Enable DNSSEC validation.

Requested by & OK claudio
Input & OK sthen
OK job, solene
Various commenting that they run with validation since a long time
without issues.

src/etc/unbound.conf

@@ -1,4 +1,4 @@
-# $OpenBSD: unbound.conf,v 1.8 2018/03/29 20:40:22 florian Exp $
+# $OpenBSD: unbound.conf,v 1.9 2018/12/07 09:21:08 florian Exp $
 
 server:
 	interface: 127.0.0.1
@@ -24,14 +24,12 @@ server:
 	#
 	#qname-minimisation: yes
 
-	# Uncomment to enable DNSSEC validation.
-	#
-	#auto-trust-anchor-file: "/var/unbound/db/root.key"
+	# Enable DNSSEC validation.
+	auto-trust-anchor-file: "/var/unbound/db/root.key"
+	val-log-level: 2
 
-	# Uncomment to synthesize NXDOMAINs from DNSSEC NSEC chains
-	# https://tools.ietf.org/html/rfc8198
-	#
-	#aggressive-nsec: yes
+	# Synthesize NXDOMAINs from DNSSEC NSEC chains.  RFC 8198
+	aggressive-nsec: yes
 
 	# Serve zones authoritatively from Unbound to resolver clients.
 	# Not for external service.