1 /* 2 * validator/val_utils.c - validator utility 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 */ 41 #include "config.h" 42 #include "validator/val_utils.h" 43 #include "validator/validator.h" 44 #include "validator/val_kentry.h" 45 #include "validator/val_sigcrypt.h" 46 #include "validator/val_anchor.h" 47 #include "validator/val_nsec.h" 48 #include "validator/val_neg.h" 49 #include "services/cache/rrset.h" 50 #include "services/cache/dns.h" 51 #include "util/data/msgreply.h" 52 #include "util/data/packed_rrset.h" 53 #include "util/data/dname.h" 54 #include "util/net_help.h" 55 #include "util/module.h" 56 #include "util/regional.h" 57 #include "util/config_file.h" 58 #include "sldns/wire2str.h" 59 #include "sldns/parseutil.h" 60 61 /** Maximum allowed digest match failures per DS, for DNSKEYs with the same 62 * properties */ 63 #define MAX_DS_MATCH_FAILURES 4 64 65 enum val_classification 66 val_classify_response(uint16_t query_flags, struct query_info* origqinf, 67 struct query_info* qinf, struct reply_info* rep, size_t skip) 68 { 69 int rcode = (int)FLAGS_GET_RCODE(rep->flags); 70 size_t i; 71 72 /* Normal Name Error's are easy to detect -- but don't mistake a CNAME 73 * chain ending in NXDOMAIN. */ 74 if(rcode == LDNS_RCODE_NXDOMAIN && rep->an_numrrsets == 0) 75 return VAL_CLASS_NAMEERROR; 76 77 /* check for referral: nonRD query and it looks like a nodata */ 78 if(!(query_flags&BIT_RD) && rep->an_numrrsets == 0 && 79 rcode == LDNS_RCODE_NOERROR) { 80 /* SOA record in auth indicates it is NODATA instead. 81 * All validation requiring NODATA messages have SOA in 82 * authority section. */ 83 /* uses fact that answer section is empty */ 84 int saw_ns = 0; 85 for(i=0; i<rep->ns_numrrsets; i++) { 86 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_SOA) 87 return VAL_CLASS_NODATA; 88 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_DS) 89 return VAL_CLASS_REFERRAL; 90 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) 91 saw_ns = 1; 92 } 93 return saw_ns?VAL_CLASS_REFERRAL:VAL_CLASS_NODATA; 94 } 95 /* root referral where NS set is in the answer section */ 96 if(!(query_flags&BIT_RD) && rep->ns_numrrsets == 0 && 97 rep->an_numrrsets == 1 && rcode == LDNS_RCODE_NOERROR && 98 ntohs(rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_NS && 99 query_dname_compare(rep->rrsets[0]->rk.dname, 100 origqinf->qname) != 0) 101 return VAL_CLASS_REFERRAL; 102 103 /* dump bad messages */ 104 if(rcode != LDNS_RCODE_NOERROR && rcode != LDNS_RCODE_NXDOMAIN) 105 return VAL_CLASS_UNKNOWN; 106 /* next check if the skip into the answer section shows no answer */ 107 if(skip>0 && rep->an_numrrsets <= skip) 108 return VAL_CLASS_CNAMENOANSWER; 109 110 /* Next is NODATA */ 111 if(rcode == LDNS_RCODE_NOERROR && rep->an_numrrsets == 0) 112 return VAL_CLASS_NODATA; 113 114 /* We distinguish between CNAME response and other positive/negative 115 * responses because CNAME answers require extra processing. */ 116 117 /* We distinguish between ANY and CNAME or POSITIVE because 118 * ANY responses are validated differently. */ 119 if(rcode == LDNS_RCODE_NOERROR && qinf->qtype == LDNS_RR_TYPE_ANY) 120 return VAL_CLASS_ANY; 121 122 /* For the query type DNAME, the name matters. Equal name is the 123 * answer looked for, but a subdomain redirects the query. */ 124 if(qinf->qtype == LDNS_RR_TYPE_DNAME) { 125 for(i=skip; i<rep->an_numrrsets; i++) { 126 if(rcode == LDNS_RCODE_NOERROR && 127 ntohs(rep->rrsets[i]->rk.type) 128 == LDNS_RR_TYPE_DNAME && 129 query_dname_compare(qinf->qname, 130 rep->rrsets[i]->rk.dname) == 0) { 131 /* type is DNAME and name is equal, it is 132 * the answer. For the query name a subdomain 133 * of the rrset.dname it would redirect. */ 134 return VAL_CLASS_POSITIVE; 135 } 136 if(ntohs(rep->rrsets[i]->rk.type) 137 == LDNS_RR_TYPE_CNAME) 138 return VAL_CLASS_CNAME; 139 } 140 log_dns_msg("validator: error. failed to classify response message: ", 141 qinf, rep); 142 return VAL_CLASS_UNKNOWN; 143 } 144 145 /* Note that DNAMEs will be ignored here, unless qtype=DNAME. Unless 146 * qtype=CNAME, this will yield a CNAME response. */ 147 for(i=skip; i<rep->an_numrrsets; i++) { 148 if(rcode == LDNS_RCODE_NOERROR && 149 ntohs(rep->rrsets[i]->rk.type) == qinf->qtype) 150 return VAL_CLASS_POSITIVE; 151 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME) 152 return VAL_CLASS_CNAME; 153 } 154 log_dns_msg("validator: error. failed to classify response message: ", 155 qinf, rep); 156 return VAL_CLASS_UNKNOWN; 157 } 158 159 /** Get signer name from RRSIG */ 160 static void 161 rrsig_get_signer(uint8_t* data, size_t len, uint8_t** sname, size_t* slen) 162 { 163 /* RRSIG rdata is not allowed to be compressed, it is stored 164 * uncompressed in memory as well, so return a ptr to the name */ 165 if(len < 21) { 166 /* too short RRSig: 167 * short, byte, byte, long, long, long, short, "." is 168 * 2 1 1 4 4 4 2 1 = 19 169 * and a skip of 18 bytes to the name. 170 * +2 for the rdatalen is 21 bytes len for root label */ 171 *sname = NULL; 172 *slen = 0; 173 return; 174 } 175 data += 20; /* skip the fixed size bits */ 176 len -= 20; 177 *slen = dname_valid(data, len); 178 if(!*slen) { 179 /* bad dname in this rrsig. */ 180 *sname = NULL; 181 return; 182 } 183 *sname = data; 184 } 185 186 void 187 val_find_rrset_signer(struct ub_packed_rrset_key* rrset, uint8_t** sname, 188 size_t* slen) 189 { 190 struct packed_rrset_data* d = (struct packed_rrset_data*) 191 rrset->entry.data; 192 /* return signer for first signature, or NULL */ 193 if(d->rrsig_count == 0) { 194 *sname = NULL; 195 *slen = 0; 196 return; 197 } 198 /* get rrsig signer name out of the signature */ 199 rrsig_get_signer(d->rr_data[d->count], d->rr_len[d->count], 200 sname, slen); 201 } 202 203 /** 204 * Find best signer name in this set of rrsigs. 205 * @param rrset: which rrsigs to look through. 206 * @param qinf: the query name that needs validation. 207 * @param signer_name: the best signer_name. Updated if a better one is found. 208 * @param signer_len: length of signer name. 209 * @param matchcount: count of current best name (starts at 0 for no match). 210 * Updated if match is improved. 211 */ 212 static void 213 val_find_best_signer(struct ub_packed_rrset_key* rrset, 214 struct query_info* qinf, uint8_t** signer_name, size_t* signer_len, 215 int* matchcount) 216 { 217 struct packed_rrset_data* d = (struct packed_rrset_data*) 218 rrset->entry.data; 219 uint8_t* sign; 220 size_t i; 221 int m; 222 for(i=d->count; i<d->count+d->rrsig_count; i++) { 223 sign = d->rr_data[i]+2+18; 224 /* look at signatures that are valid (long enough), 225 * and have a signer name that is a superdomain of qname, 226 * and then check the number of labels in the shared topdomain 227 * improve the match if possible */ 228 if(d->rr_len[i] > 2+19 && /* rdata, sig + root label*/ 229 dname_subdomain_c(qinf->qname, sign)) { 230 (void)dname_lab_cmp(qinf->qname, 231 dname_count_labels(qinf->qname), 232 sign, dname_count_labels(sign), &m); 233 if(m > *matchcount) { 234 *matchcount = m; 235 *signer_name = sign; 236 (void)dname_count_size_labels(*signer_name, 237 signer_len); 238 } 239 } 240 } 241 } 242 243 /** Detect if the, unsigned, CNAME is under a previous DNAME RR in the 244 * message, and thus it was generated from that previous DNAME. 245 */ 246 static int 247 cname_under_previous_dname(struct reply_info* rep, size_t cname_idx, 248 size_t* ret) 249 { 250 size_t i; 251 for(i=0; i<cname_idx; i++) { 252 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_DNAME && 253 dname_strict_subdomain_c(rep->rrsets[cname_idx]-> 254 rk.dname, rep->rrsets[i]->rk.dname)) { 255 *ret = i; 256 return 1; 257 } 258 } 259 *ret = 0; 260 return 0; 261 } 262 263 void 264 val_find_signer(enum val_classification subtype, struct query_info* qinf, 265 struct reply_info* rep, size_t skip, uint8_t** signer_name, 266 size_t* signer_len) 267 { 268 size_t i; 269 270 if(subtype == VAL_CLASS_POSITIVE) { 271 /* check for the answer rrset */ 272 for(i=skip; i<rep->an_numrrsets; i++) { 273 if(query_dname_compare(qinf->qname, 274 rep->rrsets[i]->rk.dname) == 0) { 275 val_find_rrset_signer(rep->rrsets[i], 276 signer_name, signer_len); 277 /* If there was no signer, and the query 278 * was for type CNAME, and this is a CNAME, 279 * and the previous is a DNAME, then this 280 * is the synthesized CNAME, use the signer 281 * of the DNAME record. */ 282 if(*signer_name == NULL && 283 qinf->qtype == LDNS_RR_TYPE_CNAME && 284 ntohs(rep->rrsets[i]->rk.type) == 285 LDNS_RR_TYPE_CNAME && i > skip && 286 ntohs(rep->rrsets[i-1]->rk.type) == 287 LDNS_RR_TYPE_DNAME && 288 dname_strict_subdomain_c(rep->rrsets[i]->rk.dname, rep->rrsets[i-1]->rk.dname)) { 289 val_find_rrset_signer(rep->rrsets[i-1], 290 signer_name, signer_len); 291 } 292 return; 293 } 294 } 295 *signer_name = NULL; 296 *signer_len = 0; 297 } else if(subtype == VAL_CLASS_CNAME) { 298 size_t j; 299 /* check for the first signed cname/dname rrset */ 300 for(i=skip; i<rep->an_numrrsets; i++) { 301 val_find_rrset_signer(rep->rrsets[i], 302 signer_name, signer_len); 303 if(*signer_name) 304 return; 305 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME 306 && cname_under_previous_dname(rep, i, &j)) { 307 val_find_rrset_signer(rep->rrsets[j], 308 signer_name, signer_len); 309 return; 310 } 311 if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_DNAME) 312 break; /* only check CNAME after a DNAME */ 313 } 314 *signer_name = NULL; 315 *signer_len = 0; 316 } else if(subtype == VAL_CLASS_NAMEERROR 317 || subtype == VAL_CLASS_NODATA) { 318 /*Check to see if the AUTH section NSEC record(s) have rrsigs*/ 319 for(i=rep->an_numrrsets; i< 320 rep->an_numrrsets+rep->ns_numrrsets; i++) { 321 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC 322 || ntohs(rep->rrsets[i]->rk.type) == 323 LDNS_RR_TYPE_NSEC3) { 324 val_find_rrset_signer(rep->rrsets[i], 325 signer_name, signer_len); 326 return; 327 } 328 } 329 } else if(subtype == VAL_CLASS_CNAMENOANSWER) { 330 /* find closest superdomain signer name in authority section 331 * NSEC and NSEC3s */ 332 int matchcount = 0; 333 *signer_name = NULL; 334 *signer_len = 0; 335 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep-> 336 ns_numrrsets; i++) { 337 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC 338 || ntohs(rep->rrsets[i]->rk.type) == 339 LDNS_RR_TYPE_NSEC3) { 340 val_find_best_signer(rep->rrsets[i], qinf, 341 signer_name, signer_len, &matchcount); 342 } 343 } 344 } else if(subtype == VAL_CLASS_ANY) { 345 /* check for one of the answer rrset that has signatures, 346 * or potentially a DNAME is in use with a different qname */ 347 for(i=skip; i<rep->an_numrrsets; i++) { 348 if(query_dname_compare(qinf->qname, 349 rep->rrsets[i]->rk.dname) == 0) { 350 val_find_rrset_signer(rep->rrsets[i], 351 signer_name, signer_len); 352 if(*signer_name) 353 return; 354 } 355 } 356 /* no answer RRSIGs with qname, try a DNAME */ 357 if(skip < rep->an_numrrsets && 358 ntohs(rep->rrsets[skip]->rk.type) == 359 LDNS_RR_TYPE_DNAME) { 360 val_find_rrset_signer(rep->rrsets[skip], 361 signer_name, signer_len); 362 if(*signer_name) 363 return; 364 } 365 *signer_name = NULL; 366 *signer_len = 0; 367 } else if(subtype == VAL_CLASS_REFERRAL) { 368 /* find keys for the item at skip */ 369 if(skip < rep->rrset_count) { 370 val_find_rrset_signer(rep->rrsets[skip], 371 signer_name, signer_len); 372 return; 373 } 374 *signer_name = NULL; 375 *signer_len = 0; 376 } else { 377 verbose(VERB_QUERY, "find_signer: could not find signer name" 378 " for unknown type response"); 379 *signer_name = NULL; 380 *signer_len = 0; 381 } 382 } 383 384 /** return number of rrs in an rrset */ 385 static size_t 386 rrset_get_count(struct ub_packed_rrset_key* rrset) 387 { 388 struct packed_rrset_data* d = (struct packed_rrset_data*) 389 rrset->entry.data; 390 if(!d) return 0; 391 return d->count; 392 } 393 394 /** return TTL of rrset */ 395 static uint32_t 396 rrset_get_ttl(struct ub_packed_rrset_key* rrset) 397 { 398 struct packed_rrset_data* d = (struct packed_rrset_data*) 399 rrset->entry.data; 400 if(!d) return 0; 401 return d->ttl; 402 } 403 404 static enum sec_status 405 val_verify_rrset(struct module_env* env, struct val_env* ve, 406 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* keys, 407 uint8_t* sigalg, char** reason, sldns_ede_code *reason_bogus, 408 sldns_pkt_section section, struct module_qstate* qstate, 409 int *verified, char* reasonbuf, size_t reasonlen) 410 { 411 enum sec_status sec; 412 struct packed_rrset_data* d = (struct packed_rrset_data*)rrset-> 413 entry.data; 414 if(d->security == sec_status_secure) { 415 /* re-verify all other statuses, because keyset may change*/ 416 log_nametypeclass(VERB_ALGO, "verify rrset cached", 417 rrset->rk.dname, ntohs(rrset->rk.type), 418 ntohs(rrset->rk.rrset_class)); 419 *verified = 0; 420 return d->security; 421 } 422 /* check in the cache if verification has already been done */ 423 rrset_check_sec_status(env->rrset_cache, rrset, *env->now); 424 if(d->security == sec_status_secure) { 425 log_nametypeclass(VERB_ALGO, "verify rrset from cache", 426 rrset->rk.dname, ntohs(rrset->rk.type), 427 ntohs(rrset->rk.rrset_class)); 428 *verified = 0; 429 return d->security; 430 } 431 log_nametypeclass(VERB_ALGO, "verify rrset", rrset->rk.dname, 432 ntohs(rrset->rk.type), ntohs(rrset->rk.rrset_class)); 433 sec = dnskeyset_verify_rrset(env, ve, rrset, keys, sigalg, reason, 434 reason_bogus, section, qstate, verified, reasonbuf, reasonlen); 435 verbose(VERB_ALGO, "verify result: %s", sec_status_to_string(sec)); 436 regional_free_all(env->scratch); 437 438 /* update rrset security status 439 * only improves security status 440 * and bogus is set only once, even if we rechecked the status */ 441 if(sec > d->security) { 442 d->security = sec; 443 if(sec == sec_status_secure) 444 d->trust = rrset_trust_validated; 445 else if(sec == sec_status_bogus) { 446 size_t i; 447 /* update ttl for rrset to fixed value. */ 448 d->ttl = ve->bogus_ttl; 449 for(i=0; i<d->count+d->rrsig_count; i++) 450 d->rr_ttl[i] = ve->bogus_ttl; 451 /* leave RR specific TTL: not used for determine 452 * if RRset timed out and clients see proper value. */ 453 lock_basic_lock(&ve->bogus_lock); 454 ve->num_rrset_bogus++; 455 lock_basic_unlock(&ve->bogus_lock); 456 } 457 /* if status updated - store in cache for reuse */ 458 rrset_update_sec_status(env->rrset_cache, rrset, *env->now); 459 } 460 461 return sec; 462 } 463 464 enum sec_status 465 val_verify_rrset_entry(struct module_env* env, struct val_env* ve, 466 struct ub_packed_rrset_key* rrset, struct key_entry_key* kkey, 467 char** reason, sldns_ede_code *reason_bogus, 468 sldns_pkt_section section, struct module_qstate* qstate, 469 int* verified, char* reasonbuf, size_t reasonlen) 470 { 471 /* temporary dnskey rrset-key */ 472 struct ub_packed_rrset_key dnskey; 473 struct key_entry_data* kd = (struct key_entry_data*)kkey->entry.data; 474 enum sec_status sec; 475 dnskey.rk.type = htons(kd->rrset_type); 476 dnskey.rk.rrset_class = htons(kkey->key_class); 477 dnskey.rk.flags = 0; 478 dnskey.rk.dname = kkey->name; 479 dnskey.rk.dname_len = kkey->namelen; 480 dnskey.entry.key = &dnskey; 481 dnskey.entry.data = kd->rrset_data; 482 sec = val_verify_rrset(env, ve, rrset, &dnskey, kd->algo, reason, 483 reason_bogus, section, qstate, verified, reasonbuf, reasonlen); 484 return sec; 485 } 486 487 /** verify that a DS RR hashes to a key and that key signs the set */ 488 static enum sec_status 489 verify_dnskeys_with_ds_rr(struct module_env* env, struct val_env* ve, 490 struct ub_packed_rrset_key* dnskey_rrset, 491 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx, char** reason, 492 sldns_ede_code *reason_bogus, struct module_qstate* qstate, 493 int *nonechecked, char* reasonbuf, size_t reasonlen) 494 { 495 enum sec_status sec = sec_status_bogus; 496 size_t i, num, numchecked = 0, numhashok = 0, numsizesupp = 0; 497 num = rrset_get_count(dnskey_rrset); 498 *nonechecked = 0; 499 for(i=0; i<num; i++) { 500 /* Skip DNSKEYs that don't match the basic criteria. */ 501 if(ds_get_key_algo(ds_rrset, ds_idx) 502 != dnskey_get_algo(dnskey_rrset, i) 503 || dnskey_calc_keytag(dnskey_rrset, i) 504 != ds_get_keytag(ds_rrset, ds_idx)) { 505 continue; 506 } 507 numchecked++; 508 verbose(VERB_ALGO, "attempt DS match algo %d keytag %d", 509 ds_get_key_algo(ds_rrset, ds_idx), 510 ds_get_keytag(ds_rrset, ds_idx)); 511 512 /* Convert the candidate DNSKEY into a hash using the 513 * same DS hash algorithm. */ 514 if(!ds_digest_match_dnskey(env, dnskey_rrset, i, ds_rrset, 515 ds_idx)) { 516 verbose(VERB_ALGO, "DS match attempt failed"); 517 if(numchecked > numhashok + MAX_DS_MATCH_FAILURES) { 518 verbose(VERB_ALGO, "DS match attempt reached " 519 "MAX_DS_MATCH_FAILURES (%d); bogus", 520 MAX_DS_MATCH_FAILURES); 521 return sec_status_bogus; 522 } 523 continue; 524 } 525 numhashok++; 526 if(!dnskey_size_is_supported(dnskey_rrset, i)) { 527 verbose(VERB_ALGO, "DS okay but that DNSKEY size is not supported"); 528 numsizesupp++; 529 continue; 530 } 531 verbose(VERB_ALGO, "DS match digest ok, trying signature"); 532 533 /* Otherwise, we have a match! Make sure that the DNSKEY 534 * verifies *with this key* */ 535 sec = dnskey_verify_rrset(env, ve, dnskey_rrset, dnskey_rrset, 536 i, reason, reason_bogus, LDNS_SECTION_ANSWER, qstate); 537 if(sec == sec_status_secure) { 538 return sec; 539 } 540 /* If it didn't validate with the DNSKEY, try the next one! */ 541 } 542 if(numsizesupp != 0 || sec == sec_status_indeterminate) { 543 /* there is a working DS, but that DNSKEY is not supported */ 544 return sec_status_insecure; 545 } 546 if(numchecked == 0) { 547 algo_needs_reason(ds_get_key_algo(ds_rrset, ds_idx), 548 reason, "no keys have a DS", reasonbuf, reasonlen); 549 *nonechecked = 1; 550 } else if(numhashok == 0) { 551 *reason = "DS hash mismatches key"; 552 } else if(!*reason) { 553 *reason = "keyset not secured by DNSKEY that matches DS"; 554 } 555 return sec_status_bogus; 556 } 557 558 int val_favorite_ds_algo(struct ub_packed_rrset_key* ds_rrset) 559 { 560 size_t i, num = rrset_get_count(ds_rrset); 561 int d, digest_algo = 0; /* DS digest algo 0 is not used. */ 562 /* find favorite algo, for now, highest number supported */ 563 for(i=0; i<num; i++) { 564 if(!ds_digest_algo_is_supported(ds_rrset, i) || 565 !ds_key_algo_is_supported(ds_rrset, i)) { 566 continue; 567 } 568 d = ds_get_digest_algo(ds_rrset, i); 569 if(d > digest_algo) 570 digest_algo = d; 571 } 572 return digest_algo; 573 } 574 575 enum sec_status 576 val_verify_DNSKEY_with_DS(struct module_env* env, struct val_env* ve, 577 struct ub_packed_rrset_key* dnskey_rrset, 578 struct ub_packed_rrset_key* ds_rrset, uint8_t* sigalg, char** reason, 579 sldns_ede_code *reason_bogus, struct module_qstate* qstate, 580 char* reasonbuf, size_t reasonlen) 581 { 582 /* as long as this is false, we can consider this DS rrset to be 583 * equivalent to no DS rrset. */ 584 int has_useful_ds = 0, digest_algo, alg, has_algo_refusal = 0, 585 nonechecked, has_checked_ds = 0; 586 struct algo_needs needs; 587 size_t i, num; 588 enum sec_status sec; 589 590 if(dnskey_rrset->rk.dname_len != ds_rrset->rk.dname_len || 591 query_dname_compare(dnskey_rrset->rk.dname, ds_rrset->rk.dname) 592 != 0) { 593 verbose(VERB_QUERY, "DNSKEY RRset did not match DS RRset " 594 "by name"); 595 *reason = "DNSKEY RRset did not match DS RRset by name"; 596 return sec_status_bogus; 597 } 598 599 if(sigalg) { 600 /* harden against algo downgrade is enabled */ 601 digest_algo = val_favorite_ds_algo(ds_rrset); 602 algo_needs_init_ds(&needs, ds_rrset, digest_algo, sigalg); 603 } else { 604 /* accept any key algo, any digest algo */ 605 digest_algo = -1; 606 } 607 num = rrset_get_count(ds_rrset); 608 for(i=0; i<num; i++) { 609 /* Check to see if we can understand this DS. 610 * And check it is the strongest digest */ 611 if(!ds_digest_algo_is_supported(ds_rrset, i) || 612 !ds_key_algo_is_supported(ds_rrset, i) || 613 (sigalg && (ds_get_digest_algo(ds_rrset, i) != digest_algo))) { 614 continue; 615 } 616 617 sec = verify_dnskeys_with_ds_rr(env, ve, dnskey_rrset, 618 ds_rrset, i, reason, reason_bogus, qstate, 619 &nonechecked, reasonbuf, reasonlen); 620 if(sec == sec_status_insecure) { 621 /* DNSKEY too large unsupported or algo refused by 622 * crypto lib. */ 623 has_algo_refusal = 1; 624 continue; 625 } 626 if(!nonechecked) 627 has_checked_ds = 1; 628 629 /* Once we see a single DS with a known digestID and 630 * algorithm, we cannot return INSECURE (with a 631 * "null" KeyEntry). */ 632 has_useful_ds = 1; 633 634 if(sec == sec_status_secure) { 635 if(!sigalg || algo_needs_set_secure(&needs, 636 (uint8_t)ds_get_key_algo(ds_rrset, i))) { 637 verbose(VERB_ALGO, "DS matched DNSKEY."); 638 if(!dnskeyset_size_is_supported(dnskey_rrset)) { 639 verbose(VERB_ALGO, "DS works, but dnskeyset contain keys that are unsupported, treat as insecure"); 640 return sec_status_insecure; 641 } 642 return sec_status_secure; 643 } 644 } else if(sigalg && sec == sec_status_bogus) { 645 algo_needs_set_bogus(&needs, 646 (uint8_t)ds_get_key_algo(ds_rrset, i)); 647 } 648 } 649 650 /* None of the DS's worked out. */ 651 652 /* If none of the DSes have been checked, eg. that means no matches 653 * for keytags, and the other dses are all algo_refusal, it is an 654 * insecure delegation point, since the only matched DS records 655 * have an algo refusal, or are unsupported. */ 656 if(has_algo_refusal && !has_checked_ds) { 657 verbose(VERB_ALGO, "No supported DS records were found -- " 658 "treating as insecure."); 659 return sec_status_insecure; 660 } 661 /* If no DSs were understandable, then this is OK. */ 662 if(!has_useful_ds) { 663 verbose(VERB_ALGO, "No usable DS records were found -- " 664 "treating as insecure."); 665 return sec_status_insecure; 666 } 667 /* If any were understandable, then it is bad. */ 668 verbose(VERB_QUERY, "Failed to match any usable DS to a DNSKEY."); 669 if(sigalg && (alg=algo_needs_missing(&needs)) != 0) { 670 algo_needs_reason(alg, reason, "missing verification of " 671 "DNSKEY signature", reasonbuf, reasonlen); 672 } 673 return sec_status_bogus; 674 } 675 676 struct key_entry_key* 677 val_verify_new_DNSKEYs(struct regional* region, struct module_env* env, 678 struct val_env* ve, struct ub_packed_rrset_key* dnskey_rrset, 679 struct ub_packed_rrset_key* ds_rrset, int downprot, char** reason, 680 sldns_ede_code *reason_bogus, struct module_qstate* qstate, 681 char* reasonbuf, size_t reasonlen) 682 { 683 uint8_t sigalg[ALGO_NEEDS_MAX+1]; 684 enum sec_status sec = val_verify_DNSKEY_with_DS(env, ve, 685 dnskey_rrset, ds_rrset, downprot?sigalg:NULL, reason, 686 reason_bogus, qstate, reasonbuf, reasonlen); 687 688 if(sec == sec_status_secure) { 689 return key_entry_create_rrset(region, 690 ds_rrset->rk.dname, ds_rrset->rk.dname_len, 691 ntohs(ds_rrset->rk.rrset_class), dnskey_rrset, 692 downprot?sigalg:NULL, LDNS_EDE_NONE, NULL, 693 *env->now); 694 } else if(sec == sec_status_insecure) { 695 return key_entry_create_null(region, ds_rrset->rk.dname, 696 ds_rrset->rk.dname_len, 697 ntohs(ds_rrset->rk.rrset_class), 698 rrset_get_ttl(ds_rrset), *reason_bogus, *reason, 699 *env->now); 700 } 701 return key_entry_create_bad(region, ds_rrset->rk.dname, 702 ds_rrset->rk.dname_len, ntohs(ds_rrset->rk.rrset_class), 703 BOGUS_KEY_TTL, *reason_bogus, *reason, *env->now); 704 } 705 706 enum sec_status 707 val_verify_DNSKEY_with_TA(struct module_env* env, struct val_env* ve, 708 struct ub_packed_rrset_key* dnskey_rrset, 709 struct ub_packed_rrset_key* ta_ds, 710 struct ub_packed_rrset_key* ta_dnskey, uint8_t* sigalg, char** reason, 711 sldns_ede_code *reason_bogus, struct module_qstate* qstate, 712 char* reasonbuf, size_t reasonlen) 713 { 714 /* as long as this is false, we can consider this anchor to be 715 * equivalent to no anchor. */ 716 int has_useful_ta = 0, digest_algo = 0, alg, has_algo_refusal = 0, 717 nonechecked, has_checked_ds = 0; 718 struct algo_needs needs; 719 size_t i, num; 720 enum sec_status sec; 721 722 if(ta_ds && (dnskey_rrset->rk.dname_len != ta_ds->rk.dname_len || 723 query_dname_compare(dnskey_rrset->rk.dname, ta_ds->rk.dname) 724 != 0)) { 725 verbose(VERB_QUERY, "DNSKEY RRset did not match DS RRset " 726 "by name"); 727 *reason = "DNSKEY RRset did not match DS RRset by name"; 728 if(reason_bogus) 729 *reason_bogus = LDNS_EDE_DNSKEY_MISSING; 730 return sec_status_bogus; 731 } 732 if(ta_dnskey && (dnskey_rrset->rk.dname_len != ta_dnskey->rk.dname_len 733 || query_dname_compare(dnskey_rrset->rk.dname, ta_dnskey->rk.dname) 734 != 0)) { 735 verbose(VERB_QUERY, "DNSKEY RRset did not match anchor RRset " 736 "by name"); 737 *reason = "DNSKEY RRset did not match anchor RRset by name"; 738 if(reason_bogus) 739 *reason_bogus = LDNS_EDE_DNSKEY_MISSING; 740 return sec_status_bogus; 741 } 742 743 if(ta_ds) 744 digest_algo = val_favorite_ds_algo(ta_ds); 745 if(sigalg) { 746 if(ta_ds) 747 algo_needs_init_ds(&needs, ta_ds, digest_algo, sigalg); 748 else memset(&needs, 0, sizeof(needs)); 749 if(ta_dnskey) 750 algo_needs_init_dnskey_add(&needs, ta_dnskey, sigalg); 751 } 752 if(ta_ds) { 753 num = rrset_get_count(ta_ds); 754 for(i=0; i<num; i++) { 755 /* Check to see if we can understand this DS. 756 * And check it is the strongest digest */ 757 if(!ds_digest_algo_is_supported(ta_ds, i) || 758 !ds_key_algo_is_supported(ta_ds, i) || 759 ds_get_digest_algo(ta_ds, i) != digest_algo) 760 continue; 761 762 sec = verify_dnskeys_with_ds_rr(env, ve, dnskey_rrset, 763 ta_ds, i, reason, reason_bogus, qstate, &nonechecked, 764 reasonbuf, reasonlen); 765 if(sec == sec_status_insecure) { 766 has_algo_refusal = 1; 767 continue; 768 } 769 if(!nonechecked) 770 has_checked_ds = 1; 771 772 /* Once we see a single DS with a known digestID and 773 * algorithm, we cannot return INSECURE (with a 774 * "null" KeyEntry). */ 775 has_useful_ta = 1; 776 777 if(sec == sec_status_secure) { 778 if(!sigalg || algo_needs_set_secure(&needs, 779 (uint8_t)ds_get_key_algo(ta_ds, i))) { 780 verbose(VERB_ALGO, "DS matched DNSKEY."); 781 if(!dnskeyset_size_is_supported(dnskey_rrset)) { 782 verbose(VERB_ALGO, "trustanchor works, but dnskeyset contain keys that are unsupported, treat as insecure"); 783 return sec_status_insecure; 784 } 785 return sec_status_secure; 786 } 787 } else if(sigalg && sec == sec_status_bogus) { 788 algo_needs_set_bogus(&needs, 789 (uint8_t)ds_get_key_algo(ta_ds, i)); 790 } 791 } 792 } 793 794 /* None of the DS's worked out: check the DNSKEYs. */ 795 if(ta_dnskey) { 796 num = rrset_get_count(ta_dnskey); 797 for(i=0; i<num; i++) { 798 /* Check to see if we can understand this DNSKEY */ 799 if(!dnskey_algo_is_supported(ta_dnskey, i)) 800 continue; 801 if(!dnskey_size_is_supported(ta_dnskey, i)) 802 continue; 803 804 /* we saw a useful TA */ 805 has_useful_ta = 1; 806 807 sec = dnskey_verify_rrset(env, ve, dnskey_rrset, 808 ta_dnskey, i, reason, reason_bogus, LDNS_SECTION_ANSWER, qstate); 809 if(sec == sec_status_secure) { 810 if(!sigalg || algo_needs_set_secure(&needs, 811 (uint8_t)dnskey_get_algo(ta_dnskey, i))) { 812 verbose(VERB_ALGO, "anchor matched DNSKEY."); 813 if(!dnskeyset_size_is_supported(dnskey_rrset)) { 814 verbose(VERB_ALGO, "trustanchor works, but dnskeyset contain keys that are unsupported, treat as insecure"); 815 return sec_status_insecure; 816 } 817 return sec_status_secure; 818 } 819 } else if(sigalg && sec == sec_status_bogus) { 820 algo_needs_set_bogus(&needs, 821 (uint8_t)dnskey_get_algo(ta_dnskey, i)); 822 } 823 } 824 } 825 826 /* If none of the DSes have been checked, eg. that means no matches 827 * for keytags, and the other dses are all algo_refusal, it is an 828 * insecure delegation point, since the only matched DS records 829 * have an algo refusal, or are unsupported. */ 830 if(has_algo_refusal && !has_checked_ds) { 831 verbose(VERB_ALGO, "No supported trust anchors were found -- " 832 "treating as insecure."); 833 return sec_status_insecure; 834 } 835 /* If no DSs were understandable, then this is OK. */ 836 if(!has_useful_ta) { 837 verbose(VERB_ALGO, "No usable trust anchors were found -- " 838 "treating as insecure."); 839 return sec_status_insecure; 840 } 841 /* If any were understandable, then it is bad. */ 842 verbose(VERB_QUERY, "Failed to match any usable anchor to a DNSKEY."); 843 if(sigalg && (alg=algo_needs_missing(&needs)) != 0) { 844 algo_needs_reason(alg, reason, "missing verification of " 845 "DNSKEY signature", reasonbuf, reasonlen); 846 } 847 return sec_status_bogus; 848 } 849 850 struct key_entry_key* 851 val_verify_new_DNSKEYs_with_ta(struct regional* region, struct module_env* env, 852 struct val_env* ve, struct ub_packed_rrset_key* dnskey_rrset, 853 struct ub_packed_rrset_key* ta_ds_rrset, 854 struct ub_packed_rrset_key* ta_dnskey_rrset, int downprot, 855 char** reason, sldns_ede_code *reason_bogus, 856 struct module_qstate* qstate, char* reasonbuf, size_t reasonlen) 857 { 858 uint8_t sigalg[ALGO_NEEDS_MAX+1]; 859 enum sec_status sec = val_verify_DNSKEY_with_TA(env, ve, 860 dnskey_rrset, ta_ds_rrset, ta_dnskey_rrset, 861 downprot?sigalg:NULL, reason, reason_bogus, qstate, 862 reasonbuf, reasonlen); 863 864 if(sec == sec_status_secure) { 865 return key_entry_create_rrset(region, 866 dnskey_rrset->rk.dname, dnskey_rrset->rk.dname_len, 867 ntohs(dnskey_rrset->rk.rrset_class), dnskey_rrset, 868 downprot?sigalg:NULL, LDNS_EDE_NONE, NULL, *env->now); 869 } else if(sec == sec_status_insecure) { 870 return key_entry_create_null(region, dnskey_rrset->rk.dname, 871 dnskey_rrset->rk.dname_len, 872 ntohs(dnskey_rrset->rk.rrset_class), 873 rrset_get_ttl(dnskey_rrset), *reason_bogus, *reason, 874 *env->now); 875 } 876 return key_entry_create_bad(region, dnskey_rrset->rk.dname, 877 dnskey_rrset->rk.dname_len, ntohs(dnskey_rrset->rk.rrset_class), 878 BOGUS_KEY_TTL, *reason_bogus, *reason, *env->now); 879 } 880 881 int 882 val_dsset_isusable(struct ub_packed_rrset_key* ds_rrset) 883 { 884 size_t i; 885 for(i=0; i<rrset_get_count(ds_rrset); i++) { 886 if(ds_digest_algo_is_supported(ds_rrset, i) && 887 ds_key_algo_is_supported(ds_rrset, i)) 888 return 1; 889 } 890 if(verbosity < VERB_ALGO) 891 return 0; 892 if(rrset_get_count(ds_rrset) == 0) 893 verbose(VERB_ALGO, "DS is not usable"); 894 else { 895 /* report usability for the first DS RR */ 896 sldns_lookup_table *lt; 897 char herr[64], aerr[64]; 898 lt = sldns_lookup_by_id(sldns_hashes, 899 (int)ds_get_digest_algo(ds_rrset, 0)); 900 if(lt) snprintf(herr, sizeof(herr), "%s", lt->name); 901 else snprintf(herr, sizeof(herr), "%d", 902 (int)ds_get_digest_algo(ds_rrset, 0)); 903 lt = sldns_lookup_by_id(sldns_algorithms, 904 (int)ds_get_key_algo(ds_rrset, 0)); 905 if(lt) snprintf(aerr, sizeof(aerr), "%s", lt->name); 906 else snprintf(aerr, sizeof(aerr), "%d", 907 (int)ds_get_key_algo(ds_rrset, 0)); 908 909 verbose(VERB_ALGO, "DS unsupported, hash %s %s, " 910 "key algorithm %s %s", herr, 911 (ds_digest_algo_is_supported(ds_rrset, 0)? 912 "(supported)":"(unsupported)"), aerr, 913 (ds_key_algo_is_supported(ds_rrset, 0)? 914 "(supported)":"(unsupported)")); 915 } 916 return 0; 917 } 918 919 /** get label count for a signature */ 920 static uint8_t 921 rrsig_get_labcount(struct packed_rrset_data* d, size_t sig) 922 { 923 if(d->rr_len[sig] < 2+4) 924 return 0; /* bad sig length */ 925 return d->rr_data[sig][2+3]; 926 } 927 928 int 929 val_rrset_wildcard(struct ub_packed_rrset_key* rrset, uint8_t** wc, 930 size_t* wc_len) 931 { 932 struct packed_rrset_data* d = (struct packed_rrset_data*)rrset-> 933 entry.data; 934 uint8_t labcount; 935 int labdiff; 936 uint8_t* wn; 937 size_t i, wl; 938 if(d->rrsig_count == 0) { 939 return 1; 940 } 941 labcount = rrsig_get_labcount(d, d->count + 0); 942 /* check rest of signatures identical */ 943 for(i=1; i<d->rrsig_count; i++) { 944 if(labcount != rrsig_get_labcount(d, d->count + i)) { 945 return 0; 946 } 947 } 948 /* OK the rrsigs check out */ 949 /* if the RRSIG label count is shorter than the number of actual 950 * labels, then this rrset was synthesized from a wildcard. 951 * Note that the RRSIG label count doesn't count the root label. */ 952 wn = rrset->rk.dname; 953 wl = rrset->rk.dname_len; 954 /* skip a leading wildcard label in the dname (RFC4035 2.2) */ 955 if(dname_is_wild(wn)) { 956 wn += 2; 957 wl -= 2; 958 } 959 labdiff = (dname_count_labels(wn) - 1) - (int)labcount; 960 if(labdiff > 0) { 961 *wc = wn; 962 dname_remove_labels(wc, &wl, labdiff); 963 *wc_len = wl; 964 return 1; 965 } 966 return 1; 967 } 968 969 int 970 val_chase_cname(struct query_info* qchase, struct reply_info* rep, 971 size_t* cname_skip) { 972 size_t i; 973 /* skip any DNAMEs, go to the CNAME for next part */ 974 for(i = *cname_skip; i < rep->an_numrrsets; i++) { 975 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME && 976 query_dname_compare(qchase->qname, rep->rrsets[i]-> 977 rk.dname) == 0) { 978 qchase->qname = NULL; 979 get_cname_target(rep->rrsets[i], &qchase->qname, 980 &qchase->qname_len); 981 if(!qchase->qname) 982 return 0; /* bad CNAME rdata */ 983 (*cname_skip) = i+1; 984 return 1; 985 } 986 } 987 return 0; /* CNAME classified but no matching CNAME ?! */ 988 } 989 990 /** see if rrset has signer name as one of the rrsig signers */ 991 static int 992 rrset_has_signer(struct ub_packed_rrset_key* rrset, uint8_t* name, size_t len) 993 { 994 struct packed_rrset_data* d = (struct packed_rrset_data*)rrset-> 995 entry.data; 996 size_t i; 997 for(i = d->count; i< d->count+d->rrsig_count; i++) { 998 if(d->rr_len[i] > 2+18+len) { 999 /* at least rdatalen + signature + signame (+1 sig)*/ 1000 if(!dname_valid(d->rr_data[i]+2+18, d->rr_len[i]-2-18)) 1001 continue; 1002 if(query_dname_compare(name, d->rr_data[i]+2+18) == 0) 1003 { 1004 return 1; 1005 } 1006 } 1007 } 1008 return 0; 1009 } 1010 1011 void 1012 val_fill_reply(struct reply_info* chase, struct reply_info* orig, 1013 size_t skip, uint8_t* name, size_t len, uint8_t* signer) 1014 { 1015 size_t i, j; 1016 int seen_dname = 0; 1017 chase->rrset_count = 0; 1018 chase->an_numrrsets = 0; 1019 chase->ns_numrrsets = 0; 1020 chase->ar_numrrsets = 0; 1021 /* ANSWER section */ 1022 for(i=skip; i<orig->an_numrrsets; i++) { 1023 if(!signer) { 1024 if(query_dname_compare(name, 1025 orig->rrsets[i]->rk.dname) == 0) 1026 chase->rrsets[chase->an_numrrsets++] = 1027 orig->rrsets[i]; 1028 } else if(seen_dname && ntohs(orig->rrsets[i]->rk.type) == 1029 LDNS_RR_TYPE_CNAME) { 1030 chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i]; 1031 seen_dname = 0; 1032 } else if(rrset_has_signer(orig->rrsets[i], name, len)) { 1033 chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i]; 1034 if(ntohs(orig->rrsets[i]->rk.type) == 1035 LDNS_RR_TYPE_DNAME) { 1036 seen_dname = 1; 1037 } 1038 } else if(ntohs(orig->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME 1039 && ((struct packed_rrset_data*)orig->rrsets[i]-> 1040 entry.data)->rrsig_count == 0 && 1041 cname_under_previous_dname(orig, i, &j) && 1042 rrset_has_signer(orig->rrsets[j], name, len)) { 1043 chase->rrsets[chase->an_numrrsets++] = orig->rrsets[j]; 1044 chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i]; 1045 } 1046 } 1047 /* AUTHORITY section */ 1048 for(i = (skip > orig->an_numrrsets)?skip:orig->an_numrrsets; 1049 i<orig->an_numrrsets+orig->ns_numrrsets; 1050 i++) { 1051 if(!signer) { 1052 if(query_dname_compare(name, 1053 orig->rrsets[i]->rk.dname) == 0) 1054 chase->rrsets[chase->an_numrrsets+ 1055 chase->ns_numrrsets++] = orig->rrsets[i]; 1056 } else if(rrset_has_signer(orig->rrsets[i], name, len)) { 1057 chase->rrsets[chase->an_numrrsets+ 1058 chase->ns_numrrsets++] = orig->rrsets[i]; 1059 } 1060 } 1061 /* ADDITIONAL section */ 1062 for(i= (skip>orig->an_numrrsets+orig->ns_numrrsets)? 1063 skip:orig->an_numrrsets+orig->ns_numrrsets; 1064 i<orig->rrset_count; i++) { 1065 if(!signer) { 1066 if(query_dname_compare(name, 1067 orig->rrsets[i]->rk.dname) == 0) 1068 chase->rrsets[chase->an_numrrsets 1069 +orig->ns_numrrsets+chase->ar_numrrsets++] 1070 = orig->rrsets[i]; 1071 } else if(rrset_has_signer(orig->rrsets[i], name, len)) { 1072 chase->rrsets[chase->an_numrrsets+orig->ns_numrrsets+ 1073 chase->ar_numrrsets++] = orig->rrsets[i]; 1074 } 1075 } 1076 chase->rrset_count = chase->an_numrrsets + chase->ns_numrrsets + 1077 chase->ar_numrrsets; 1078 } 1079 1080 void val_reply_remove_auth(struct reply_info* rep, size_t index) 1081 { 1082 log_assert(index < rep->rrset_count); 1083 log_assert(index >= rep->an_numrrsets); 1084 log_assert(index < rep->an_numrrsets+rep->ns_numrrsets); 1085 memmove(rep->rrsets+index, rep->rrsets+index+1, 1086 sizeof(struct ub_packed_rrset_key*)* 1087 (rep->rrset_count - index - 1)); 1088 rep->ns_numrrsets--; 1089 rep->rrset_count--; 1090 } 1091 1092 void 1093 val_check_nonsecure(struct module_env* env, struct reply_info* rep) 1094 { 1095 size_t i; 1096 /* authority */ 1097 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) { 1098 if(((struct packed_rrset_data*)rep->rrsets[i]->entry.data) 1099 ->security != sec_status_secure) { 1100 /* because we want to return the authentic original 1101 * message when presented with CD-flagged queries, 1102 * we need to preserve AUTHORITY section data. 1103 * However, this rrset is not signed or signed 1104 * with the wrong keys. Validation has tried to 1105 * verify this rrset with the keysets of import. 1106 * But this rrset did not verify. 1107 * Therefore the message is bogus. 1108 */ 1109 1110 /* check if authority has an NS record 1111 * which is bad, and there is an answer section with 1112 * data. In that case, delete NS and additional to 1113 * be lenient and make a minimal response */ 1114 if(rep->an_numrrsets != 0 && 1115 ntohs(rep->rrsets[i]->rk.type) 1116 == LDNS_RR_TYPE_NS) { 1117 verbose(VERB_ALGO, "truncate to minimal"); 1118 rep->ar_numrrsets = 0; 1119 rep->rrset_count = rep->an_numrrsets + 1120 rep->ns_numrrsets; 1121 /* remove this unneeded authority rrset */ 1122 memmove(rep->rrsets+i, rep->rrsets+i+1, 1123 sizeof(struct ub_packed_rrset_key*)* 1124 (rep->rrset_count - i - 1)); 1125 rep->ns_numrrsets--; 1126 rep->rrset_count--; 1127 i--; 1128 return; 1129 } 1130 1131 log_nametypeclass(VERB_QUERY, "message is bogus, " 1132 "non secure rrset", 1133 rep->rrsets[i]->rk.dname, 1134 ntohs(rep->rrsets[i]->rk.type), 1135 ntohs(rep->rrsets[i]->rk.rrset_class)); 1136 rep->security = sec_status_bogus; 1137 return; 1138 } 1139 } 1140 /* additional */ 1141 if(!env->cfg->val_clean_additional) 1142 return; 1143 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { 1144 if(((struct packed_rrset_data*)rep->rrsets[i]->entry.data) 1145 ->security != sec_status_secure) { 1146 /* This does not cause message invalidation. It was 1147 * simply unsigned data in the additional. The 1148 * RRSIG must have been truncated off the message. 1149 * 1150 * However, we do not want to return possible bogus 1151 * data to clients that rely on this service for 1152 * their authentication. 1153 */ 1154 /* remove this unneeded additional rrset */ 1155 memmove(rep->rrsets+i, rep->rrsets+i+1, 1156 sizeof(struct ub_packed_rrset_key*)* 1157 (rep->rrset_count - i - 1)); 1158 rep->ar_numrrsets--; 1159 rep->rrset_count--; 1160 i--; 1161 } 1162 } 1163 } 1164 1165 /** check no anchor and unlock */ 1166 static int 1167 check_no_anchor(struct val_anchors* anchors, uint8_t* nm, size_t l, uint16_t c) 1168 { 1169 struct trust_anchor* ta; 1170 if((ta=anchors_lookup(anchors, nm, l, c))) { 1171 lock_basic_unlock(&ta->lock); 1172 } 1173 return !ta; 1174 } 1175 1176 void 1177 val_mark_indeterminate(struct reply_info* rep, struct val_anchors* anchors, 1178 struct rrset_cache* r, struct module_env* env) 1179 { 1180 size_t i; 1181 struct packed_rrset_data* d; 1182 for(i=0; i<rep->rrset_count; i++) { 1183 d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data; 1184 if(d->security == sec_status_unchecked && 1185 check_no_anchor(anchors, rep->rrsets[i]->rk.dname, 1186 rep->rrsets[i]->rk.dname_len, 1187 ntohs(rep->rrsets[i]->rk.rrset_class))) 1188 { 1189 /* mark as indeterminate */ 1190 d->security = sec_status_indeterminate; 1191 rrset_update_sec_status(r, rep->rrsets[i], *env->now); 1192 } 1193 } 1194 } 1195 1196 void 1197 val_mark_insecure(struct reply_info* rep, uint8_t* kname, 1198 struct rrset_cache* r, struct module_env* env) 1199 { 1200 size_t i; 1201 struct packed_rrset_data* d; 1202 for(i=0; i<rep->rrset_count; i++) { 1203 d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data; 1204 if(d->security == sec_status_unchecked && 1205 dname_subdomain_c(rep->rrsets[i]->rk.dname, kname)) { 1206 /* mark as insecure */ 1207 d->security = sec_status_insecure; 1208 rrset_update_sec_status(r, rep->rrsets[i], *env->now); 1209 } 1210 } 1211 } 1212 1213 size_t 1214 val_next_unchecked(struct reply_info* rep, size_t skip) 1215 { 1216 size_t i; 1217 struct packed_rrset_data* d; 1218 for(i=skip+1; i<rep->rrset_count; i++) { 1219 d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data; 1220 if(d->security == sec_status_unchecked) { 1221 return i; 1222 } 1223 } 1224 return rep->rrset_count; 1225 } 1226 1227 const char* 1228 val_classification_to_string(enum val_classification subtype) 1229 { 1230 switch(subtype) { 1231 case VAL_CLASS_UNTYPED: return "untyped"; 1232 case VAL_CLASS_UNKNOWN: return "unknown"; 1233 case VAL_CLASS_POSITIVE: return "positive"; 1234 case VAL_CLASS_CNAME: return "cname"; 1235 case VAL_CLASS_NODATA: return "nodata"; 1236 case VAL_CLASS_NAMEERROR: return "nameerror"; 1237 case VAL_CLASS_CNAMENOANSWER: return "cnamenoanswer"; 1238 case VAL_CLASS_REFERRAL: return "referral"; 1239 case VAL_CLASS_ANY: return "qtype_any"; 1240 default: 1241 return "bad_val_classification"; 1242 } 1243 } 1244 1245 /** log a sock_list entry */ 1246 static void 1247 sock_list_logentry(enum verbosity_value v, const char* s, struct sock_list* p) 1248 { 1249 if(p->len) 1250 log_addr(v, s, &p->addr, p->len); 1251 else verbose(v, "%s cache", s); 1252 } 1253 1254 void val_blacklist(struct sock_list** blacklist, struct regional* region, 1255 struct sock_list* origin, int cross) 1256 { 1257 /* debug printout */ 1258 if(verbosity >= VERB_ALGO) { 1259 struct sock_list* p; 1260 for(p=*blacklist; p; p=p->next) 1261 sock_list_logentry(VERB_ALGO, "blacklist", p); 1262 if(!origin) 1263 verbose(VERB_ALGO, "blacklist add: cache"); 1264 for(p=origin; p; p=p->next) 1265 sock_list_logentry(VERB_ALGO, "blacklist add", p); 1266 } 1267 /* blacklist the IPs or the cache */ 1268 if(!origin) { 1269 /* only add if nothing there. anything else also stops cache*/ 1270 if(!*blacklist) 1271 sock_list_insert(blacklist, NULL, 0, region); 1272 } else if(!cross) 1273 sock_list_prepend(blacklist, origin); 1274 else sock_list_merge(blacklist, region, origin); 1275 } 1276 1277 int val_has_signed_nsecs(struct reply_info* rep, char** reason) 1278 { 1279 size_t i, num_nsec = 0, num_nsec3 = 0; 1280 struct packed_rrset_data* d; 1281 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) { 1282 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC)) 1283 num_nsec++; 1284 else if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC3)) 1285 num_nsec3++; 1286 else continue; 1287 d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data; 1288 if(d && d->rrsig_count != 0) { 1289 return 1; 1290 } 1291 } 1292 if(num_nsec == 0 && num_nsec3 == 0) 1293 *reason = "no DNSSEC records"; 1294 else if(num_nsec != 0) 1295 *reason = "no signatures over NSECs"; 1296 else *reason = "no signatures over NSEC3s"; 1297 return 0; 1298 } 1299 1300 struct dns_msg* 1301 val_find_DS(struct module_env* env, uint8_t* nm, size_t nmlen, uint16_t c, 1302 struct regional* region, uint8_t* topname) 1303 { 1304 struct dns_msg* msg; 1305 struct query_info qinfo; 1306 struct ub_packed_rrset_key *rrset = rrset_cache_lookup( 1307 env->rrset_cache, nm, nmlen, LDNS_RR_TYPE_DS, c, 0, 1308 *env->now, 0); 1309 if(rrset) { 1310 /* DS rrset exists. Return it to the validator immediately*/ 1311 struct ub_packed_rrset_key* copy = packed_rrset_copy_region( 1312 rrset, region, *env->now); 1313 lock_rw_unlock(&rrset->entry.lock); 1314 if(!copy) 1315 return NULL; 1316 msg = dns_msg_create(nm, nmlen, LDNS_RR_TYPE_DS, c, region, 1); 1317 if(!msg) 1318 return NULL; 1319 msg->rep->rrsets[0] = copy; 1320 msg->rep->rrset_count++; 1321 msg->rep->an_numrrsets++; 1322 return msg; 1323 } 1324 /* lookup in rrset and negative cache for NSEC/NSEC3 */ 1325 qinfo.qname = nm; 1326 qinfo.qname_len = nmlen; 1327 qinfo.qtype = LDNS_RR_TYPE_DS; 1328 qinfo.qclass = c; 1329 qinfo.local_alias = NULL; 1330 /* do not add SOA to reply message, it is going to be used internal */ 1331 msg = val_neg_getmsg(env->neg_cache, &qinfo, region, env->rrset_cache, 1332 env->scratch_buffer, *env->now, 0, topname, env->cfg); 1333 return msg; 1334 } 1335