Merge pull request #529 from dedis/service_aggregate

Service Aggregate calculation

overlay.go

@@ -171,7 +171,8 @@ func (o *Overlay) TransmitMsg(onetMsg *ProtocolMsg, io MessageProxy) error {
 			defer func() {
 				if r := recover(); r != nil {
 					svc := ServiceFactory.Name(tni.Token().ServiceID)
-					log.Errorf("Panic in %v %s.Dispatch(): %v", svc, o.server.ServerIdentity, r)
+					log.Errorf("Panic in call to protocol <%s>.Dispatch() from service <%s> at address %s: %v",
+						tni.ProtocolName(), svc, o.server.ServerIdentity, r)
 				}
 			}()
 

overlay_test.go

@@ -201,7 +201,7 @@ func TestOverlayCatastrophicFailure(t *testing.T) {
 
 	stderr := log.GetStdErr()
 	assert.Contains(t, stderr, "Start(): start panic")
-	assert.Contains(t, stderr, "Dispatch(): dispatch panic")
+	assert.Contains(t, stderr, "Panic in call to protocol")
 	assert.Contains(t, stderr, "Dispatch(): root dispatch panic")
 }
 

tree.go

@@ -14,7 +14,7 @@ import (
 	"go.dedis.ch/kyber/v3"
 	"go.dedis.ch/onet/v3/log"
 	"go.dedis.ch/onet/v3/network"
-	uuid "gopkg.in/satori/go.uuid.v1"
+	"gopkg.in/satori/go.uuid.v1"
 )
 
 // In this file we define the main structures used for a running protocol
@@ -517,6 +517,22 @@ func (ro *Roster) ServicePublics(name string) []kyber.Point {
 	return res
 }
 
+// ServiceAggregate returns the sum of all public keys of a given service. This
+// is often used as the aggregate public key.
+// If one or more of the service public keys are not present, it will return an error.
+func (ro Roster) ServiceAggregate(name string) (kyber.Point, error) {
+	for _, si := range ro.List {
+		if !si.HasServiceKeyPair(name) {
+			return nil, errors.New("not all nodes have this service keypair")
+		}
+	}
+	aggregate := ro.List[0].ServicePublic(name).Clone().Null()
+	for _, p := range ro.ServicePublics(name) {
+		aggregate.Add(aggregate, p)
+	}
+	return aggregate, nil
+}
+
 // GenerateBigNaryTree creates a tree where each node has N children.
 // It will make a tree with exactly 'nodes' elements, regardless of the
 // size of the Roster. If 'nodes' is bigger than the number of elements

treenode.go

@@ -653,6 +653,18 @@ func (n *TreeNodeInstance) Public() kyber.Point {
 	return n.Host().ServerIdentity.ServicePublic(serviceName)
 }
 
+// Aggregate returns the sum of all public key of the roster for this TreeNodeInstance, either the specific
+// or the default if one or more of the nodes don't have the service-public key available.
+func (n *TreeNodeInstance) Aggregate() kyber.Point {
+	serviceName := ServiceFactory.Name(n.token.ServiceID)
+
+	agg, err := n.Roster().ServiceAggregate(serviceName)
+	if err != nil {
+		return n.Roster().Aggregate
+	}
+	return agg
+}
+
 // Publics makes a list of public keys for the service
 // associated with the instance
 func (n *TreeNodeInstance) Publics() []kyber.Point {