Revert "[9.18] fix: usr: Fix NSEC3 closest encloser lookup for names with empty non-terminals"

This reverts merge request !9632

bin/tests/system/dnssec/tests.sh

@@ -4468,35 +4468,5 @@ n=$((n + 1))
 if [ "$ret" -ne 0 ]; then echo_i "failed"; fi
 status=$((status + ret))
 
-echo_i "checking NSEC3 nxdomain response closest encloser with 0 ENT ($n)"
-ret=0
-dig_with_opts @10.53.0.3 b.b.b.b.b.a.nsec3.example. >dig.out.ns3.test$n
-grep "status: NXDOMAIN" dig.out.ns3.test$n >/dev/null || ret=1
-pat="^6OVDUHTN094ML2PV8AN90U0DPU823GH2\.nsec3.example\..*NSEC3 1 0 0 - 7AT0S0RIDCJRFF2M5H5AAV22CSFJBUL4 A RRSIG\$"
-grep "$pat" dig.out.ns3.test$n >/dev/null || ret=1
-n=$((n + 1))
-if [ "$ret" -ne 0 ]; then echo_i "failed"; fi
-status=$((status + ret))
-
-echo_i "checking NSEC3 nxdomain response closest encloser with 1 ENTs ($n)"
-ret=0
-dig_with_opts @10.53.0.3 b.b.b.b.b.a.a.nsec3.example. >dig.out.ns3.test$n
-grep "status: NXDOMAIN" dig.out.ns3.test$n >/dev/null || ret=1
-pat="^NGCJFSOLJUUE27PFNQNJIME4TQ0OU2DH\.nsec3.example\..*NSEC3 1 0 0 - R8EVDMNIGNOKME4LH2H90OSP2PRSNJ1Q\$"
-grep "$pat" dig.out.ns3.test$n >/dev/null || ret=1
-n=$((n + 1))
-if [ "$ret" -ne 0 ]; then echo_i "failed"; fi
-status=$((status + ret))
-
-echo_i "checking NSEC3 nxdomain response closest encloser with 2 ENTs ($n)"
-ret=0
-dig_with_opts @10.53.0.3 b.b.b.b.b.a.a.a.nsec3.example. >dig.out.ns3.test$n
-grep "status: NXDOMAIN" dig.out.ns3.test$n >/dev/null || ret=1
-pat="^H7RHPDCHSVVRAND332F878C8AB6IBJQV\.nsec3.example\..*NSEC3 1 0 0 - K8IG76R2UPQ13IKFO49L7IB9JRVB6QJI\$"
-grep "$pat" dig.out.ns3.test$n >/dev/null || ret=1
-n=$((n + 1))
-if [ "$ret" -ne 0 ]; then echo_i "failed"; fi
-status=$((status + ret))
-
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1

lib/ns/query.c

@@ -11565,33 +11565,24 @@ again:
 		 * No NSEC proof available, return NSEC3 proofs instead.
 		 */
 		cname = dns_fixedname_initname(&cfixed);
-
 		/*
-		 * Find the closest encloser using a binary search.
-		 * maxlabels: suffix length of NXDOMAIN result
-		 * minlabels: suffix length of non NXDOMAIN result
+		 * Find the closest encloser.
 		 */
-		unsigned int maxlabels = dns_name_countlabels(name);
-		unsigned int minlabels = dns_name_countlabels(fname);
-		bool search = result == DNS_R_NXDOMAIN;
 		dns_name_copy(name, cname);
-		while (search) {
-			labels = (maxlabels + minlabels) / 2;
-			dns_name_split(name, labels, NULL, cname);
-			if (labels == minlabels) {
-				break;
+		while (result == DNS_R_NXDOMAIN) {
+			labels = dns_name_countlabels(cname) - 1;
+			/*
+			 * Sanity check.
+			 */
+			if (labels == 0U) {
+				goto cleanup;
 			}
+			dns_name_split(cname, labels, NULL, cname);
 			result = dns_db_findext(qctx->db, cname, qctx->version,
 						dns_rdatatype_nsec, options, 0,
 						NULL, fname, &cm, &ci, NULL,
 						NULL);
-			if (result == DNS_R_NXDOMAIN) {
-				maxlabels = labels;
-			} else {
-				minlabels = labels;
-			}
 		}
-
 		/*
 		 * Add closest (provable) encloser NSEC3.
 		 */