[v9_9] fix incorrect nsec3 check

- check for NSEC3 in empty nodes when not due to optout delegations - fixed typo in output ("Bad record NSEC record") - incidentally fixed an error in signzone that caused an incorrect warning about missing DNSKEYs when using -S and -3 together 3473. [bug] dnssec-signzone/verify could incorrectly report an error condition due to an empty node above an opt-out delegation lacking an NSEC3. [RT #32072] (cherry picked from commit 9a0dd99a75)
2026-06-11 16:30:01 -04:00 · 2013-01-23 14:57:18 -08:00 · 2013-01-23 14:57:18 -08:00 · bf9d2fd260
commit bf9d2fd260
parent d2c5763ef4
6 changed files with 149 additions and 43 deletions
--- a/4
+++ b/4
@ -1,3 +1,7 @@
+3473.	[bug]		dnssec-signzone/verify could incorrectly report
+			an error condition due to an empty node above an
+			opt-out delegation lacking an NSEC3. [RT #32072]
+
 3471.	[bug]		The number of UDP dispatches now defaults to
 			the number of CPUs even if -n has been set to
 			a higher value. [RT #30964]
--- a/bin/dnssec/dnssec-signzone.c
+++ b/bin/dnssec/dnssec-signzone.c
@ -2329,7 +2329,7 @@ nsec3ify(unsigned int hashalg, unsigned int iterations,
 				continue;
 			}
 			if (is_delegation(gdb, gversion, gorigin,
-							  nextname, nextnode, NULL))
+					  nextname, nextnode, NULL))
 			{
 				zonecut = dns_fixedname_name(&fzonecut);
 				dns_name_copy(nextname, zonecut, NULL);
@ -3481,23 +3481,6 @@ main(int argc, char *argv[]) {
 	else
 		set_nsec3params(update_chain, set_salt, set_optout, set_iter);

-	if (IS_NSEC3) {
-		isc_boolean_t answer;
-		hash_length = dns_nsec3_hashlength(dns_hash_sha1);
-		hashlist_init(&hashlist, dns_db_nodecount(gdb) * 2,
-			      hash_length);
-		result = dns_nsec_nseconly(gdb, gversion, &answer);
-		if (result == ISC_R_NOTFOUND)
-			fprintf(stderr, "%s: warning: NSEC3 generation "
-				"requested with no DNSKEY; ignoring\n",
-				program);
-		else if (result != ISC_R_SUCCESS)
-			check_result(result, "dns_nsec_nseconly");
-		else if (answer)
-			fatal("NSEC3 generation requested with "
-			      "NSEC-only DNSKEY");
-	}
-
 	/*
 	 * We need to do this early on, as we start messing with the list
 	 * of keys rather early.
@ -3550,6 +3533,22 @@ main(int argc, char *argv[]) {

 	if (IS_NSEC3) {
 		unsigned int max;
+		isc_boolean_t answer;
+
+		hash_length = dns_nsec3_hashlength(dns_hash_sha1);
+		hashlist_init(&hashlist, dns_db_nodecount(gdb) * 2,
+			      hash_length);
+		result = dns_nsec_nseconly(gdb, gversion, &answer);
+		if (result == ISC_R_NOTFOUND)
+			fprintf(stderr, "%s: warning: NSEC3 generation "
+				"requested with no DNSKEY; ignoring\n",
+				program);
+		else if (result != ISC_R_SUCCESS)
+			check_result(result, "dns_nsec_nseconly");
+		else if (answer)
+			fatal("NSEC3 generation requested with "
+			      "NSEC-only DNSKEY");
+
 		result = dns_nsec3_maxiterations(gdb, NULL, mctx, &max);
 		check_result(result, "dns_nsec3_maxiterations()");
 		if (nsec3iter > max)
--- a/bin/dnssec/dnssectool.c
+++ b/bin/dnssec/dnssectool.c
@ -583,7 +583,7 @@ verifynsec(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
 		dns_name_format(name, namebuf, sizeof(namebuf));
 		dns_name_format(nextname, nextbuf, sizeof(nextbuf));
 		dns_name_format(&nsec.next, found, sizeof(found));
-		fprintf(stderr, "Bad record NSEC record for %s, next name "
+		fprintf(stderr, "Bad NSEC record for %s, next name "
 				"mismatch (expected:%s, found:%s)\n", namebuf,
 				nextbuf, found);
 		goto failure;
@ -594,7 +594,7 @@ verifynsec(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
 	check_result(result, "dns_nsec_buildrdata()");
 	if (dns_rdata_compare(&rdata, &tmprdata) != 0) {
 		dns_name_format(name, namebuf, sizeof(namebuf));
-		fprintf(stderr, "Bad record NSEC record for %s, bit map "
+		fprintf(stderr, "Bad NSEC record for %s, bit map "
 				"mismatch\n", namebuf);
 		goto failure;
 	}
@ -770,7 +770,7 @@ match_nsec3(dns_name_t *name, isc_mem_t *mctx,
 	len = dns_nsec_compressbitmap(cbm, types, maxtype);
 	if (nsec3.len != len || memcmp(cbm, nsec3.typebits, len) != 0) {
 		dns_name_format(name, namebuf, sizeof(namebuf));
-		fprintf(stderr, "Bad record NSEC3 record for %s, bit map "
+		fprintf(stderr, "Bad NSEC3 record for %s, bit map "
 				"mismatch\n", namebuf);
 		return (ISC_R_FAILURE);
 	}
@ -891,11 +891,64 @@ record_found(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx,
 	return (ISC_R_SUCCESS);
 }

+static isc_boolean_t
+isoptout(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
+	 dns_rdata_t *nsec3rdata)
+{
+	dns_rdataset_t rdataset;
+	dns_rdata_t rdata = DNS_RDATA_INIT;
+	dns_rdata_nsec3_t nsec3;
+	dns_rdata_nsec3param_t nsec3param;
+	dns_fixedname_t fixed;
+	dns_name_t *hashname;
+	isc_result_t result;
+	dns_dbnode_t *node = NULL;
+	unsigned char rawhash[NSEC3_MAX_HASH_LENGTH];
+	size_t rhsize = sizeof(rawhash);
+	isc_boolean_t ret;
+
+	result = dns_rdata_tostruct(nsec3rdata, &nsec3param, NULL);
+	check_result(result, "dns_rdata_tostruct()");
+
+	dns_fixedname_init(&fixed);
+	result = dns_nsec3_hashname(&fixed, rawhash, &rhsize, origin, origin,
+				    nsec3param.hash, nsec3param.iterations,
+				    nsec3param.salt, nsec3param.salt_length);
+	check_result(result, "dns_nsec3_hashname()");
+
+	dns_rdataset_init(&rdataset);
+	hashname = dns_fixedname_name(&fixed);
+	result = dns_db_findnsec3node(db, hashname, ISC_FALSE, &node);
+	if (result == ISC_R_SUCCESS)
+		result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3,
+					     0, 0, &rdataset, NULL);
+	if (result != ISC_R_SUCCESS)
+		return (ISC_FALSE);
+
+	result = dns_rdataset_first(&rdataset);
+	check_result(result, "dns_rdataset_first()");
+
+	dns_rdataset_current(&rdataset, &rdata);
+
+	result = dns_rdata_tostruct(&rdata, &nsec3, NULL);
+	if (result != ISC_R_SUCCESS)
+		ret = ISC_FALSE;
+	else
+		ret = ISC_TF((nsec3.flags & DNS_NSEC3FLAG_OPTOUT) != 0);
+
+	if (dns_rdataset_isassociated(&rdataset))
+		dns_rdataset_disassociate(&rdataset);
+	if (node != NULL)
+		dns_db_detachnode(db, &node);
+
+	return (ret);
+}
+
 static isc_result_t
 verifynsec3(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 	    isc_mem_t *mctx, dns_name_t *name, dns_rdata_t *rdata,
-	    isc_boolean_t delegation, unsigned char types[8192],
-	    unsigned int maxtype)
+	    isc_boolean_t delegation, isc_boolean_t empty,
+	    unsigned char types[8192], unsigned int maxtype)
 {
 	char namebuf[DNS_NAME_FORMATSIZE];
 	char hashbuf[DNS_NAME_FORMATSIZE];
@ -907,6 +960,7 @@ verifynsec3(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 	dns_dbnode_t *node = NULL;
 	unsigned char rawhash[NSEC3_MAX_HASH_LENGTH];
 	size_t rhsize = sizeof(rawhash);
+	isc_boolean_t optout;

 	result = dns_rdata_tostruct(rdata, &nsec3param, NULL);
 	check_result(result, "dns_rdata_tostruct()");
@ -917,6 +971,8 @@ verifynsec3(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 	if (!dns_nsec3_supportedhash(nsec3param.hash))
 		return (ISC_R_SUCCESS);

+	optout = isoptout(db, ver, origin, rdata);
+
 	dns_fixedname_init(&fixed);
 	result = dns_nsec3_hashname(&fixed, rawhash, &rhsize, name, origin,
 				    nsec3param.hash, nsec3param.iterations,
@ -936,16 +992,22 @@ verifynsec3(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 		result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3,
 					     0, 0, &rdataset, NULL);
 	if (result != ISC_R_SUCCESS &&
-	    (!delegation || dns_nsec_isset(types, dns_rdatatype_ds))) {
+	    (!delegation || (empty && !optout) ||
+	     (!empty && dns_nsec_isset(types, dns_rdatatype_ds))))
+	{
 		dns_name_format(name, namebuf, sizeof(namebuf));
 		dns_name_format(hashname, hashbuf, sizeof(hashbuf));
 		fprintf(stderr, "Missing NSEC3 record for %s (%s)\n",
 			namebuf, hashbuf);
+	} else if (result == ISC_R_NOTFOUND &&
+		   delegation && (!empty || optout))
+	{
+		result = ISC_R_SUCCESS;
 	} else if (result == ISC_R_SUCCESS) {
 		result = match_nsec3(name, mctx, &nsec3param, &rdataset,
 				     types, maxtype, rawhash, rhsize);
-	} else if (result == ISC_R_NOTFOUND && delegation)
-		result = ISC_R_SUCCESS;
+	}
+
 	if (dns_rdataset_isassociated(&rdataset))
 		dns_rdataset_disassociate(&rdataset);
 	if (node != NULL)
@ -957,8 +1019,8 @@ verifynsec3(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 static isc_result_t
 verifynsec3s(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 	     isc_mem_t *mctx, dns_name_t *name, dns_rdataset_t *nsec3paramset,
-	     isc_boolean_t delegation, unsigned char types[8192],
-	     unsigned int maxtype)
+	     isc_boolean_t delegation, isc_boolean_t empty,
+	     unsigned char types[8192], unsigned int maxtype)
 {
 	isc_result_t result;

@ -969,7 +1031,7 @@ verifynsec3s(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,

 		dns_rdataset_current(nsec3paramset, &rdata);
 		result = verifynsec3(db, ver, origin, mctx, name, &rdata,
-				     delegation, types, maxtype);
+				     delegation, empty, types, maxtype);
 		if (result != ISC_R_SUCCESS)
 			break;
 	}
@ -1114,8 +1176,8 @@ verifynode(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,

 	if (nsec3paramset != NULL && dns_rdataset_isassociated(nsec3paramset)) {
 		tresult = verifynsec3s(db, ver, origin, mctx, name,
-				       nsec3paramset, delegation, types,
-				       maxtype);
+				       nsec3paramset, delegation, ISC_FALSE,
+				       types, maxtype);
 		if (result == ISC_R_SUCCESS && tresult != ISC_R_SUCCESS)
 			result = tresult;
 	}
@ -1304,8 +1366,8 @@ verify_nsec3_chains(isc_mem_t *mctx) {

 static isc_result_t
 verifyemptynodes(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
-		 isc_mem_t *mctx, dns_name_t *name, dns_name_t *nextname,
-		 dns_rdataset_t *nsec3paramset)
+		 isc_mem_t *mctx, dns_name_t *name, dns_name_t *prevname,
+		 isc_boolean_t isdelegation, dns_rdataset_t *nsec3paramset)
 {
 	dns_namereln_t reln;
 	int order;
@ -1313,23 +1375,24 @@ verifyemptynodes(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *origin,
 	dns_name_t suffix;
 	isc_result_t result = ISC_R_SUCCESS, tresult;

-	reln = dns_name_fullcompare(name, nextname, &order, &labels);
+	reln = dns_name_fullcompare(prevname, name, &order, &labels);
 	if (order >= 0)
 		return (result);

-	nlabels = dns_name_countlabels(nextname);
+	nlabels = dns_name_countlabels(name);

 	if (reln == dns_namereln_commonancestor ||
 	    reln == dns_namereln_contains) {
 		dns_name_init(&suffix, NULL);
 		for (i = labels + 1; i < nlabels; i++) {
-			dns_name_getlabelsequence(nextname, nlabels - i, i,
+			dns_name_getlabelsequence(name, nlabels - i, i,
 						  &suffix);
 			if (nsec3paramset != NULL &&
 			     dns_rdataset_isassociated(nsec3paramset)) {
 				tresult = verifynsec3s(db, ver, origin, mctx,
 						       &suffix, nsec3paramset,
-						       ISC_FALSE, NULL, 0);
+						       isdelegation, ISC_TRUE,
+						       NULL, 0);
 				if (result == ISC_R_SUCCESS &&
 				    tresult != ISC_R_SUCCESS)
 					result = tresult;
@ -1359,8 +1422,8 @@ verifyzone(dns_db_t *db, dns_dbversion_t *ver,
 	char algbuf[80];
 	dns_dbiterator_t *dbiter = NULL;
 	dns_dbnode_t *node = NULL, *nextnode = NULL;
-	dns_fixedname_t fname, fnextname, fzonecut;
-	dns_name_t *name, *nextname, *zonecut;
+	dns_fixedname_t fname, fnextname, fprevname, fzonecut;
+	dns_name_t *name, *nextname, *prevname, *zonecut;
 	dns_rdata_dnskey_t dnskey;
 	dns_rdata_t rdata = DNS_RDATA_INIT;
 	dns_rdataset_t keyset, soaset;
@ -1572,6 +1635,8 @@ verifyzone(dns_db_t *db, dns_dbversion_t *ver,
 	name = dns_fixedname_name(&fname);
 	dns_fixedname_init(&fnextname);
 	nextname = dns_fixedname_name(&fnextname);
+	dns_fixedname_init(&fprevname);
+	prevname = NULL;
 	dns_fixedname_init(&fzonecut);
 	zonecut = NULL;

@ -1638,8 +1703,13 @@ verifyzone(dns_db_t *db, dns_dbversion_t *ver,
 			vresult = ISC_R_SUCCESS;
 		if (vresult == ISC_R_SUCCESS && result != ISC_R_SUCCESS)
 			vresult = result;
-		result = verifyemptynodes(db, ver, origin, mctx, name,
-					  nextname, &nsec3paramset);
+		if (prevname != NULL) {
+			result = verifyemptynodes(db, ver, origin, mctx, name,
+						  prevname, isdelegation,
+						  &nsec3paramset);
+		} else
+			prevname = dns_fixedname_name(&fprevname);
+		dns_name_copy(name, prevname, NULL);
 		if (vresult == ISC_R_SUCCESS && result != ISC_R_SUCCESS)
 			vresult = result;
 		dns_db_detachnode(db, &node);
--- a/bin/tests/system/dnssec/tests.sh
+++ b/bin/tests/system/dnssec/tests.sh
@ -1050,6 +1050,32 @@ n=`expr $n + 1`
 if [ $ret != 0 ]; then echo "I:failed"; fi
 status=`expr $status + $ret`

+echo "I:checking NSEC3 signing with empty nonterminals above a delegation ($n)"
+ret=0
+zone=example
+key1=`$KEYGEN -K signer -q -r $RANDFILE -a NSEC3RSASHA1 -b 1024 -n zone $zone`
+key2=`$KEYGEN -K signer -q -r $RANDFILE -f KSK -a NSEC3RSASHA1 -b 1024 -n zone $zone`
+(
+cd signer
+cat example.db.in $key1.key $key2.key > example3.db
+echo "some.empty.nonterminal.nodes.example 60 IN NS ns.example.tld" >> example3.db
+$SIGNER -3 - -A -H 10 -o example -f example3.db example3.db > /dev/null 2>&1
+awk '/^IQF9LQTLK/ {
+		printf("%s", $0);
+		while (!index($0, ")")) {
+			if (getline <= 0)
+				break;
+			printf (" %s", $0); 
+		}
+		printf("\n");
+	}' example.db | sed 's/[ 	][ 	]*/ /g' > nsec3param.out
+
+grep "IQF9LQTLKKNFK0KVIFELRAK4IC4QLTMG.example. 0 IN NSEC3 1 0 10 - ( IQF9LQTLKKNFK0KVIFELRAK4IC4QLTMG A NS SOA RRSIG DNSKEY NSEC3PARAM )" nsec3param.out > /dev/null
+) || ret=1
+n=`expr $n + 1`
+if [ $ret != 0 ]; then echo "I:failed"; fi
+status=`expr $status + $ret`
+
 echo "I:checking that dnsssec-signzone updates originalttl on ttl changes ($n)"
 ret=0
 zone=example
--- a/bin/tests/system/verify/tests.sh
+++ b/bin/tests/system/verify/tests.sh
@ -69,7 +69,7 @@ do
 		expect1="unexpected NSEC RRset at"
 		;;
 	*.nsec.broken-chain)
-		expect1="Bad record NSEC record for.*, next name mismatch"
+		expect1="Bad NSEC record for.*, next name mismatch"
 		;;
 	*.bad-bitmap)
 		expect1="bit map mismatch"
--- a/bin/tests/system/verify/zones/genzones.sh
+++ b/bin/tests/system/verify/zones/genzones.sh
@ -170,12 +170,19 @@ $SIGNER -Px -Z nonsecify -O full -o ${zone} -f ${file}.tmp ${file} $zsk > s.out$
 awk '$1 ~ /^ns.sub/ && $4 == "RRSIG" && $5 != "NSEC" { next; } { print; }' ${file}.tmp > ${file}

 # missing NSEC3 record at empty node
+# extract the hash fields from the empty node's NSEC 3 record then fix up
+# the NSEC3 chain to remove it
 setup ksk+zsk.nsec3.missing-empty bad
 zsk=`$KEYGEN -3 -r $RANDFILE ${zone} 2> kg1.out$n` || dumpit kg1.out$n
 ksk=`$KEYGEN -3 -r $RANDFILE -fK ${zone} 2> kg2.out$n` || dumpit kg2.out$n
 cat unsigned.db $ksk.key $zsk.key > $file
 $SIGNER -3 - -P -O full -o ${zone} -f ${file} ${file} $ksk > s.out$n 2>&1 || dumpit s.out$n
-awk '$4 == "NSEC3" && NF == 9 { next; } { print; }' ${file} > ${file}.tmp
+a=`awk '$4 == "NSEC3" && NF == 9 { split($1, a, "."); print a[1]; }' ${file}`
+b=`awk '$4 == "NSEC3" && NF == 9 { print $9; }' ${file}`
+awk '
+$4 == "NSEC3" && $9 == "'$a'" { $9 = "'$b'"; print; next; }
+$4 == "NSEC3" && NF == 9 { next; }
+{ print; }' ${file} > ${file}.tmp
 $SIGNER -3 - -Px -Z nonsecify -O full -o ${zone} -f ${file} ${file}.tmp $zsk > s.out$n 2>&1 || dumpit s.out$n

 # extra NSEC3 record