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