[1579] add RESULT_NSEC3_SIGNED flag if the zone is signed using nsec3 in

the response of NXDOMAIN and NXRRSET

src/lib/datasrc/database.cc

@@ -812,7 +812,18 @@ DatabaseClient::Finder::findNoNameResult(const Name& name, const RRType& type,
                                          target)
 {
     const bool dnssec_data = ((options & FIND_DNSSEC) != 0);
-
+    //verify whether the zonefile is signed by NSEC3 method
+    //If the NSEC3PARAMETER type exists in the zonefile,NSEC3 is definitly used
+    //in this zone signature.
+    bool is_NSEC3 = false;
+    WantedTypes nsec3PARAM;
+    nsec3PARAM.insert(RRType::NSEC3PARAM()); 
+    const FoundRRsets NSEC3Found = getRRsets(origin_.toText(),nsec3PARAM,
+                                        false);
+    const FoundIterator nfi(NSEC3Found.second.find(RRType::NSEC3PARAM()));
+    if (nfi != NSEC3Found.second.end()) {
+        is_NSEC3 = true;
+    }
     // On entry to this method, we know that the database doesn't have any
     // entry for this name.  Before returning NXDOMAIN, we need to check
     // for special cases.
@@ -826,8 +837,13 @@ DatabaseClient::Finder::findNoNameResult(const Name& name, const RRType& type,
             arg(accessor_->getDBName()).arg(name);
         const ConstRRsetPtr nsec = dnssec_data ? findNSECCover(name) :
             ConstRRsetPtr();
-        return (ResultContext(NXRRSET, nsec,
-                              nsec ? RESULT_NSEC_SIGNED : RESULT_DEFAULT));
+        if (is_NSEC3 == true) {
+            return (ResultContext(NXRRSET, nsec,
+                                  nsec ? RESULT_NSEC_SIGNED : RESULT_NSEC3_SIGNED));
+        } else {
+            return (ResultContext(NXRRSET, nsec,
+                                  nsec ? RESULT_NSEC_SIGNED : RESULT_DEFAULT));
+        }
     } else if ((options & NO_WILDCARD) == 0) {
         // It's not an empty non-terminal and wildcard matching is not
         // disabled, so check for wildcards. If there is a wildcard match
@@ -846,8 +862,13 @@ DatabaseClient::Finder::findNoNameResult(const Name& name, const RRType& type,
               arg(accessor_->getDBName()).arg(name).arg(type).arg(getClass());
     const ConstRRsetPtr nsec = dnssec_data ? findNSECCover(name) :
         ConstRRsetPtr();
-    return (ResultContext(NXDOMAIN, nsec,
-                          nsec ? RESULT_NSEC_SIGNED : RESULT_DEFAULT));
+    if (is_NSEC3 == true ) {
+        return (ResultContext(NXDOMAIN, nsec,
+                              nsec ? RESULT_NSEC_SIGNED : RESULT_NSEC3_SIGNED));
+    } else {
+        return (ResultContext(NXDOMAIN, nsec,
+                              nsec ? RESULT_NSEC_SIGNED : RESULT_DEFAULT));
+    }
 }
 
 ZoneFinder::ResultContext