 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
1708 chase_reply->ns_numrrsets; i++) {
1709 s = chase_reply->rrsets[i];
1710
1711 /* If this is a positive wildcard response, and we have a
1712 * (just verified) NSEC record, try to use it to 1) prove
1713 * that qname doesn't exist and 2) that the correct wildcard
1714 * was used. */
1715 if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1716 if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
1717 wc_NSEC_ok = 1;
1718 }
1719 /* if not, continue looking for proof */
1720 }
1721
1722 /* Otherwise, if this is a positive wildcard response and
1723 * we have NSEC3 records */
1724 if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1725 nsec3s_seen = 1;
1726 }
1727 }
1728
1729 /* If this was a positive wildcard response that we haven't already
1730 * proven, and we have NSEC3 records, try to prove it using the NSEC3
1731 * records. */
1732 if(wc != NULL && !wc_NSEC_ok && nsec3s_seen &&
1733 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1734 enum sec_status sec = nsec3_prove_wildcard(env, ve,
1735 chase_reply->rrsets+chase_reply->an_numrrsets,
1736 chase_reply->ns_numrrsets, qchase, kkey, wc,
1737 &vq->nsec3_cache_table, nsec3_calculations);
1738 if(sec == sec_status_insecure) {
1739 verbose(VERB_ALGO, "wildcard CNAME response is "
1740 "insecure");
1741 chase_reply->security = sec_status_insecure;
1742 return;
1743 } else if(sec == sec_status_secure) {
1744 wc_NSEC_ok = 1;
1745 } else if(sec == sec_status_unchecked) {
1746 *suspend = 1;
1747 return;
1748 }
1749 }
1750
1751 /* If after all this, we still haven't proven the positive wildcard
1752 * response, fail. */
1753 if(wc != NULL && !wc_NSEC_ok) {
1754 verbose(VERB_QUERY, "CNAME response was wildcard "
1755 "expansion and did not prove original data "
1756 "did not exist");
1757 chase_reply->security = sec_status_bogus;
1758 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1759 if(wc_rrset)
1760 ((struct packed_rrset_data*)wc_rrset->
1761 entry.data)->security = sec_status_bogus;
1762 return;
1763 }
1764
1765 verbose(VERB_ALGO, "Successfully validated CNAME response");
1766 chase_reply->security = sec_status_secure;
1767 }
1768
1769 /**
1770 * Validate CNAME NOANSWER response, no more data after a CNAME chain.
1771 * This can be a NODATA or a NAME ERROR case, but not both at the same time.
1772 * We don't know because the rcode has been set to NOERROR by the CNAME.
1773 *
1774 * The answer and authority rrsets must already be verified as secure.
1775 *
1776 * @param env: module env for verify.
1777 * @param ve: validator env for verify.
1778 * @param qchase: query that was made.
1779 * @param chase_reply: answer to that query to validate.
1780 * @param kkey: the key entry, which is trusted, and which matches
1781 * the signer of the answer. The key entry isgood().
1782 * @param qstate: query state for the region.
1783 * @param vq: validator state for the nsec3 cache table.
1784 * @param nsec3_calculations: current nsec3 hash calculations.
1785 * @param suspend: returned true if the task takes too long and needs to
1786 * suspend to continue the effort later.
1787 */
1788 static void
validate_cname_noanswer_response(struct module_env * env,struct val_env * ve,struct query_info * qchase,struct reply_info * chase_reply,struct key_entry_key * kkey,struct module_qstate * qstate,struct val_qstate * vq,int * nsec3_calculations,int * suspend)1789 validate_cname_noanswer_response(struct module_env* env, struct val_env* ve,
1790 struct query_info* qchase, struct reply_info* chase_reply,
1791 struct key_entry_key* kkey, struct module_qstate* qstate,
1792 struct val_qstate* vq, int* nsec3_calculations, int* suspend)
1793 {
1794 int nodata_valid_nsec = 0; /* If true, then NODATA has been proven.*/
1795 uint8_t* ce = NULL; /* for wildcard nodata responses. This is the
1796 proven closest encloser. */
1797 uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
1798 int nxdomain_valid_nsec = 0; /* if true, nameerror has been proven */
1799 int nxdomain_valid_wnsec = 0;
1800 int nsec3s_seen = 0; /* nsec3s seen */
1801 struct ub_packed_rrset_key* s;
1802 size_t i;
1803 uint8_t* nsec_ce; /* Used to find the NSEC with the longest ce */
1804 int ce_labs = 0;
1805 int prev_ce_labs = 0;
1806 *suspend = 0;
1807
1808 /* the AUTHORITY section */
1809 for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
1810 chase_reply->ns_numrrsets; i++) {
1811 s = chase_reply->rrsets[i];
1812
1813 /* If we encounter an NSEC record, try to use it to prove
1814 * NODATA. This needs to handle the ENT NODATA case.
1815 * Also try to prove NAMEERROR, and absence of a wildcard */
1816 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
1817 if(nsec_proves_nodata(s, qchase, &wc)) {
1818 nodata_valid_nsec = 1;
1819 /* set wc encloser if wildcard applicable */
1820 }
1821 if(val_nsec_proves_name_error(s, qchase->qname)) {
1822 ce = nsec_closest_encloser(qchase->qname, s);
1823 nxdomain_valid_nsec = 1;
1824 }
1825 nsec_ce = nsec_closest_encloser(qchase->qname, s);
1826 ce_labs = dname_count_labels(nsec_ce);
1827 /* Use longest closest encloser to prove wildcard. */
1828 if(ce_labs > prev_ce_labs ||
1829 (ce_labs == prev_ce_labs &&
1830 nxdomain_valid_wnsec == 0)) {
1831 if(val_nsec_proves_no_wc(s, qchase->qname,
1832 qchase->qname_len))
1833 nxdomain_valid_wnsec = 1;
1834 else
1835 nxdomain_valid_wnsec = 0;
1836 }
1837 prev_ce_labs = ce_labs;
1838 if(val_nsec_proves_insecuredelegation(s, qchase)) {
1839 verbose(VERB_ALGO, "delegation is insecure");
1840 chase_reply->security = sec_status_insecure;
1841 return;
1842 }
1843 } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1844 nsec3s_seen = 1;
1845 }
1846 }
1847
1848 /* check to see if we have a wildcard NODATA proof. */
1849
1850 /* The wildcard NODATA is 1 NSEC proving that qname does not exists
1851 * (and also proving what the closest encloser is), and 1 NSEC
1852 * showing the matching wildcard, which must be *.closest_encloser. */
1853 if(wc && !ce)
1854 nodata_valid_nsec = 0;
1855 else if(wc && ce) {
1856 if(query_dname_compare(wc, ce) != 0) {
1857 nodata_valid_nsec = 0;
1858 }
1859 }
1860 if(nxdomain_valid_nsec && !nxdomain_valid_wnsec) {
1861 /* name error is missing wildcard denial proof */
1862 nxdomain_valid_nsec = 0;
1863 }
1864
1865 if(nodata_valid_nsec && nxdomain_valid_nsec) {
1866 verbose(VERB_QUERY, "CNAMEchain to noanswer proves that name "
1867 "exists and not exists, bogus");
1868 chase_reply->security = sec_status_bogus;
1869 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1870 return;
1871 }
1872 if(!nodata_valid_nsec && !nxdomain_valid_nsec && nsec3s_seen &&
1873 nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
1874 int nodata;
1875 enum sec_status sec = nsec3_prove_nxornodata(env, ve,
1876 chase_reply->rrsets+chase_reply->an_numrrsets,
1877 chase_reply->ns_numrrsets, qchase, kkey, &nodata,
1878 &vq->nsec3_cache_table, nsec3_calculations);
1879 if(sec == sec_status_insecure) {
1880 verbose(VERB_ALGO, "CNAMEchain to noanswer response "
1881 "is insecure");
1882 chase_reply->security = sec_status_insecure;
1883 return;
1884 } else if(sec == sec_status_secure) {
1885 if(nodata)
1886 nodata_valid_nsec = 1;
1887 else nxdomain_valid_nsec = 1;
1888 } else if(sec == sec_status_unchecked) {
1889 *suspend = 1;
1890 return;
1891 }
1892 }
1893
1894 if(!nodata_valid_nsec && !nxdomain_valid_nsec) {
1895 verbose(VERB_QUERY, "CNAMEchain to noanswer response failed "
1896 "to prove status with NSEC/NSEC3");
1897 if(verbosity >= VERB_ALGO)
1898 log_dns_msg("Failed CNAMEnoanswer", qchase, chase_reply);
1899 chase_reply->security = sec_status_bogus;
1900 update_reason_bogus(chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1901 return;
1902 }
1903
1904 if(nodata_valid_nsec)
1905 verbose(VERB_ALGO, "successfully validated CNAME chain to a "
1906 "NODATA response.");
1907 else verbose(VERB_ALGO, "successfully validated CNAME chain to a "
1908 "NAMEERROR response.");
1909 chase_reply->security = sec_status_secure;
1910 }
1911
1912 /**
1913 * Process init state for validator.
1914 * Process the INIT state. First tier responses start in the INIT state.
1915 * This is where they are vetted for validation suitability, and the initial
1916 * key search is done.
1917 *
1918 * Currently, events the come through this routine will be either promoted
1919 * to FINISHED/CNAME_RESP (no validation needed), FINDKEY (next step to
1920 * validation), or will be (temporarily) retired and a new priming request
1921 * event will be generated.
1922 *
1923 * @param qstate: query state.
1924 * @param vq: validator query state.
1925 * @param ve: validator shared global environment.
1926 * @param id: module id.
1927 * @return true if the event should be processed further on return, false if
1928 * not.
1929 */
1930 static int
processInit(struct module_qstate * qstate,struct val_qstate * vq,struct val_env * ve,int id)1931 processInit(struct module_qstate* qstate, struct val_qstate* vq,
1932 struct val_env* ve, int id)
1933 {
1934 uint8_t* lookup_name;
1935 size_t lookup_len;
1936 struct trust_anchor* anchor;
1937 enum val_classification subtype = val_classify_response(
1938 qstate->query_flags, &qstate->qinfo, &vq->qchase,
1939 vq->orig_msg->rep, vq->rrset_skip);
1940 if(vq->restart_count > ve->max_restart) {
1941 verbose(VERB_ALGO, "restart count exceeded");
1942 return val_error(qstate, id);
1943 }
1944
1945 /* correctly initialize reason_bogus */
1946 update_reason_bogus(vq->chase_reply, LDNS_EDE_DNSSEC_BOGUS);
1947
1948 verbose(VERB_ALGO, "validator classification %s",
1949 val_classification_to_string(subtype));
1950 if(subtype == VAL_CLASS_REFERRAL &&
1951 vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
1952 /* referral uses the rrset name as qchase, to find keys for
1953 * that rrset */
1954 vq->qchase.qname = vq->orig_msg->rep->
1955 rrsets[vq->rrset_skip]->rk.dname;
1956 vq->qchase.qname_len = vq->orig_msg->rep->
1957 rrsets[vq->rrset_skip]->rk.dname_len;
1958 vq->qchase.qtype = ntohs(vq->orig_msg->rep->
1959 rrsets[vq->rrset_skip]->rk.type);
1960 vq->qchase.qclass = ntohs(vq->orig_msg->rep->
1961 rrsets[vq->rrset_skip]->rk.rrset_class);
1962 }
1963 lookup_name = vq->qchase.qname;
1964 lookup_len = vq->qchase.qname_len;
1965 /* for type DS look at the parent side for keys/trustanchor */
1966 /* also for NSEC not at apex */
1967 if(vq->qchase.qtype == LDNS_RR_TYPE_DS ||
1968 (vq->qchase.qtype == LDNS_RR_TYPE_NSEC &&
1969 vq->orig_msg->rep->rrset_count > vq->rrset_skip &&
1970 ntohs(vq->orig_msg->rep->rrsets[vq->rrset_skip]->rk.type) ==
1971 LDNS_RR_TYPE_NSEC &&
1972 !(vq->orig_msg->rep->rrsets[vq->rrset_skip]->
1973 rk.flags&PACKED_RRSET_NSEC_AT_APEX))) {
1974 dname_remove_label(&lookup_name, &lookup_len);
1975 }
1976
1977 val_mark_indeterminate(vq->chase_reply, qstate->env->anchors,
1978 qstate->env->rrset_cache, qstate->env);
1979 vq->key_entry = NULL;
1980 vq->empty_DS_name = NULL;
1981 vq->ds_rrset = 0;
1982 anchor = anchors_lookup(qstate->env->anchors,
1983 lookup_name, lookup_len, vq->qchase.qclass);
1984
1985 /* Determine the signer/lookup name */
1986 val_find_signer(subtype, &vq->qchase, vq->orig_msg->rep,
1987 vq->rrset_skip, &vq->signer_name, &vq->signer_len);
1988 if(vq->signer_name != NULL &&
1989 !dname_subdomain_c(lookup_name, vq->signer_name)) {
1990 log_nametypeclass(VERB_ALGO, "this signer name is not a parent "
1991 "of lookupname, omitted", vq->signer_name, 0, 0);
1992 vq->signer_name = NULL;
1993 }
1994 if(vq->signer_name == NULL) {
1995 log_nametypeclass(VERB_ALGO, "no signer, using", lookup_name,
1996 0, 0);
1997 } else {
1998 lookup_name = vq->signer_name;
1999 lookup_len = vq->signer_len;
2000 log_nametypeclass(VERB_ALGO, "signer is", lookup_name, 0, 0);
2001 }
2002
2003 /* for NXDOMAIN it could be signed by a parent of the trust anchor */
2004 if(subtype == VAL_CLASS_NAMEERROR && vq->signer_name &&
2005 anchor && dname_strict_subdomain_c(anchor->name, lookup_name)){
2006 lock_basic_unlock(&anchor->lock);
2007 anchor = anchors_lookup(qstate->env->anchors,
2008 lookup_name, lookup_len, vq->qchase.qclass);
2009 if(!anchor) { /* unsigned parent denies anchor*/
2010 verbose(VERB_QUERY, "unsigned parent zone denies"
2011 " trust anchor, indeterminate");
2012 vq->chase_reply->security = sec_status_indeterminate;
2013 update_reason_bogus(vq->chase_reply, LDNS_EDE_DNSSEC_INDETERMINATE);
2014 vq->state = VAL_FINISHED_STATE;
2015 return 1;
2016 }
2017 verbose(VERB_ALGO, "trust anchor NXDOMAIN by signed parent");
2018 } else if(subtype == VAL_CLASS_POSITIVE &&
2019 qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
2020 query_dname_compare(lookup_name, qstate->qinfo.qname) == 0) {
2021 /* is a DNSKEY so lookup a bit higher since we want to
2022 * get it from a parent or from trustanchor */
2023 dname_remove_label(&lookup_name, &lookup_len);
2024 }
2025
2026 if(vq->rrset_skip > 0 || subtype == VAL_CLASS_CNAME ||
2027 subtype == VAL_CLASS_REFERRAL) {
2028 /* extract this part of orig_msg into chase_reply for
2029 * the eventual VALIDATE stage */
2030 val_fill_reply(vq->chase_reply, vq->orig_msg->rep,
2031 vq->rrset_skip, lookup_name, lookup_len,
2032 vq->signer_name);
2033 if(verbosity >= VERB_ALGO)
2034 log_dns_msg("chased extract", &vq->qchase,
2035 vq->chase_reply);
2036 }
2037
2038 vq->key_entry = key_cache_obtain(ve->kcache, lookup_name, lookup_len,
2039 vq->qchase.qclass, qstate->region, *qstate->env->now);
2040
2041 /* there is no key and no trust anchor */
2042 if(vq->key_entry == NULL && anchor == NULL) {
2043 /*response isn't under a trust anchor, so we cannot validate.*/
2044 vq->chase_reply->security = sec_status_indeterminate;
2045 update_reason_bogus(vq->chase_reply, LDNS_EDE_DNSSEC_INDETERMINATE);
2046 /* go to finished state to cache this result */
2047 vq->state = VAL_FINISHED_STATE;
2048 return 1;
2049 }
2050 /* if not key, or if keyentry is *above* the trustanchor, i.e.
2051 * the keyentry is based on another (higher) trustanchor */
2052 else if(vq->key_entry == NULL || (anchor &&
2053 dname_strict_subdomain_c(anchor->name, vq->key_entry->name))) {
2054 /* trust anchor is an 'unsigned' trust anchor */
2055 if(anchor && anchor->numDS == 0 && anchor->numDNSKEY == 0) {
2056 vq->chase_reply->security = sec_status_insecure;
2057 val_mark_insecure(vq->chase_reply, anchor->name,
2058 qstate->env->rrset_cache, qstate->env);
2059 lock_basic_unlock(&anchor->lock);
2060 /* go to finished state to cache this result */
2061 vq->state = VAL_FINISHED_STATE;
2062 return 1;
2063 }
2064 /* fire off a trust anchor priming query. */
2065 verbose(VERB_DETAIL, "prime trust anchor");
2066 if(!prime_trust_anchor(qstate, vq, id, anchor)) {
2067 lock_basic_unlock(&anchor->lock);
2068 return val_error(qstate, id);
2069 }
2070 lock_basic_unlock(&anchor->lock);
2071 /* and otherwise, don't continue processing this event.
2072 * (it will be reactivated when the priming query returns). */
2073 vq->state = VAL_FINDKEY_STATE;
2074 return 0;
2075 }
2076 if(anchor) {
2077 lock_basic_unlock(&anchor->lock);
2078 }
2079
2080 if(key_entry_isnull(vq->key_entry)) {
2081 /* response is under a null key, so we cannot validate
2082 * However, we do set the status to INSECURE, since it is
2083 * essentially proven insecure. */
2084 vq->chase_reply->security = sec_status_insecure;
2085 val_mark_insecure(vq->chase_reply, vq->key_entry->name,
2086 qstate->env->rrset_cache, qstate->env);
2087 /* go to finished state to cache this result */
2088 vq->state = VAL_FINISHED_STATE;
2089 return 1;
2090 } else if(key_entry_isbad(vq->key_entry)) {
2091 /* Bad keys should have the relevant EDE code and text */
2092 sldns_ede_code ede = key_entry_get_reason_bogus(vq->key_entry);
2093 /* key is bad, chain is bad, reply is bogus */
2094 errinf_dname(qstate, "key for validation", vq->key_entry->name);
2095 errinf_ede(qstate, "is marked as invalid", ede);
2096 errinf(qstate, "because of a previous");
2097 errinf(qstate, key_entry_get_reason(vq->key_entry));
2098
2099 /* no retries, stop bothering the authority until timeout */
2100 vq->restart_count = ve->max_restart;
2101 vq->chase_reply->security = sec_status_bogus;
2102 update_reason_bogus(vq->chase_reply, ede);
2103 vq->state = VAL_FINISHED_STATE;
2104 return 1;
2105 }
2106
2107 /* otherwise, we have our "closest" cached key -- continue
2108 * processing in the next state. */
2109 vq->state = VAL_FINDKEY_STATE;
2110 return 1;
2111 }
2112
2113 /**
2114 * Process the FINDKEY state. Generally this just calculates the next name
2115 * to query and either issues a DS or a DNSKEY query. It will check to see
2116 * if the correct key has already been reached, in which case it will
2117 * advance the event to the next state.
2118 *
2119 * @param qstate: query state.
2120 * @param vq: validator query state.
2121 * @param id: module id.
2122 * @return true if the event should be processed further on return, false if
2123 * not.
2124 */
2125 static int
processFindKey(struct module_qstate * qstate,struct val_qstate * vq,int id)2126 processFindKey(struct module_qstate* qstate, struct val_qstate* vq, int id)
2127 {
2128 uint8_t* target_key_name, *current_key_name;
2129 size_t target_key_len;
2130 int strip_lab;
2131 struct module_qstate* newq = NULL;
2132
2133 log_query_info(VERB_ALGO, "validator: FindKey", &vq->qchase);
2134 /* We know that state.key_entry is not 0 or bad key -- if it were,
2135 * then previous processing should have directed this event to
2136 * a different state.
2137 * It could be an isnull key, which signals the DNSKEY failed
2138 * with retry and has to be looked up again. */
2139 log_assert(vq->key_entry && !key_entry_isbad(vq->key_entry));
2140 if(key_entry_isnull(vq->key_entry)) {
2141 if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
2142 vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
2143 vq->qchase.qclass, BIT_CD, &newq, 0)) {
2144 verbose(VERB_ALGO, "error generating DNSKEY request");
2145 return val_error(qstate, id);
2146 }
2147 return 0;
2148 }
2149
2150 target_key_name = vq->signer_name;
2151 target_key_len = vq->signer_len;
2152 if(!target_key_name) {
2153 target_key_name = vq->qchase.qname;
2154 target_key_len = vq->qchase.qname_len;
2155 }
2156
2157 current_key_name = vq->key_entry->name;
2158
2159 /* If our current key entry matches our target, then we are done. */
2160 if(query_dname_compare(target_key_name, current_key_name) == 0) {
2161 vq->state = VAL_VALIDATE_STATE;
2162 return 1;
2163 }
2164
2165 if(vq->empty_DS_name) {
2166 /* if the last empty nonterminal/emptyDS name we detected is
2167 * below the current key, use that name to make progress
2168 * along the chain of trust */
2169 if(query_dname_compare(target_key_name,
2170 vq->empty_DS_name) == 0) {
2171 /* do not query for empty_DS_name again */
2172 verbose(VERB_ALGO, "Cannot retrieve DS for signature");
2173 errinf_ede(qstate, "no signatures", LDNS_EDE_RRSIGS_MISSING);
2174 errinf_origin(qstate, qstate->reply_origin);
2175 vq->chase_reply->security = sec_status_bogus;
2176 update_reason_bogus(vq->chase_reply, LDNS_EDE_RRSIGS_MISSING);
2177 vq->state = VAL_FINISHED_STATE;
2178 return 1;
2179 }
2180 current_key_name = vq->empty_DS_name;
2181 }
2182
2183 log_nametypeclass(VERB_ALGO, "current keyname", current_key_name,
2184 LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
2185 log_nametypeclass(VERB_ALGO, "target keyname", target_key_name,
2186 LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
2187 /* assert we are walking down the DNS tree */
2188 if(!dname_subdomain_c(target_key_name, current_key_name)) {
2189 verbose(VERB_ALGO, "bad signer name");
2190 vq->chase_reply->security = sec_status_bogus;
2191 vq->state = VAL_FINISHED_STATE;
2192 return 1;
2193 }
2194 /* so this value is >= -1 */
2195 strip_lab = dname_count_labels(target_key_name) -
2196 dname_count_labels(current_key_name) - 1;
2197 log_assert(strip_lab >= -1);
2198 verbose(VERB_ALGO, "striplab %d", strip_lab);
2199 if(strip_lab > 0) {
2200 dname_remove_labels(&target_key_name, &target_key_len,
2201 strip_lab);
2202 }
2203 log_nametypeclass(VERB_ALGO, "next keyname", target_key_name,
2204 LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
2205
2206 /* The next step is either to query for the next DS, or to query
2207 * for the next DNSKEY. */
2208 if(vq->ds_rrset)
2209 log_nametypeclass(VERB_ALGO, "DS RRset", vq->ds_rrset->rk.dname, LDNS_RR_TYPE_DS, LDNS_RR_CLASS_IN);
2210 else verbose(VERB_ALGO, "No DS RRset");
2211
2212 if(vq->ds_rrset && query_dname_compare(vq->ds_rrset->rk.dname,
2213 vq->key_entry->name) != 0) {
2214 if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
2215 vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
2216 vq->qchase.qclass, BIT_CD, &newq, 0)) {
2217 verbose(VERB_ALGO, "error generating DNSKEY request");
2218 return val_error(qstate, id);
2219 }
2220 return 0;
2221 }
2222
2223 if(!vq->ds_rrset || query_dname_compare(vq->ds_rrset->rk.dname,
2224 target_key_name) != 0) {
2225 /* check if there is a cache entry : pick up an NSEC if
2226 * there is no DS, check if that NSEC has DS-bit unset, and
2227 * thus can disprove the secure delegation we seek.
2228 * We can then use that NSEC even in the absence of a SOA
2229 * record that would be required by the iterator to supply
2230 * a completely protocol-correct response.
2231 * Uses negative cache for NSEC3 lookup of DS responses. */
2232 /* only if cache not blacklisted, of course */
2233 struct dns_msg* msg;
2234 int suspend;
2235 if(vq->sub_ds_msg) {
2236 /* We have a suspended DS reply from a sub-query;
2237 * process it. */
2238 verbose(VERB_ALGO, "Process suspended sub DS response");
2239 msg = vq->sub_ds_msg;
2240 process_ds_response(qstate, vq, id, LDNS_RCODE_NOERROR,
2241 msg, &msg->qinfo, NULL, &suspend, NULL);
2242 if(suspend) {
2243 /* we'll come back here later to continue */
2244 if(!validate_suspend_setup_timer(qstate, vq,
2245 id, VAL_FINDKEY_STATE))
2246 return val_error(qstate, id);
2247 return 0;
2248 }
2249 vq->sub_ds_msg = NULL;
2250 return 1; /* continue processing ds-response results */
2251 } else if(!qstate->blacklist && !vq->chain_blacklist &&
2252 (msg=val_find_DS(qstate->env, target_key_name,
2253 target_key_len, vq->qchase.qclass, qstate->region,
2254 vq->key_entry->name)) ) {
2255 verbose(VERB_ALGO, "Process cached DS response");
2256 process_ds_response(qstate, vq, id, LDNS_RCODE_NOERROR,
2257 msg, &msg->qinfo, NULL, &suspend, NULL);
2258 if(suspend) {
2259 /* we'll come back here later to continue */
2260 if(!validate_suspend_setup_timer(qstate, vq,
2261 id, VAL_FINDKEY_STATE))
2262 return val_error(qstate, id);
2263 return 0;
2264 }
2265 return 1; /* continue processing ds-response results */
2266 }
2267 if(!generate_request(qstate, id, target_key_name,
2268 target_key_len, LDNS_RR_TYPE_DS, vq->qchase.qclass,
2269 BIT_CD, &newq, 0)) {
2270 verbose(VERB_ALGO, "error generating DS request");
2271 return val_error(qstate, id);
2272 }
2273 return 0;
2274 }
2275
2276 /* Otherwise, it is time to query for the DNSKEY */
2277 if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
2278 vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
2279 vq->qchase.qclass, BIT_CD, &newq, 0)) {
2280 verbose(VERB_ALGO, "error generating DNSKEY request");
2281 return val_error(qstate, id);
2282 }
2283
2284 return 0;
2285 }
2286
2287 /**
2288 * Process the VALIDATE stage, the init and findkey stages are finished,
2289 * and the right keys are available to validate the response.
2290 * Or, there are no keys available, in order to invalidate the response.
2291 *
2292 * After validation, the status is recorded in the message and rrsets,
2293 * and finished state is started.
2294 *
2295 * @param qstate: query state.
2296 * @param vq: validator query state.
2297 * @param ve: validator shared global environment.
2298 * @param id: module id.
2299 * @return true if the event should be processed further on return, false if
2300 * not.
2301 */
2302 static int
processValidate(struct module_qstate * qstate,struct val_qstate * vq,struct val_env * ve,int id)2303 processValidate(struct module_qstate* qstate, struct val_qstate* vq,
2304 struct val_env* ve, int id)
2305 {
2306 enum val_classification subtype;
2307 int rcode, suspend, nsec3_calculations = 0;
2308
2309 if(!vq->key_entry) {
2310 verbose(VERB_ALGO, "validate: no key entry, failed");
2311 return val_error(qstate, id);
2312 }
2313
2314 /* This is the default next state. */
2315 vq->state = VAL_FINISHED_STATE;
2316
2317 /* Unsigned responses must be underneath a "null" key entry.*/
2318 if(key_entry_isnull(vq->key_entry)) {
2319 verbose(VERB_DETAIL, "Verified that %sresponse is INSECURE",
2320 vq->signer_name?"":"unsigned ");
2321 vq->chase_reply->security = sec_status_insecure;
2322 val_mark_insecure(vq->chase_reply, vq->key_entry->name,
2323 qstate->env->rrset_cache, qstate->env);
2324 key_cache_insert(ve->kcache, vq->key_entry,
2325 qstate->env->cfg->val_log_level >= 2);
2326 return 1;
2327 }
2328
2329 if(key_entry_isbad(vq->key_entry)) {
2330 log_nametypeclass(VERB_DETAIL, "Could not establish a chain "
2331 "of trust to keys for", vq->key_entry->name,
2332 LDNS_RR_TYPE_DNSKEY, vq->key_entry->key_class);
2333 vq->chase_reply->security = sec_status_bogus;
2334 update_reason_bogus(vq->chase_reply,
2335 key_entry_get_reason_bogus(vq->key_entry));
2336 errinf_ede(qstate, "while building chain of trust",
2337 key_entry_get_reason_bogus(vq->key_entry));
2338 if(!val_can_restart(qstate, vq, ve))
2339 key_cache_insert(ve->kcache, vq->key_entry,
2340 qstate->env->cfg->val_log_level >= 2);
2341 return 1;
2342 }
2343
2344 /* signerName being null is the indicator that this response was
2345 * unsigned */
2346 if(vq->signer_name == NULL) {
2347 log_query_info(VERB_ALGO, "processValidate: state has no "
2348 "signer name", &vq->qchase);
2349 verbose(VERB_DETAIL, "Could not establish validation of "
2350 "INSECURE status of unsigned response.");
2351 errinf_ede(qstate, "no signatures", LDNS_EDE_RRSIGS_MISSING);
2352 errinf_origin(qstate, qstate->reply_origin);
2353 vq->chase_reply->security = sec_status_bogus;
2354 update_reason_bogus(vq->chase_reply, LDNS_EDE_RRSIGS_MISSING);
2355 return 1;
2356 }
2357 subtype = val_classify_response(qstate->query_flags, &qstate->qinfo,
2358 &vq->qchase, vq->orig_msg->rep, vq->rrset_skip);
2359 if(subtype != VAL_CLASS_REFERRAL)
2360 remove_spurious_authority(vq->chase_reply, vq->orig_msg->rep);
2361 if(subtype == VAL_CLASS_ANY)
2362 shorten_answer_any(vq->chase_reply, vq->orig_msg->rep,
2363 vq->rrset_skip, MAX_RRSETS_ANY_VALIDATED);
2364
2365 /* check signatures in the message;
2366 * answer and authority must be valid, additional is only checked. */
2367 if(!validate_msg_signatures(qstate, vq, qstate->env, ve,
2368 vq->chase_reply, vq->key_entry, &suspend)) {
2369 if(suspend) {
2370 if(!validate_suspend_setup_timer(qstate, vq,
2371 id, VAL_VALIDATE_STATE))
2372 return val_error(qstate, id);
2373 return 0;
2374 }
2375 /* workaround bad recursor out there that truncates (even
2376 * with EDNS4k) to 512 by removing RRSIG from auth section
2377 * for positive replies*/
2378 if((subtype == VAL_CLASS_POSITIVE || subtype == VAL_CLASS_ANY
2379 || subtype == VAL_CLASS_CNAME) &&
2380 detect_wrongly_truncated(vq->orig_msg->rep)) {
2381 /* truncate the message some more */
2382 vq->orig_msg->rep->ns_numrrsets = 0;
2383 vq->orig_msg->rep->ar_numrrsets = 0;
2384 vq->orig_msg->rep->rrset_count =
2385 vq->orig_msg->rep->an_numrrsets;
2386 vq->chase_reply->ns_numrrsets = 0;
2387 vq->chase_reply->ar_numrrsets = 0;
2388 vq->chase_reply->rrset_count =
2389 vq->chase_reply->an_numrrsets;
2390 qstate->errinf = NULL;
2391 }
2392 else {
2393 verbose(VERB_DETAIL, "Validate: message contains "
2394 "bad rrsets");
2395 return 1;
2396 }
2397 }
2398
2399 switch(subtype) {
2400 case VAL_CLASS_POSITIVE:
2401 verbose(VERB_ALGO, "Validating a positive response");
2402 validate_positive_response(qstate->env, ve,
2403 &vq->qchase, vq->chase_reply, vq->key_entry,
2404 qstate, vq, &nsec3_calculations, &suspend);
2405 if(suspend) {
2406 if(!validate_suspend_setup_timer(qstate,
2407 vq, id, VAL_VALIDATE_STATE))
2408 return val_error(qstate, id);
2409 return 0;
2410 }
2411 verbose(VERB_DETAIL, "validate(positive): %s",
2412 sec_status_to_string(
2413 vq->chase_reply->security));
2414 break;
2415
2416 case VAL_CLASS_NODATA:
2417 verbose(VERB_ALGO, "Validating a nodata response");
2418 validate_nodata_response(qstate->env, ve,
2419 &vq->qchase, vq->chase_reply, vq->key_entry,
2420 qstate, vq, &nsec3_calculations, &suspend);
2421 if(suspend) {
2422 if(!validate_suspend_setup_timer(qstate,
2423 vq, id, VAL_VALIDATE_STATE))
2424 return val_error(qstate, id);
2425 return 0;
2426 }
2427 verbose(VERB_DETAIL, "validate(nodata): %s",
2428 sec_status_to_string(
2429 vq->chase_reply->security));
2430 break;
2431
2432 case VAL_CLASS_NAMEERROR:
2433 rcode = (int)FLAGS_GET_RCODE(vq->orig_msg->rep->flags);
2434 verbose(VERB_ALGO, "Validating a nxdomain response");
2435 validate_nameerror_response(qstate->env, ve,
2436 &vq->qchase, vq->chase_reply, vq->key_entry, &rcode,
2437 qstate, vq, &nsec3_calculations, &suspend);
2438 if(suspend) {
2439 if(!validate_suspend_setup_timer(qstate,
2440 vq, id, VAL_VALIDATE_STATE))
2441 return val_error(qstate, id);
2442 return 0;
2443 }
2444 verbose(VERB_DETAIL, "validate(nxdomain): %s",
2445 sec_status_to_string(
2446 vq->chase_reply->security));
2447 FLAGS_SET_RCODE(vq->orig_msg->rep->flags, rcode);
2448 FLAGS_SET_RCODE(vq->chase_reply->flags, rcode);
2449 break;
2450
2451 case VAL_CLASS_CNAME:
2452 verbose(VERB_ALGO, "Validating a cname response");
2453 validate_cname_response(qstate->env, ve,
2454 &vq->qchase, vq->chase_reply, vq->key_entry,
2455 qstate, vq, &nsec3_calculations, &suspend);
2456 if(suspend) {
2457 if(!validate_suspend_setup_timer(qstate,
2458 vq, id, VAL_VALIDATE_STATE))
2459 return val_error(qstate, id);
2460 return 0;
2461 }
2462 verbose(VERB_DETAIL, "validate(cname): %s",
2463 sec_status_to_string(
2464 vq->chase_reply->security));
2465 break;
2466
2467 case VAL_CLASS_CNAMENOANSWER:
2468 verbose(VERB_ALGO, "Validating a cname noanswer "
2469 "response");
2470 validate_cname_noanswer_response(qstate->env, ve,
2471 &vq->qchase, vq->chase_reply, vq->key_entry,
2472 qstate, vq, &nsec3_calculations, &suspend);
2473 if(suspend) {
2474 if(!validate_suspend_setup_timer(qstate,
2475 vq, id, VAL_VALIDATE_STATE))
2476 return val_error(qstate, id);
2477 return 0;
2478 }
2479 verbose(VERB_DETAIL, "validate(cname_noanswer): %s",
2480 sec_status_to_string(
2481 vq->chase_reply->security));
2482 break;
2483
2484 case VAL_CLASS_REFERRAL:
2485 verbose(VERB_ALGO, "Validating a referral response");
2486 validate_referral_response(qstate->env, vq->chase_reply);
2487 verbose(VERB_DETAIL, "validate(referral): %s",
2488 sec_status_to_string(
2489 vq->chase_reply->security));
2490 break;
2491
2492 case VAL_CLASS_ANY:
2493 verbose(VERB_ALGO, "Validating a positive ANY "
2494 "response");
2495 validate_any_response(qstate->env, ve, &vq->qchase,
2496 vq->chase_reply, vq->key_entry, qstate, vq,
2497 &nsec3_calculations, &suspend);
2498 if(suspend) {
2499 if(!validate_suspend_setup_timer(qstate,
2500 vq, id, VAL_VALIDATE_STATE))
2501 return val_error(qstate, id);
2502 return 0;
2503 }
2504 verbose(VERB_DETAIL, "validate(positive_any): %s",
2505 sec_status_to_string(
2506 vq->chase_reply->security));
2507 break;
2508
2509 default:
2510 log_err("validate: unhandled response subtype: %d",
2511 subtype);
2512 }
2513 if(vq->chase_reply->security == sec_status_bogus) {
2514 if(subtype == VAL_CLASS_POSITIVE)
2515 errinf(qstate, "wildcard");
2516 else errinf(qstate, val_classification_to_string(subtype));
2517 errinf(qstate, "proof failed");
2518 errinf_origin(qstate, qstate->reply_origin);
2519 }
2520
2521 return 1;
2522 }
2523
2524 /**
2525 * The Finished state. The validation status (good or bad) has been determined.
2526 *
2527 * @param qstate: query state.
2528 * @param vq: validator query state.
2529 * @param ve: validator shared global environment.
2530 * @param id: module id.
2531 * @return true if the event should be processed further on return, false if
2532 * not.
2533 */
2534 static int
processFinished(struct module_qstate * qstate,struct val_qstate * vq,struct val_env * ve,int id)2535 processFinished(struct module_qstate* qstate, struct val_qstate* vq,
2536 struct val_env* ve, int id)
2537 {
2538 enum val_classification subtype = val_classify_response(
2539 qstate->query_flags, &qstate->qinfo, &vq->qchase,
2540 vq->orig_msg->rep, vq->rrset_skip);
2541
2542 /* store overall validation result in orig_msg */
2543 if(vq->rrset_skip == 0) {
2544 vq->orig_msg->rep->security = vq->chase_reply->security;
2545 update_reason_bogus(vq->orig_msg->rep, vq->chase_reply->reason_bogus);
2546 } else if(subtype != VAL_CLASS_REFERRAL ||
2547 vq->rrset_skip < vq->orig_msg->rep->an_numrrsets +
2548 vq->orig_msg->rep->ns_numrrsets) {
2549 /* ignore sec status of additional section if a referral
2550 * type message skips there and
2551 * use the lowest security status as end result. */
2552 if(vq->chase_reply->security < vq->orig_msg->rep->security) {
2553 vq->orig_msg->rep->security =
2554 vq->chase_reply->security;
2555 update_reason_bogus(vq->orig_msg->rep, vq->chase_reply->reason_bogus);
2556 }
2557 }
2558
2559 if(subtype == VAL_CLASS_REFERRAL) {
2560 if(qstate->env->cfg->val_clean_additional) {
2561 /* for a referral, move to next unchecked rrset and check it*/
2562 vq->rrset_skip = val_next_unchecked(vq->orig_msg->rep,
2563 vq->rrset_skip);
2564 if(vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
2565 /* and restart for this rrset */
2566 verbose(VERB_ALGO, "validator: go to next rrset");
2567 vq->chase_reply->security = sec_status_unchecked;
2568 vq->state = VAL_INIT_STATE;
2569 return 1;
2570 }
2571 }
2572 /* referral chase is done */
2573 }
2574 if(vq->chase_reply->security != sec_status_bogus &&
2575 subtype == VAL_CLASS_CNAME) {
2576 /* chase the CNAME; process next part of the message */
2577 if(!val_chase_cname(&vq->qchase, vq->orig_msg->rep,
2578 &vq->rrset_skip)) {
2579 verbose(VERB_ALGO, "validator: failed to chase CNAME");
2580 vq->orig_msg->rep->security = sec_status_bogus;
2581 update_reason_bogus(vq->orig_msg->rep, LDNS_EDE_DNSSEC_BOGUS);
2582 } else {
2583 /* restart process for new qchase at rrset_skip */
2584 log_query_info(VERB_ALGO, "validator: chased to",
2585 &vq->qchase);
2586 vq->chase_reply->security = sec_status_unchecked;
2587 vq->state = VAL_INIT_STATE;
2588 return 1;
2589 }
2590 }
2591
2592 if(vq->orig_msg->rep->security == sec_status_secure) {
2593 /* If the message is secure, check that all rrsets are
2594 * secure (i.e. some inserted RRset for CNAME chain with
2595 * a different signer name). And drop additional rrsets
2596 * that are not secure (if clean-additional option is set) */
2597 /* this may cause the msg to be marked bogus */
2598 val_check_nonsecure(qstate->env, vq->orig_msg->rep);
2599 if(vq->orig_msg->rep->security == sec_status_secure) {
2600 log_query_info(VERB_DETAIL, "validation success",
2601 &qstate->qinfo);
2602 if(!qstate->no_cache_store) {
2603 val_neg_addreply(qstate->env->neg_cache,
2604 vq->orig_msg->rep);
2605 }
2606 }
2607 }
2608
2609 /* if the result is bogus - set message ttl to bogus ttl to avoid
2610 * endless bogus revalidation */
2611 if(vq->orig_msg->rep->security == sec_status_bogus) {
2612 struct msgreply_entry* e;
2613
2614 /* see if we can try again to fetch data */
2615 if(val_can_restart(qstate, vq, ve)) {
2616 verbose(VERB_ALGO, "validation failed, "
2617 "blacklist and retry to fetch data");
2618 val_blacklist(&qstate->blacklist, qstate->region,
2619 qstate->reply_origin, 0);
2620 qstate->reply_origin = NULL;
2621 qstate->errinf = NULL;
2622 val_restart(vq);
2623 verbose(VERB_ALGO, "pass back to next module");
2624 qstate->ext_state[id] = module_restart_next;
2625 return 0;
2626 }
2627
2628 if(qstate->env->cfg->serve_expired &&
2629 (e=msg_cache_lookup(qstate->env, qstate->qinfo.qname,
2630 qstate->qinfo.qname_len, qstate->qinfo.qtype,
2631 qstate->qinfo.qclass, qstate->query_flags,
2632 0 /*now; allow expired*/,
2633 1 /*wr; we may update the data*/))) {
2634 struct reply_info* rep = (struct reply_info*)e->entry.data;
2635 if(rep && rep->security > sec_status_bogus &&
2636 (!qstate->env->cfg->serve_expired_ttl ||
2637 qstate->env->cfg->serve_expired_ttl_reset ||
2638 *qstate->env->now <= rep->serve_expired_ttl)) {
2639 verbose(VERB_ALGO, "validation failed but "
2640 "previously cached valid response "
2641 "exists; set serve-expired-norec-ttl "
2642 "for response in cache");
2643 rep->serve_expired_norec_ttl = NORR_TTL +
2644 *qstate->env->now;
2645 if(qstate->env->cfg->serve_expired_ttl_reset &&
2646 *qstate->env->now + qstate->env->cfg->serve_expired_ttl
2647 > rep->serve_expired_ttl) {
2648 verbose(VERB_ALGO, "reset serve-expired-ttl for "
2649 "valid response in cache");
2650 rep->serve_expired_ttl = *qstate->env->now +
2651 qstate->env->cfg->serve_expired_ttl;
2652 }
2653 /* Return an error response.
2654 * If serve-expired-client-timeout is enabled,
2655 * the client-timeout logic will try to find an
2656 * (expired) answer in the cache as last
2657 * resort. If it is not enabled, expired
2658 * answers are already used before the mesh
2659 * activation. */
2660 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
2661 qstate->return_msg = NULL;
2662 qstate->ext_state[id] = module_finished;
2663 lock_rw_unlock(&e->entry.lock);
2664 return 0;
2665 }
2666 lock_rw_unlock(&e->entry.lock);
2667 }
2668
2669 vq->orig_msg->rep->ttl = ve->bogus_ttl;
2670 vq->orig_msg->rep->prefetch_ttl =
2671 PREFETCH_TTL_CALC(vq->orig_msg->rep->ttl);
2672 vq->orig_msg->rep->serve_expired_ttl =
2673 vq->orig_msg->rep->ttl + qstate->env->cfg->serve_expired_ttl;
2674 if((qstate->env->cfg->val_log_level >= 1 ||
2675 qstate->env->cfg->log_servfail) &&
2676 !qstate->env->cfg->val_log_squelch) {
2677 if(qstate->env->cfg->val_log_level < 2 &&
2678 !qstate->env->cfg->log_servfail)
2679 log_query_info(NO_VERBOSE, "validation failure",
2680 &qstate->qinfo);
2681 else {
2682 char* err_str = errinf_to_str_bogus(qstate,
2683 qstate->region);
2684 if(err_str) {
2685 log_info("%s", err_str);
2686 vq->orig_msg->rep->reason_bogus_str = err_str;
2687 }
2688 }
2689 }
2690 /*
2691 * If set, the validator will not make messages bogus, instead
2692 * indeterminate is issued, so that no clients receive SERVFAIL.
2693 * This allows an operator to run validation 'shadow' without
2694 * hurting responses to clients.
2695 */
2696 /* If we are in permissive mode, bogus gets indeterminate */
2697 if(qstate->env->cfg->val_permissive_mode)
2698 vq->orig_msg->rep->security = sec_status_indeterminate;
2699 }
2700
2701 if(vq->orig_msg->rep->security == sec_status_secure &&
2702 qstate->env->cfg->root_key_sentinel &&
2703 (qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
2704 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA)) {
2705 char* keytag_start;
2706 uint16_t keytag;
2707 if(*qstate->qinfo.qname == strlen(SENTINEL_IS) +
2708 SENTINEL_KEYTAG_LEN &&
2709 dname_lab_startswith(qstate->qinfo.qname, SENTINEL_IS,
2710 &keytag_start)) {
2711 if(sentinel_get_keytag(keytag_start, &keytag) &&
2712 !anchor_has_keytag(qstate->env->anchors,
2713 (uint8_t*)"", 1, 0, vq->qchase.qclass, keytag)) {
2714 vq->orig_msg->rep->security =
2715 sec_status_secure_sentinel_fail;
2716 }
2717 } else if(*qstate->qinfo.qname == strlen(SENTINEL_NOT) +
2718 SENTINEL_KEYTAG_LEN &&
2719 dname_lab_startswith(qstate->qinfo.qname, SENTINEL_NOT,
2720 &keytag_start)) {
2721 if(sentinel_get_keytag(keytag_start, &keytag) &&
2722 anchor_has_keytag(qstate->env->anchors,
2723 (uint8_t*)"", 1, 0, vq->qchase.qclass, keytag)) {
2724 vq->orig_msg->rep->security =
2725 sec_status_secure_sentinel_fail;
2726 }
2727 }
2728 }
2729
2730 /* Update rep->reason_bogus as it is the one being cached */
2731 update_reason_bogus(vq->orig_msg->rep, errinf_to_reason_bogus(qstate));
2732 if(vq->orig_msg->rep->security != sec_status_bogus &&
2733 vq->orig_msg->rep->security != sec_status_secure_sentinel_fail
2734 && vq->orig_msg->rep->reason_bogus == LDNS_EDE_DNSSEC_BOGUS) {
2735 /* Not interested in any DNSSEC EDE here, validator by default
2736 * uses LDNS_EDE_DNSSEC_BOGUS;
2737 * TODO revisit default value for the module */
2738 vq->orig_msg->rep->reason_bogus = LDNS_EDE_NONE;
2739 }
2740
2741 /* store results in cache */
2742 if((qstate->query_flags&BIT_RD)) {
2743 /* if secure, this will override cache anyway, no need
2744 * to check if from parentNS */
2745 if(!qstate->no_cache_store) {
2746 if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo,
2747 vq->orig_msg->rep, 0, qstate->prefetch_leeway,
2748 0, qstate->region, qstate->query_flags,
2749 qstate->qstarttime, qstate->is_valrec)) {
2750 log_err("out of memory caching validator results");
2751 }
2752 }
2753 } else {
2754 /* for a referral, store the verified RRsets */
2755 /* and this does not get prefetched, so no leeway */
2756 if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo,
2757 vq->orig_msg->rep, 1, 0, 0, qstate->region,
2758 qstate->query_flags, qstate->qstarttime,
2759 qstate->is_valrec)) {
2760 log_err("out of memory caching validator results");
2761 }
2762 }
2763 qstate->return_rcode = LDNS_RCODE_NOERROR;
2764 qstate->return_msg = vq->orig_msg;
2765 qstate->ext_state[id] = module_finished;
2766 return 0;
2767 }
2768
2769 /**
2770 * Handle validator state.
2771 * If a method returns true, the next state is started. If false, then
2772 * processing will stop.
2773 * @param qstate: query state.
2774 * @param vq: validator query state.
2775 * @param ve: validator shared global environment.
2776 * @param id: module id.
2777 */
2778 static void
val_handle(struct module_qstate * qstate,struct val_qstate * vq,struct val_env * ve,int id)2779 val_handle(struct module_qstate* qstate, struct val_qstate* vq,
2780 struct val_env* ve, int id)
2781 {
2782 int cont = 1;
2783 while(cont) {
2784 verbose(VERB_ALGO, "val handle processing q with state %s",
2785 val_state_to_string(vq->state));
2786 switch(vq->state) {
2787 case VAL_INIT_STATE:
2788 cont = processInit(qstate, vq, ve, id);
2789 break;
2790 case VAL_FINDKEY_STATE:
2791 cont = processFindKey(qstate, vq, id);
2792 break;
2793 case VAL_VALIDATE_STATE:
2794 cont = processValidate(qstate, vq, ve, id);
2795 break;
2796 case VAL_FINISHED_STATE:
2797 cont = processFinished(qstate, vq, ve, id);
2798 break;
2799 default:
2800 log_warn("validator: invalid state %d",
2801 vq->state);
2802 cont = 0;
2803 break;
2804 }
2805 }
2806 }
2807
2808 void
val_operate(struct module_qstate * qstate,enum module_ev event,int id,struct outbound_entry * outbound)2809 val_operate(struct module_qstate* qstate, enum module_ev event, int id,
2810 struct outbound_entry* outbound)
2811 {
2812 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
2813 struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
2814 verbose(VERB_QUERY, "validator[module %d] operate: extstate:%s "
2815 "event:%s", id, strextstate(qstate->ext_state[id]),
2816 strmodulevent(event));
2817 log_query_info(VERB_QUERY, "validator operate: query",
2818 &qstate->qinfo);
2819 if(vq && qstate->qinfo.qname != vq->qchase.qname)
2820 log_query_info(VERB_QUERY, "validator operate: chased to",
2821 &vq->qchase);
2822 (void)outbound;
2823 if(event == module_event_new ||
2824 (event == module_event_pass && vq == NULL)) {
2825
2826 /* pass request to next module, to get it */
2827 verbose(VERB_ALGO, "validator: pass to next module");
2828 qstate->ext_state[id] = module_wait_module;
2829 return;
2830 }
2831 if(event == module_event_moddone) {
2832 /* check if validation is needed */
2833 verbose(VERB_ALGO, "validator: nextmodule returned");
2834
2835 if(!needs_validation(qstate, qstate->return_rcode,
2836 qstate->return_msg)) {
2837 /* no need to validate this */
2838 /* For valrec responses, leave at sec_status_unchecked,
2839 * no security status has been requested for it. */
2840 if(qstate->return_msg && !qstate->is_valrec)
2841 qstate->return_msg->rep->security =
2842 sec_status_indeterminate;
2843 qstate->ext_state[id] = module_finished;
2844 return;
2845 }
2846 if(already_validated(qstate->return_msg)) {
2847 qstate->ext_state[id] = module_finished;
2848 return;
2849 }
2850 if(qstate->rpz_applied) {
2851 verbose(VERB_ALGO, "rpz applied, mark it as insecure");
2852 if(qstate->return_msg)
2853 qstate->return_msg->rep->security =
2854 sec_status_insecure;
2855 qstate->ext_state[id] = module_finished;
2856 return;
2857 }
2858 /* qclass ANY should have validation result from spawned
2859 * queries. If we get here, it is bogus or an internal error */
2860 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
2861 verbose(VERB_ALGO, "cannot validate classANY: bogus");
2862 if(qstate->return_msg) {
2863 qstate->return_msg->rep->security =
2864 sec_status_bogus;
2865 update_reason_bogus(qstate->return_msg->rep, LDNS_EDE_DNSSEC_BOGUS);
2866 }
2867 qstate->ext_state[id] = module_finished;
2868 return;
2869 }
2870 /* create state to start validation */
2871 qstate->ext_state[id] = module_error; /* override this */
2872 if(!vq) {
2873 vq = val_new(qstate, id);
2874 if(!vq) {
2875 log_err("validator: malloc failure");
2876 qstate->ext_state[id] = module_error;
2877 return;
2878 }
2879 } else if(!vq->orig_msg) {
2880 if(!val_new_getmsg(qstate, vq)) {
2881 log_err("validator: malloc failure");
2882 qstate->ext_state[id] = module_error;
2883 return;
2884 }
2885 }
2886 val_handle(qstate, vq, ve, id);
2887 return;
2888 }
2889 if(event == module_event_pass) {
2890 qstate->ext_state[id] = module_error; /* override this */
2891 /* continue processing, since val_env exists */
2892 val_handle(qstate, vq, ve, id);
2893 return;
2894 }
2895 log_err("validator: bad event %s", strmodulevent(event));
2896 qstate->ext_state[id] = module_error;
2897 return;
2898 }
2899
2900 /**
2901 * Evaluate the response to a priming request.
2902 *
2903 * @param dnskey_rrset: DNSKEY rrset (can be NULL if none) in prime reply.
2904 * (this rrset is allocated in the wrong region, not the qstate).
2905 * @param ta: trust anchor.
2906 * @param qstate: qstate that needs key.
2907 * @param vq: validator qstate.
2908 * @param id: module id.
2909 * @param sub_qstate: the sub query state, that is the lookup that fetched
2910 * the trust anchor data, it contains error information for the answer.
2911 * @return new key entry or NULL on allocation failure.
2912 * The key entry will either contain a validated DNSKEY rrset, or
2913 * represent a Null key (query failed, but validation did not), or a
2914 * Bad key (validation failed).
2915 */
2916 static struct key_entry_key*
primeResponseToKE(struct ub_packed_rrset_key * dnskey_rrset,struct trust_anchor * ta,struct module_qstate * qstate,struct val_qstate * vq,int id,struct module_qstate * sub_qstate)2917 primeResponseToKE(struct ub_packed_rrset_key* dnskey_rrset,
2918 struct trust_anchor* ta, struct module_qstate* qstate,
2919 struct val_qstate* vq, int id, struct module_qstate* sub_qstate)
2920 {
2921 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
2922 struct key_entry_key* kkey = NULL;
2923 enum sec_status sec = sec_status_unchecked;
2924 char reasonbuf[256];
2925 char* reason = NULL;
2926 sldns_ede_code reason_bogus = LDNS_EDE_DNSSEC_BOGUS;
2927 int downprot = qstate->env->cfg->harden_algo_downgrade;
2928
2929 if(!dnskey_rrset) {
2930 char* err = errinf_to_str_misc(sub_qstate);
2931 char rstr[1024];
2932 log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
2933 "could not fetch DNSKEY rrset",
2934 ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
2935 reason_bogus = LDNS_EDE_DNSKEY_MISSING;
2936 if(!err) {
2937 snprintf(rstr, sizeof(rstr), "no DNSKEY rrset");
2938 } else {
2939 snprintf(rstr, sizeof(rstr), "no DNSKEY rrset "
2940 "[%s]", err);
2941 }
2942 if(qstate->env->cfg->harden_dnssec_stripped) {
2943 errinf_ede(qstate, rstr, reason_bogus);
2944 kkey = key_entry_create_bad(qstate->region, ta->name,
2945 ta->namelen, ta->dclass, BOGUS_KEY_TTL,
2946 reason_bogus, rstr, *qstate->env->now);
2947 } else kkey = key_entry_create_null(qstate->region, ta->name,
2948 ta->namelen, ta->dclass, NULL_KEY_TTL,
2949 reason_bogus, rstr, *qstate->env->now);
2950 if(!kkey) {
2951 log_err("out of memory: allocate fail prime key");
2952 return NULL;
2953 }
2954 return kkey;
2955 }
2956 /* attempt to verify with trust anchor DS and DNSKEY */
2957 kkey = val_verify_new_DNSKEYs_with_ta(qstate->region, qstate->env, ve,
2958 dnskey_rrset, ta->ds_rrset, ta->dnskey_rrset, downprot,
2959 &reason, &reason_bogus, qstate, vq, reasonbuf,
2960 sizeof(reasonbuf));
2961 if(!kkey) {
2962 log_err("out of memory: verifying prime TA");
2963 return NULL;
2964 }
2965 if(key_entry_isgood(kkey))
2966 sec = sec_status_secure;
2967 else
2968 sec = sec_status_bogus;
2969 verbose(VERB_DETAIL, "validate keys with anchor(DS): %s",
2970 sec_status_to_string(sec));
2971
2972 if(sec != sec_status_secure) {
2973 log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
2974 "DNSKEY rrset is not secure",
2975 ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
2976 /* NOTE: in this case, we should probably reject the trust
2977 * anchor for longer, perhaps forever. */
2978 if(qstate->env->cfg->harden_dnssec_stripped) {
2979 errinf_ede(qstate, reason, reason_bogus);
2980 kkey = key_entry_create_bad(qstate->region, ta->name,
2981 ta->namelen, ta->dclass, BOGUS_KEY_TTL,
2982 reason_bogus, reason,
2983 *qstate->env->now);
2984 } else kkey = key_entry_create_null(qstate->region, ta->name,
2985 ta->namelen, ta->dclass, NULL_KEY_TTL,
2986 reason_bogus, reason,
2987 *qstate->env->now);
2988 if(!kkey) {
2989 log_err("out of memory: allocate null prime key");
2990 return NULL;
2991 }
2992 return kkey;
2993 }
2994
2995 log_nametypeclass(VERB_DETAIL, "Successfully primed trust anchor",
2996 ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
2997 return kkey;
2998 }
2999
3000 /**
3001 * In inform supers, with the resulting message and rcode and the current
3002 * keyset in the super state, validate the DS response, returning a KeyEntry.
3003 *
3004 * @param qstate: query state that is validating and asked for a DS.
3005 * @param vq: validator query state
3006 * @param id: module id.
3007 * @param rcode: rcode result value.
3008 * @param msg: result message (if rcode is OK).
3009 * @param qinfo: from the sub query state, query info.
3010 * @param ke: the key entry to return. It returns
3011 * is_bad if the DS response fails to validate, is_null if the
3012 * DS response indicated an end to secure space, is_good if the DS
3013 * validated. It returns ke=NULL if the DS response indicated that the
3014 * request wasn't a delegation point.
3015 * @param sub_qstate: the sub query state, that is the lookup that fetched
3016 * the trust anchor data, it contains error information for the answer.
3017 * Can be NULL.
3018 * @return
3019 * 0 on success,
3020 * 1 on servfail error (malloc failure),
3021 * 2 on NSEC3 suspend.
3022 */
3023 static int
ds_response_to_ke(struct module_qstate * qstate,struct val_qstate * vq,int id,int rcode,struct dns_msg * msg,struct query_info * qinfo,struct key_entry_key ** ke,struct module_qstate * sub_qstate)3024 ds_response_to_ke(struct module_qstate* qstate, struct val_qstate* vq,
3025 int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
3026 struct key_entry_key** ke, struct module_qstate* sub_qstate)
3027 {
3028 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
3029 char reasonbuf[256];
3030 char* reason = NULL;
3031 sldns_ede_code reason_bogus = LDNS_EDE_DNSSEC_BOGUS;
3032 enum val_classification subtype;
3033 int verified;
3034 if(rcode != LDNS_RCODE_NOERROR) {
3035 char rc[16];
3036 rc[0]=0;
3037 (void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
3038 /* errors here pretty much break validation */
3039 verbose(VERB_DETAIL, "DS response was error, thus bogus");
3040 errinf(qstate, rc);
3041 reason = "no DS";
3042 if(sub_qstate) {
3043 char* err = errinf_to_str_misc(sub_qstate);
3044 if(err) {
3045 char buf[1024];
3046 snprintf(buf, sizeof(buf), "[%s]", err);
3047 errinf(qstate, buf);
3048 }
3049 }
3050 reason_bogus = LDNS_EDE_NETWORK_ERROR;
3051 errinf_ede(qstate, reason, reason_bogus);
3052 goto return_bogus;
3053 }
3054
3055 subtype = val_classify_response(BIT_RD, qinfo, qinfo, msg->rep, 0);
3056 if(subtype == VAL_CLASS_POSITIVE) {
3057 struct ub_packed_rrset_key* ds;
3058 enum sec_status sec;
3059 ds = reply_find_answer_rrset(qinfo, msg->rep);
3060 /* If there was no DS rrset, then we have misclassified
3061 * this message. */
3062 if(!ds) {
3063 log_warn("internal error: POSITIVE DS response was "
3064 "missing DS.");
3065 reason = "no DS record";
3066 errinf_ede(qstate, reason, reason_bogus);
3067 goto return_bogus;
3068 }
3069 /* Verify only returns BOGUS or SECURE. If the rrset is
3070 * bogus, then we are done. */
3071 sec = val_verify_rrset_entry(qstate->env, ve, ds,
3072 vq->key_entry, &reason, &reason_bogus,
3073 LDNS_SECTION_ANSWER, qstate, vq, &verified, reasonbuf,
3074 sizeof(reasonbuf));
3075 if(sec != sec_status_secure) {
3076 verbose(VERB_DETAIL, "DS rrset in DS response did "
3077 "not verify");
3078 errinf_ede(qstate, reason, reason_bogus);
3079 goto return_bogus;
3080 }
3081
3082 /* If the DS rrset validates, we still have to make sure
3083 * that they are usable. */
3084 if(!val_dsset_isusable(ds)) {
3085 /* If they aren't usable, then we treat it like
3086 * there was no DS. */
3087 *ke = key_entry_create_null(qstate->region,
3088 qinfo->qname, qinfo->qname_len, qinfo->qclass,
3089 ub_packed_rrset_ttl(ds),
3090 LDNS_EDE_UNSUPPORTED_DS_DIGEST, NULL,
3091 *qstate->env->now);
3092 return (*ke) == NULL;
3093 }
3094
3095 /* Otherwise, we return the positive response. */
3096 log_query_info(VERB_DETAIL, "validated DS", qinfo);
3097 *ke = key_entry_create_rrset(qstate->region,
3098 qinfo->qname, qinfo->qname_len, qinfo->qclass, ds,
3099 NULL, LDNS_EDE_NONE, NULL, *qstate->env->now);
3100 return (*ke) == NULL;
3101 } else if(subtype == VAL_CLASS_NODATA ||
3102 subtype == VAL_CLASS_NAMEERROR) {
3103 /* NODATA means that the qname exists, but that there was
3104 * no DS. This is a pretty normal case. */
3105 time_t proof_ttl = 0;
3106 enum sec_status sec;
3107
3108 /* make sure there are NSECs or NSEC3s with signatures */
3109 if(!val_has_signed_nsecs(msg->rep, &reason)) {
3110 verbose(VERB_ALGO, "no NSECs: %s", reason);
3111 reason_bogus = LDNS_EDE_NSEC_MISSING;
3112 errinf_ede(qstate, reason, reason_bogus);
3113 goto return_bogus;
3114 }
3115
3116 /* For subtype Name Error.
3117 * attempt ANS 2.8.1.0 compatibility where it sets rcode
3118 * to nxdomain, but really this is an Nodata/Noerror response.
3119 * Find and prove the empty nonterminal in that case */
3120
3121 /* Try to prove absence of the DS with NSEC */
3122 sec = val_nsec_prove_nodata_dsreply(
3123 qstate->env, ve, qinfo, msg->rep, vq->key_entry,
3124 &proof_ttl, &reason, &reason_bogus, qstate, vq,
3125 reasonbuf, sizeof(reasonbuf));
3126 switch(sec) {
3127 case sec_status_secure:
3128 verbose(VERB_DETAIL, "NSEC RRset for the "
3129 "referral proved no DS.");
3130 *ke = key_entry_create_null(qstate->region,
3131 qinfo->qname, qinfo->qname_len,
3132 qinfo->qclass, proof_ttl,
3133 LDNS_EDE_NONE, NULL,
3134 *qstate->env->now);
3135 return (*ke) == NULL;
3136 case sec_status_insecure:
3137 verbose(VERB_DETAIL, "NSEC RRset for the "
3138 "referral proved not a delegation point");
3139 *ke = NULL;
3140 return 0;
3141 case sec_status_bogus:
3142 verbose(VERB_DETAIL, "NSEC RRset for the "
3143 "referral did not prove no DS.");
3144 errinf(qstate, reason);
3145 goto return_bogus;
3146 case sec_status_unchecked:
3147 default:
3148 /* NSEC proof did not work, try next */
3149 break;
3150 }
3151
3152 if(!nsec3_cache_table_init(&vq->nsec3_cache_table, qstate->region)) {
3153 log_err("malloc failure in ds_response_to_ke for "
3154 "NSEC3 cache");
3155 reason = "malloc failure";
3156 errinf_ede(qstate, reason, 0);
3157 goto return_bogus;
3158 }
3159 sec = nsec3_prove_nods(qstate->env, ve,
3160 msg->rep->rrsets + msg->rep->an_numrrsets,
3161 msg->rep->ns_numrrsets, qinfo, vq->key_entry, &reason,
3162 &reason_bogus, qstate, vq, &vq->nsec3_cache_table,
3163 reasonbuf, sizeof(reasonbuf));
3164 switch(sec) {
3165 case sec_status_insecure:
3166 /* case insecure also continues to unsigned
3167 * space. If nsec3-iter-count too high or
3168 * optout, then treat below as unsigned */
3169 case sec_status_secure:
3170 verbose(VERB_DETAIL, "NSEC3s for the "
3171 "referral proved no DS.");
3172 *ke = key_entry_create_null(qstate->region,
3173 qinfo->qname, qinfo->qname_len,
3174 qinfo->qclass, proof_ttl,
3175 LDNS_EDE_NONE, NULL,
3176 *qstate->env->now);
3177 return (*ke) == NULL;
3178 case sec_status_indeterminate:
3179 verbose(VERB_DETAIL, "NSEC3s for the "
3180 "referral proved no delegation");
3181 *ke = NULL;
3182 return 0;
3183 case sec_status_bogus:
3184 verbose(VERB_DETAIL, "NSEC3s for the "
3185 "referral did not prove no DS.");
3186 errinf_ede(qstate, reason, reason_bogus);
3187 goto return_bogus;
3188 case sec_status_unchecked:
3189 return 2;
3190 default:
3191 /* NSEC3 proof did not work */
3192 break;
3193 }
3194
3195 /* Apparently, no available NSEC/NSEC3 proved NODATA, so
3196 * this is BOGUS. */
3197 verbose(VERB_DETAIL, "DS %s ran out of options, so return "
3198 "bogus", val_classification_to_string(subtype));
3199 reason = "no DS but also no proof of that";
3200 errinf_ede(qstate, reason, reason_bogus);
3201 goto return_bogus;
3202 } else if(subtype == VAL_CLASS_CNAME ||
3203 subtype == VAL_CLASS_CNAMENOANSWER) {
3204 /* if the CNAME matches the exact name we want and is signed
3205 * properly, then also, we are sure that no DS exists there,
3206 * much like a NODATA proof */
3207 enum sec_status sec;
3208 struct ub_packed_rrset_key* cname;
3209 cname = reply_find_rrset_section_an(msg->rep, qinfo->qname,
3210 qinfo->qname_len, LDNS_RR_TYPE_CNAME, qinfo->qclass);
3211 if(!cname) {
3212 reason = "validator classified CNAME but no "
3213 "CNAME of the queried name for DS";
3214 errinf_ede(qstate, reason, reason_bogus);
3215 goto return_bogus;
3216 }
3217 if(((struct packed_rrset_data*)cname->entry.data)->rrsig_count
3218 == 0) {
3219 if(msg->rep->an_numrrsets != 0 && ntohs(msg->rep->
3220 rrsets[0]->rk.type)==LDNS_RR_TYPE_DNAME) {
3221 reason = "DS got DNAME answer";
3222 } else {
3223 reason = "DS got unsigned CNAME answer";
3224 }
3225 errinf_ede(qstate, reason, reason_bogus);
3226 goto return_bogus;
3227 }
3228 sec = val_verify_rrset_entry(qstate->env, ve, cname,
3229 vq->key_entry, &reason, &reason_bogus,
3230 LDNS_SECTION_ANSWER, qstate, vq, &verified, reasonbuf,
3231 sizeof(reasonbuf));
3232 if(sec == sec_status_secure) {
3233 /* Check for wildcard expansion */
3234 uint8_t* wc = NULL;
3235 size_t wl = 0;
3236
3237 if(!val_rrset_wildcard(cname, &wc, &wl)) {
3238 verbose(VERB_ALGO, "CNAME has inconsistent wildcard signatures");
3239 reason = "wildcard CNAME inconsistent signatures";
3240 errinf_ede(qstate, reason, reason_bogus);
3241 goto return_bogus;
3242 }
3243
3244 if(wc != NULL) {
3245 /* Wildcard expansion detected - require NSEC proof */
3246 /* So this is a wildcard CNAME response to DS.
3247 * If the wildcard is bogus then we have bogus.
3248 * If the wildcard is true, then there is
3249 * not a referral point here or lower,
3250 * that can be insecure,
3251 * and also no DS records, here or lower. */
3252 /* For a valid chain, to DS, but this
3253 * wildcard CNAME happens in a middle label,
3254 * then that can not happen, because there is
3255 * data under that label, and thus the wildcard
3256 * should not expand.
3257 * If we are going to the wildcard, that also
3258 * does not expand the wildcard, when above it.
3259 * So for valids lookup chains to DS, no
3260 * wildcard CNAME is expected on middle labels.
3261 * For lookups to an insecure point, the
3262 * delegation is information under the label,
3263 * and thus the wildcard does not expand.
3264 * So, no insecure point is possible.
3265 * Can not get a valid chain of trust, or
3266 * to a delegation point for insecure.
3267 * Or the wildcard, its nxdomain for the qname
3268 * proof, is invalid, in which case this is
3269 * a bogus reply.
3270 * If this was a lookup where a wildcard
3271 * expansion is genuinely expected, eg,
3272 * a dnssec valid wildcard query, then the
3273 * lookup should go to the right point, and
3274 * not into the wildcard under the zone name.
3275 * For insecure, or wildcard missing
3276 * signatures, it would have to have found
3277 * the DS or insecure point earlier, in the
3278 * downwards search.
3279 * So for missing signatures, it turns the
3280 * missing signatures into a failure to the
3281 * wildcard CNAME, as the reported log.
3282 */
3283 verbose(VERB_ALGO, "wildcard CNAME in chain of trust means no DS can be found and it is also not a delegation point that can be insecure");
3284 reason = "wildcard CNAME in chain of trust means no DS found and it is also not a delegation point that can be insecure";
3285 errinf_ede(qstate, reason, reason_bogus);
3286 goto return_bogus;
3287 }
3288
3289 verbose(VERB_ALGO, "CNAME validated, "
3290 "proof that DS does not exist");
3291 /* and that it is not a referral point */
3292 *ke = NULL;
3293 return 0;
3294 }
3295 errinf(qstate, "CNAME in DS response was not secure.");
3296 errinf_ede(qstate, reason, reason_bogus);
3297 goto return_bogus;
3298 } else {
3299 verbose(VERB_QUERY, "Encountered an unhandled type of "
3300 "DS response, thus bogus.");
3301 errinf(qstate, "no DS and");
3302 reason = "no DS";
3303 if(FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NOERROR) {
3304 char rc[16];
3305 rc[0]=0;
3306 (void)sldns_wire2str_rcode_buf((int)FLAGS_GET_RCODE(
3307 msg->rep->flags), rc, sizeof(rc));
3308 errinf(qstate, rc);
3309 } else errinf(qstate, val_classification_to_string(subtype));
3310 errinf(qstate, "message fails to prove that");
3311 goto return_bogus;
3312 }
3313 return_bogus:
3314 *ke = key_entry_create_bad(qstate->region, qinfo->qname,
3315 qinfo->qname_len, qinfo->qclass, BOGUS_KEY_TTL,
3316 reason_bogus, reason, *qstate->env->now);
3317 return (*ke) == NULL;
3318 }
3319
3320 /**
3321 * Process DS response. Called from inform_supers.
3322 * Because it is in inform_supers, the mesh itself is busy doing callbacks
3323 * for a state that is to be deleted soon; don't touch the mesh; instead
3324 * set a state in the super, as the super will be reactivated soon.
3325 * Perform processing to determine what state to set in the super.
3326 *
3327 * @param qstate: query state that is validating and asked for a DS.
3328 * @param vq: validator query state
3329 * @param id: module id.
3330 * @param rcode: rcode result value.
3331 * @param msg: result message (if rcode is OK).
3332 * @param qinfo: from the sub query state, query info.
3333 * @param origin: the origin of msg.
3334 * @param suspend: returned true if the task takes too long and needs to
3335 * suspend to continue the effort later.
3336 * @param sub_qstate: the sub query state, that is the lookup that fetched
3337 * the trust anchor data, it contains error information for the answer.
3338 * Can be NULL.
3339 */
3340 static void
process_ds_response(struct module_qstate * qstate,struct val_qstate * vq,int id,int rcode,struct dns_msg * msg,struct query_info * qinfo,struct sock_list * origin,int * suspend,struct module_qstate * sub_qstate)3341 process_ds_response(struct module_qstate* qstate, struct val_qstate* vq,
3342 int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
3343 struct sock_list* origin, int* suspend,
3344 struct module_qstate* sub_qstate)
3345 {
3346 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
3347 struct key_entry_key* dske = NULL;
3348 uint8_t* olds = vq->empty_DS_name;
3349 int ret;
3350 *suspend = 0;
3351 vq->num_nsec_attempts = 0;
3352 vq->empty_DS_name = NULL;
3353 if(sub_qstate && sub_qstate->rpz_applied) {
3354 verbose(VERB_ALGO, "rpz was applied to the DS lookup, "
3355 "make it insecure");
3356 vq->key_entry = NULL;
3357 vq->state = VAL_FINISHED_STATE;
3358 vq->chase_reply->security = sec_status_insecure;
3359 return;
3360 }
3361 ret = ds_response_to_ke(qstate, vq, id, rcode, msg, qinfo, &dske,
3362 sub_qstate);
3363 /* New NSEC attempt count for next message validation. */
3364 vq->num_nsec_attempts = 0;
3365 if(ret != 0) {
3366 switch(ret) {
3367 case 1:
3368 log_err("malloc failure in process_ds_response");
3369 vq->key_entry = NULL; /* make it error */
3370 vq->state = VAL_VALIDATE_STATE;
3371 return;
3372 case 2:
3373 *suspend = 1;
3374 return;
3375 default:
3376 log_err("unhandled error value for ds_response_to_ke");
3377 vq->key_entry = NULL; /* make it error */
3378 vq->state = VAL_VALIDATE_STATE;
3379 return;
3380 }
3381 }
3382 if(dske == NULL) {
3383 vq->empty_DS_name = regional_alloc_init(qstate->region,
3384 qinfo->qname, qinfo->qname_len);
3385 if(!vq->empty_DS_name) {
3386 log_err("malloc failure in empty_DS_name");
3387 vq->key_entry = NULL; /* make it error */
3388 vq->state = VAL_VALIDATE_STATE;
3389 return;
3390 }
3391 vq->empty_DS_len = qinfo->qname_len;
3392 vq->chain_blacklist = NULL;
3393 /* ds response indicated that we aren't on a delegation point.
3394 * Keep the forState.state on FINDKEY. */
3395 } else if(key_entry_isgood(dske)) {
3396 vq->ds_rrset = key_entry_get_rrset(dske, qstate->region);
3397 if(!vq->ds_rrset) {
3398 log_err("malloc failure in process DS");
3399 vq->key_entry = NULL; /* make it error */
3400 vq->state = VAL_VALIDATE_STATE;
3401 return;
3402 }
3403 vq->chain_blacklist = NULL; /* fresh blacklist for next part*/
3404 /* Keep the forState.state on FINDKEY. */
3405 } else if(key_entry_isbad(dske)
3406 && val_can_restart(qstate, vq, ve)) {
3407 vq->empty_DS_name = olds;
3408 val_blacklist(&vq->chain_blacklist, qstate->region, origin, 1);
3409 qstate->errinf = NULL;
3410 vq->restart_count++;
3411 } else {
3412 if(key_entry_isbad(dske)) {
3413 errinf_origin(qstate, origin);
3414 errinf_dname(qstate, "for DS", qinfo->qname);
3415 }
3416 /* NOTE: the reason for the DS to be not good (that is,
3417 * either bad or null) should have been logged by
3418 * dsResponseToKE. */
3419 vq->key_entry = dske;
3420 /* The FINDKEY phase has ended, so move on. */
3421 vq->state = VAL_VALIDATE_STATE;
3422 }
3423 }
3424
3425 /**
3426 * Process DNSKEY response. Called from inform_supers.
3427 * Sets the key entry in the state.
3428 * Because it is in inform_supers, the mesh itself is busy doing callbacks
3429 * for a state that is to be deleted soon; don't touch the mesh; instead
3430 * set a state in the super, as the super will be reactivated soon.
3431 * Perform processing to determine what state to set in the super.
3432 *
3433 * @param qstate: query state that is validating and asked for a DNSKEY.
3434 * @param vq: validator query state
3435 * @param id: module id.
3436 * @param rcode: rcode result value.
3437 * @param msg: result message (if rcode is OK).
3438 * @param qinfo: from the sub query state, query info.
3439 * @param origin: the origin of msg.
3440 * @param sub_qstate: the sub query state, that is the lookup that fetched
3441 * the trust anchor data, it contains error information for the answer.
3442 */
3443 static void
process_dnskey_response(struct module_qstate * qstate,struct val_qstate * vq,int id,int rcode,struct dns_msg * msg,struct query_info * qinfo,struct sock_list * origin,struct module_qstate * sub_qstate)3444 process_dnskey_response(struct module_qstate* qstate, struct val_qstate* vq,
3445 int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
3446 struct sock_list* origin, struct module_qstate* sub_qstate)
3447 {
3448 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
3449 struct key_entry_key* old = vq->key_entry;
3450 struct ub_packed_rrset_key* dnskey = NULL;
3451 int downprot;
3452 char reasonbuf[256];
3453 char* reason = NULL;
3454 sldns_ede_code reason_bogus = LDNS_EDE_DNSSEC_BOGUS;
3455
3456 vq->num_nsec_attempts = 0;
3457 if(sub_qstate && sub_qstate->rpz_applied) {
3458 verbose(VERB_ALGO, "rpz was applied to the DNSKEY lookup, "
3459 "make it insecure");
3460 vq->key_entry = NULL;
3461 vq->state = VAL_FINISHED_STATE;
3462 vq->chase_reply->security = sec_status_insecure;
3463 return;
3464 }
3465
3466 if(rcode == LDNS_RCODE_NOERROR)
3467 dnskey = reply_find_answer_rrset(qinfo, msg->rep);
3468
3469 if(dnskey == NULL) {
3470 char* err;
3471 char rstr[1024];
3472 /* bad response */
3473 verbose(VERB_DETAIL, "Missing DNSKEY RRset in response to "
3474 "DNSKEY query.");
3475
3476 if(val_can_restart(qstate, vq, ve)) {
3477 val_blacklist(&vq->chain_blacklist, qstate->region,
3478 origin, 1);
3479 qstate->errinf = NULL;
3480 vq->restart_count++;
3481 return;
3482 }
3483 err = errinf_to_str_misc(sub_qstate);
3484 if(!err) {
3485 snprintf(rstr, sizeof(rstr), "No DNSKEY record");
3486 } else {
3487 snprintf(rstr, sizeof(rstr), "No DNSKEY record "
3488 "[%s]", err);
3489 }
3490 reason_bogus = LDNS_EDE_DNSKEY_MISSING;
3491 vq->key_entry = key_entry_create_bad(qstate->region,
3492 qinfo->qname, qinfo->qname_len, qinfo->qclass,
3493 BOGUS_KEY_TTL, reason_bogus, rstr, *qstate->env->now);
3494 if(!vq->key_entry) {
3495 log_err("alloc failure in missing dnskey response");
3496 /* key_entry is NULL for failure in Validate */
3497 }
3498 errinf_ede(qstate, rstr, reason_bogus);
3499 errinf_origin(qstate, origin);
3500 errinf_dname(qstate, "for key", qinfo->qname);
3501 vq->state = VAL_VALIDATE_STATE;
3502 return;
3503 }
3504 if(!vq->ds_rrset) {
3505 log_err("internal error: no DS rrset for new DNSKEY response");
3506 vq->key_entry = NULL;
3507 vq->state = VAL_VALIDATE_STATE;
3508 return;
3509 }
3510 downprot = qstate->env->cfg->harden_algo_downgrade;
3511 vq->key_entry = val_verify_new_DNSKEYs(qstate->region, qstate->env,
3512 ve, dnskey, vq->ds_rrset, downprot, &reason, &reason_bogus,
3513 qstate, vq, reasonbuf, sizeof(reasonbuf));
3514 /* New NSEC attempt count for next message validation. */
3515 vq->num_nsec_attempts = 0;
3516
3517 if(!vq->key_entry) {
3518 log_err("out of memory in verify new DNSKEYs");
3519 vq->state = VAL_VALIDATE_STATE;
3520 return;
3521 }
3522 /* If the key entry isBad or isNull, then we can move on to the next
3523 * state. */
3524 if(!key_entry_isgood(vq->key_entry)) {
3525 if(key_entry_isbad(vq->key_entry)) {
3526 if(val_can_restart(qstate, vq, ve)) {
3527 val_blacklist(&vq->chain_blacklist,
3528 qstate->region, origin, 1);
3529 qstate->errinf = NULL;
3530 vq->restart_count++;
3531 vq->key_entry = old;
3532 return;
3533 }
3534 verbose(VERB_DETAIL, "Did not match a DS to a DNSKEY, "
3535 "thus bogus.");
3536 errinf_ede(qstate, reason, reason_bogus);
3537 errinf_origin(qstate, origin);
3538 errinf_dname(qstate, "for key", qinfo->qname);
3539 }
3540 vq->chain_blacklist = NULL;
3541 vq->state = VAL_VALIDATE_STATE;
3542 return;
3543 }
3544 vq->chain_blacklist = NULL;
3545 qstate->errinf = NULL;
3546
3547 /* The DNSKEY validated, so cache it as a trusted key rrset. */
3548 key_cache_insert(ve->kcache, vq->key_entry,
3549 qstate->env->cfg->val_log_level >= 2);
3550
3551 /* If good, we stay in the FINDKEY state. */
3552 log_query_info(VERB_DETAIL, "validated DNSKEY", qinfo);
3553 }
3554
3555 /**
3556 * Process prime response
3557 * Sets the key entry in the state.
3558 *
3559 * @param qstate: query state that is validating and primed a trust anchor.
3560 * @param vq: validator query state
3561 * @param id: module id.
3562 * @param rcode: rcode result value.
3563 * @param msg: result message (if rcode is OK).
3564 * @param origin: the origin of msg.
3565 * @param sub_qstate: the sub query state, that is the lookup that fetched
3566 * the trust anchor data, it contains error information for the answer.
3567 */
3568 static void
process_prime_response(struct module_qstate * qstate,struct val_qstate * vq,int id,int rcode,struct dns_msg * msg,struct sock_list * origin,struct module_qstate * sub_qstate)3569 process_prime_response(struct module_qstate* qstate, struct val_qstate* vq,
3570 int id, int rcode, struct dns_msg* msg, struct sock_list* origin,
3571 struct module_qstate* sub_qstate)
3572 {
3573 struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
3574 struct ub_packed_rrset_key* dnskey_rrset = NULL;
3575 struct trust_anchor* ta = anchor_find(qstate->env->anchors,
3576 vq->trust_anchor_name, vq->trust_anchor_labs,
3577 vq->trust_anchor_len, vq->qchase.qclass);
3578 vq->num_nsec_attempts = 0;
3579 if(!ta) {
3580 /* trust anchor revoked, restart with less anchors */
3581 vq->state = VAL_INIT_STATE;
3582 if(!vq->trust_anchor_name)
3583 vq->state = VAL_VALIDATE_STATE; /* break a loop */
3584 vq->trust_anchor_name = NULL;
3585 return;
3586 }
3587 /* Fetch and validate the keyEntry that corresponds to the
3588 * current trust anchor. */
3589 if(rcode == LDNS_RCODE_NOERROR) {
3590 dnskey_rrset = reply_find_rrset_section_an(msg->rep,
3591 ta->name, ta->namelen, LDNS_RR_TYPE_DNSKEY,
3592 ta->dclass);
3593 }
3594
3595 if(ta->autr) {
3596 if(!autr_process_prime(qstate->env, ve, ta, dnskey_rrset,
3597 qstate, vq)) {
3598 /* New NSEC attempt count for next message validation. */
3599 vq->num_nsec_attempts = 0;
3600 /* trust anchor revoked, restart with less anchors */
3601 vq->state = VAL_INIT_STATE;
3602 vq->trust_anchor_name = NULL;
3603 return;
3604 }
3605 }
3606 vq->key_entry = primeResponseToKE(dnskey_rrset, ta, qstate, vq, id,
3607 sub_qstate);
3608 lock_basic_unlock(&ta->lock);
3609 /* New NSEC attempt count for next message validation. */
3610 vq->num_nsec_attempts = 0;
3611 if(vq->key_entry) {
3612 if(key_entry_isbad(vq->key_entry)
3613 && val_can_restart(qstate, vq, ve)) {
3614 val_blacklist(&vq->chain_blacklist, qstate->region,
3615 origin, 1);
3616 qstate->errinf = NULL;
3617 vq->restart_count++;
3618 vq->key_entry = NULL;
3619 vq->state = VAL_INIT_STATE;
3620 return;
3621 }
3622 vq->chain_blacklist = NULL;
3623 errinf_origin(qstate, origin);
3624 errinf_dname(qstate, "for trust anchor", ta->name);
3625 /* store the freshly primed entry in the cache */
3626 key_cache_insert(ve->kcache, vq->key_entry,
3627 qstate->env->cfg->val_log_level >= 2);
3628 }
3629
3630 /* If the result of the prime is a null key, skip the FINDKEY state.*/
3631 if(!vq->key_entry || key_entry_isnull(vq->key_entry) ||
3632 key_entry_isbad(vq->key_entry)) {
3633 vq->state = VAL_VALIDATE_STATE;
3634 }
3635 /* the qstate will be reactivated after inform_super is done */
3636 }
3637
3638 /*
3639 * inform validator super.
3640 *
3641 * @param qstate: query state that finished.
3642 * @param id: module id.
3643 * @param super: the qstate to inform.
3644 */
3645 void
val_inform_super(struct module_qstate * qstate,int id,struct module_qstate * super)3646 val_inform_super(struct module_qstate* qstate, int id,
3647 struct module_qstate* super)
3648 {
3649 struct val_qstate* vq = (struct val_qstate*)super->minfo[id];
3650 log_query_info(VERB_ALGO, "validator: inform_super, sub is",
3651 &qstate->qinfo);
3652 log_query_info(VERB_ALGO, "super is", &super->qinfo);
3653 if(!vq) {
3654 verbose(VERB_ALGO, "super: has no validator state");
3655 return;
3656 }
3657 /* Pick up the global quota limit from the subquery. */
3658 if(qstate->global_quota_reached > qstate->global_quota_started) {
3659 super->global_quota_reached += qstate->global_quota_reached -
3660 qstate->global_quota_started;
3661 }
3662 if(vq->wait_prime_ta) {
3663 vq->wait_prime_ta = 0;
3664 process_prime_response(super, vq, id, qstate->return_rcode,
3665 qstate->return_msg, qstate->reply_origin, qstate);
3666 return;
3667 }
3668 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS) {
3669 int suspend;
3670 process_ds_response(super, vq, id, qstate->return_rcode,
3671 qstate->return_msg, &qstate->qinfo,
3672 qstate->reply_origin, &suspend, qstate);
3673 /* If NSEC3 was needed during validation, NULL the NSEC3 cache;
3674 * it will be re-initiated if needed later on.
3675 * Validation (and the cache table) are happening/allocated in
3676 * the super qstate whilst the RRs are allocated (and pointed
3677 * to) in this sub qstate. */
3678 if(vq->nsec3_cache_table.ct) {
3679 vq->nsec3_cache_table.ct = NULL;
3680 }
3681 if(suspend) {
3682 /* deep copy the return_msg to vq->sub_ds_msg; it will
3683 * be resumed later in the super state with the caveat
3684 * that the initial calculations will be re-calculated
3685 * and re-suspended there before continuing. */
3686 vq->sub_ds_msg = dns_msg_deepcopy_region(
3687 qstate->return_msg, super->region);
3688 }
3689 return;
3690 } else if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY) {
3691 process_dnskey_response(super, vq, id, qstate->return_rcode,
3692 qstate->return_msg, &qstate->qinfo,
3693 qstate->reply_origin, qstate);
3694 return;
3695 }
3696 log_err("internal error in validator: no inform_supers possible");
3697 }
3698
3699 void
val_clear(struct module_qstate * qstate,int id)3700 val_clear(struct module_qstate* qstate, int id)
3701 {
3702 struct val_qstate* vq;
3703 if(!qstate)
3704 return;
3705 vq = (struct val_qstate*)qstate->minfo[id];
3706 if(vq) {
3707 if(vq->suspend_timer) {
3708 comm_timer_delete(vq->suspend_timer);
3709 }
3710 }
3711 /* everything is allocated in the region, so assign NULL */
3712 qstate->minfo[id] = NULL;
3713 }
3714
3715 size_t
val_get_mem(struct module_env * env,int id)3716 val_get_mem(struct module_env* env, int id)
3717 {
3718 struct val_env* ve = (struct val_env*)env->modinfo[id];
3719 if(!ve)
3720 return 0;
3721 return sizeof(*ve) + key_cache_get_mem(ve->kcache) +
3722 val_neg_get_mem(ve->neg_cache) +
3723 sizeof(size_t)*2*ve->nsec3_keyiter_count;
3724 }
3725
3726 /**
3727 * The validator function block
3728 */
3729 static struct module_func_block val_block = {
3730 "validator",
3731 NULL, NULL, &val_init, &val_deinit, &val_operate, &val_inform_super,
3732 &val_clear, &val_get_mem
3733 };
3734
3735 struct module_func_block*
val_get_funcblock(void)3736 val_get_funcblock(void)
3737 {
3738 return &val_block;
3739 }
3740
3741 const char*
val_state_to_string(enum val_state state)3742 val_state_to_string(enum val_state state)
3743 {
3744 switch(state) {
3745 case VAL_INIT_STATE: return "VAL_INIT_STATE";
3746 case VAL_FINDKEY_STATE: return "VAL_FINDKEY_STATE";
3747 case VAL_VALIDATE_STATE: return "VAL_VALIDATE_STATE";
3748 case VAL_FINISHED_STATE: return "VAL_FINISHED_STATE";
3749 }
3750 return "UNKNOWN VALIDATOR STATE";
3751 }
3752
3753