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