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 "sldns/keyraw.h"
55 #include "sldns/sbuffer.h"
56 #include "sldns/parseutil.h"
57 #include "sldns/wire2str.h"
60 #if !defined(HAVE_SSL) && !defined(HAVE_NSS) && !defined(HAVE_NETTLE)
61 #error "Need crypto library to do digital signature cryptography"
64 #ifdef HAVE_OPENSSL_ERR_H
65 #include <openssl/err.h>
68 #ifdef HAVE_OPENSSL_RAND_H
69 #include <openssl/rand.h>
72 #ifdef HAVE_OPENSSL_CONF_H
73 #include <openssl/conf.h>
76 #ifdef HAVE_OPENSSL_ENGINE_H
77 #include <openssl/engine.h>
80 /** return number of rrs in an rrset */
82 rrset_get_count(struct ub_packed_rrset_key* rrset)
84 struct packed_rrset_data* d = (struct packed_rrset_data*)
91 * Get RR signature count
94 rrset_get_sigcount(struct ub_packed_rrset_key* k)
96 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
97 return d->rrsig_count;
101 * Get signature keytag value
102 * @param k: rrset (with signatures)
103 * @param sig_idx: signature index.
104 * @return keytag or 0 if malformed rrsig.
107 rrset_get_sig_keytag(struct ub_packed_rrset_key* k, size_t sig_idx)
110 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
111 log_assert(sig_idx < d->rrsig_count);
112 if(d->rr_len[d->count + sig_idx] < 2+18)
114 memmove(&t, d->rr_data[d->count + sig_idx]+2+16, 2);
119 * Get signature signing algorithm value
120 * @param k: rrset (with signatures)
121 * @param sig_idx: signature index.
122 * @return algo or 0 if malformed rrsig.
125 rrset_get_sig_algo(struct ub_packed_rrset_key* k, size_t sig_idx)
127 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
128 log_assert(sig_idx < d->rrsig_count);
129 if(d->rr_len[d->count + sig_idx] < 2+3)
131 return (int)d->rr_data[d->count + sig_idx][2+2];
134 /** get rdata pointer and size */
136 rrset_get_rdata(struct ub_packed_rrset_key* k, size_t idx, uint8_t** rdata,
139 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
140 log_assert(d && idx < (d->count + d->rrsig_count));
141 *rdata = d->rr_data[idx];
142 *len = d->rr_len[idx];
146 dnskey_get_flags(struct ub_packed_rrset_key* k, size_t idx)
151 rrset_get_rdata(k, idx, &rdata, &len);
154 memmove(&f, rdata+2, 2);
160 * Get DNSKEY protocol value from rdata
161 * @param k: DNSKEY rrset.
162 * @param idx: which key.
163 * @return protocol octet value
166 dnskey_get_protocol(struct ub_packed_rrset_key* k, size_t idx)
170 rrset_get_rdata(k, idx, &rdata, &len);
173 return (int)rdata[2+2];
177 dnskey_get_algo(struct ub_packed_rrset_key* k, size_t idx)
181 rrset_get_rdata(k, idx, &rdata, &len);
184 return (int)rdata[2+3];
187 /** get public key rdata field from a dnskey RR and do some checks */
189 dnskey_get_pubkey(struct ub_packed_rrset_key* k, size_t idx,
190 unsigned char** pk, unsigned int* pklen)
194 rrset_get_rdata(k, idx, &rdata, &len);
200 *pk = (unsigned char*)rdata+2+4;
201 *pklen = (unsigned)len-2-4;
205 ds_get_key_algo(struct ub_packed_rrset_key* k, size_t idx)
209 rrset_get_rdata(k, idx, &rdata, &len);
212 return (int)rdata[2+2];
216 ds_get_digest_algo(struct ub_packed_rrset_key* k, size_t idx)
220 rrset_get_rdata(k, idx, &rdata, &len);
223 return (int)rdata[2+3];
227 ds_get_keytag(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx)
232 rrset_get_rdata(ds_rrset, ds_idx, &rdata, &len);
235 memmove(&t, rdata+2, 2);
240 * Return pointer to the digest in a DS RR.
241 * @param k: DS rrset.
242 * @param idx: which DS.
243 * @param digest: digest data is returned.
244 * on error, this is NULL.
245 * @param len: length of digest is returned.
246 * on error, the length is 0.
249 ds_get_sigdata(struct ub_packed_rrset_key* k, size_t idx, uint8_t** digest,
254 rrset_get_rdata(k, idx, &rdata, &rdlen);
260 *digest = rdata + 2 + 4;
261 *len = rdlen - 2 - 4;
265 * Return size of DS digest according to its hash algorithm.
266 * @param k: DS rrset.
267 * @param idx: which DS.
268 * @return size in bytes of digest, or 0 if not supported.
271 ds_digest_size_algo(struct ub_packed_rrset_key* k, size_t idx)
273 return ds_digest_size_supported(ds_get_digest_algo(k, idx));
277 * Create a DS digest for a DNSKEY entry.
279 * @param env: module environment. Uses scratch space.
280 * @param dnskey_rrset: DNSKEY rrset.
281 * @param dnskey_idx: index of RR in rrset.
282 * @param ds_rrset: DS rrset
283 * @param ds_idx: index of RR in DS rrset.
284 * @param digest: digest is returned in here (must be correctly sized).
285 * @return false on error.
288 ds_create_dnskey_digest(struct module_env* env,
289 struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx,
290 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx,
293 sldns_buffer* b = env->scratch_buffer;
294 uint8_t* dnskey_rdata;
296 rrset_get_rdata(dnskey_rrset, dnskey_idx, &dnskey_rdata, &dnskey_len);
298 /* create digest source material in buffer
299 * digest = digest_algorithm( DNSKEY owner name | DNSKEY RDATA);
300 * DNSKEY RDATA = Flags | Protocol | Algorithm | Public Key. */
301 sldns_buffer_clear(b);
302 sldns_buffer_write(b, dnskey_rrset->rk.dname,
303 dnskey_rrset->rk.dname_len);
304 query_dname_tolower(sldns_buffer_begin(b));
305 sldns_buffer_write(b, dnskey_rdata+2, dnskey_len-2); /* skip rdatalen*/
306 sldns_buffer_flip(b);
308 return secalgo_ds_digest(ds_get_digest_algo(ds_rrset, ds_idx),
309 (unsigned char*)sldns_buffer_begin(b), sldns_buffer_limit(b),
310 (unsigned char*)digest);
313 int ds_digest_match_dnskey(struct module_env* env,
314 struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx,
315 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx)
317 uint8_t* ds; /* DS digest */
319 uint8_t* digest; /* generated digest */
320 size_t digestlen = ds_digest_size_algo(ds_rrset, ds_idx);
323 verbose(VERB_QUERY, "DS fail: not supported, or DS RR "
325 return 0; /* not supported, or DS RR format error */
327 /* check digest length in DS with length from hash function */
328 ds_get_sigdata(ds_rrset, ds_idx, &ds, &dslen);
329 if(!ds || dslen != digestlen) {
330 verbose(VERB_QUERY, "DS fail: DS RR algo and digest do not "
332 return 0; /* DS algorithm and digest do not match */
335 digest = regional_alloc(env->scratch, digestlen);
337 verbose(VERB_QUERY, "DS fail: out of memory");
338 return 0; /* mem error */
340 if(!ds_create_dnskey_digest(env, dnskey_rrset, dnskey_idx, ds_rrset,
342 verbose(VERB_QUERY, "DS fail: could not calc key digest");
343 return 0; /* digest algo failed */
345 if(memcmp(digest, ds, dslen) != 0) {
346 verbose(VERB_QUERY, "DS fail: digest is different");
347 return 0; /* digest different */
353 ds_digest_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
356 return (ds_digest_size_algo(ds_rrset, ds_idx) != 0);
360 ds_key_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
363 return dnskey_algo_id_is_supported(ds_get_key_algo(ds_rrset, ds_idx));
367 dnskey_calc_keytag(struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx)
371 rrset_get_rdata(dnskey_rrset, dnskey_idx, &data, &len);
372 /* do not pass rdatalen to ldns */
373 return sldns_calc_keytag_raw(data+2, len-2);
376 int dnskey_algo_is_supported(struct ub_packed_rrset_key* dnskey_rrset,
379 return dnskey_algo_id_is_supported(dnskey_get_algo(dnskey_rrset,
383 void algo_needs_init_dnskey_add(struct algo_needs* n,
384 struct ub_packed_rrset_key* dnskey, uint8_t* sigalg)
387 size_t i, total = n->num;
388 size_t num = rrset_get_count(dnskey);
390 for(i=0; i<num; i++) {
391 algo = (uint8_t)dnskey_get_algo(dnskey, i);
392 if(!dnskey_algo_id_is_supported((int)algo))
394 if(n->needs[algo] == 0) {
396 sigalg[total] = algo;
404 void algo_needs_init_list(struct algo_needs* n, uint8_t* sigalg)
409 memset(n->needs, 0, sizeof(uint8_t)*ALGO_NEEDS_MAX);
410 while( (algo=*sigalg++) != 0) {
411 log_assert(dnskey_algo_id_is_supported((int)algo));
412 log_assert(n->needs[algo] == 0);
419 void algo_needs_init_ds(struct algo_needs* n, struct ub_packed_rrset_key* ds,
420 int fav_ds_algo, uint8_t* sigalg)
424 size_t num = rrset_get_count(ds);
426 memset(n->needs, 0, sizeof(uint8_t)*ALGO_NEEDS_MAX);
427 for(i=0; i<num; i++) {
428 if(ds_get_digest_algo(ds, i) != fav_ds_algo)
430 algo = (uint8_t)ds_get_key_algo(ds, i);
431 if(!dnskey_algo_id_is_supported((int)algo))
433 log_assert(algo != 0); /* we do not support 0 and is EOS */
434 if(n->needs[algo] == 0) {
436 sigalg[total] = algo;
444 int algo_needs_set_secure(struct algo_needs* n, uint8_t algo)
449 if(n->num == 0) /* done! */
455 void algo_needs_set_bogus(struct algo_needs* n, uint8_t algo)
457 if(n->needs[algo]) n->needs[algo] = 2; /* need it, but bogus */
460 size_t algo_needs_num_missing(struct algo_needs* n)
465 int algo_needs_missing(struct algo_needs* n)
468 /* first check if a needed algo was bogus - report that */
469 for(i=0; i<ALGO_NEEDS_MAX; i++)
472 /* now check which algo is missing */
473 for(i=0; i<ALGO_NEEDS_MAX; i++)
480 dnskeyset_verify_rrset(struct module_env* env, struct val_env* ve,
481 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
482 uint8_t* sigalg, char** reason)
486 rbtree_type* sortree = NULL;
487 /* make sure that for all DNSKEY algorithms there are valid sigs */
488 struct algo_needs needs;
491 num = rrset_get_sigcount(rrset);
493 verbose(VERB_QUERY, "rrset failed to verify due to a lack of "
495 *reason = "no signatures";
496 return sec_status_bogus;
500 algo_needs_init_list(&needs, sigalg);
501 if(algo_needs_num_missing(&needs) == 0) {
502 verbose(VERB_QUERY, "zone has no known algorithms");
503 *reason = "zone has no known algorithms";
504 return sec_status_insecure;
507 for(i=0; i<num; i++) {
508 sec = dnskeyset_verify_rrset_sig(env, ve, *env->now, rrset,
509 dnskey, i, &sortree, reason);
510 /* see which algorithm has been fixed up */
511 if(sec == sec_status_secure) {
513 return sec; /* done! */
514 else if(algo_needs_set_secure(&needs,
515 (uint8_t)rrset_get_sig_algo(rrset, i)))
516 return sec; /* done! */
517 } else if(sigalg && sec == sec_status_bogus) {
518 algo_needs_set_bogus(&needs,
519 (uint8_t)rrset_get_sig_algo(rrset, i));
522 if(sigalg && (alg=algo_needs_missing(&needs)) != 0) {
523 verbose(VERB_ALGO, "rrset failed to verify: "
524 "no valid signatures for %d algorithms",
525 (int)algo_needs_num_missing(&needs));
526 algo_needs_reason(env, alg, reason, "no signatures");
528 verbose(VERB_ALGO, "rrset failed to verify: "
529 "no valid signatures");
531 return sec_status_bogus;
534 void algo_needs_reason(struct module_env* env, int alg, char** reason, char* s)
537 sldns_lookup_table *t = sldns_lookup_by_id(sldns_algorithms, alg);
539 snprintf(buf, sizeof(buf), "%s with algorithm %s", s, t->name);
540 else snprintf(buf, sizeof(buf), "%s with algorithm ALG%u", s,
542 *reason = regional_strdup(env->scratch, buf);
548 dnskey_verify_rrset(struct module_env* env, struct val_env* ve,
549 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
550 size_t dnskey_idx, char** reason)
553 size_t i, num, numchecked = 0;
554 rbtree_type* sortree = NULL;
556 uint16_t tag = dnskey_calc_keytag(dnskey, dnskey_idx);
557 int algo = dnskey_get_algo(dnskey, dnskey_idx);
559 num = rrset_get_sigcount(rrset);
561 verbose(VERB_QUERY, "rrset failed to verify due to a lack of "
563 *reason = "no signatures";
564 return sec_status_bogus;
566 for(i=0; i<num; i++) {
567 /* see if sig matches keytag and algo */
568 if(algo != rrset_get_sig_algo(rrset, i) ||
569 tag != rrset_get_sig_keytag(rrset, i))
572 sec = dnskey_verify_rrset_sig(env->scratch,
573 env->scratch_buffer, ve, *env->now, rrset,
574 dnskey, dnskey_idx, i, &sortree, &buf_canon, reason);
575 if(sec == sec_status_secure)
579 verbose(VERB_ALGO, "rrset failed to verify: all signatures are bogus");
580 if(!numchecked) *reason = "signature missing";
581 return sec_status_bogus;
585 dnskeyset_verify_rrset_sig(struct module_env* env, struct val_env* ve,
586 time_t now, struct ub_packed_rrset_key* rrset,
587 struct ub_packed_rrset_key* dnskey, size_t sig_idx,
588 struct rbtree_type** sortree, char** reason)
590 /* find matching keys and check them */
591 enum sec_status sec = sec_status_bogus;
592 uint16_t tag = rrset_get_sig_keytag(rrset, sig_idx);
593 int algo = rrset_get_sig_algo(rrset, sig_idx);
594 size_t i, num = rrset_get_count(dnskey);
595 size_t numchecked = 0;
597 verbose(VERB_ALGO, "verify sig %d %d", (int)tag, algo);
598 if(!dnskey_algo_id_is_supported(algo)) {
599 verbose(VERB_QUERY, "verify sig: unknown algorithm");
600 return sec_status_insecure;
603 for(i=0; i<num; i++) {
604 /* see if key matches keytag and algo */
605 if(algo != dnskey_get_algo(dnskey, i) ||
606 tag != dnskey_calc_keytag(dnskey, i))
610 /* see if key verifies */
611 sec = dnskey_verify_rrset_sig(env->scratch,
612 env->scratch_buffer, ve, now, rrset, dnskey, i,
613 sig_idx, sortree, &buf_canon, reason);
614 if(sec == sec_status_secure)
617 if(numchecked == 0) {
618 *reason = "signatures from unknown keys";
619 verbose(VERB_QUERY, "verify: could not find appropriate key");
620 return sec_status_bogus;
622 return sec_status_bogus;
626 * RR entries in a canonical sorted tree of RRs
629 /** rbtree node, key is this structure */
631 /** rrset the RR is in */
632 struct ub_packed_rrset_key* rrset;
633 /** which RR in the rrset */
638 * Compare two RR for canonical order, in a field-style sweep.
639 * @param d: rrset data
640 * @param desc: ldns wireformat descriptor.
641 * @param i: first RR to compare
642 * @param j: first RR to compare
643 * @return comparison code.
646 canonical_compare_byfield(struct packed_rrset_data* d,
647 const sldns_rr_descriptor* desc, size_t i, size_t j)
649 /* sweep across rdata, keep track of some state:
650 * which rr field, and bytes left in field.
651 * current position in rdata, length left.
652 * are we in a dname, length left in a label.
654 int wfi = -1; /* current wireformat rdata field (rdf) */
656 uint8_t* di = d->rr_data[i]+2; /* ptr to current rdata byte */
657 uint8_t* dj = d->rr_data[j]+2;
658 size_t ilen = d->rr_len[i]-2; /* length left in rdata */
659 size_t jlen = d->rr_len[j]-2;
660 int dname_i = 0; /* true if these bytes are part of a name */
662 size_t lablen_i = 0; /* 0 for label length byte,for first byte of rdf*/
663 size_t lablen_j = 0; /* otherwise remaining length of rdf or label */
664 int dname_num_i = (int)desc->_dname_count; /* decreased at root label */
665 int dname_num_j = (int)desc->_dname_count;
667 /* loop while there are rdata bytes available for both rrs,
668 * and still some lowercasing needs to be done; either the dnames
669 * have not been reached yet, or they are currently being processed */
670 while(ilen > 0 && jlen > 0 && (dname_num_i > 0 || dname_num_j > 0)) {
671 /* compare these two bytes */
672 /* lowercase if in a dname and not a label length byte */
673 if( ((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
674 != ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj)
676 if(((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
677 < ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj))
683 /* bytes are equal */
685 /* advance field i */
686 /* lablen 0 means that this byte is the first byte of the
687 * next rdata field; inspect this rdata field and setup
688 * to process the rest of this rdata field.
689 * The reason to first read the byte, then setup the rdf,
690 * is that we are then sure the byte is available and short
691 * rdata is handled gracefully (even if it is a formerr). */
694 /* scan this dname label */
695 /* capture length to lowercase */
696 lablen_i = (size_t)*di;
701 /* if dname num is 0, then the
702 * remainder is binary only */
707 /* scan this rdata field */
709 if(desc->_wireformat[wfi]
710 == LDNS_RDF_TYPE_DNAME) {
712 lablen_i = (size_t)*di;
719 } else if(desc->_wireformat[wfi]
720 == LDNS_RDF_TYPE_STR)
721 lablen_i = (size_t)*di;
722 else lablen_i = get_rdf_size(
723 desc->_wireformat[wfi]) - 1;
727 /* advance field j; same as for i */
730 lablen_j = (size_t)*dj;
739 if(desc->_wireformat[wfj]
740 == LDNS_RDF_TYPE_DNAME) {
742 lablen_j = (size_t)*dj;
749 } else if(desc->_wireformat[wfj]
750 == LDNS_RDF_TYPE_STR)
751 lablen_j = (size_t)*dj;
752 else lablen_j = get_rdf_size(
753 desc->_wireformat[wfj]) - 1;
759 /* end of the loop; because we advanced byte by byte; now we have
760 * that the rdata has ended, or that there is a binary remainder */
762 if(ilen == 0 && jlen == 0)
768 /* binary remainder, capture comparison in wfi variable */
769 if((wfi = memcmp(di, dj, (ilen<jlen)?ilen:jlen)) != 0)
779 * Compare two RRs in the same RRset and determine their relative
781 * @param rrset: the rrset in which to perform compares.
782 * @param i: first RR to compare
783 * @param j: first RR to compare
784 * @return 0 if RR i== RR j, -1 if <, +1 if >.
787 canonical_compare(struct ub_packed_rrset_key* rrset, size_t i, size_t j)
789 struct packed_rrset_data* d = (struct packed_rrset_data*)
791 const sldns_rr_descriptor* desc;
792 uint16_t type = ntohs(rrset->rk.type);
800 /* These RR types have only a name as RDATA.
801 * This name has to be canonicalized.*/
802 case LDNS_RR_TYPE_NS:
803 case LDNS_RR_TYPE_MD:
804 case LDNS_RR_TYPE_MF:
805 case LDNS_RR_TYPE_CNAME:
806 case LDNS_RR_TYPE_MB:
807 case LDNS_RR_TYPE_MG:
808 case LDNS_RR_TYPE_MR:
809 case LDNS_RR_TYPE_PTR:
810 case LDNS_RR_TYPE_DNAME:
811 /* the wireread function has already checked these
812 * dname's for correctness, and this double checks */
813 if(!dname_valid(d->rr_data[i]+2, d->rr_len[i]-2) ||
814 !dname_valid(d->rr_data[j]+2, d->rr_len[j]-2))
816 return query_dname_compare(d->rr_data[i]+2,
819 /* These RR types have STR and fixed size rdata fields
820 * before one or more name fields that need canonicalizing,
821 * and after that a byte-for byte remainder can be compared.
823 /* type starts with the name; remainder is binary compared */
824 case LDNS_RR_TYPE_NXT:
825 /* use rdata field formats */
826 case LDNS_RR_TYPE_MINFO:
827 case LDNS_RR_TYPE_RP:
828 case LDNS_RR_TYPE_SOA:
829 case LDNS_RR_TYPE_RT:
830 case LDNS_RR_TYPE_AFSDB:
831 case LDNS_RR_TYPE_KX:
832 case LDNS_RR_TYPE_MX:
833 case LDNS_RR_TYPE_SIG:
834 /* RRSIG signer name has to be downcased */
835 case LDNS_RR_TYPE_RRSIG:
836 case LDNS_RR_TYPE_PX:
837 case LDNS_RR_TYPE_NAPTR:
838 case LDNS_RR_TYPE_SRV:
839 desc = sldns_rr_descript(type);
841 /* this holds for the types that need canonicalizing */
842 log_assert(desc->_minimum == desc->_maximum);
843 return canonical_compare_byfield(d, desc, i, j);
845 case LDNS_RR_TYPE_HINFO: /* no longer downcased */
846 case LDNS_RR_TYPE_NSEC:
848 /* For unknown RR types, or types not listed above,
849 * no canonicalization is needed, do binary compare */
850 /* byte for byte compare, equal means shortest first*/
851 minlen = d->rr_len[i]-2;
852 if(minlen > d->rr_len[j]-2)
853 minlen = d->rr_len[j]-2;
854 c = memcmp(d->rr_data[i]+2, d->rr_data[j]+2, minlen);
857 /* rdata equal, shortest is first */
858 if(d->rr_len[i] < d->rr_len[j])
860 if(d->rr_len[i] > d->rr_len[j])
862 /* rdata equal, length equal */
869 canonical_tree_compare(const void* k1, const void* k2)
871 struct canon_rr* r1 = (struct canon_rr*)k1;
872 struct canon_rr* r2 = (struct canon_rr*)k2;
873 log_assert(r1->rrset == r2->rrset);
874 return canonical_compare(r1->rrset, r1->rr_idx, r2->rr_idx);
878 * Sort RRs for rrset in canonical order.
879 * Does not actually canonicalize the RR rdatas.
880 * Does not touch rrsigs.
881 * @param rrset: to sort.
882 * @param d: rrset data.
883 * @param sortree: tree to sort into.
884 * @param rrs: rr storage.
887 canonical_sort(struct ub_packed_rrset_key* rrset, struct packed_rrset_data* d,
888 rbtree_type* sortree, struct canon_rr* rrs)
891 /* insert into rbtree to sort and detect duplicates */
892 for(i=0; i<d->count; i++) {
893 rrs[i].node.key = &rrs[i];
894 rrs[i].rrset = rrset;
896 if(!rbtree_insert(sortree, &rrs[i].node)) {
897 /* this was a duplicate */
903 * Inser canonical owner name into buffer.
904 * @param buf: buffer to insert into at current position.
905 * @param k: rrset with its owner name.
906 * @param sig: signature with signer name and label count.
907 * must be length checked, at least 18 bytes long.
908 * @param can_owner: position in buffer returned for future use.
909 * @param can_owner_len: length of canonical owner name.
912 insert_can_owner(sldns_buffer* buf, struct ub_packed_rrset_key* k,
913 uint8_t* sig, uint8_t** can_owner, size_t* can_owner_len)
915 int rrsig_labels = (int)sig[3];
916 int fqdn_labels = dname_signame_label_count(k->rk.dname);
917 *can_owner = sldns_buffer_current(buf);
918 if(rrsig_labels == fqdn_labels) {
920 sldns_buffer_write(buf, k->rk.dname, k->rk.dname_len);
921 query_dname_tolower(*can_owner);
922 *can_owner_len = k->rk.dname_len;
925 log_assert(rrsig_labels < fqdn_labels);
926 /* *. | fqdn(rightmost rrsig_labels) */
927 if(rrsig_labels < fqdn_labels) {
929 uint8_t* nm = k->rk.dname;
930 size_t len = k->rk.dname_len;
931 /* so skip fqdn_labels-rrsig_labels */
932 for(i=0; i<fqdn_labels-rrsig_labels; i++) {
933 dname_remove_label(&nm, &len);
935 *can_owner_len = len+2;
936 sldns_buffer_write(buf, (uint8_t*)"\001*", 2);
937 sldns_buffer_write(buf, nm, len);
938 query_dname_tolower(*can_owner);
943 * Canonicalize Rdata in buffer.
944 * @param buf: buffer at position just after the rdata.
945 * @param rrset: rrset with type.
946 * @param len: length of the rdata (including rdatalen uint16).
949 canonicalize_rdata(sldns_buffer* buf, struct ub_packed_rrset_key* rrset,
952 uint8_t* datstart = sldns_buffer_current(buf)-len+2;
953 switch(ntohs(rrset->rk.type)) {
954 case LDNS_RR_TYPE_NXT:
955 case LDNS_RR_TYPE_NS:
956 case LDNS_RR_TYPE_MD:
957 case LDNS_RR_TYPE_MF:
958 case LDNS_RR_TYPE_CNAME:
959 case LDNS_RR_TYPE_MB:
960 case LDNS_RR_TYPE_MG:
961 case LDNS_RR_TYPE_MR:
962 case LDNS_RR_TYPE_PTR:
963 case LDNS_RR_TYPE_DNAME:
964 /* type only has a single argument, the name */
965 query_dname_tolower(datstart);
967 case LDNS_RR_TYPE_MINFO:
968 case LDNS_RR_TYPE_RP:
969 case LDNS_RR_TYPE_SOA:
970 /* two names after another */
971 query_dname_tolower(datstart);
972 query_dname_tolower(datstart +
973 dname_valid(datstart, len-2));
975 case LDNS_RR_TYPE_RT:
976 case LDNS_RR_TYPE_AFSDB:
977 case LDNS_RR_TYPE_KX:
978 case LDNS_RR_TYPE_MX:
979 /* skip fixed part */
980 if(len < 2+2+1) /* rdlen, skiplen, 1byteroot */
983 query_dname_tolower(datstart);
985 case LDNS_RR_TYPE_SIG:
986 /* downcase the RRSIG, compat with BIND (kept it from SIG) */
987 case LDNS_RR_TYPE_RRSIG:
988 /* skip fixed part */
992 query_dname_tolower(datstart);
994 case LDNS_RR_TYPE_PX:
995 /* skip, then two names after another */
999 query_dname_tolower(datstart);
1000 query_dname_tolower(datstart +
1001 dname_valid(datstart, len-2-2));
1003 case LDNS_RR_TYPE_NAPTR:
1008 if(len < (size_t)datstart[0]+1) /* skip text field */
1010 len -= (size_t)datstart[0]+1;
1011 datstart += (size_t)datstart[0]+1;
1012 if(len < (size_t)datstart[0]+1) /* skip text field */
1014 len -= (size_t)datstart[0]+1;
1015 datstart += (size_t)datstart[0]+1;
1016 if(len < (size_t)datstart[0]+1) /* skip text field */
1018 len -= (size_t)datstart[0]+1;
1019 datstart += (size_t)datstart[0]+1;
1020 if(len < 1) /* check name is at least 1 byte*/
1022 query_dname_tolower(datstart);
1024 case LDNS_RR_TYPE_SRV:
1025 /* skip fixed part */
1029 query_dname_tolower(datstart);
1032 /* do not canonicalize NSEC rdata name, compat with
1033 * from bind 9.4 signer, where it does not do so */
1034 case LDNS_RR_TYPE_NSEC: /* type starts with the name */
1035 case LDNS_RR_TYPE_HINFO: /* not downcased */
1036 /* A6 not supported */
1038 /* nothing to do for unknown types */
1043 int rrset_canonical_equal(struct regional* region,
1044 struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2)
1046 struct rbtree_type sortree1, sortree2;
1047 struct canon_rr *rrs1, *rrs2, *p1, *p2;
1048 struct packed_rrset_data* d1=(struct packed_rrset_data*)k1->entry.data;
1049 struct packed_rrset_data* d2=(struct packed_rrset_data*)k2->entry.data;
1050 struct ub_packed_rrset_key fk;
1051 struct packed_rrset_data fd;
1056 if(k1->rk.dname_len != k2->rk.dname_len ||
1057 k1->rk.flags != k2->rk.flags ||
1058 k1->rk.type != k2->rk.type ||
1059 k1->rk.rrset_class != k2->rk.rrset_class ||
1060 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0)
1062 if(d1->ttl != d2->ttl ||
1063 d1->count != d2->count ||
1064 d1->rrsig_count != d2->rrsig_count ||
1065 d1->trust != d2->trust ||
1066 d1->security != d2->security)
1070 memset(&fk, 0, sizeof(fk));
1071 memset(&fd, 0, sizeof(fd));
1072 fk.entry.data = &fd;
1076 rbtree_init(&sortree1, &canonical_tree_compare);
1077 rbtree_init(&sortree2, &canonical_tree_compare);
1078 if(d1->count > RR_COUNT_MAX || d2->count > RR_COUNT_MAX)
1079 return 1; /* protection against integer overflow */
1080 rrs1 = regional_alloc(region, sizeof(struct canon_rr)*d1->count);
1081 rrs2 = regional_alloc(region, sizeof(struct canon_rr)*d2->count);
1082 if(!rrs1 || !rrs2) return 1; /* alloc failure */
1085 canonical_sort(k1, d1, &sortree1, rrs1);
1086 canonical_sort(k2, d2, &sortree2, rrs2);
1088 /* compare canonical-sorted RRs for canonical-equality */
1089 if(sortree1.count != sortree2.count)
1091 p1 = (struct canon_rr*)rbtree_first(&sortree1);
1092 p2 = (struct canon_rr*)rbtree_first(&sortree2);
1093 while(p1 != (struct canon_rr*)RBTREE_NULL &&
1094 p2 != (struct canon_rr*)RBTREE_NULL) {
1095 flen[0] = d1->rr_len[p1->rr_idx];
1096 flen[1] = d2->rr_len[p2->rr_idx];
1097 fdata[0] = d1->rr_data[p1->rr_idx];
1098 fdata[1] = d2->rr_data[p2->rr_idx];
1100 if(canonical_compare(&fk, 0, 1) != 0)
1102 p1 = (struct canon_rr*)rbtree_next(&p1->node);
1103 p2 = (struct canon_rr*)rbtree_next(&p2->node);
1109 * Create canonical form of rrset in the scratch buffer.
1110 * @param region: temporary region.
1111 * @param buf: the buffer to use.
1112 * @param k: the rrset to insert.
1113 * @param sig: RRSIG rdata to include.
1114 * @param siglen: RRSIG rdata len excluding signature field, but inclusive
1115 * signer name length.
1116 * @param sortree: if NULL is passed a new sorted rrset tree is built.
1117 * Otherwise it is reused.
1118 * @return false on alloc error.
1121 rrset_canonical(struct regional* region, sldns_buffer* buf,
1122 struct ub_packed_rrset_key* k, uint8_t* sig, size_t siglen,
1123 struct rbtree_type** sortree)
1125 struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data;
1126 uint8_t* can_owner = NULL;
1127 size_t can_owner_len = 0;
1128 struct canon_rr* walk;
1129 struct canon_rr* rrs;
1132 *sortree = (struct rbtree_type*)regional_alloc(region,
1133 sizeof(rbtree_type));
1136 if(d->count > RR_COUNT_MAX)
1137 return 0; /* integer overflow protection */
1138 rrs = regional_alloc(region, sizeof(struct canon_rr)*d->count);
1143 rbtree_init(*sortree, &canonical_tree_compare);
1144 canonical_sort(k, d, *sortree, rrs);
1147 sldns_buffer_clear(buf);
1148 sldns_buffer_write(buf, sig, siglen);
1149 /* canonicalize signer name */
1150 query_dname_tolower(sldns_buffer_begin(buf)+18);
1151 RBTREE_FOR(walk, struct canon_rr*, (*sortree)) {
1152 /* see if there is enough space left in the buffer */
1153 if(sldns_buffer_remaining(buf) < can_owner_len + 2 + 2 + 4
1154 + d->rr_len[walk->rr_idx]) {
1155 log_err("verify: failed to canonicalize, "
1159 /* determine canonical owner name */
1161 sldns_buffer_write(buf, can_owner, can_owner_len);
1162 else insert_can_owner(buf, k, sig, &can_owner,
1164 sldns_buffer_write(buf, &k->rk.type, 2);
1165 sldns_buffer_write(buf, &k->rk.rrset_class, 2);
1166 sldns_buffer_write(buf, sig+4, 4);
1167 sldns_buffer_write(buf, d->rr_data[walk->rr_idx],
1168 d->rr_len[walk->rr_idx]);
1169 canonicalize_rdata(buf, k, d->rr_len[walk->rr_idx]);
1171 sldns_buffer_flip(buf);
1175 /** pretty print rrsig error with dates */
1177 sigdate_error(const char* str, int32_t expi, int32_t incep, int32_t now)
1185 if(verbosity < VERB_QUERY)
1190 memset(&tm, 0, sizeof(tm));
1191 if(gmtime_r(&te, &tm) && strftime(expi_buf, 15, "%Y%m%d%H%M%S", &tm)
1192 &&gmtime_r(&ti, &tm) && strftime(incep_buf, 15, "%Y%m%d%H%M%S", &tm)
1193 &&gmtime_r(&tn, &tm) && strftime(now_buf, 15, "%Y%m%d%H%M%S", &tm)) {
1194 log_info("%s expi=%s incep=%s now=%s", str, expi_buf,
1195 incep_buf, now_buf);
1197 log_info("%s expi=%u incep=%u now=%u", str, (unsigned)expi,
1198 (unsigned)incep, (unsigned)now);
1201 /** check rrsig dates */
1203 check_dates(struct val_env* ve, uint32_t unow,
1204 uint8_t* expi_p, uint8_t* incep_p, char** reason)
1206 /* read out the dates */
1207 int32_t expi, incep, now;
1208 memmove(&expi, expi_p, sizeof(expi));
1209 memmove(&incep, incep_p, sizeof(incep));
1211 incep = ntohl(incep);
1213 /* get current date */
1214 if(ve->date_override) {
1215 if(ve->date_override == -1) {
1216 verbose(VERB_ALGO, "date override: ignore date");
1219 now = ve->date_override;
1220 verbose(VERB_ALGO, "date override option %d", (int)now);
1221 } else now = (int32_t)unow;
1224 if(incep - expi > 0) {
1225 sigdate_error("verify: inception after expiration, "
1226 "signature bad", expi, incep, now);
1227 *reason = "signature inception after expiration";
1230 if(incep - now > 0) {
1231 /* within skew ? (calc here to avoid calculation normally) */
1232 int32_t skew = (expi-incep)/10;
1233 if(skew < ve->skew_min) skew = ve->skew_min;
1234 if(skew > ve->skew_max) skew = ve->skew_max;
1235 if(incep - now > skew) {
1236 sigdate_error("verify: signature bad, current time is"
1237 " before inception date", expi, incep, now);
1238 *reason = "signature before inception date";
1241 sigdate_error("verify warning suspicious signature inception "
1242 " or bad local clock", expi, incep, now);
1244 if(now - expi > 0) {
1245 int32_t skew = (expi-incep)/10;
1246 if(skew < ve->skew_min) skew = ve->skew_min;
1247 if(skew > ve->skew_max) skew = ve->skew_max;
1248 if(now - expi > skew) {
1249 sigdate_error("verify: signature expired", expi,
1251 *reason = "signature expired";
1254 sigdate_error("verify warning suspicious signature expiration "
1255 " or bad local clock", expi, incep, now);
1260 /** adjust rrset TTL for verified rrset, compare to original TTL and expi */
1262 adjust_ttl(struct val_env* ve, uint32_t unow,
1263 struct ub_packed_rrset_key* rrset, uint8_t* orig_p,
1264 uint8_t* expi_p, uint8_t* incep_p)
1266 struct packed_rrset_data* d =
1267 (struct packed_rrset_data*)rrset->entry.data;
1268 /* read out the dates */
1269 int32_t origttl, expittl, expi, incep, now;
1270 memmove(&origttl, orig_p, sizeof(origttl));
1271 memmove(&expi, expi_p, sizeof(expi));
1272 memmove(&incep, incep_p, sizeof(incep));
1274 incep = ntohl(incep);
1275 origttl = ntohl(origttl);
1277 /* get current date */
1278 if(ve->date_override) {
1279 now = ve->date_override;
1280 } else now = (int32_t)unow;
1281 expittl = expi - now;
1284 * d->ttl: rrset ttl read from message or cache. May be reduced
1285 * origttl: original TTL from signature, authoritative TTL max.
1286 * MIN_TTL: minimum TTL from config.
1287 * expittl: TTL until the signature expires.
1289 * Use the smallest of these, but don't let origttl set the TTL
1290 * below the minimum.
1292 if(MIN_TTL > (time_t)origttl && d->ttl > MIN_TTL) {
1293 verbose(VERB_QUERY, "rrset TTL larger than original and minimum"
1294 " TTL, adjusting TTL downwards to minimum ttl");
1297 else if(MIN_TTL <= origttl && d->ttl > (time_t)origttl) {
1298 verbose(VERB_QUERY, "rrset TTL larger than original TTL, "
1299 "adjusting TTL downwards to original ttl");
1303 if(expittl > 0 && d->ttl > (time_t)expittl) {
1304 verbose(VERB_ALGO, "rrset TTL larger than sig expiration ttl,"
1305 " adjusting TTL downwards");
1311 dnskey_verify_rrset_sig(struct regional* region, sldns_buffer* buf,
1312 struct val_env* ve, time_t now,
1313 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
1314 size_t dnskey_idx, size_t sig_idx,
1315 struct rbtree_type** sortree, int* buf_canon, char** reason)
1317 enum sec_status sec;
1318 uint8_t* sig; /* RRSIG rdata */
1320 size_t rrnum = rrset_get_count(rrset);
1321 uint8_t* signer; /* rrsig signer name */
1323 unsigned char* sigblock; /* signature rdata field */
1324 unsigned int sigblock_len;
1325 uint16_t ktag; /* DNSKEY key tag */
1326 unsigned char* key; /* public key rdata field */
1327 unsigned int keylen;
1328 rrset_get_rdata(rrset, rrnum + sig_idx, &sig, &siglen);
1329 /* min length of rdatalen, fixed rrsig, root signer, 1 byte sig */
1331 verbose(VERB_QUERY, "verify: signature too short");
1332 *reason = "signature too short";
1333 return sec_status_bogus;
1336 if(!(dnskey_get_flags(dnskey, dnskey_idx) & DNSKEY_BIT_ZSK)) {
1337 verbose(VERB_QUERY, "verify: dnskey without ZSK flag");
1338 *reason = "dnskey without ZSK flag";
1339 return sec_status_bogus;
1342 if(dnskey_get_protocol(dnskey, dnskey_idx) != LDNS_DNSSEC_KEYPROTO) {
1343 /* RFC 4034 says DNSKEY PROTOCOL MUST be 3 */
1344 verbose(VERB_QUERY, "verify: dnskey has wrong key protocol");
1345 *reason = "dnskey has wrong protocolnumber";
1346 return sec_status_bogus;
1349 /* verify as many fields in rrsig as possible */
1351 signer_len = dname_valid(signer, siglen-2-18);
1353 verbose(VERB_QUERY, "verify: malformed signer name");
1354 *reason = "signer name malformed";
1355 return sec_status_bogus; /* signer name invalid */
1357 if(!dname_subdomain_c(rrset->rk.dname, signer)) {
1358 verbose(VERB_QUERY, "verify: signer name is off-tree");
1359 *reason = "signer name off-tree";
1360 return sec_status_bogus; /* signer name offtree */
1362 sigblock = (unsigned char*)signer+signer_len;
1363 if(siglen < 2+18+signer_len+1) {
1364 verbose(VERB_QUERY, "verify: too short, no signature data");
1365 *reason = "signature too short, no signature data";
1366 return sec_status_bogus; /* sig rdf is < 1 byte */
1368 sigblock_len = (unsigned int)(siglen - 2 - 18 - signer_len);
1370 /* verify key dname == sig signer name */
1371 if(query_dname_compare(signer, dnskey->rk.dname) != 0) {
1372 verbose(VERB_QUERY, "verify: wrong key for rrsig");
1373 log_nametypeclass(VERB_QUERY, "RRSIG signername is",
1375 log_nametypeclass(VERB_QUERY, "the key name is",
1376 dnskey->rk.dname, 0, 0);
1377 *reason = "signer name mismatches key name";
1378 return sec_status_bogus;
1381 /* verify covered type */
1382 /* memcmp works because type is in network format for rrset */
1383 if(memcmp(sig+2, &rrset->rk.type, 2) != 0) {
1384 verbose(VERB_QUERY, "verify: wrong type covered");
1385 *reason = "signature covers wrong type";
1386 return sec_status_bogus;
1388 /* verify keytag and sig algo (possibly again) */
1389 if((int)sig[2+2] != dnskey_get_algo(dnskey, dnskey_idx)) {
1390 verbose(VERB_QUERY, "verify: wrong algorithm");
1391 *reason = "signature has wrong algorithm";
1392 return sec_status_bogus;
1394 ktag = htons(dnskey_calc_keytag(dnskey, dnskey_idx));
1395 if(memcmp(sig+2+16, &ktag, 2) != 0) {
1396 verbose(VERB_QUERY, "verify: wrong keytag");
1397 *reason = "signature has wrong keytag";
1398 return sec_status_bogus;
1401 /* verify labels is in a valid range */
1402 if((int)sig[2+3] > dname_signame_label_count(rrset->rk.dname)) {
1403 verbose(VERB_QUERY, "verify: labelcount out of range");
1404 *reason = "signature labelcount out of range";
1405 return sec_status_bogus;
1408 /* original ttl, always ok */
1411 /* create rrset canonical format in buffer, ready for
1413 if(!rrset_canonical(region, buf, rrset, sig+2,
1414 18 + signer_len, sortree)) {
1415 log_err("verify: failed due to alloc error");
1416 return sec_status_unchecked;
1421 /* check that dnskey is available */
1422 dnskey_get_pubkey(dnskey, dnskey_idx, &key, &keylen);
1424 verbose(VERB_QUERY, "verify: short DNSKEY RR");
1425 return sec_status_unchecked;
1429 sec = verify_canonrrset(buf, (int)sig[2+2],
1430 sigblock, sigblock_len, key, keylen, reason);
1432 if(sec == sec_status_secure) {
1433 /* check if TTL is too high - reduce if so */
1434 adjust_ttl(ve, now, rrset, sig+2+4, sig+2+8, sig+2+12);
1436 /* verify inception, expiration dates
1437 * Do this last so that if you ignore expired-sigs the
1438 * rest is sure to be OK. */
1439 if(!check_dates(ve, now, sig+2+8, sig+2+12, reason)) {
1440 return sec_status_bogus;