2 * validator/val_sigcrypt.c - validator signature crypto functions.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
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.
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.
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.
39 * This file contains helper functions for the validator module.
40 * The functions help with signature verification and checking, the
41 * bridging between RR wireformat data and crypto calls.
44 #include "validator/val_sigcrypt.h"
45 #include "validator/val_secalgo.h"
46 #include "validator/validator.h"
47 #include "util/data/msgreply.h"
48 #include "util/data/msgparse.h"
49 #include "util/data/dname.h"
50 #include "util/rbtree.h"
51 #include "util/module.h"
52 #include "util/net_help.h"
53 #include "util/regional.h"
54 #include "util/config_file.h"
55 #include "sldns/keyraw.h"
56 #include "sldns/sbuffer.h"
57 #include "sldns/parseutil.h"
58 #include "sldns/wire2str.h"
61 #if !defined(HAVE_SSL) && !defined(HAVE_NSS) && !defined(HAVE_NETTLE)
62 #error "Need crypto library to do digital signature cryptography"
65 #ifdef HAVE_OPENSSL_ERR_H
66 #include <openssl/err.h>
69 #ifdef HAVE_OPENSSL_RAND_H
70 #include <openssl/rand.h>
73 #ifdef HAVE_OPENSSL_CONF_H
74 #include <openssl/conf.h>
77 #ifdef HAVE_OPENSSL_ENGINE_H
78 #include <openssl/engine.h>
81 /** return number of rrs in an rrset */
83 rrset_get_count(struct ub_packed_rrset_key* rrset)
85 struct packed_rrset_data* d = (struct packed_rrset_data*)
92 * Get RR signature count
95 rrset_get_sigcount(struct ub_packed_rrset_key* k)
97 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
98 return d->rrsig_count;
102 * Get signature keytag value
103 * @param k: rrset (with signatures)
104 * @param sig_idx: signature index.
105 * @return keytag or 0 if malformed rrsig.
108 rrset_get_sig_keytag(struct ub_packed_rrset_key* k, size_t sig_idx)
111 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
112 log_assert(sig_idx < d->rrsig_count);
113 if(d->rr_len[d->count + sig_idx] < 2+18)
115 memmove(&t, d->rr_data[d->count + sig_idx]+2+16, 2);
120 * Get signature signing algorithm value
121 * @param k: rrset (with signatures)
122 * @param sig_idx: signature index.
123 * @return algo or 0 if malformed rrsig.
126 rrset_get_sig_algo(struct ub_packed_rrset_key* k, size_t sig_idx)
128 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
129 log_assert(sig_idx < d->rrsig_count);
130 if(d->rr_len[d->count + sig_idx] < 2+3)
132 return (int)d->rr_data[d->count + sig_idx][2+2];
135 /** get rdata pointer and size */
137 rrset_get_rdata(struct ub_packed_rrset_key* k, size_t idx, uint8_t** rdata,
140 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
141 log_assert(d && idx < (d->count + d->rrsig_count));
142 *rdata = d->rr_data[idx];
143 *len = d->rr_len[idx];
147 dnskey_get_flags(struct ub_packed_rrset_key* k, size_t idx)
152 rrset_get_rdata(k, idx, &rdata, &len);
155 memmove(&f, rdata+2, 2);
161 * Get DNSKEY protocol value from rdata
162 * @param k: DNSKEY rrset.
163 * @param idx: which key.
164 * @return protocol octet value
167 dnskey_get_protocol(struct ub_packed_rrset_key* k, size_t idx)
171 rrset_get_rdata(k, idx, &rdata, &len);
174 return (int)rdata[2+2];
178 dnskey_get_algo(struct ub_packed_rrset_key* k, size_t idx)
182 rrset_get_rdata(k, idx, &rdata, &len);
185 return (int)rdata[2+3];
188 /** get public key rdata field from a dnskey RR and do some checks */
190 dnskey_get_pubkey(struct ub_packed_rrset_key* k, size_t idx,
191 unsigned char** pk, unsigned int* pklen)
195 rrset_get_rdata(k, idx, &rdata, &len);
201 *pk = (unsigned char*)rdata+2+4;
202 *pklen = (unsigned)len-2-4;
206 ds_get_key_algo(struct ub_packed_rrset_key* k, size_t idx)
210 rrset_get_rdata(k, idx, &rdata, &len);
213 return (int)rdata[2+2];
217 ds_get_digest_algo(struct ub_packed_rrset_key* k, size_t idx)
221 rrset_get_rdata(k, idx, &rdata, &len);
224 return (int)rdata[2+3];
228 ds_get_keytag(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx)
233 rrset_get_rdata(ds_rrset, ds_idx, &rdata, &len);
236 memmove(&t, rdata+2, 2);
241 * Return pointer to the digest in a DS RR.
242 * @param k: DS rrset.
243 * @param idx: which DS.
244 * @param digest: digest data is returned.
245 * on error, this is NULL.
246 * @param len: length of digest is returned.
247 * on error, the length is 0.
250 ds_get_sigdata(struct ub_packed_rrset_key* k, size_t idx, uint8_t** digest,
255 rrset_get_rdata(k, idx, &rdata, &rdlen);
261 *digest = rdata + 2 + 4;
262 *len = rdlen - 2 - 4;
266 * Return size of DS digest according to its hash algorithm.
267 * @param k: DS rrset.
268 * @param idx: which DS.
269 * @return size in bytes of digest, or 0 if not supported.
272 ds_digest_size_algo(struct ub_packed_rrset_key* k, size_t idx)
274 return ds_digest_size_supported(ds_get_digest_algo(k, idx));
278 * Create a DS digest for a DNSKEY entry.
280 * @param env: module environment. Uses scratch space.
281 * @param dnskey_rrset: DNSKEY rrset.
282 * @param dnskey_idx: index of RR in rrset.
283 * @param ds_rrset: DS rrset
284 * @param ds_idx: index of RR in DS rrset.
285 * @param digest: digest is returned in here (must be correctly sized).
286 * @return false on error.
289 ds_create_dnskey_digest(struct module_env* env,
290 struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx,
291 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx,
294 sldns_buffer* b = env->scratch_buffer;
295 uint8_t* dnskey_rdata;
297 rrset_get_rdata(dnskey_rrset, dnskey_idx, &dnskey_rdata, &dnskey_len);
299 /* create digest source material in buffer
300 * digest = digest_algorithm( DNSKEY owner name | DNSKEY RDATA);
301 * DNSKEY RDATA = Flags | Protocol | Algorithm | Public Key. */
302 sldns_buffer_clear(b);
303 sldns_buffer_write(b, dnskey_rrset->rk.dname,
304 dnskey_rrset->rk.dname_len);
305 query_dname_tolower(sldns_buffer_begin(b));
306 sldns_buffer_write(b, dnskey_rdata+2, dnskey_len-2); /* skip rdatalen*/
307 sldns_buffer_flip(b);
309 return secalgo_ds_digest(ds_get_digest_algo(ds_rrset, ds_idx),
310 (unsigned char*)sldns_buffer_begin(b), sldns_buffer_limit(b),
311 (unsigned char*)digest);
314 int ds_digest_match_dnskey(struct module_env* env,
315 struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx,
316 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx)
318 uint8_t* ds; /* DS digest */
320 uint8_t* digest; /* generated digest */
321 size_t digestlen = ds_digest_size_algo(ds_rrset, ds_idx);
324 verbose(VERB_QUERY, "DS fail: not supported, or DS RR "
326 return 0; /* not supported, or DS RR format error */
329 if(fake_sha1 && ds_get_digest_algo(ds_rrset, ds_idx)==LDNS_SHA1)
333 /* check digest length in DS with length from hash function */
334 ds_get_sigdata(ds_rrset, ds_idx, &ds, &dslen);
335 if(!ds || dslen != digestlen) {
336 verbose(VERB_QUERY, "DS fail: DS RR algo and digest do not "
338 return 0; /* DS algorithm and digest do not match */
341 digest = regional_alloc(env->scratch, digestlen);
343 verbose(VERB_QUERY, "DS fail: out of memory");
344 return 0; /* mem error */
346 if(!ds_create_dnskey_digest(env, dnskey_rrset, dnskey_idx, ds_rrset,
348 verbose(VERB_QUERY, "DS fail: could not calc key digest");
349 return 0; /* digest algo failed */
351 if(memcmp(digest, ds, dslen) != 0) {
352 verbose(VERB_QUERY, "DS fail: digest is different");
353 return 0; /* digest different */
359 ds_digest_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
362 return (ds_digest_size_algo(ds_rrset, ds_idx) != 0);
366 ds_key_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
369 return dnskey_algo_id_is_supported(ds_get_key_algo(ds_rrset, ds_idx));
373 dnskey_calc_keytag(struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx)
377 rrset_get_rdata(dnskey_rrset, dnskey_idx, &data, &len);
378 /* do not pass rdatalen to ldns */
379 return sldns_calc_keytag_raw(data+2, len-2);
382 int dnskey_algo_is_supported(struct ub_packed_rrset_key* dnskey_rrset,
385 return dnskey_algo_id_is_supported(dnskey_get_algo(dnskey_rrset,
389 void algo_needs_init_dnskey_add(struct algo_needs* n,
390 struct ub_packed_rrset_key* dnskey, uint8_t* sigalg)
393 size_t i, total = n->num;
394 size_t num = rrset_get_count(dnskey);
396 for(i=0; i<num; i++) {
397 algo = (uint8_t)dnskey_get_algo(dnskey, i);
398 if(!dnskey_algo_id_is_supported((int)algo))
400 if(n->needs[algo] == 0) {
402 sigalg[total] = algo;
410 void algo_needs_init_list(struct algo_needs* n, uint8_t* sigalg)
415 memset(n->needs, 0, sizeof(uint8_t)*ALGO_NEEDS_MAX);
416 while( (algo=*sigalg++) != 0) {
417 log_assert(dnskey_algo_id_is_supported((int)algo));
418 log_assert(n->needs[algo] == 0);
425 void algo_needs_init_ds(struct algo_needs* n, struct ub_packed_rrset_key* ds,
426 int fav_ds_algo, uint8_t* sigalg)
430 size_t num = rrset_get_count(ds);
432 memset(n->needs, 0, sizeof(uint8_t)*ALGO_NEEDS_MAX);
433 for(i=0; i<num; i++) {
434 if(ds_get_digest_algo(ds, i) != fav_ds_algo)
436 algo = (uint8_t)ds_get_key_algo(ds, i);
437 if(!dnskey_algo_id_is_supported((int)algo))
439 log_assert(algo != 0); /* we do not support 0 and is EOS */
440 if(n->needs[algo] == 0) {
442 sigalg[total] = algo;
450 int algo_needs_set_secure(struct algo_needs* n, uint8_t algo)
455 if(n->num == 0) /* done! */
461 void algo_needs_set_bogus(struct algo_needs* n, uint8_t algo)
463 if(n->needs[algo]) n->needs[algo] = 2; /* need it, but bogus */
466 size_t algo_needs_num_missing(struct algo_needs* n)
471 int algo_needs_missing(struct algo_needs* n)
474 /* first check if a needed algo was bogus - report that */
475 for(i=0; i<ALGO_NEEDS_MAX; i++)
478 /* now check which algo is missing */
479 for(i=0; i<ALGO_NEEDS_MAX; i++)
486 dnskeyset_verify_rrset(struct module_env* env, struct val_env* ve,
487 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
488 uint8_t* sigalg, char** reason)
492 rbtree_type* sortree = NULL;
493 /* make sure that for all DNSKEY algorithms there are valid sigs */
494 struct algo_needs needs;
497 num = rrset_get_sigcount(rrset);
499 verbose(VERB_QUERY, "rrset failed to verify due to a lack of "
501 *reason = "no signatures";
502 return sec_status_bogus;
506 algo_needs_init_list(&needs, sigalg);
507 if(algo_needs_num_missing(&needs) == 0) {
508 verbose(VERB_QUERY, "zone has no known algorithms");
509 *reason = "zone has no known algorithms";
510 return sec_status_insecure;
513 for(i=0; i<num; i++) {
514 sec = dnskeyset_verify_rrset_sig(env, ve, *env->now, rrset,
515 dnskey, i, &sortree, reason);
516 /* see which algorithm has been fixed up */
517 if(sec == sec_status_secure) {
519 return sec; /* done! */
520 else if(algo_needs_set_secure(&needs,
521 (uint8_t)rrset_get_sig_algo(rrset, i)))
522 return sec; /* done! */
523 } else if(sigalg && sec == sec_status_bogus) {
524 algo_needs_set_bogus(&needs,
525 (uint8_t)rrset_get_sig_algo(rrset, i));
528 if(sigalg && (alg=algo_needs_missing(&needs)) != 0) {
529 verbose(VERB_ALGO, "rrset failed to verify: "
530 "no valid signatures for %d algorithms",
531 (int)algo_needs_num_missing(&needs));
532 algo_needs_reason(env, alg, reason, "no signatures");
534 verbose(VERB_ALGO, "rrset failed to verify: "
535 "no valid signatures");
537 return sec_status_bogus;
540 void algo_needs_reason(struct module_env* env, int alg, char** reason, char* s)
543 sldns_lookup_table *t = sldns_lookup_by_id(sldns_algorithms, alg);
545 snprintf(buf, sizeof(buf), "%s with algorithm %s", s, t->name);
546 else snprintf(buf, sizeof(buf), "%s with algorithm ALG%u", s,
548 *reason = regional_strdup(env->scratch, buf);
554 dnskey_verify_rrset(struct module_env* env, struct val_env* ve,
555 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
556 size_t dnskey_idx, char** reason)
559 size_t i, num, numchecked = 0;
560 rbtree_type* sortree = NULL;
562 uint16_t tag = dnskey_calc_keytag(dnskey, dnskey_idx);
563 int algo = dnskey_get_algo(dnskey, dnskey_idx);
565 num = rrset_get_sigcount(rrset);
567 verbose(VERB_QUERY, "rrset failed to verify due to a lack of "
569 *reason = "no signatures";
570 return sec_status_bogus;
572 for(i=0; i<num; i++) {
573 /* see if sig matches keytag and algo */
574 if(algo != rrset_get_sig_algo(rrset, i) ||
575 tag != rrset_get_sig_keytag(rrset, i))
578 sec = dnskey_verify_rrset_sig(env->scratch,
579 env->scratch_buffer, ve, *env->now, rrset,
580 dnskey, dnskey_idx, i, &sortree, &buf_canon, reason);
581 if(sec == sec_status_secure)
585 verbose(VERB_ALGO, "rrset failed to verify: all signatures are bogus");
586 if(!numchecked) *reason = "signature missing";
587 return sec_status_bogus;
591 dnskeyset_verify_rrset_sig(struct module_env* env, struct val_env* ve,
592 time_t now, struct ub_packed_rrset_key* rrset,
593 struct ub_packed_rrset_key* dnskey, size_t sig_idx,
594 struct rbtree_type** sortree, char** reason)
596 /* find matching keys and check them */
597 enum sec_status sec = sec_status_bogus;
598 uint16_t tag = rrset_get_sig_keytag(rrset, sig_idx);
599 int algo = rrset_get_sig_algo(rrset, sig_idx);
600 size_t i, num = rrset_get_count(dnskey);
601 size_t numchecked = 0;
603 verbose(VERB_ALGO, "verify sig %d %d", (int)tag, algo);
604 if(!dnskey_algo_id_is_supported(algo)) {
605 verbose(VERB_QUERY, "verify sig: unknown algorithm");
606 return sec_status_insecure;
609 for(i=0; i<num; i++) {
610 /* see if key matches keytag and algo */
611 if(algo != dnskey_get_algo(dnskey, i) ||
612 tag != dnskey_calc_keytag(dnskey, i))
616 /* see if key verifies */
617 sec = dnskey_verify_rrset_sig(env->scratch,
618 env->scratch_buffer, ve, now, rrset, dnskey, i,
619 sig_idx, sortree, &buf_canon, reason);
620 if(sec == sec_status_secure)
623 if(numchecked == 0) {
624 *reason = "signatures from unknown keys";
625 verbose(VERB_QUERY, "verify: could not find appropriate key");
626 return sec_status_bogus;
628 return sec_status_bogus;
632 * RR entries in a canonical sorted tree of RRs
635 /** rbtree node, key is this structure */
637 /** rrset the RR is in */
638 struct ub_packed_rrset_key* rrset;
639 /** which RR in the rrset */
644 * Compare two RR for canonical order, in a field-style sweep.
645 * @param d: rrset data
646 * @param desc: ldns wireformat descriptor.
647 * @param i: first RR to compare
648 * @param j: first RR to compare
649 * @return comparison code.
652 canonical_compare_byfield(struct packed_rrset_data* d,
653 const sldns_rr_descriptor* desc, size_t i, size_t j)
655 /* sweep across rdata, keep track of some state:
656 * which rr field, and bytes left in field.
657 * current position in rdata, length left.
658 * are we in a dname, length left in a label.
660 int wfi = -1; /* current wireformat rdata field (rdf) */
662 uint8_t* di = d->rr_data[i]+2; /* ptr to current rdata byte */
663 uint8_t* dj = d->rr_data[j]+2;
664 size_t ilen = d->rr_len[i]-2; /* length left in rdata */
665 size_t jlen = d->rr_len[j]-2;
666 int dname_i = 0; /* true if these bytes are part of a name */
668 size_t lablen_i = 0; /* 0 for label length byte,for first byte of rdf*/
669 size_t lablen_j = 0; /* otherwise remaining length of rdf or label */
670 int dname_num_i = (int)desc->_dname_count; /* decreased at root label */
671 int dname_num_j = (int)desc->_dname_count;
673 /* loop while there are rdata bytes available for both rrs,
674 * and still some lowercasing needs to be done; either the dnames
675 * have not been reached yet, or they are currently being processed */
676 while(ilen > 0 && jlen > 0 && (dname_num_i > 0 || dname_num_j > 0)) {
677 /* compare these two bytes */
678 /* lowercase if in a dname and not a label length byte */
679 if( ((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
680 != ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj)
682 if(((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
683 < ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj))
689 /* bytes are equal */
691 /* advance field i */
692 /* lablen 0 means that this byte is the first byte of the
693 * next rdata field; inspect this rdata field and setup
694 * to process the rest of this rdata field.
695 * The reason to first read the byte, then setup the rdf,
696 * is that we are then sure the byte is available and short
697 * rdata is handled gracefully (even if it is a formerr). */
700 /* scan this dname label */
701 /* capture length to lowercase */
702 lablen_i = (size_t)*di;
707 /* if dname num is 0, then the
708 * remainder is binary only */
713 /* scan this rdata field */
715 if(desc->_wireformat[wfi]
716 == LDNS_RDF_TYPE_DNAME) {
718 lablen_i = (size_t)*di;
725 } else if(desc->_wireformat[wfi]
726 == LDNS_RDF_TYPE_STR)
727 lablen_i = (size_t)*di;
728 else lablen_i = get_rdf_size(
729 desc->_wireformat[wfi]) - 1;
733 /* advance field j; same as for i */
736 lablen_j = (size_t)*dj;
745 if(desc->_wireformat[wfj]
746 == LDNS_RDF_TYPE_DNAME) {
748 lablen_j = (size_t)*dj;
755 } else if(desc->_wireformat[wfj]
756 == LDNS_RDF_TYPE_STR)
757 lablen_j = (size_t)*dj;
758 else lablen_j = get_rdf_size(
759 desc->_wireformat[wfj]) - 1;
765 /* end of the loop; because we advanced byte by byte; now we have
766 * that the rdata has ended, or that there is a binary remainder */
768 if(ilen == 0 && jlen == 0)
774 /* binary remainder, capture comparison in wfi variable */
775 if((wfi = memcmp(di, dj, (ilen<jlen)?ilen:jlen)) != 0)
785 * Compare two RRs in the same RRset and determine their relative
787 * @param rrset: the rrset in which to perform compares.
788 * @param i: first RR to compare
789 * @param j: first RR to compare
790 * @return 0 if RR i== RR j, -1 if <, +1 if >.
793 canonical_compare(struct ub_packed_rrset_key* rrset, size_t i, size_t j)
795 struct packed_rrset_data* d = (struct packed_rrset_data*)
797 const sldns_rr_descriptor* desc;
798 uint16_t type = ntohs(rrset->rk.type);
806 /* These RR types have only a name as RDATA.
807 * This name has to be canonicalized.*/
808 case LDNS_RR_TYPE_NS:
809 case LDNS_RR_TYPE_MD:
810 case LDNS_RR_TYPE_MF:
811 case LDNS_RR_TYPE_CNAME:
812 case LDNS_RR_TYPE_MB:
813 case LDNS_RR_TYPE_MG:
814 case LDNS_RR_TYPE_MR:
815 case LDNS_RR_TYPE_PTR:
816 case LDNS_RR_TYPE_DNAME:
817 /* the wireread function has already checked these
818 * dname's for correctness, and this double checks */
819 if(!dname_valid(d->rr_data[i]+2, d->rr_len[i]-2) ||
820 !dname_valid(d->rr_data[j]+2, d->rr_len[j]-2))
822 return query_dname_compare(d->rr_data[i]+2,
825 /* These RR types have STR and fixed size rdata fields
826 * before one or more name fields that need canonicalizing,
827 * and after that a byte-for byte remainder can be compared.
829 /* type starts with the name; remainder is binary compared */
830 case LDNS_RR_TYPE_NXT:
831 /* use rdata field formats */
832 case LDNS_RR_TYPE_MINFO:
833 case LDNS_RR_TYPE_RP:
834 case LDNS_RR_TYPE_SOA:
835 case LDNS_RR_TYPE_RT:
836 case LDNS_RR_TYPE_AFSDB:
837 case LDNS_RR_TYPE_KX:
838 case LDNS_RR_TYPE_MX:
839 case LDNS_RR_TYPE_SIG:
840 /* RRSIG signer name has to be downcased */
841 case LDNS_RR_TYPE_RRSIG:
842 case LDNS_RR_TYPE_PX:
843 case LDNS_RR_TYPE_NAPTR:
844 case LDNS_RR_TYPE_SRV:
845 desc = sldns_rr_descript(type);
847 /* this holds for the types that need canonicalizing */
848 log_assert(desc->_minimum == desc->_maximum);
849 return canonical_compare_byfield(d, desc, i, j);
851 case LDNS_RR_TYPE_HINFO: /* no longer downcased */
852 case LDNS_RR_TYPE_NSEC:
854 /* For unknown RR types, or types not listed above,
855 * no canonicalization is needed, do binary compare */
856 /* byte for byte compare, equal means shortest first*/
857 minlen = d->rr_len[i]-2;
858 if(minlen > d->rr_len[j]-2)
859 minlen = d->rr_len[j]-2;
860 c = memcmp(d->rr_data[i]+2, d->rr_data[j]+2, minlen);
863 /* rdata equal, shortest is first */
864 if(d->rr_len[i] < d->rr_len[j])
866 if(d->rr_len[i] > d->rr_len[j])
868 /* rdata equal, length equal */
875 canonical_tree_compare(const void* k1, const void* k2)
877 struct canon_rr* r1 = (struct canon_rr*)k1;
878 struct canon_rr* r2 = (struct canon_rr*)k2;
879 log_assert(r1->rrset == r2->rrset);
880 return canonical_compare(r1->rrset, r1->rr_idx, r2->rr_idx);
884 * Sort RRs for rrset in canonical order.
885 * Does not actually canonicalize the RR rdatas.
886 * Does not touch rrsigs.
887 * @param rrset: to sort.
888 * @param d: rrset data.
889 * @param sortree: tree to sort into.
890 * @param rrs: rr storage.
893 canonical_sort(struct ub_packed_rrset_key* rrset, struct packed_rrset_data* d,
894 rbtree_type* sortree, struct canon_rr* rrs)
897 /* insert into rbtree to sort and detect duplicates */
898 for(i=0; i<d->count; i++) {
899 rrs[i].node.key = &rrs[i];
900 rrs[i].rrset = rrset;
902 if(!rbtree_insert(sortree, &rrs[i].node)) {
903 /* this was a duplicate */
909 * Insert canonical owner name into buffer.
910 * @param buf: buffer to insert into at current position.
911 * @param k: rrset with its owner name.
912 * @param sig: signature with signer name and label count.
913 * must be length checked, at least 18 bytes long.
914 * @param can_owner: position in buffer returned for future use.
915 * @param can_owner_len: length of canonical owner name.
918 insert_can_owner(sldns_buffer* buf, struct ub_packed_rrset_key* k,
919 uint8_t* sig, uint8_t** can_owner, size_t* can_owner_len)
921 int rrsig_labels = (int)sig[3];
922 int fqdn_labels = dname_signame_label_count(k->rk.dname);
923 *can_owner = sldns_buffer_current(buf);
924 if(rrsig_labels == fqdn_labels) {
926 sldns_buffer_write(buf, k->rk.dname, k->rk.dname_len);
927 query_dname_tolower(*can_owner);
928 *can_owner_len = k->rk.dname_len;
931 log_assert(rrsig_labels < fqdn_labels);
932 /* *. | fqdn(rightmost rrsig_labels) */
933 if(rrsig_labels < fqdn_labels) {
935 uint8_t* nm = k->rk.dname;
936 size_t len = k->rk.dname_len;
937 /* so skip fqdn_labels-rrsig_labels */
938 for(i=0; i<fqdn_labels-rrsig_labels; i++) {
939 dname_remove_label(&nm, &len);
941 *can_owner_len = len+2;
942 sldns_buffer_write(buf, (uint8_t*)"\001*", 2);
943 sldns_buffer_write(buf, nm, len);
944 query_dname_tolower(*can_owner);
949 * Canonicalize Rdata in buffer.
950 * @param buf: buffer at position just after the rdata.
951 * @param rrset: rrset with type.
952 * @param len: length of the rdata (including rdatalen uint16).
955 canonicalize_rdata(sldns_buffer* buf, struct ub_packed_rrset_key* rrset,
958 uint8_t* datstart = sldns_buffer_current(buf)-len+2;
959 switch(ntohs(rrset->rk.type)) {
960 case LDNS_RR_TYPE_NXT:
961 case LDNS_RR_TYPE_NS:
962 case LDNS_RR_TYPE_MD:
963 case LDNS_RR_TYPE_MF:
964 case LDNS_RR_TYPE_CNAME:
965 case LDNS_RR_TYPE_MB:
966 case LDNS_RR_TYPE_MG:
967 case LDNS_RR_TYPE_MR:
968 case LDNS_RR_TYPE_PTR:
969 case LDNS_RR_TYPE_DNAME:
970 /* type only has a single argument, the name */
971 query_dname_tolower(datstart);
973 case LDNS_RR_TYPE_MINFO:
974 case LDNS_RR_TYPE_RP:
975 case LDNS_RR_TYPE_SOA:
976 /* two names after another */
977 query_dname_tolower(datstart);
978 query_dname_tolower(datstart +
979 dname_valid(datstart, len-2));
981 case LDNS_RR_TYPE_RT:
982 case LDNS_RR_TYPE_AFSDB:
983 case LDNS_RR_TYPE_KX:
984 case LDNS_RR_TYPE_MX:
985 /* skip fixed part */
986 if(len < 2+2+1) /* rdlen, skiplen, 1byteroot */
989 query_dname_tolower(datstart);
991 case LDNS_RR_TYPE_SIG:
992 /* downcase the RRSIG, compat with BIND (kept it from SIG) */
993 case LDNS_RR_TYPE_RRSIG:
994 /* skip fixed part */
998 query_dname_tolower(datstart);
1000 case LDNS_RR_TYPE_PX:
1001 /* skip, then two names after another */
1005 query_dname_tolower(datstart);
1006 query_dname_tolower(datstart +
1007 dname_valid(datstart, len-2-2));
1009 case LDNS_RR_TYPE_NAPTR:
1014 if(len < (size_t)datstart[0]+1) /* skip text field */
1016 len -= (size_t)datstart[0]+1;
1017 datstart += (size_t)datstart[0]+1;
1018 if(len < (size_t)datstart[0]+1) /* skip text field */
1020 len -= (size_t)datstart[0]+1;
1021 datstart += (size_t)datstart[0]+1;
1022 if(len < (size_t)datstart[0]+1) /* skip text field */
1024 len -= (size_t)datstart[0]+1;
1025 datstart += (size_t)datstart[0]+1;
1026 if(len < 1) /* check name is at least 1 byte*/
1028 query_dname_tolower(datstart);
1030 case LDNS_RR_TYPE_SRV:
1031 /* skip fixed part */
1035 query_dname_tolower(datstart);
1038 /* do not canonicalize NSEC rdata name, compat with
1039 * from bind 9.4 signer, where it does not do so */
1040 case LDNS_RR_TYPE_NSEC: /* type starts with the name */
1041 case LDNS_RR_TYPE_HINFO: /* not downcased */
1042 /* A6 not supported */
1044 /* nothing to do for unknown types */
1049 int rrset_canonical_equal(struct regional* region,
1050 struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2)
1052 struct rbtree_type sortree1, sortree2;
1053 struct canon_rr *rrs1, *rrs2, *p1, *p2;
1054 struct packed_rrset_data* d1=(struct packed_rrset_data*)k1->entry.data;
1055 struct packed_rrset_data* d2=(struct packed_rrset_data*)k2->entry.data;
1056 struct ub_packed_rrset_key fk;
1057 struct packed_rrset_data fd;
1062 if(k1->rk.dname_len != k2->rk.dname_len ||
1063 k1->rk.flags != k2->rk.flags ||
1064 k1->rk.type != k2->rk.type ||
1065 k1->rk.rrset_class != k2->rk.rrset_class ||
1066 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0)
1068 if(d1->ttl != d2->ttl ||
1069 d1->count != d2->count ||
1070 d1->rrsig_count != d2->rrsig_count ||
1071 d1->trust != d2->trust ||
1072 d1->security != d2->security)
1076 memset(&fk, 0, sizeof(fk));
1077 memset(&fd, 0, sizeof(fd));
1078 fk.entry.data = &fd;
1082 rbtree_init(&sortree1, &canonical_tree_compare);
1083 rbtree_init(&sortree2, &canonical_tree_compare);
1084 if(d1->count > RR_COUNT_MAX || d2->count > RR_COUNT_MAX)
1085 return 1; /* protection against integer overflow */
1086 rrs1 = regional_alloc(region, sizeof(struct canon_rr)*d1->count);
1087 rrs2 = regional_alloc(region, sizeof(struct canon_rr)*d2->count);
1088 if(!rrs1 || !rrs2) return 1; /* alloc failure */
1091 canonical_sort(k1, d1, &sortree1, rrs1);
1092 canonical_sort(k2, d2, &sortree2, rrs2);
1094 /* compare canonical-sorted RRs for canonical-equality */
1095 if(sortree1.count != sortree2.count)
1097 p1 = (struct canon_rr*)rbtree_first(&sortree1);
1098 p2 = (struct canon_rr*)rbtree_first(&sortree2);
1099 while(p1 != (struct canon_rr*)RBTREE_NULL &&
1100 p2 != (struct canon_rr*)RBTREE_NULL) {
1101 flen[0] = d1->rr_len[p1->rr_idx];
1102 flen[1] = d2->rr_len[p2->rr_idx];
1103 fdata[0] = d1->rr_data[p1->rr_idx];
1104 fdata[1] = d2->rr_data[p2->rr_idx];
1106 if(canonical_compare(&fk, 0, 1) != 0)
1108 p1 = (struct canon_rr*)rbtree_next(&p1->node);
1109 p2 = (struct canon_rr*)rbtree_next(&p2->node);
1115 * Create canonical form of rrset in the scratch buffer.
1116 * @param region: temporary region.
1117 * @param buf: the buffer to use.
1118 * @param k: the rrset to insert.
1119 * @param sig: RRSIG rdata to include.
1120 * @param siglen: RRSIG rdata len excluding signature field, but inclusive
1121 * signer name length.
1122 * @param sortree: if NULL is passed a new sorted rrset tree is built.
1123 * Otherwise it is reused.
1124 * @return false on alloc error.
1127 rrset_canonical(struct regional* region, sldns_buffer* buf,
1128 struct ub_packed_rrset_key* k, uint8_t* sig, size_t siglen,
1129 struct rbtree_type** sortree)
1131 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
1132 uint8_t* can_owner = NULL;
1133 size_t can_owner_len = 0;
1134 struct canon_rr* walk;
1135 struct canon_rr* rrs;
1138 *sortree = (struct rbtree_type*)regional_alloc(region,
1139 sizeof(rbtree_type));
1142 if(d->count > RR_COUNT_MAX)
1143 return 0; /* integer overflow protection */
1144 rrs = regional_alloc(region, sizeof(struct canon_rr)*d->count);
1149 rbtree_init(*sortree, &canonical_tree_compare);
1150 canonical_sort(k, d, *sortree, rrs);
1153 sldns_buffer_clear(buf);
1154 sldns_buffer_write(buf, sig, siglen);
1155 /* canonicalize signer name */
1156 query_dname_tolower(sldns_buffer_begin(buf)+18);
1157 RBTREE_FOR(walk, struct canon_rr*, (*sortree)) {
1158 /* see if there is enough space left in the buffer */
1159 if(sldns_buffer_remaining(buf) < can_owner_len + 2 + 2 + 4
1160 + d->rr_len[walk->rr_idx]) {
1161 log_err("verify: failed to canonicalize, "
1165 /* determine canonical owner name */
1167 sldns_buffer_write(buf, can_owner, can_owner_len);
1168 else insert_can_owner(buf, k, sig, &can_owner,
1170 sldns_buffer_write(buf, &k->rk.type, 2);
1171 sldns_buffer_write(buf, &k->rk.rrset_class, 2);
1172 sldns_buffer_write(buf, sig+4, 4);
1173 sldns_buffer_write(buf, d->rr_data[walk->rr_idx],
1174 d->rr_len[walk->rr_idx]);
1175 canonicalize_rdata(buf, k, d->rr_len[walk->rr_idx]);
1177 sldns_buffer_flip(buf);
1181 /** pretty print rrsig error with dates */
1183 sigdate_error(const char* str, int32_t expi, int32_t incep, int32_t now)
1191 if(verbosity < VERB_QUERY)
1196 memset(&tm, 0, sizeof(tm));
1197 if(gmtime_r(&te, &tm) && strftime(expi_buf, 15, "%Y%m%d%H%M%S", &tm)
1198 &&gmtime_r(&ti, &tm) && strftime(incep_buf, 15, "%Y%m%d%H%M%S", &tm)
1199 &&gmtime_r(&tn, &tm) && strftime(now_buf, 15, "%Y%m%d%H%M%S", &tm)) {
1200 log_info("%s expi=%s incep=%s now=%s", str, expi_buf,
1201 incep_buf, now_buf);
1203 log_info("%s expi=%u incep=%u now=%u", str, (unsigned)expi,
1204 (unsigned)incep, (unsigned)now);
1207 /** check rrsig dates */
1209 check_dates(struct val_env* ve, uint32_t unow,
1210 uint8_t* expi_p, uint8_t* incep_p, char** reason)
1212 /* read out the dates */
1213 int32_t expi, incep, now;
1214 memmove(&expi, expi_p, sizeof(expi));
1215 memmove(&incep, incep_p, sizeof(incep));
1217 incep = ntohl(incep);
1219 /* get current date */
1220 if(ve->date_override) {
1221 if(ve->date_override == -1) {
1222 verbose(VERB_ALGO, "date override: ignore date");
1225 now = ve->date_override;
1226 verbose(VERB_ALGO, "date override option %d", (int)now);
1227 } else now = (int32_t)unow;
1230 if(incep - expi > 0) {
1231 sigdate_error("verify: inception after expiration, "
1232 "signature bad", expi, incep, now);
1233 *reason = "signature inception after expiration";
1236 if(incep - now > 0) {
1237 /* within skew ? (calc here to avoid calculation normally) */
1238 int32_t skew = (expi-incep)/10;
1239 if(skew < ve->skew_min) skew = ve->skew_min;
1240 if(skew > ve->skew_max) skew = ve->skew_max;
1241 if(incep - now > skew) {
1242 sigdate_error("verify: signature bad, current time is"
1243 " before inception date", expi, incep, now);
1244 *reason = "signature before inception date";
1247 sigdate_error("verify warning suspicious signature inception "
1248 " or bad local clock", expi, incep, now);
1250 if(now - expi > 0) {
1251 int32_t skew = (expi-incep)/10;
1252 if(skew < ve->skew_min) skew = ve->skew_min;
1253 if(skew > ve->skew_max) skew = ve->skew_max;
1254 if(now - expi > skew) {
1255 sigdate_error("verify: signature expired", expi,
1257 *reason = "signature expired";
1260 sigdate_error("verify warning suspicious signature expiration "
1261 " or bad local clock", expi, incep, now);
1266 /** adjust rrset TTL for verified rrset, compare to original TTL and expi */
1268 adjust_ttl(struct val_env* ve, uint32_t unow,
1269 struct ub_packed_rrset_key* rrset, uint8_t* orig_p,
1270 uint8_t* expi_p, uint8_t* incep_p)
1272 struct packed_rrset_data* d =
1273 (struct packed_rrset_data*)rrset->entry.data;
1274 /* read out the dates */
1275 int32_t origttl, expittl, expi, incep, now;
1276 memmove(&origttl, orig_p, sizeof(origttl));
1277 memmove(&expi, expi_p, sizeof(expi));
1278 memmove(&incep, incep_p, sizeof(incep));
1280 incep = ntohl(incep);
1281 origttl = ntohl(origttl);
1283 /* get current date */
1284 if(ve->date_override) {
1285 now = ve->date_override;
1286 } else now = (int32_t)unow;
1287 expittl = expi - now;
1290 * d->ttl: rrset ttl read from message or cache. May be reduced
1291 * origttl: original TTL from signature, authoritative TTL max.
1292 * MIN_TTL: minimum TTL from config.
1293 * expittl: TTL until the signature expires.
1295 * Use the smallest of these, but don't let origttl set the TTL
1296 * below the minimum.
1298 if(MIN_TTL > (time_t)origttl && d->ttl > MIN_TTL) {
1299 verbose(VERB_QUERY, "rrset TTL larger than original and minimum"
1300 " TTL, adjusting TTL downwards to minimum ttl");
1303 else if(MIN_TTL <= origttl && d->ttl > (time_t)origttl) {
1304 verbose(VERB_QUERY, "rrset TTL larger than original TTL, "
1305 "adjusting TTL downwards to original ttl");
1309 if(expittl > 0 && d->ttl > (time_t)expittl) {
1310 verbose(VERB_ALGO, "rrset TTL larger than sig expiration ttl,"
1311 " adjusting TTL downwards");
1317 dnskey_verify_rrset_sig(struct regional* region, sldns_buffer* buf,
1318 struct val_env* ve, time_t now,
1319 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
1320 size_t dnskey_idx, size_t sig_idx,
1321 struct rbtree_type** sortree, int* buf_canon, char** reason)
1323 enum sec_status sec;
1324 uint8_t* sig; /* RRSIG rdata */
1326 size_t rrnum = rrset_get_count(rrset);
1327 uint8_t* signer; /* rrsig signer name */
1329 unsigned char* sigblock; /* signature rdata field */
1330 unsigned int sigblock_len;
1331 uint16_t ktag; /* DNSKEY key tag */
1332 unsigned char* key; /* public key rdata field */
1333 unsigned int keylen;
1334 rrset_get_rdata(rrset, rrnum + sig_idx, &sig, &siglen);
1335 /* min length of rdatalen, fixed rrsig, root signer, 1 byte sig */
1337 verbose(VERB_QUERY, "verify: signature too short");
1338 *reason = "signature too short";
1339 return sec_status_bogus;
1342 if(!(dnskey_get_flags(dnskey, dnskey_idx) & DNSKEY_BIT_ZSK)) {
1343 verbose(VERB_QUERY, "verify: dnskey without ZSK flag");
1344 *reason = "dnskey without ZSK flag";
1345 return sec_status_bogus;
1348 if(dnskey_get_protocol(dnskey, dnskey_idx) != LDNS_DNSSEC_KEYPROTO) {
1349 /* RFC 4034 says DNSKEY PROTOCOL MUST be 3 */
1350 verbose(VERB_QUERY, "verify: dnskey has wrong key protocol");
1351 *reason = "dnskey has wrong protocolnumber";
1352 return sec_status_bogus;
1355 /* verify as many fields in rrsig as possible */
1357 signer_len = dname_valid(signer, siglen-2-18);
1359 verbose(VERB_QUERY, "verify: malformed signer name");
1360 *reason = "signer name malformed";
1361 return sec_status_bogus; /* signer name invalid */
1363 if(!dname_subdomain_c(rrset->rk.dname, signer)) {
1364 verbose(VERB_QUERY, "verify: signer name is off-tree");
1365 *reason = "signer name off-tree";
1366 return sec_status_bogus; /* signer name offtree */
1368 sigblock = (unsigned char*)signer+signer_len;
1369 if(siglen < 2+18+signer_len+1) {
1370 verbose(VERB_QUERY, "verify: too short, no signature data");
1371 *reason = "signature too short, no signature data";
1372 return sec_status_bogus; /* sig rdf is < 1 byte */
1374 sigblock_len = (unsigned int)(siglen - 2 - 18 - signer_len);
1376 /* verify key dname == sig signer name */
1377 if(query_dname_compare(signer, dnskey->rk.dname) != 0) {
1378 verbose(VERB_QUERY, "verify: wrong key for rrsig");
1379 log_nametypeclass(VERB_QUERY, "RRSIG signername is",
1381 log_nametypeclass(VERB_QUERY, "the key name is",
1382 dnskey->rk.dname, 0, 0);
1383 *reason = "signer name mismatches key name";
1384 return sec_status_bogus;
1387 /* verify covered type */
1388 /* memcmp works because type is in network format for rrset */
1389 if(memcmp(sig+2, &rrset->rk.type, 2) != 0) {
1390 verbose(VERB_QUERY, "verify: wrong type covered");
1391 *reason = "signature covers wrong type";
1392 return sec_status_bogus;
1394 /* verify keytag and sig algo (possibly again) */
1395 if((int)sig[2+2] != dnskey_get_algo(dnskey, dnskey_idx)) {
1396 verbose(VERB_QUERY, "verify: wrong algorithm");
1397 *reason = "signature has wrong algorithm";
1398 return sec_status_bogus;
1400 ktag = htons(dnskey_calc_keytag(dnskey, dnskey_idx));
1401 if(memcmp(sig+2+16, &ktag, 2) != 0) {
1402 verbose(VERB_QUERY, "verify: wrong keytag");
1403 *reason = "signature has wrong keytag";
1404 return sec_status_bogus;
1407 /* verify labels is in a valid range */
1408 if((int)sig[2+3] > dname_signame_label_count(rrset->rk.dname)) {
1409 verbose(VERB_QUERY, "verify: labelcount out of range");
1410 *reason = "signature labelcount out of range";
1411 return sec_status_bogus;
1414 /* original ttl, always ok */
1417 /* create rrset canonical format in buffer, ready for
1419 if(!rrset_canonical(region, buf, rrset, sig+2,
1420 18 + signer_len, sortree)) {
1421 log_err("verify: failed due to alloc error");
1422 return sec_status_unchecked;
1427 /* check that dnskey is available */
1428 dnskey_get_pubkey(dnskey, dnskey_idx, &key, &keylen);
1430 verbose(VERB_QUERY, "verify: short DNSKEY RR");
1431 return sec_status_unchecked;
1435 sec = verify_canonrrset(buf, (int)sig[2+2],
1436 sigblock, sigblock_len, key, keylen, reason);
1438 if(sec == sec_status_secure) {
1439 /* check if TTL is too high - reduce if so */
1440 adjust_ttl(ve, now, rrset, sig+2+4, sig+2+8, sig+2+12);
1442 /* verify inception, expiration dates
1443 * Do this last so that if you ignore expired-sigs the
1444 * rest is sure to be OK. */
1445 if(!check_dates(ve, now, sig+2+8, sig+2+12, reason)) {
1446 return sec_status_bogus;