1 /*
2 * validator/val_nsec3.c - validator NSEC3 denial of existence functions.
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 helper functions for the validator module.
40 * The functions help with NSEC3 checking, the different NSEC3 proofs
41 * for denial of existence, and proofs for presence of types.
42 */
43 #include "config.h"
44 #include <ctype.h>
45 #include "validator/val_nsec3.h"
46 #include "validator/val_secalgo.h"
47 #include "validator/validator.h"
48 #include "validator/val_kentry.h"
49 #include "services/cache/rrset.h"
50 #include "util/regional.h"
51 #include "util/rbtree.h"
52 #include "util/module.h"
53 #include "util/net_help.h"
54 #include "util/data/packed_rrset.h"
55 #include "util/data/dname.h"
56 #include "util/data/msgreply.h"
57 /* we include nsec.h for the bitmap_has_type function */
58 #include "validator/val_nsec.h"
59 #include "sldns/sbuffer.h"
60 #include "util/config_file.h"
61
62 /**
63 * Max number of NSEC3 calculations at once, suspend query for later.
64 * 8 is low enough and allows for cases where multiple proofs are needed.
65 */
66 #define MAX_NSEC3_CALCULATIONS 8
67 /**
68 * When all allowed NSEC3 calculations at once resulted in error treat as
69 * bogus. NSEC3 hash errors are not cached and this helps breaks loops with
70 * erroneous data.
71 */
72 #define MAX_NSEC3_ERRORS -1
73
74 /**
75 * This function we get from ldns-compat or from base system
76 * it returns the number of data bytes stored at the target, or <0 on error.
77 */
78 int sldns_b32_ntop_extended_hex(uint8_t const *src, size_t srclength,
79 char *target, size_t targsize);
80 /**
81 * This function we get from ldns-compat or from base system
82 * it returns the number of data bytes stored at the target, or <0 on error.
83 */
84 int sldns_b32_pton_extended_hex(char const *src, size_t hashed_owner_str_len,
85 uint8_t *target, size_t targsize);
86
87 /**
88 * Closest encloser (ce) proof results
89 * Contains the ce and the next-closer (nc) proof.
90 */
91 struct ce_response {
92 /** the closest encloser name */
93 uint8_t* ce;
94 /** length of ce */
95 size_t ce_len;
96 /** NSEC3 record that proved ce. rrset */
97 struct ub_packed_rrset_key* ce_rrset;
98 /** NSEC3 record that proved ce. rr number */
99 int ce_rr;
100 /** NSEC3 record that proved nc. rrset */
101 struct ub_packed_rrset_key* nc_rrset;
102 /** NSEC3 record that proved nc. rr*/
103 int nc_rr;
104 };
105
106 /**
107 * Filter conditions for NSEC3 proof
108 * Used to iterate over the applicable NSEC3 RRs.
109 */
110 struct nsec3_filter {
111 /** Zone name, only NSEC3 records for this zone are considered */
112 uint8_t* zone;
113 /** length of the zonename */
114 size_t zone_len;
115 /** the list of NSEC3s to filter; array */
116 struct ub_packed_rrset_key** list;
117 /** number of rrsets in list */
118 size_t num;
119 /** class of records for the NSEC3, only this class applies */
120 uint16_t fclass;
121 };
122
123 /** return number of rrs in an rrset */
124 static size_t
rrset_get_count(struct ub_packed_rrset_key * rrset)125 rrset_get_count(struct ub_packed_rrset_key* rrset)
126 {
127 struct packed_rrset_data* d = (struct packed_rrset_data*)
128 rrset->entry.data;
129 if(!d) return 0;
130 return d->count;
131 }
132
133 /** return if nsec3 RR has unknown flags */
134 static int
nsec3_unknown_flags(struct ub_packed_rrset_key * rrset,int r)135 nsec3_unknown_flags(struct ub_packed_rrset_key* rrset, int r)
136 {
137 struct packed_rrset_data* d = (struct packed_rrset_data*)
138 rrset->entry.data;
139 log_assert(d && r < (int)d->count);
140 if(d->rr_len[r] < 2+2)
141 return 0; /* malformed */
142 return (int)(d->rr_data[r][2+1] & NSEC3_UNKNOWN_FLAGS);
143 }
144
145 int
nsec3_has_optout(struct ub_packed_rrset_key * rrset,int r)146 nsec3_has_optout(struct ub_packed_rrset_key* rrset, int r)
147 {
148 struct packed_rrset_data* d = (struct packed_rrset_data*)
149 rrset->entry.data;
150 log_assert(d && r < (int)d->count);
151 if(d->rr_len[r] < 2+2)
152 return 0; /* malformed */
153 return (int)(d->rr_data[r][2+1] & NSEC3_OPTOUT);
154 }
155
156 /** return nsec3 RR algorithm */
157 static int
nsec3_get_algo(struct ub_packed_rrset_key * rrset,int r)158 nsec3_get_algo(struct ub_packed_rrset_key* rrset, int r)
159 {
160 struct packed_rrset_data* d = (struct packed_rrset_data*)
161 rrset->entry.data;
162 log_assert(d && r < (int)d->count);
163 if(d->rr_len[r] < 2+1)
164 return 0; /* malformed */
165 return (int)(d->rr_data[r][2+0]);
166 }
167
168 /** return if nsec3 RR has known algorithm */
169 static int
nsec3_known_algo(struct ub_packed_rrset_key * rrset,int r)170 nsec3_known_algo(struct ub_packed_rrset_key* rrset, int r)
171 {
172 struct packed_rrset_data* d = (struct packed_rrset_data*)
173 rrset->entry.data;
174 log_assert(d && r < (int)d->count);
175 if(d->rr_len[r] < 2+1)
176 return 0; /* malformed */
177 switch(d->rr_data[r][2+0]) {
178 case NSEC3_HASH_SHA1:
179 return 1;
180 }
181 return 0;
182 }
183
184 /** return nsec3 RR iteration count */
185 static size_t
nsec3_get_iter(struct ub_packed_rrset_key * rrset,int r)186 nsec3_get_iter(struct ub_packed_rrset_key* rrset, int r)
187 {
188 uint16_t i;
189 struct packed_rrset_data* d = (struct packed_rrset_data*)
190 rrset->entry.data;
191 log_assert(d && r < (int)d->count);
192 if(d->rr_len[r] < 2+4)
193 return 0; /* malformed */
194 memmove(&i, d->rr_data[r]+2+2, sizeof(i));
195 i = ntohs(i);
196 return (size_t)i;
197 }
198
199 /** return nsec3 RR salt */
200 static int
nsec3_get_salt(struct ub_packed_rrset_key * rrset,int r,uint8_t ** salt,size_t * saltlen)201 nsec3_get_salt(struct ub_packed_rrset_key* rrset, int r,
202 uint8_t** salt, size_t* saltlen)
203 {
204 struct packed_rrset_data* d = (struct packed_rrset_data*)
205 rrset->entry.data;
206 log_assert(d && r < (int)d->count);
207 if(d->rr_len[r] < 2+5) {
208 *salt = 0;
209 *saltlen = 0;
210 return 0; /* malformed */
211 }
212 *saltlen = (size_t)d->rr_data[r][2+4];
213 if(d->rr_len[r] < 2+5+(size_t)*saltlen) {
214 *salt = 0;
215 *saltlen = 0;
216 return 0; /* malformed */
217 }
218 *salt = d->rr_data[r]+2+5;
219 return 1;
220 }
221
nsec3_get_params(struct ub_packed_rrset_key * rrset,int r,int * algo,size_t * iter,uint8_t ** salt,size_t * saltlen)222 int nsec3_get_params(struct ub_packed_rrset_key* rrset, int r,
223 int* algo, size_t* iter, uint8_t** salt, size_t* saltlen)
224 {
225 if(!nsec3_known_algo(rrset, r) || nsec3_unknown_flags(rrset, r))
226 return 0;
227 if(!nsec3_get_salt(rrset, r, salt, saltlen))
228 return 0;
229 *algo = nsec3_get_algo(rrset, r);
230 *iter = nsec3_get_iter(rrset, r);
231 return 1;
232 }
233
234 int
nsec3_get_nextowner(struct ub_packed_rrset_key * rrset,int r,uint8_t ** next,size_t * nextlen)235 nsec3_get_nextowner(struct ub_packed_rrset_key* rrset, int r,
236 uint8_t** next, size_t* nextlen)
237 {
238 size_t saltlen;
239 struct packed_rrset_data* d = (struct packed_rrset_data*)
240 rrset->entry.data;
241 log_assert(d && r < (int)d->count);
242 if(d->rr_len[r] < 2+5) {
243 *next = 0;
244 *nextlen = 0;
245 return 0; /* malformed */
246 }
247 saltlen = (size_t)d->rr_data[r][2+4];
248 if(d->rr_len[r] < 2+5+saltlen+1) {
249 *next = 0;
250 *nextlen = 0;
251 return 0; /* malformed */
252 }
253 *nextlen = (size_t)d->rr_data[r][2+5+saltlen];
254 if(d->rr_len[r] < 2+5+saltlen+1+*nextlen) {
255 *next = 0;
256 *nextlen = 0;
257 return 0; /* malformed */
258 }
259 *next = d->rr_data[r]+2+5+saltlen+1;
260 return 1;
261 }
262
nsec3_hash_to_b32(uint8_t * hash,size_t hashlen,uint8_t * zone,size_t zonelen,uint8_t * buf,size_t max)263 size_t nsec3_hash_to_b32(uint8_t* hash, size_t hashlen, uint8_t* zone,
264 size_t zonelen, uint8_t* buf, size_t max)
265 {
266 /* write b32 of name, leave one for length */
267 int ret;
268 if(max < hashlen*2+1) /* quick approx of b32, as if hexb16 */
269 return 0;
270 ret = sldns_b32_ntop_extended_hex(hash, hashlen, (char*)buf+1, max-1);
271 if(ret < 1)
272 return 0;
273 buf[0] = (uint8_t)ret; /* length of b32 label */
274 ret++;
275 if(max - ret < zonelen)
276 return 0;
277 memmove(buf+ret, zone, zonelen);
278 return zonelen+(size_t)ret;
279 }
280
nsec3_get_nextowner_b32(struct ub_packed_rrset_key * rrset,int r,uint8_t * buf,size_t max)281 size_t nsec3_get_nextowner_b32(struct ub_packed_rrset_key* rrset, int r,
282 uint8_t* buf, size_t max)
283 {
284 uint8_t* nm, *zone;
285 size_t nmlen, zonelen;
286 if(!nsec3_get_nextowner(rrset, r, &nm, &nmlen))
287 return 0;
288 /* append zone name; the owner name must be <b32>.zone */
289 zone = rrset->rk.dname;
290 zonelen = rrset->rk.dname_len;
291 dname_remove_label(&zone, &zonelen);
292 return nsec3_hash_to_b32(nm, nmlen, zone, zonelen, buf, max);
293 }
294
295 int
nsec3_has_type(struct ub_packed_rrset_key * rrset,int r,uint16_t type)296 nsec3_has_type(struct ub_packed_rrset_key* rrset, int r, uint16_t type)
297 {
298 uint8_t* bitmap;
299 size_t bitlen, skiplen;
300 struct packed_rrset_data* d = (struct packed_rrset_data*)
301 rrset->entry.data;
302 log_assert(d && r < (int)d->count);
303 skiplen = 2+4;
304 /* skip salt */
305 if(d->rr_len[r] < skiplen+1)
306 return 0; /* malformed, too short */
307 skiplen += 1+(size_t)d->rr_data[r][skiplen];
308 /* skip next hashed owner */
309 if(d->rr_len[r] < skiplen+1)
310 return 0; /* malformed, too short */
311 skiplen += 1+(size_t)d->rr_data[r][skiplen];
312 if(d->rr_len[r] < skiplen)
313 return 0; /* malformed, too short */
314 bitlen = d->rr_len[r] - skiplen;
315 bitmap = d->rr_data[r]+skiplen;
316 return nsecbitmap_has_type_rdata(bitmap, bitlen, type);
317 }
318
319 /**
320 * Iterate through NSEC3 list, per RR
321 * This routine gives the next RR in the list (or sets rrset null).
322 * Usage:
323 *
324 * size_t rrsetnum;
325 * int rrnum;
326 * struct ub_packed_rrset_key* rrset;
327 * for(rrset=filter_first(filter, &rrsetnum, &rrnum); rrset;
328 * rrset=filter_next(filter, &rrsetnum, &rrnum))
329 * do_stuff;
330 *
331 * Also filters out
332 * o unknown flag NSEC3s
333 * o unknown algorithm NSEC3s.
334 * @param filter: nsec3 filter structure.
335 * @param rrsetnum: in/out rrset number to look at.
336 * @param rrnum: in/out rr number in rrset to look at.
337 * @returns ptr to the next rrset (or NULL at end).
338 */
339 static struct ub_packed_rrset_key*
filter_next(struct nsec3_filter * filter,size_t * rrsetnum,int * rrnum)340 filter_next(struct nsec3_filter* filter, size_t* rrsetnum, int* rrnum)
341 {
342 size_t i;
343 int r;
344 uint8_t* nm;
345 size_t nmlen;
346 if(!filter->zone) /* empty list */
347 return NULL;
348 for(i=*rrsetnum; i<filter->num; i++) {
349 /* see if RRset qualifies */
350 if(ntohs(filter->list[i]->rk.type) != LDNS_RR_TYPE_NSEC3 ||
351 ntohs(filter->list[i]->rk.rrset_class) !=
352 filter->fclass)
353 continue;
354 /* check RRset zone */
355 nm = filter->list[i]->rk.dname;
356 nmlen = filter->list[i]->rk.dname_len;
357 dname_remove_label(&nm, &nmlen);
358 if(query_dname_compare(nm, filter->zone) != 0)
359 continue;
360 if(i == *rrsetnum)
361 r = (*rrnum) + 1; /* continue at next RR */
362 else r = 0; /* new RRset start at first RR */
363 for(; r < (int)rrset_get_count(filter->list[i]); r++) {
364 /* skip unknown flags, algo */
365 if(nsec3_unknown_flags(filter->list[i], r) ||
366 !nsec3_known_algo(filter->list[i], r))
367 continue;
368 /* this one is a good target */
369 *rrsetnum = i;
370 *rrnum = r;
371 return filter->list[i];
372 }
373 }
374 return NULL;
375 }
376
377 /**
378 * Start iterating over NSEC3 records.
379 * @param filter: the filter structure, must have been filter_init-ed.
380 * @param rrsetnum: can be undefined on call, initialised.
381 * @param rrnum: can be undefined on call, initialised.
382 * @return first rrset of an NSEC3, together with rrnum this points to
383 * the first RR to examine. Is NULL on empty list.
384 */
385 static struct ub_packed_rrset_key*
filter_first(struct nsec3_filter * filter,size_t * rrsetnum,int * rrnum)386 filter_first(struct nsec3_filter* filter, size_t* rrsetnum, int* rrnum)
387 {
388 *rrsetnum = 0;
389 *rrnum = -1;
390 return filter_next(filter, rrsetnum, rrnum);
391 }
392
393 /** see if at least one RR is known (flags, algo) */
394 static int
nsec3_rrset_has_known(struct ub_packed_rrset_key * s)395 nsec3_rrset_has_known(struct ub_packed_rrset_key* s)
396 {
397 int r;
398 for(r=0; r < (int)rrset_get_count(s); r++) {
399 if(!nsec3_unknown_flags(s, r) && nsec3_known_algo(s, r))
400 return 1;
401 }
402 return 0;
403 }
404
405 /**
406 * Initialize the filter structure.
407 * Finds the zone by looking at available NSEC3 records and best match.
408 * (skips the unknown flag and unknown algo NSEC3s).
409 *
410 * @param filter: nsec3 filter structure.
411 * @param list: list of rrsets, an array of them.
412 * @param num: number of rrsets in list.
413 * @param qinfo:
414 * query name to match a zone for.
415 * query type (if DS a higher zone must be chosen)
416 * qclass, to filter NSEC3s with.
417 */
418 static void
filter_init(struct nsec3_filter * filter,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo)419 filter_init(struct nsec3_filter* filter, struct ub_packed_rrset_key** list,
420 size_t num, struct query_info* qinfo)
421 {
422 size_t i;
423 uint8_t* nm;
424 size_t nmlen;
425 filter->zone = NULL;
426 filter->zone_len = 0;
427 filter->list = list;
428 filter->num = num;
429 filter->fclass = qinfo->qclass;
430 for(i=0; i<num; i++) {
431 /* ignore other stuff in the list */
432 if(ntohs(list[i]->rk.type) != LDNS_RR_TYPE_NSEC3 ||
433 ntohs(list[i]->rk.rrset_class) != qinfo->qclass)
434 continue;
435 /* skip unknown flags, algo */
436 if(!nsec3_rrset_has_known(list[i]))
437 continue;
438
439 /* since NSEC3s are base32.zonename, we can find the zone
440 * name by stripping off the first label of the record */
441 nm = list[i]->rk.dname;
442 nmlen = list[i]->rk.dname_len;
443 dname_remove_label(&nm, &nmlen);
444 /* if we find a domain that can prove about the qname,
445 * and if this domain is closer to the qname */
446 if(dname_subdomain_c(qinfo->qname, nm) && (!filter->zone ||
447 dname_subdomain_c(nm, filter->zone))) {
448 /* for a type DS do not accept a zone equal to qname*/
449 if(qinfo->qtype == LDNS_RR_TYPE_DS &&
450 query_dname_compare(qinfo->qname, nm) == 0 &&
451 !dname_is_root(qinfo->qname))
452 continue;
453 filter->zone = nm;
454 filter->zone_len = nmlen;
455 }
456 }
457 }
458
459 /**
460 * Find max iteration count using config settings and key size
461 * @param ve: validator environment with iteration count config settings.
462 * @param bits: key size
463 * @return max iteration count
464 */
465 static size_t
get_max_iter(struct val_env * ve,size_t bits)466 get_max_iter(struct val_env* ve, size_t bits)
467 {
468 int i;
469 log_assert(ve->nsec3_keyiter_count > 0);
470 /* round up to nearest config keysize, linear search, keep it small */
471 for(i=0; i<ve->nsec3_keyiter_count; i++) {
472 if(bits <= ve->nsec3_keysize[i])
473 return ve->nsec3_maxiter[i];
474 }
475 /* else, use value for biggest key */
476 return ve->nsec3_maxiter[ve->nsec3_keyiter_count-1];
477 }
478
479 /**
480 * Determine if any of the NSEC3 rrs iteration count is too high, from key.
481 * @param ve: validator environment with iteration count config settings.
482 * @param filter: what NSEC3s to loop over.
483 * @param kkey: key entry used for verification; used for iteration counts.
484 * @return 1 if some nsec3s are above the max iteration count.
485 */
486 static int
nsec3_iteration_count_high(struct val_env * ve,struct nsec3_filter * filter,struct key_entry_key * kkey)487 nsec3_iteration_count_high(struct val_env* ve, struct nsec3_filter* filter,
488 struct key_entry_key* kkey)
489 {
490 size_t rrsetnum;
491 int rrnum;
492 struct ub_packed_rrset_key* rrset;
493 /* first determine the max number of iterations */
494 size_t bits = key_entry_keysize(kkey);
495 size_t max_iter = get_max_iter(ve, bits);
496 verbose(VERB_ALGO, "nsec3: keysize %d bits, max iterations %d",
497 (int)bits, (int)max_iter);
498
499 for(rrset=filter_first(filter, &rrsetnum, &rrnum); rrset;
500 rrset=filter_next(filter, &rrsetnum, &rrnum)) {
501 if(nsec3_get_iter(rrset, rrnum) > max_iter)
502 return 1;
503 }
504 return 0;
505 }
506
507 /* nsec3_cache_compare for rbtree */
508 int
nsec3_hash_cmp(const void * c1,const void * c2)509 nsec3_hash_cmp(const void* c1, const void* c2)
510 {
511 struct nsec3_cached_hash* h1 = (struct nsec3_cached_hash*)c1;
512 struct nsec3_cached_hash* h2 = (struct nsec3_cached_hash*)c2;
513 uint8_t* s1, *s2;
514 size_t s1len, s2len;
515 int c = query_dname_compare(h1->dname, h2->dname);
516 if(c != 0)
517 return c;
518 /* compare parameters */
519 /* if both malformed, its equal, robustness */
520 if(nsec3_get_algo(h1->nsec3, h1->rr) !=
521 nsec3_get_algo(h2->nsec3, h2->rr)) {
522 if(nsec3_get_algo(h1->nsec3, h1->rr) <
523 nsec3_get_algo(h2->nsec3, h2->rr))
524 return -1;
525 return 1;
526 }
527 if(nsec3_get_iter(h1->nsec3, h1->rr) !=
528 nsec3_get_iter(h2->nsec3, h2->rr)) {
529 if(nsec3_get_iter(h1->nsec3, h1->rr) <
530 nsec3_get_iter(h2->nsec3, h2->rr))
531 return -1;
532 return 1;
533 }
534 (void)nsec3_get_salt(h1->nsec3, h1->rr, &s1, &s1len);
535 (void)nsec3_get_salt(h2->nsec3, h2->rr, &s2, &s2len);
536 if(s1len == 0 && s2len == 0)
537 return 0;
538 if(!s1) return -1;
539 if(!s2) return 1;
540 if(s1len != s2len) {
541 if(s1len < s2len)
542 return -1;
543 return 1;
544 }
545 return memcmp(s1, s2, s1len);
546 }
547
548 int
nsec3_cache_table_init(struct nsec3_cache_table * ct,struct regional * region)549 nsec3_cache_table_init(struct nsec3_cache_table* ct, struct regional* region)
550 {
551 if(ct->ct) return 1;
552 ct->ct = (rbtree_type*)regional_alloc(region, sizeof(*ct->ct));
553 if(!ct->ct) return 0;
554 ct->region = region;
555 rbtree_init(ct->ct, &nsec3_hash_cmp);
556 return 1;
557 }
558
559 size_t
nsec3_get_hashed(sldns_buffer * buf,uint8_t * nm,size_t nmlen,int algo,size_t iter,uint8_t * salt,size_t saltlen,uint8_t * res,size_t max)560 nsec3_get_hashed(sldns_buffer* buf, uint8_t* nm, size_t nmlen, int algo,
561 size_t iter, uint8_t* salt, size_t saltlen, uint8_t* res, size_t max)
562 {
563 size_t i, hash_len;
564 /* prepare buffer for first iteration */
565 sldns_buffer_clear(buf);
566 sldns_buffer_write(buf, nm, nmlen);
567 query_dname_tolower(sldns_buffer_begin(buf));
568 if(saltlen != 0)
569 sldns_buffer_write(buf, salt, saltlen);
570 sldns_buffer_flip(buf);
571 hash_len = nsec3_hash_algo_size_supported(algo);
572 if(hash_len == 0) {
573 log_err("nsec3 hash of unknown algo %d", algo);
574 return 0;
575 }
576 if(hash_len > max)
577 return 0;
578 if(!secalgo_nsec3_hash(algo, (unsigned char*)sldns_buffer_begin(buf),
579 sldns_buffer_limit(buf), (unsigned char*)res))
580 return 0;
581 for(i=0; i<iter; i++) {
582 sldns_buffer_clear(buf);
583 sldns_buffer_write(buf, res, hash_len);
584 if(saltlen != 0)
585 sldns_buffer_write(buf, salt, saltlen);
586 sldns_buffer_flip(buf);
587 if(!secalgo_nsec3_hash(algo,
588 (unsigned char*)sldns_buffer_begin(buf),
589 sldns_buffer_limit(buf), (unsigned char*)res))
590 return 0;
591 }
592 return hash_len;
593 }
594
595 /** perform hash of name */
596 static int
nsec3_calc_hash(struct regional * region,sldns_buffer * buf,struct nsec3_cached_hash * c)597 nsec3_calc_hash(struct regional* region, sldns_buffer* buf,
598 struct nsec3_cached_hash* c)
599 {
600 int algo = nsec3_get_algo(c->nsec3, c->rr);
601 size_t iter = nsec3_get_iter(c->nsec3, c->rr);
602 uint8_t* salt;
603 size_t saltlen, i;
604 if(!nsec3_get_salt(c->nsec3, c->rr, &salt, &saltlen))
605 return -1;
606 /* prepare buffer for first iteration */
607 sldns_buffer_clear(buf);
608 sldns_buffer_write(buf, c->dname, c->dname_len);
609 query_dname_tolower(sldns_buffer_begin(buf));
610 sldns_buffer_write(buf, salt, saltlen);
611 sldns_buffer_flip(buf);
612 c->hash_len = nsec3_hash_algo_size_supported(algo);
613 if(c->hash_len == 0) {
614 log_err("nsec3 hash of unknown algo %d", algo);
615 return -1;
616 }
617 c->hash = (uint8_t*)regional_alloc(region, c->hash_len);
618 if(!c->hash)
619 return 0;
620 (void)secalgo_nsec3_hash(algo, (unsigned char*)sldns_buffer_begin(buf),
621 sldns_buffer_limit(buf), (unsigned char*)c->hash);
622 for(i=0; i<iter; i++) {
623 sldns_buffer_clear(buf);
624 sldns_buffer_write(buf, c->hash, c->hash_len);
625 sldns_buffer_write(buf, salt, saltlen);
626 sldns_buffer_flip(buf);
627 (void)secalgo_nsec3_hash(algo,
628 (unsigned char*)sldns_buffer_begin(buf),
629 sldns_buffer_limit(buf), (unsigned char*)c->hash);
630 }
631 return 1;
632 }
633
634 /** perform b32 encoding of hash */
635 static int
nsec3_calc_b32(struct regional * region,sldns_buffer * buf,struct nsec3_cached_hash * c)636 nsec3_calc_b32(struct regional* region, sldns_buffer* buf,
637 struct nsec3_cached_hash* c)
638 {
639 int r;
640 sldns_buffer_clear(buf);
641 r = sldns_b32_ntop_extended_hex(c->hash, c->hash_len,
642 (char*)sldns_buffer_begin(buf), sldns_buffer_limit(buf));
643 if(r < 1) {
644 log_err("b32_ntop_extended_hex: error in encoding: %d", r);
645 return 0;
646 }
647 c->b32_len = (size_t)r;
648 c->b32 = regional_alloc_init(region, sldns_buffer_begin(buf),
649 c->b32_len);
650 if(!c->b32)
651 return 0;
652 return 1;
653 }
654
655 int
nsec3_hash_name(rbtree_type * table,struct regional * region,sldns_buffer * buf,struct ub_packed_rrset_key * nsec3,int rr,uint8_t * dname,size_t dname_len,struct nsec3_cached_hash ** hash)656 nsec3_hash_name(rbtree_type* table, struct regional* region, sldns_buffer* buf,
657 struct ub_packed_rrset_key* nsec3, int rr, uint8_t* dname,
658 size_t dname_len, struct nsec3_cached_hash** hash)
659 {
660 struct nsec3_cached_hash* c;
661 struct nsec3_cached_hash looki;
662 #ifdef UNBOUND_DEBUG
663 rbnode_type* n;
664 #endif
665 int r;
666 looki.node.key = &looki;
667 looki.nsec3 = nsec3;
668 looki.rr = rr;
669 looki.dname = dname;
670 looki.dname_len = dname_len;
671 /* lookup first in cache */
672 c = (struct nsec3_cached_hash*)rbtree_search(table, &looki);
673 if(c) {
674 *hash = c;
675 return 2;
676 }
677 /* create a new entry */
678 c = (struct nsec3_cached_hash*)regional_alloc(region, sizeof(*c));
679 if(!c) return 0;
680 c->node.key = c;
681 c->nsec3 = nsec3;
682 c->rr = rr;
683 c->dname = dname;
684 c->dname_len = dname_len;
685 r = nsec3_calc_hash(region, buf, c);
686 if(r != 1)
687 return r; /* returns -1 or 0 */
688 r = nsec3_calc_b32(region, buf, c);
689 if(r != 1)
690 return r; /* returns 0 */
691 #ifdef UNBOUND_DEBUG
692 n =
693 #else
694 (void)
695 #endif
696 rbtree_insert(table, &c->node);
697 log_assert(n); /* cannot be duplicate, just did lookup */
698 *hash = c;
699 return 1;
700 }
701
702 /**
703 * compare a label lowercased
704 */
705 static int
label_compare_lower(uint8_t * lab1,uint8_t * lab2,size_t lablen)706 label_compare_lower(uint8_t* lab1, uint8_t* lab2, size_t lablen)
707 {
708 size_t i;
709 for(i=0; i<lablen; i++) {
710 if(tolower((unsigned char)*lab1) != tolower((unsigned char)*lab2)) {
711 if(tolower((unsigned char)*lab1) < tolower((unsigned char)*lab2))
712 return -1;
713 return 1;
714 }
715 lab1++;
716 lab2++;
717 }
718 return 0;
719 }
720
721 /**
722 * Compare a hashed name with the owner name of an NSEC3 RRset.
723 * @param flt: filter with zone name.
724 * @param hash: the hashed name.
725 * @param s: rrset with owner name.
726 * @return true if matches exactly, false if not.
727 */
728 static int
nsec3_hash_matches_owner(struct nsec3_filter * flt,struct nsec3_cached_hash * hash,struct ub_packed_rrset_key * s)729 nsec3_hash_matches_owner(struct nsec3_filter* flt,
730 struct nsec3_cached_hash* hash, struct ub_packed_rrset_key* s)
731 {
732 uint8_t* nm = s->rk.dname;
733 if(!hash) return 0; /* please clang */
734 /* compare, does hash of name based on params in this NSEC3
735 * match the owner name of this NSEC3?
736 * name must be: <hashlength>base32 . zone name
737 * so; first label must not be root label (not zero length),
738 * and match the b32 encoded hash length,
739 * and the label content match the b32 encoded hash
740 * and the rest must be the zone name.
741 */
742 if(hash->b32_len != 0 && (size_t)nm[0] == hash->b32_len &&
743 label_compare_lower(nm+1, hash->b32, hash->b32_len) == 0 &&
744 query_dname_compare(nm+(size_t)nm[0]+1, flt->zone) == 0) {
745 return 1;
746 }
747 return 0;
748 }
749
750 /**
751 * Find matching NSEC3
752 * Find the NSEC3Record that matches a hash of a name.
753 * @param env: module environment with temporary region and buffer.
754 * @param flt: the NSEC3 RR filter, contains zone name and RRs.
755 * @param ct: cached hashes table.
756 * @param nm: name to look for.
757 * @param nmlen: length of name.
758 * @param rrset: nsec3 that matches is returned here.
759 * @param rr: rr number in nsec3 rrset that matches.
760 * @param calculations: current hash calculations.
761 * @return true if a matching NSEC3 is found, false if not.
762 */
763 static int
find_matching_nsec3(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,uint8_t * nm,size_t nmlen,struct ub_packed_rrset_key ** rrset,int * rr,int * calculations)764 find_matching_nsec3(struct module_env* env, struct nsec3_filter* flt,
765 struct nsec3_cache_table* ct, uint8_t* nm, size_t nmlen,
766 struct ub_packed_rrset_key** rrset, int* rr,
767 int* calculations)
768 {
769 size_t i_rs;
770 int i_rr;
771 struct ub_packed_rrset_key* s;
772 struct nsec3_cached_hash* hash = NULL;
773 int r;
774 int calc_errors = 0;
775
776 /* this loop skips other-zone and unknown NSEC3s, also non-NSEC3 RRs */
777 for(s=filter_first(flt, &i_rs, &i_rr); s;
778 s=filter_next(flt, &i_rs, &i_rr)) {
779 /* check if we are allowed more calculations */
780 if(*calculations >= MAX_NSEC3_CALCULATIONS) {
781 if(calc_errors == *calculations) {
782 *calculations = MAX_NSEC3_ERRORS;
783 }
784 break;
785 }
786 /* get name hashed for this NSEC3 RR */
787 r = nsec3_hash_name(ct->ct, ct->region, env->scratch_buffer,
788 s, i_rr, nm, nmlen, &hash);
789 if(r == 0) {
790 log_err("nsec3: malloc failure");
791 break; /* alloc failure */
792 } else if(r < 0) {
793 /* malformed NSEC3 */
794 calc_errors++;
795 (*calculations)++;
796 continue;
797 } else {
798 if(r == 1) (*calculations)++;
799 if(nsec3_hash_matches_owner(flt, hash, s)) {
800 *rrset = s; /* rrset with this name */
801 *rr = i_rr; /* matches hash with these parameters */
802 return 1;
803 }
804 }
805 }
806 *rrset = NULL;
807 *rr = 0;
808 return 0;
809 }
810
811 int
nsec3_covers(uint8_t * zone,struct nsec3_cached_hash * hash,struct ub_packed_rrset_key * rrset,int rr,sldns_buffer * buf)812 nsec3_covers(uint8_t* zone, struct nsec3_cached_hash* hash,
813 struct ub_packed_rrset_key* rrset, int rr, sldns_buffer* buf)
814 {
815 uint8_t* next, *owner;
816 size_t nextlen;
817 int len;
818 if(!nsec3_get_nextowner(rrset, rr, &next, &nextlen))
819 return 0; /* malformed RR proves nothing */
820
821 if(!hash) return 0; /* please clang */
822 /* check the owner name is a hashed value . apex
823 * base32 encoded values must have equal length.
824 * hash_value and next hash value must have equal length. */
825 if(nextlen != hash->hash_len || hash->hash_len==0||hash->b32_len==0||
826 (size_t)*rrset->rk.dname != hash->b32_len ||
827 query_dname_compare(rrset->rk.dname+1+
828 (size_t)*rrset->rk.dname, zone) != 0)
829 return 0; /* bad lengths or owner name */
830
831 /* This is the "normal case: owner < next and owner < hash < next */
832 if(label_compare_lower(rrset->rk.dname+1, hash->b32,
833 hash->b32_len) < 0 &&
834 memcmp(hash->hash, next, nextlen) < 0)
835 return 1;
836
837 /* convert owner name from text to binary */
838 sldns_buffer_clear(buf);
839 owner = sldns_buffer_begin(buf);
840 len = sldns_b32_pton_extended_hex((char*)rrset->rk.dname+1,
841 hash->b32_len, owner, sldns_buffer_limit(buf));
842 if(len<1)
843 return 0; /* bad owner name in some way */
844 if((size_t)len != hash->hash_len || (size_t)len != nextlen)
845 return 0; /* wrong length */
846
847 /* this is the end of zone case: next <= owner &&
848 * (hash > owner || hash < next)
849 * this also covers the only-apex case of next==owner.
850 */
851 if(memcmp(next, owner, nextlen) <= 0 &&
852 ( memcmp(hash->hash, owner, nextlen) > 0 ||
853 memcmp(hash->hash, next, nextlen) < 0)) {
854 return 1;
855 }
856 return 0;
857 }
858
859 /**
860 * findCoveringNSEC3
861 * Given a name, find a covering NSEC3 from among a list of NSEC3s.
862 *
863 * @param env: module environment with temporary region and buffer.
864 * @param flt: the NSEC3 RR filter, contains zone name and RRs.
865 * @param ct: cached hashes table.
866 * @param nm: name to check if covered.
867 * @param nmlen: length of name.
868 * @param rrset: covering NSEC3 rrset is returned here.
869 * @param rr: rr of cover is returned here.
870 * @param calculations: current hash calculations.
871 * @return true if a covering NSEC3 is found, false if not.
872 */
873 static int
find_covering_nsec3(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,uint8_t * nm,size_t nmlen,struct ub_packed_rrset_key ** rrset,int * rr,int * calculations)874 find_covering_nsec3(struct module_env* env, struct nsec3_filter* flt,
875 struct nsec3_cache_table* ct, uint8_t* nm, size_t nmlen,
876 struct ub_packed_rrset_key** rrset, int* rr,
877 int* calculations)
878 {
879 size_t i_rs;
880 int i_rr;
881 struct ub_packed_rrset_key* s;
882 struct nsec3_cached_hash* hash = NULL;
883 int r;
884 int calc_errors = 0;
885
886 /* this loop skips other-zone and unknown NSEC3s, also non-NSEC3 RRs */
887 for(s=filter_first(flt, &i_rs, &i_rr); s;
888 s=filter_next(flt, &i_rs, &i_rr)) {
889 /* check if we are allowed more calculations */
890 if(*calculations >= MAX_NSEC3_CALCULATIONS) {
891 if(calc_errors == *calculations) {
892 *calculations = MAX_NSEC3_ERRORS;
893 }
894 break;
895 }
896 /* get name hashed for this NSEC3 RR */
897 r = nsec3_hash_name(ct->ct, ct->region, env->scratch_buffer,
898 s, i_rr, nm, nmlen, &hash);
899 if(r == 0) {
900 log_err("nsec3: malloc failure");
901 break; /* alloc failure */
902 } else if(r < 0) {
903 /* malformed NSEC3 */
904 calc_errors++;
905 (*calculations)++;
906 continue;
907 } else {
908 if(r == 1) (*calculations)++;
909 if(nsec3_covers(flt->zone, hash, s, i_rr,
910 env->scratch_buffer)) {
911 *rrset = s; /* rrset with this name */
912 *rr = i_rr; /* covers hash with these parameters */
913 return 1;
914 }
915 }
916 }
917 *rrset = NULL;
918 *rr = 0;
919 return 0;
920 }
921
922 /**
923 * findClosestEncloser
924 * Given a name and a list of NSEC3s, find the candidate closest encloser.
925 * This will be the first ancestor of 'name' (including itself) to have a
926 * matching NSEC3 RR.
927 * @param env: module environment with temporary region and buffer.
928 * @param flt: the NSEC3 RR filter, contains zone name and RRs.
929 * @param ct: cached hashes table.
930 * @param qinfo: query that is verified for.
931 * @param ce: closest encloser information is returned in here.
932 * @param calculations: current hash calculations.
933 * @return true if a closest encloser candidate is found, false if not.
934 */
935 static int
nsec3_find_closest_encloser(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,struct query_info * qinfo,struct ce_response * ce,int * calculations)936 nsec3_find_closest_encloser(struct module_env* env, struct nsec3_filter* flt,
937 struct nsec3_cache_table* ct, struct query_info* qinfo,
938 struct ce_response* ce, int* calculations)
939 {
940 uint8_t* nm = qinfo->qname;
941 size_t nmlen = qinfo->qname_len;
942
943 /* This scans from longest name to shortest, so the first match
944 * we find is the only viable candidate. */
945
946 /* (David:) FIXME: modify so that the NSEC3 matching the zone apex need
947 * not be present. (Mark Andrews idea).
948 * (Wouter:) But make sure you check for DNAME bit in zone apex,
949 * if the NSEC3 you find is the only NSEC3 in the zone, then this
950 * may be the case. */
951
952 while(dname_subdomain_c(nm, flt->zone)) {
953 if(*calculations >= MAX_NSEC3_CALCULATIONS ||
954 *calculations == MAX_NSEC3_ERRORS) {
955 return 0;
956 }
957 if(find_matching_nsec3(env, flt, ct, nm, nmlen,
958 &ce->ce_rrset, &ce->ce_rr, calculations)) {
959 ce->ce = nm;
960 ce->ce_len = nmlen;
961 return 1;
962 }
963 dname_remove_label(&nm, &nmlen);
964 }
965 return 0;
966 }
967
968 /**
969 * Given a qname and its proven closest encloser, calculate the "next
970 * closest" name. Basically, this is the name that is one label longer than
971 * the closest encloser that is still a subdomain of qname.
972 *
973 * @param qname: query name.
974 * @param qnamelen: length of qname.
975 * @param ce: closest encloser
976 * @param nm: result name.
977 * @param nmlen: length of nm.
978 */
979 static void
next_closer(uint8_t * qname,size_t qnamelen,uint8_t * ce,uint8_t ** nm,size_t * nmlen)980 next_closer(uint8_t* qname, size_t qnamelen, uint8_t* ce,
981 uint8_t** nm, size_t* nmlen)
982 {
983 int strip = dname_count_labels(qname) - dname_count_labels(ce) -1;
984 *nm = qname;
985 *nmlen = qnamelen;
986 if(strip>0)
987 dname_remove_labels(nm, nmlen, strip);
988 }
989
990 /**
991 * proveClosestEncloser
992 * Given a List of nsec3 RRs, find and prove the closest encloser to qname.
993 * @param env: module environment with temporary region and buffer.
994 * @param flt: the NSEC3 RR filter, contains zone name and RRs.
995 * @param ct: cached hashes table.
996 * @param qinfo: query that is verified for.
997 * @param prove_does_not_exist: If true, then if the closest encloser
998 * turns out to be qname, then null is returned.
999 * If set true, and the return value is true, then you can be
1000 * certain that the ce.nc_rrset and ce.nc_rr are set properly.
1001 * @param ce: closest encloser information is returned in here.
1002 * @param calculations: pointer to the current NSEC3 hash calculations.
1003 * @return bogus if no closest encloser could be proven.
1004 * secure if a closest encloser could be proven, ce is set.
1005 * insecure if the closest-encloser candidate turns out to prove
1006 * that an insecure delegation exists above the qname.
1007 * unchecked if no more hash calculations are allowed at this point.
1008 */
1009 static enum sec_status
nsec3_prove_closest_encloser(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,struct query_info * qinfo,int prove_does_not_exist,struct ce_response * ce,int * calculations)1010 nsec3_prove_closest_encloser(struct module_env* env, struct nsec3_filter* flt,
1011 struct nsec3_cache_table* ct, struct query_info* qinfo,
1012 int prove_does_not_exist, struct ce_response* ce, int* calculations)
1013 {
1014 uint8_t* nc;
1015 size_t nc_len;
1016 /* robust: clean out ce, in case it gets abused later */
1017 memset(ce, 0, sizeof(*ce));
1018
1019 if(!nsec3_find_closest_encloser(env, flt, ct, qinfo, ce, calculations)) {
1020 if(*calculations == MAX_NSEC3_ERRORS) {
1021 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: could "
1022 "not find a candidate for the closest "
1023 "encloser; all attempted hash calculations "
1024 "were erroneous; bogus");
1025 return sec_status_bogus;
1026 } else if(*calculations >= MAX_NSEC3_CALCULATIONS) {
1027 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: could "
1028 "not find a candidate for the closest "
1029 "encloser; reached MAX_NSEC3_CALCULATIONS "
1030 "(%d); unchecked still",
1031 MAX_NSEC3_CALCULATIONS);
1032 return sec_status_unchecked;
1033 }
1034 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: could "
1035 "not find a candidate for the closest encloser.");
1036 return sec_status_bogus;
1037 }
1038 log_nametypeclass(VERB_ALGO, "ce candidate", ce->ce, 0, 0);
1039
1040 if(query_dname_compare(ce->ce, qinfo->qname) == 0) {
1041 if(prove_does_not_exist) {
1042 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: "
1043 "proved that qname existed, bad");
1044 return sec_status_bogus;
1045 }
1046 /* otherwise, we need to nothing else to prove that qname
1047 * is its own closest encloser. */
1048 return sec_status_secure;
1049 }
1050
1051 /* If the closest encloser is actually a delegation, then the
1052 * response should have been a referral. If it is a DNAME, then
1053 * it should have been a DNAME response. */
1054 if(nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_NS) &&
1055 !nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_SOA)) {
1056 if(!nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_DS)) {
1057 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: "
1058 "closest encloser is insecure delegation");
1059 return sec_status_insecure;
1060 }
1061 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: closest "
1062 "encloser was a delegation, bad");
1063 return sec_status_bogus;
1064 }
1065 if(nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_DNAME)) {
1066 verbose(VERB_ALGO, "nsec3 proveClosestEncloser: closest "
1067 "encloser was a DNAME, bad");
1068 return sec_status_bogus;
1069 }
1070
1071 /* Otherwise, we need to show that the next closer name is covered. */
1072 next_closer(qinfo->qname, qinfo->qname_len, ce->ce, &nc, &nc_len);
1073 if(!find_covering_nsec3(env, flt, ct, nc, nc_len,
1074 &ce->nc_rrset, &ce->nc_rr, calculations)) {
1075 if(*calculations == MAX_NSEC3_ERRORS) {
1076 verbose(VERB_ALGO, "nsec3: Could not find proof that the "
1077 "candidate encloser was the closest encloser; "
1078 "all attempted hash calculations were "
1079 "erroneous; bogus");
1080 return sec_status_bogus;
1081 } else if(*calculations >= MAX_NSEC3_CALCULATIONS) {
1082 verbose(VERB_ALGO, "nsec3: Could not find proof that the "
1083 "candidate encloser was the closest encloser; "
1084 "reached MAX_NSEC3_CALCULATIONS (%d); "
1085 "unchecked still",
1086 MAX_NSEC3_CALCULATIONS);
1087 return sec_status_unchecked;
1088 }
1089 verbose(VERB_ALGO, "nsec3: Could not find proof that the "
1090 "candidate encloser was the closest encloser");
1091 return sec_status_bogus;
1092 }
1093 return sec_status_secure;
1094 }
1095
1096 /** allocate a wildcard for the closest encloser */
1097 static uint8_t*
nsec3_ce_wildcard(struct regional * region,uint8_t * ce,size_t celen,size_t * len)1098 nsec3_ce_wildcard(struct regional* region, uint8_t* ce, size_t celen,
1099 size_t* len)
1100 {
1101 uint8_t* nm;
1102 if(celen > LDNS_MAX_DOMAINLEN - 2)
1103 return 0; /* too long */
1104 nm = (uint8_t*)regional_alloc(region, celen+2);
1105 if(!nm) {
1106 log_err("nsec3 wildcard: out of memory");
1107 return 0; /* alloc failure */
1108 }
1109 nm[0] = 1;
1110 nm[1] = (uint8_t)'*'; /* wildcard label */
1111 memmove(nm+2, ce, celen);
1112 *len = celen+2;
1113 return nm;
1114 }
1115
1116 /** Do the name error proof */
1117 static enum sec_status
nsec3_do_prove_nameerror(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,struct query_info * qinfo,int * calc)1118 nsec3_do_prove_nameerror(struct module_env* env, struct nsec3_filter* flt,
1119 struct nsec3_cache_table* ct, struct query_info* qinfo, int* calc)
1120 {
1121 struct ce_response ce;
1122 uint8_t* wc;
1123 size_t wclen;
1124 struct ub_packed_rrset_key* wc_rrset;
1125 int wc_rr;
1126 enum sec_status sec;
1127
1128 /* First locate and prove the closest encloser to qname. We will
1129 * use the variant that fails if the closest encloser turns out
1130 * to be qname. */
1131 sec = nsec3_prove_closest_encloser(env, flt, ct, qinfo, 1, &ce, calc);
1132 if(sec != sec_status_secure) {
1133 if(sec == sec_status_bogus)
1134 verbose(VERB_ALGO, "nsec3 nameerror proof: failed "
1135 "to prove a closest encloser");
1136 else if(sec == sec_status_unchecked)
1137 verbose(VERB_ALGO, "nsec3 nameerror proof: will "
1138 "continue proving closest encloser after "
1139 "suspend");
1140 else verbose(VERB_ALGO, "nsec3 nameerror proof: closest "
1141 "nsec3 is an insecure delegation");
1142 return sec;
1143 }
1144 log_nametypeclass(VERB_ALGO, "nsec3 nameerror: proven ce=", ce.ce,0,0);
1145
1146 /* At this point, we know that qname does not exist. Now we need
1147 * to prove that the wildcard does not exist. */
1148 log_assert(ce.ce);
1149 wc = nsec3_ce_wildcard(ct->region, ce.ce, ce.ce_len, &wclen);
1150 if(!wc) {
1151 verbose(VERB_ALGO, "nsec3 nameerror proof: could not prove "
1152 "that the applicable wildcard did not exist.");
1153 return sec_status_bogus;
1154 }
1155 if(!find_covering_nsec3(env, flt, ct, wc, wclen, &wc_rrset, &wc_rr, calc)) {
1156 if(*calc == MAX_NSEC3_ERRORS) {
1157 verbose(VERB_ALGO, "nsec3 nameerror proof: could not prove "
1158 "that the applicable wildcard did not exist; "
1159 "all attempted hash calculations were "
1160 "erroneous; bogus");
1161 return sec_status_bogus;
1162 } else if(*calc >= MAX_NSEC3_CALCULATIONS) {
1163 verbose(VERB_ALGO, "nsec3 nameerror proof: could not prove "
1164 "that the applicable wildcard did not exist; "
1165 "reached MAX_NSEC3_CALCULATIONS (%d); "
1166 "unchecked still",
1167 MAX_NSEC3_CALCULATIONS);
1168 return sec_status_unchecked;
1169 }
1170 verbose(VERB_ALGO, "nsec3 nameerror proof: could not prove "
1171 "that the applicable wildcard did not exist.");
1172 return sec_status_bogus;
1173 }
1174
1175 if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
1176 verbose(VERB_ALGO, "nsec3 nameerror proof: nc has optout");
1177 return sec_status_insecure;
1178 }
1179 return sec_status_secure;
1180 }
1181
1182 enum sec_status
nsec3_prove_nameerror(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo,struct key_entry_key * kkey,struct nsec3_cache_table * ct,int * calc)1183 nsec3_prove_nameerror(struct module_env* env, struct val_env* ve,
1184 struct ub_packed_rrset_key** list, size_t num,
1185 struct query_info* qinfo, struct key_entry_key* kkey,
1186 struct nsec3_cache_table* ct, int* calc)
1187 {
1188 struct nsec3_filter flt;
1189
1190 if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
1191 return sec_status_bogus; /* no valid NSEC3s, bogus */
1192 filter_init(&flt, list, num, qinfo); /* init RR iterator */
1193 if(!flt.zone)
1194 return sec_status_bogus; /* no RRs */
1195 if(nsec3_iteration_count_high(ve, &flt, kkey))
1196 return sec_status_insecure; /* iteration count too high */
1197 log_nametypeclass(VERB_ALGO, "start nsec3 nameerror proof, zone",
1198 flt.zone, 0, 0);
1199 return nsec3_do_prove_nameerror(env, &flt, ct, qinfo, calc);
1200 }
1201
1202 /*
1203 * No code to handle qtype=NSEC3 specially.
1204 * This existed in early drafts, but was later (-05) removed.
1205 */
1206
1207 /** Do the nodata proof */
1208 static enum sec_status
nsec3_do_prove_nodata(struct module_env * env,struct nsec3_filter * flt,struct nsec3_cache_table * ct,struct query_info * qinfo,int * calc)1209 nsec3_do_prove_nodata(struct module_env* env, struct nsec3_filter* flt,
1210 struct nsec3_cache_table* ct, struct query_info* qinfo,
1211 int* calc)
1212 {
1213 struct ce_response ce;
1214 uint8_t* wc;
1215 size_t wclen;
1216 struct ub_packed_rrset_key* rrset;
1217 int rr;
1218 enum sec_status sec;
1219
1220 if(find_matching_nsec3(env, flt, ct, qinfo->qname, qinfo->qname_len,
1221 &rrset, &rr, calc)) {
1222 /* cases 1 and 2 */
1223 if(nsec3_has_type(rrset, rr, qinfo->qtype)) {
1224 verbose(VERB_ALGO, "proveNodata: Matching NSEC3 "
1225 "proved that type existed, bogus");
1226 return sec_status_bogus;
1227 } else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_CNAME)) {
1228 verbose(VERB_ALGO, "proveNodata: Matching NSEC3 "
1229 "proved that a CNAME existed, bogus");
1230 return sec_status_bogus;
1231 }
1232
1233 /*
1234 * If type DS: filter_init zone find already found a parent
1235 * zone, so this nsec3 is from a parent zone.
1236 * o can be not a delegation (unusual query for normal name,
1237 * no DS anyway, but we can verify that).
1238 * o can be a delegation (which is the usual DS check).
1239 * o may not have the SOA bit set (only the top of the
1240 * zone, which must have been above the name, has that).
1241 * Except for the root; which is checked by itself.
1242 *
1243 * If not type DS: matching nsec3 must not be a delegation.
1244 */
1245 if(qinfo->qtype == LDNS_RR_TYPE_DS && qinfo->qname_len != 1
1246 && nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA) &&
1247 !dname_is_root(qinfo->qname)) {
1248 verbose(VERB_ALGO, "proveNodata: apex NSEC3 "
1249 "abused for no DS proof, bogus");
1250 return sec_status_bogus;
1251 } else if(qinfo->qtype != LDNS_RR_TYPE_DS &&
1252 nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS) &&
1253 !nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
1254 if(!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_DS)) {
1255 verbose(VERB_ALGO, "proveNodata: matching "
1256 "NSEC3 is insecure delegation");
1257 return sec_status_insecure;
1258 }
1259 verbose(VERB_ALGO, "proveNodata: matching "
1260 "NSEC3 is a delegation, bogus");
1261 return sec_status_bogus;
1262 }
1263 return sec_status_secure;
1264 }
1265 if(*calc == MAX_NSEC3_ERRORS) {
1266 verbose(VERB_ALGO, "proveNodata: all attempted hash "
1267 "calculations were erroneous while finding a matching "
1268 "NSEC3, bogus");
1269 return sec_status_bogus;
1270 } else if(*calc >= MAX_NSEC3_CALCULATIONS) {
1271 verbose(VERB_ALGO, "proveNodata: reached "
1272 "MAX_NSEC3_CALCULATIONS (%d) while finding a "
1273 "matching NSEC3; unchecked still",
1274 MAX_NSEC3_CALCULATIONS);
1275 return sec_status_unchecked;
1276 }
1277
1278 /* For cases 3 - 5, we need the proven closest encloser, and it
1279 * can't match qname. Although, at this point, we know that it
1280 * won't since we just checked that. */
1281 sec = nsec3_prove_closest_encloser(env, flt, ct, qinfo, 1, &ce, calc);
1282 if(sec == sec_status_bogus) {
1283 verbose(VERB_ALGO, "proveNodata: did not match qname, "
1284 "nor found a proven closest encloser.");
1285 return sec_status_bogus;
1286 } else if(sec==sec_status_insecure && qinfo->qtype!=LDNS_RR_TYPE_DS){
1287 verbose(VERB_ALGO, "proveNodata: closest nsec3 is insecure "
1288 "delegation.");
1289 return sec_status_insecure;
1290 } else if(sec==sec_status_unchecked) {
1291 return sec_status_unchecked;
1292 }
1293
1294 /* Case 3: removed */
1295
1296 /* Case 4: */
1297 log_assert(ce.ce);
1298 wc = nsec3_ce_wildcard(ct->region, ce.ce, ce.ce_len, &wclen);
1299 if(wc && find_matching_nsec3(env, flt, ct, wc, wclen, &rrset, &rr,
1300 calc)) {
1301 /* found wildcard */
1302 if(nsec3_has_type(rrset, rr, qinfo->qtype)) {
1303 verbose(VERB_ALGO, "nsec3 nodata proof: matching "
1304 "wildcard had qtype, bogus");
1305 return sec_status_bogus;
1306 } else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_CNAME)) {
1307 verbose(VERB_ALGO, "nsec3 nodata proof: matching "
1308 "wildcard had a CNAME, bogus");
1309 return sec_status_bogus;
1310 }
1311 if(qinfo->qtype == LDNS_RR_TYPE_DS && qinfo->qname_len != 1
1312 && nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
1313 verbose(VERB_ALGO, "nsec3 nodata proof: matching "
1314 "wildcard for no DS proof has a SOA, bogus");
1315 return sec_status_bogus;
1316 } else if(qinfo->qtype != LDNS_RR_TYPE_DS &&
1317 nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS) &&
1318 !nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
1319 verbose(VERB_ALGO, "nsec3 nodata proof: matching "
1320 "wildcard is a delegation, bogus");
1321 return sec_status_bogus;
1322 }
1323 /* everything is peachy keen, except for optout spans */
1324 if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
1325 verbose(VERB_ALGO, "nsec3 nodata proof: matching "
1326 "wildcard is in optout range, insecure");
1327 return sec_status_insecure;
1328 }
1329 return sec_status_secure;
1330 }
1331 if(*calc == MAX_NSEC3_ERRORS) {
1332 verbose(VERB_ALGO, "nsec3 nodata proof: all attempted hash "
1333 "calculations were erroneous while matching "
1334 "wildcard, bogus");
1335 return sec_status_bogus;
1336 } else if(*calc >= MAX_NSEC3_CALCULATIONS) {
1337 verbose(VERB_ALGO, "nsec3 nodata proof: reached "
1338 "MAX_NSEC3_CALCULATIONS (%d) while matching "
1339 "wildcard, unchecked still",
1340 MAX_NSEC3_CALCULATIONS);
1341 return sec_status_unchecked;
1342 }
1343
1344 /* Case 5: */
1345 /* Due to forwarders, cnames, and other collating effects, we
1346 * can see the ordinary unsigned data from a zone beneath an
1347 * insecure delegation under an optout here */
1348 if(!ce.nc_rrset) {
1349 verbose(VERB_ALGO, "nsec3 nodata proof: no next closer nsec3");
1350 return sec_status_bogus;
1351 }
1352
1353 /* We need to make sure that the covering NSEC3 is opt-out. */
1354 log_assert(ce.nc_rrset);
1355 if(!nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
1356 if(qinfo->qtype == LDNS_RR_TYPE_DS)
1357 verbose(VERB_ALGO, "proveNodata: covering NSEC3 was not "
1358 "opt-out in an opt-out DS NOERROR/NODATA case.");
1359 else verbose(VERB_ALGO, "proveNodata: could not find matching "
1360 "NSEC3, nor matching wildcard, nor optout NSEC3 "
1361 "-- no more options, bogus.");
1362 return sec_status_bogus;
1363 }
1364 /* RFC5155 section 9.2: if nc has optout then no AD flag set */
1365 return sec_status_insecure;
1366 }
1367
1368 enum sec_status
nsec3_prove_nodata(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo,struct key_entry_key * kkey,struct nsec3_cache_table * ct,int * calc)1369 nsec3_prove_nodata(struct module_env* env, struct val_env* ve,
1370 struct ub_packed_rrset_key** list, size_t num,
1371 struct query_info* qinfo, struct key_entry_key* kkey,
1372 struct nsec3_cache_table* ct, int* calc)
1373 {
1374 struct nsec3_filter flt;
1375
1376 if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
1377 return sec_status_bogus; /* no valid NSEC3s, bogus */
1378 filter_init(&flt, list, num, qinfo); /* init RR iterator */
1379 if(!flt.zone)
1380 return sec_status_bogus; /* no RRs */
1381 if(nsec3_iteration_count_high(ve, &flt, kkey))
1382 return sec_status_insecure; /* iteration count too high */
1383 return nsec3_do_prove_nodata(env, &flt, ct, qinfo, calc);
1384 }
1385
1386 enum sec_status
nsec3_prove_wildcard(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo,struct key_entry_key * kkey,uint8_t * wc,struct nsec3_cache_table * ct,int * calc)1387 nsec3_prove_wildcard(struct module_env* env, struct val_env* ve,
1388 struct ub_packed_rrset_key** list, size_t num,
1389 struct query_info* qinfo, struct key_entry_key* kkey, uint8_t* wc,
1390 struct nsec3_cache_table* ct, int* calc)
1391 {
1392 struct nsec3_filter flt;
1393 struct ce_response ce;
1394 uint8_t* nc;
1395 size_t nc_len;
1396 size_t wclen;
1397 (void)dname_count_size_labels(wc, &wclen);
1398
1399 if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
1400 return sec_status_bogus; /* no valid NSEC3s, bogus */
1401 filter_init(&flt, list, num, qinfo); /* init RR iterator */
1402 if(!flt.zone)
1403 return sec_status_bogus; /* no RRs */
1404 if(nsec3_iteration_count_high(ve, &flt, kkey))
1405 return sec_status_insecure; /* iteration count too high */
1406
1407 /* We know what the (purported) closest encloser is by just
1408 * looking at the supposed generating wildcard.
1409 * The *. has already been removed from the wc name.
1410 */
1411 memset(&ce, 0, sizeof(ce));
1412 ce.ce = wc;
1413 ce.ce_len = wclen;
1414
1415 /* Now we still need to prove that the original data did not exist.
1416 * Otherwise, we need to show that the next closer name is covered. */
1417 next_closer(qinfo->qname, qinfo->qname_len, ce.ce, &nc, &nc_len);
1418 if(!find_covering_nsec3(env, &flt, ct, nc, nc_len,
1419 &ce.nc_rrset, &ce.nc_rr, calc)) {
1420 if(*calc == MAX_NSEC3_ERRORS) {
1421 verbose(VERB_ALGO, "proveWildcard: did not find a "
1422 "covering NSEC3 that covered the next closer "
1423 "name; all attempted hash calculations were "
1424 "erroneous; bogus");
1425 return sec_status_bogus;
1426 } else if(*calc >= MAX_NSEC3_CALCULATIONS) {
1427 verbose(VERB_ALGO, "proveWildcard: did not find a "
1428 "covering NSEC3 that covered the next closer "
1429 "name; reached MAX_NSEC3_CALCULATIONS "
1430 "(%d); unchecked still",
1431 MAX_NSEC3_CALCULATIONS);
1432 return sec_status_unchecked;
1433 }
1434 verbose(VERB_ALGO, "proveWildcard: did not find a covering "
1435 "NSEC3 that covered the next closer name.");
1436 return sec_status_bogus;
1437 }
1438 if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
1439 verbose(VERB_ALGO, "proveWildcard: NSEC3 optout");
1440 return sec_status_insecure;
1441 }
1442 return sec_status_secure;
1443 }
1444
1445 /** test if list is all secure */
1446 static int
list_is_secure(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct key_entry_key * kkey,char ** reason,sldns_ede_code * reason_bogus,struct module_qstate * qstate,char * reasonbuf,size_t reasonlen)1447 list_is_secure(struct module_env* env, struct val_env* ve,
1448 struct ub_packed_rrset_key** list, size_t num,
1449 struct key_entry_key* kkey, char** reason, sldns_ede_code *reason_bogus,
1450 struct module_qstate* qstate, char* reasonbuf, size_t reasonlen)
1451 {
1452 struct packed_rrset_data* d;
1453 size_t i;
1454 int verified = 0;
1455 for(i=0; i<num; i++) {
1456 d = (struct packed_rrset_data*)list[i]->entry.data;
1457 if(list[i]->rk.type != htons(LDNS_RR_TYPE_NSEC3))
1458 continue;
1459 if(d->security == sec_status_secure)
1460 continue;
1461 rrset_check_sec_status(env->rrset_cache, list[i], *env->now);
1462 if(d->security == sec_status_secure)
1463 continue;
1464 d->security = val_verify_rrset_entry(env, ve, list[i], kkey,
1465 reason, reason_bogus, LDNS_SECTION_AUTHORITY, qstate,
1466 &verified, reasonbuf, reasonlen);
1467 if(d->security != sec_status_secure) {
1468 verbose(VERB_ALGO, "NSEC3 did not verify");
1469 return 0;
1470 }
1471 rrset_update_sec_status(env->rrset_cache, list[i], *env->now);
1472 }
1473 return 1;
1474 }
1475
1476 enum sec_status
nsec3_prove_nods(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo,struct key_entry_key * kkey,char ** reason,sldns_ede_code * reason_bogus,struct module_qstate * qstate,struct nsec3_cache_table * ct,char * reasonbuf,size_t reasonlen)1477 nsec3_prove_nods(struct module_env* env, struct val_env* ve,
1478 struct ub_packed_rrset_key** list, size_t num,
1479 struct query_info* qinfo, struct key_entry_key* kkey, char** reason,
1480 sldns_ede_code* reason_bogus, struct module_qstate* qstate,
1481 struct nsec3_cache_table* ct, char* reasonbuf, size_t reasonlen)
1482 {
1483 struct nsec3_filter flt;
1484 struct ce_response ce;
1485 struct ub_packed_rrset_key* rrset;
1486 int rr;
1487 int calc = 0;
1488 enum sec_status sec;
1489
1490 log_assert(qinfo->qtype == LDNS_RR_TYPE_DS);
1491
1492 if(!list || num == 0 || !kkey || !key_entry_isgood(kkey)) {
1493 *reason = "no valid NSEC3s";
1494 return sec_status_bogus; /* no valid NSEC3s, bogus */
1495 }
1496 if(!list_is_secure(env, ve, list, num, kkey, reason, reason_bogus,
1497 qstate, reasonbuf, reasonlen)) {
1498 *reason = "not all NSEC3 records secure";
1499 return sec_status_bogus; /* not all NSEC3 records secure */
1500 }
1501 filter_init(&flt, list, num, qinfo); /* init RR iterator */
1502 if(!flt.zone) {
1503 *reason = "no NSEC3 records";
1504 return sec_status_bogus; /* no RRs */
1505 }
1506 if(nsec3_iteration_count_high(ve, &flt, kkey))
1507 return sec_status_insecure; /* iteration count too high */
1508
1509 /* Look for a matching NSEC3 to qname -- this is the normal
1510 * NODATA case. */
1511 if(find_matching_nsec3(env, &flt, ct, qinfo->qname, qinfo->qname_len,
1512 &rrset, &rr, &calc)) {
1513 /* If the matching NSEC3 has the SOA bit set, it is from
1514 * the wrong zone (the child instead of the parent). If
1515 * it has the DS bit set, then we were lied to. */
1516 if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA) &&
1517 qinfo->qname_len != 1) {
1518 verbose(VERB_ALGO, "nsec3 provenods: NSEC3 is from"
1519 " child zone, bogus");
1520 *reason = "NSEC3 from child zone";
1521 return sec_status_bogus;
1522 } else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_DS)) {
1523 verbose(VERB_ALGO, "nsec3 provenods: NSEC3 has qtype"
1524 " DS, bogus");
1525 *reason = "NSEC3 has DS in bitmap";
1526 return sec_status_bogus;
1527 }
1528 /* If the NSEC3 RR doesn't have the NS bit set, then
1529 * this wasn't a delegation point. */
1530 if(!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS))
1531 return sec_status_indeterminate;
1532 /* Otherwise, this proves no DS. */
1533 return sec_status_secure;
1534 }
1535 if(calc == MAX_NSEC3_ERRORS) {
1536 verbose(VERB_ALGO, "nsec3 provenods: all attempted hash "
1537 "calculations were erroneous while finding a matching "
1538 "NSEC3, bogus");
1539 return sec_status_bogus;
1540 } else if(calc >= MAX_NSEC3_CALCULATIONS) {
1541 verbose(VERB_ALGO, "nsec3 provenods: reached "
1542 "MAX_NSEC3_CALCULATIONS (%d) while finding a "
1543 "matching NSEC3, unchecked still",
1544 MAX_NSEC3_CALCULATIONS);
1545 return sec_status_unchecked;
1546 }
1547
1548 /* Otherwise, we are probably in the opt-out case. */
1549 sec = nsec3_prove_closest_encloser(env, &flt, ct, qinfo, 1, &ce, &calc);
1550 if(sec == sec_status_unchecked) {
1551 return sec_status_unchecked;
1552 } else if(sec != sec_status_secure) {
1553 /* an insecure delegation *above* the qname does not prove
1554 * anything about this qname exactly, and bogus is bogus */
1555 verbose(VERB_ALGO, "nsec3 provenods: did not match qname, "
1556 "nor found a proven closest encloser.");
1557 *reason = "no NSEC3 closest encloser";
1558 return sec_status_bogus;
1559 }
1560
1561 /* robust extra check */
1562 if(!ce.nc_rrset) {
1563 verbose(VERB_ALGO, "nsec3 nods proof: no next closer nsec3");
1564 *reason = "no NSEC3 next closer";
1565 return sec_status_bogus;
1566 }
1567
1568 /* we had the closest encloser proof, then we need to check that the
1569 * covering NSEC3 was opt-out -- the proveClosestEncloser step already
1570 * checked to see if the closest encloser was a delegation or DNAME.
1571 */
1572 log_assert(ce.nc_rrset);
1573 if(!nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
1574 verbose(VERB_ALGO, "nsec3 provenods: covering NSEC3 was not "
1575 "opt-out in an opt-out DS NOERROR/NODATA case.");
1576 *reason = "covering NSEC3 was not opt-out in an opt-out "
1577 "DS NOERROR/NODATA case";
1578 return sec_status_bogus;
1579 }
1580 /* RFC5155 section 9.2: if nc has optout then no AD flag set */
1581 return sec_status_insecure;
1582 }
1583
1584 enum sec_status
nsec3_prove_nxornodata(struct module_env * env,struct val_env * ve,struct ub_packed_rrset_key ** list,size_t num,struct query_info * qinfo,struct key_entry_key * kkey,int * nodata,struct nsec3_cache_table * ct,int * calc)1585 nsec3_prove_nxornodata(struct module_env* env, struct val_env* ve,
1586 struct ub_packed_rrset_key** list, size_t num,
1587 struct query_info* qinfo, struct key_entry_key* kkey, int* nodata,
1588 struct nsec3_cache_table* ct, int* calc)
1589 {
1590 enum sec_status sec, secnx;
1591 struct nsec3_filter flt;
1592 *nodata = 0;
1593
1594 if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
1595 return sec_status_bogus; /* no valid NSEC3s, bogus */
1596 filter_init(&flt, list, num, qinfo); /* init RR iterator */
1597 if(!flt.zone)
1598 return sec_status_bogus; /* no RRs */
1599 if(nsec3_iteration_count_high(ve, &flt, kkey))
1600 return sec_status_insecure; /* iteration count too high */
1601
1602 /* try nxdomain and nodata after another, while keeping the
1603 * hash cache intact */
1604
1605 secnx = nsec3_do_prove_nameerror(env, &flt, ct, qinfo, calc);
1606 if(secnx==sec_status_secure)
1607 return sec_status_secure;
1608 else if(secnx == sec_status_unchecked)
1609 return sec_status_unchecked;
1610 sec = nsec3_do_prove_nodata(env, &flt, ct, qinfo, calc);
1611 if(sec==sec_status_secure) {
1612 *nodata = 1;
1613 } else if(sec == sec_status_insecure) {
1614 *nodata = 1;
1615 } else if(secnx == sec_status_insecure) {
1616 sec = sec_status_insecure;
1617 } else if(sec == sec_status_unchecked) {
1618 return sec_status_unchecked;
1619 }
1620 return sec;
1621 }
1622