[FAB-3450] Prevent panic on msg signing

This addresses a missed nil check in the code that
https://gerrit.hyperledger.org/r/#/c/10259/ introduced.

Change-Id: Ie6a854ce85964d0252f9dcca95374a3bba6d1155
Signed-off-by: Yacov Manevich <[email protected]>

Author: yacovm

gossip/discovery/discovery_impl.go

@@ -18,6 +18,7 @@ package discovery
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"math"
 	"strconv"
@@ -172,7 +173,12 @@ func (d *gossipDiscoveryImpl) Connect(member NetworkMember, id identifier) {
 				Endpoint:         member.Endpoint,
 				PKIid:            id.ID,
 			}
-			req, err := d.createMembershipRequest(id.SelfOrg).NoopSign()
+			m, err := d.createMembershipRequest(id.SelfOrg)
+			if err != nil {
+				d.logger.Warning("Failed creating membership request:", err)
+				continue
+			}
+			req, err := m.NoopSign()
 			if err != nil {
 				d.logger.Warning("Failed creating SignedGossipMessage:", err)
 				continue
@@ -234,7 +240,12 @@ func (d *gossipDiscoveryImpl) InitiateSync(peerNum int) {
 		return
 	}
 	var peers2SendTo []*NetworkMember
-	memReq, err := d.createMembershipRequest(true).NoopSign()
+	m, err := d.createMembershipRequest(true)
+	if err != nil {
+		d.logger.Warning("Failed creating membership request:", err)
+		return
+	}
+	memReq, err := m.NoopSign()
 	if err != nil {
 		d.logger.Warning("Failed creating SignedGossipMessage:", err)
 		return
@@ -409,8 +420,9 @@ func (d *gossipDiscoveryImpl) sendMemResponse(targetMember *proto.Member, intern
 		InternalEndpoint: internalEndpoint,
 	}
 
-	aliveMsg := d.createAliveMessage(true)
-	if aliveMsg == nil {
+	aliveMsg, err := d.createAliveMessage(true)
+	if err != nil {
+		d.logger.Warning("Failed creating alive message:", err)
 		return
 	}
 	memResp := d.createMembershipResponse(aliveMsg, targetPeer)
@@ -607,17 +619,26 @@ func (d *gossipDiscoveryImpl) periodicalReconnectToDead() {
 }
 
 func (d *gossipDiscoveryImpl) sendMembershipRequest(member *NetworkMember, includeInternalEndpoint bool) {
-	req, err := d.createMembershipRequest(includeInternalEndpoint).NoopSign()
+	m, err := d.createMembershipRequest(includeInternalEndpoint)
+	if err != nil {
+		d.logger.Warning("Failed creating membership request:", err)
+		return
+	}
+	req, err := m.NoopSign()
 	if err != nil {
 		d.logger.Error("Failed creating SignedGossipMessage:", err)
 		return
 	}
 	d.comm.SendToPeer(member, req)
 }
 
-func (d *gossipDiscoveryImpl) createMembershipRequest(includeInternalEndpoint bool) *proto.GossipMessage {
+func (d *gossipDiscoveryImpl) createMembershipRequest(includeInternalEndpoint bool) (*proto.GossipMessage, error) {
+	am, err := d.createAliveMessage(includeInternalEndpoint)
+	if err != nil {
+		return nil, err
+	}
 	req := &proto.MembershipRequest{
-		SelfInformation: d.createAliveMessage(includeInternalEndpoint).Envelope,
+		SelfInformation: am.Envelope,
 		// TODO: sending the known peers is not secure because the remote peer might shouldn't know
 		// TODO: about the known peers. I'm deprecating this until a secure mechanism will be implemented.
 		// TODO: See FAB-2570 for tracking this issue.
@@ -629,7 +650,7 @@ func (d *gossipDiscoveryImpl) createMembershipRequest(includeInternalEndpoint bo
 		Content: &proto.GossipMessage_MemReq{
 			MemReq: req,
 		},
-	}
+	}, nil
 }
 
 func (d *gossipDiscoveryImpl) copyLastSeen(lastSeenMap map[string]*timestamp) []NetworkMember {
@@ -711,15 +732,16 @@ func (d *gossipDiscoveryImpl) periodicalSendAlive() {
 	for !d.toDie() {
 		d.logger.Debug("Sleeping", getAliveTimeInterval())
 		time.Sleep(getAliveTimeInterval())
-		msg := d.createAliveMessage(true)
-		if msg == nil {
+		msg, err := d.createAliveMessage(true)
+		if err != nil {
+			d.logger.Warning("Failed creating alive message:", err)
 			return
 		}
 		d.comm.Gossip(msg)
 	}
 }
 
-func (d *gossipDiscoveryImpl) createAliveMessage(includeInternalEndpoint bool) *proto.SignedGossipMessage {
+func (d *gossipDiscoveryImpl) createAliveMessage(includeInternalEndpoint bool) (*proto.SignedGossipMessage, error) {
 	d.lock.Lock()
 	d.seqNum++
 	seqNum := d.seqNum
@@ -750,7 +772,7 @@ func (d *gossipDiscoveryImpl) createAliveMessage(includeInternalEndpoint bool) *
 
 	envp := d.crypt.SignMessage(msg2Gossip, internalEndpoint)
 	if envp == nil {
-		return nil
+		return nil, errors.New("Failed signing message")
 	}
 	signedMsg := &proto.SignedGossipMessage{
 		GossipMessage: msg2Gossip,
@@ -761,7 +783,7 @@ func (d *gossipDiscoveryImpl) createAliveMessage(includeInternalEndpoint bool) *
 		signedMsg.Envelope.SecretEnvelope = nil
 	}
 
-	return signedMsg
+	return signedMsg, nil
 }
 
 func (d *gossipDiscoveryImpl) learnExistingMembers(aliveArr []*proto.SignedGossipMessage) {

gossip/discovery/discovery_test.go

@@ -413,9 +413,11 @@ func TestConnect(t *testing.T) {
 	waitUntilOrFail(t, fullMembership)
 
 	discInst := instances[rand.Intn(len(instances))].Discovery.(*gossipDiscoveryImpl)
-	am, _ := discInst.createMembershipRequest(true).GetMemReq().SelfInformation.ToGossipMessage()
+	mr, _ := discInst.createMembershipRequest(true)
+	am, _ := mr.GetMemReq().SelfInformation.ToGossipMessage()
 	assert.NotNil(t, am.SecretEnvelope)
-	am, _ = discInst.createMembershipRequest(false).GetMemReq().SelfInformation.ToGossipMessage()
+	mr2, _ := discInst.createMembershipRequest(false)
+	am, _ = mr2.GetMemReq().SelfInformation.ToGossipMessage()
 	assert.Nil(t, am.SecretEnvelope)
 	stopInstances(t, instances)
 }
@@ -920,13 +922,13 @@ func TestMsgStoreExpirationWithMembershipMessages(t *testing.T) {
 
 	// Creating MembershipRequest messages
 	for i := 0; i < peersNum; i++ {
-		memReqMsg := instances[i].discoveryImpl().createMembershipRequest(true)
+		memReqMsg, _ := instances[i].discoveryImpl().createMembershipRequest(true)
 		sMsg, _ := memReqMsg.NoopSign()
 		memReqMsgs = append(memReqMsgs, sMsg)
 	}
 	// Creating Alive messages
 	for i := 0; i < peersNum; i++ {
-		aliveMsg := instances[i].discoveryImpl().createAliveMessage(true)
+		aliveMsg, _ := instances[i].discoveryImpl().createAliveMessage(true)
 		aliveMsgs = append(aliveMsgs, aliveMsg)
 	}
 
@@ -989,15 +991,15 @@ func TestMsgStoreExpirationWithMembershipMessages(t *testing.T) {
 				return k == i
 			},
 			func(k int) {
-				aliveMsg := instances[k].discoveryImpl().createAliveMessage(true)
+				aliveMsg, _ := instances[k].discoveryImpl().createAliveMessage(true)
 				memResp := instances[k].discoveryImpl().createMembershipResponse(aliveMsg, peerToResponse)
 				memRespMsgs[i] = append(memRespMsgs[i], memResp)
 			})
 	}
 
 	// Re-creating Alive msgs with highest seq_num, to make sure Alive msgs in memReq and memResp are older
 	for i := 0; i < peersNum; i++ {
-		aliveMsg := instances[i].discoveryImpl().createAliveMessage(true)
+		aliveMsg, _ := instances[i].discoveryImpl().createAliveMessage(true)
 		newAliveMsgs = append(newAliveMsgs, aliveMsg)
 	}
 
@@ -1104,13 +1106,13 @@ func TestAliveMsgStore(t *testing.T) {
 
 	// Creating MembershipRequest messages
 	for i := 0; i < peersNum; i++ {
-		memReqMsg := instances[i].discoveryImpl().createMembershipRequest(true)
+		memReqMsg, _ := instances[i].discoveryImpl().createMembershipRequest(true)
 		sMsg, _ := memReqMsg.NoopSign()
 		memReqMsgs = append(memReqMsgs, sMsg)
 	}
 	// Creating Alive messages
 	for i := 0; i < peersNum; i++ {
-		aliveMsg := instances[i].discoveryImpl().createAliveMessage(true)
+		aliveMsg, _ := instances[i].discoveryImpl().createAliveMessage(true)
 		aliveMsgs = append(aliveMsgs, aliveMsg)
 	}