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