Added Process check to DBSigs to avoid accepting bad signatures. Cach…

…ed the valid result. Return 0 if the height isn't right

common/messages/directoryBlockSignature.go

@@ -119,6 +119,15 @@ func (m *DirectoryBlockSignature) Type() byte {
 //  0   -- Cannot tell if message is Valid
 //  1   -- Message is valid
 func (m *DirectoryBlockSignature) Validate(state interfaces.IState) int {
+
+	if m.IsValid() {
+		return 1
+	}
+
+	if m.DBHeight != state.GetLLeaderHeight() {
+		return 0
+	}
+
 	if m.DBHeight < state.GetHighestSavedBlk() {
 		state.AddStatus(fmt.Sprintf("DirectoryBlockSignature: Fail dbstate ht: %v < dbht: %v  %s", m.DBHeight, state.GetHighestSavedBlk(), m.String()))
 		return -1
@@ -135,6 +144,7 @@ func (m *DirectoryBlockSignature) Validate(state interfaces.IState) int {
 	}
 
 	if m.IsLocal() {
+		m.SetValid()
 		return 1
 	}
 
@@ -144,17 +154,18 @@ func (m *DirectoryBlockSignature) Validate(state interfaces.IState) int {
 		// if there is an error during signature verification
 		// or if the signature is invalid
 		// the message is considered invalid
-		return 0
+		return -1
 	}
 
 	marshalledMsg, _ := m.MarshalForSignature()
 	authorityLevel, err := state.VerifyAuthoritySignature(marshalledMsg, m.Signature.GetSignature(), m.DBHeight)
 	if err != nil || authorityLevel < 1 {
 		//This authority is not a Fed Server (it's either an Audit or not an Authority at all)
 		state.AddStatus(fmt.Sprintf("DirectoryBlockSignature: Fail to Verify Sig (not from a Fed Server) dbht: %v %s", state.GetLLeaderHeight(), m.String()))
-		return 0
+		return -1
 	}
 
+	m.SetValid()
 	return 1
 }
 

state/stateConsensus.go

@@ -1406,6 +1406,13 @@ func (s *State) ProcessDBSig(dbheight uint32, msg interfaces.IMsg) bool {
 	pl := s.ProcessLists.Get(dbheight)
 	vm := s.ProcessLists.Get(dbheight).VMs[msg.GetVMIndex()]
 
+	// If the DBSig doesn't validate, we are done.  Toss it, and return.
+	if msg.Validate(s) != 1 {
+		vm.List[0] = nil
+		vm.ListAck[0] = nil
+		return false
+	}
+
 	if uint32(pl.System.Height) >= dbs.SysHeight {
 		s.DBSigSys = true
 	}