Add support for wss (#10)

* Add support for secure websockets

* Implement test for wss

* Adjust websocket tls options

* Update documentation and docker files

* Use ecdsa key for self-signed certificate generation

Author: lorenzodonini

.travis.yml

@@ -14,8 +14,8 @@ jobs:
   include:
     - stage: test
       script:
-        - go test ./...
         - go build ./...
+        - go test ./...
     - stage: publish_latest
       script:
         - docker build -t ldonini/ocpp1.6-central-system:latest -f example/cs/Dockerfile .

README.md

@@ -6,8 +6,6 @@ Open Charge Point Protocol implementation in Go.
 
 The library targets modern charge points and central systems, running OCPP version 1.6+.
 
-**The implementation for OCPP version 2.0 is currently in WIP.**
-
 Given that SOAP will no longer be supported in future versions of OCPP, only OCPP-J is supported in this library.
 There are currently no plans of supporting OCPP-S.
 
@@ -31,7 +29,7 @@ go get github.com/lorenzodonini/ocpp-go
 You will also need to fetch some dependencies:
 ```sh
 cd <path-to-ocpp-go>
-go mod tidy
+go mod download
 ```
 
 Your application may either act as a Central System (server) or as a Charge Point (client).

example/cp/Dockerfile

@@ -1,13 +1,13 @@
 ############################
 # STEP 1 build executable binary
 ############################
-FROM golang:stretch AS builder
+FROM golang:alpine AS builder
 
 ENV GO111MODULE on
 WORKDIR $GOPATH/src/github.com/lorenzodonini/ocpp-go
 COPY . .
 # Fetch dependencies.
-RUN go mod tidy
+RUN go mod download
 # Build the binary.
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o /go/bin/charge_point example/cp/charge_point_sim.go
 

example/cs/Dockerfile

@@ -1,13 +1,13 @@
 ############################
 # STEP 1 build executable binary
 ############################
-FROM golang:stretch AS builder
+FROM golang:alpine AS builder
 
 ENV GO111MODULE on
 WORKDIR $GOPATH/src/github.com/lorenzodonini/ocpp-go
 COPY . .
 # Fetch dependencies.
-RUN go mod tidy
+RUN go mod download
 # Build the binary.
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o /go/bin/central_system example/cs/central_system_sim.go
 

ocpp1.6/v16.go

@@ -2,6 +2,7 @@ package ocpp16
 
 import (
 	"fmt"
+
 	"github.com/lorenzodonini/ocpp-go/ocpp"
 	"github.com/lorenzodonini/ocpp-go/ocppj"
 	"github.com/lorenzodonini/ocpp-go/ws"
@@ -243,7 +244,7 @@ func (cp *chargePoint) SendRequest(request ocpp.Request) (ocpp.Confirmation, err
 func (cp *chargePoint) SendRequestAsync(request ocpp.Request, callback func(confirmation ocpp.Confirmation, err error)) error {
 	switch request.GetFeatureName() {
 	case AuthorizeFeatureName, BootNotificationFeatureName, DataTransferFeatureName, HeartbeatFeatureName, MeterValuesFeatureName, StartTransactionFeatureName, StopTransactionFeatureName, StatusNotificationFeatureName,
-	DiagnosticsStatusNotificationFeatureName, FirmwareStatusNotificationFeatureName:
+		DiagnosticsStatusNotificationFeatureName, FirmwareStatusNotificationFeatureName:
 		break
 	default:
 		return fmt.Errorf("unsupported action %v on charge point, cannot send request", request.GetFeatureName())
@@ -281,6 +282,9 @@ func (cp *chargePoint) sendResponse(confirmation ocpp.Confirmation, err error, r
 // Connects to the central system and starts the charge point routine.
 // The function doesn't block and returns right away, after having attempted to open a connection to the central system.
 // If the connection couldn't be opened, an error is returned.
+//
+// Optional client options must be set before calling this function. Refer to NewChargePoint.
+//
 // No auto-reconnect logic is implemented as of now, but is planned for the future.
 func (cp *chargePoint) Start(centralSystemUrl string) error {
 	// TODO: implement auto-reconnect logic
@@ -405,7 +409,25 @@ func (cp *chargePoint) handleIncomingRequest(request ocpp.Request, requestId str
 // The dispatcher and client parameters may be omitted, in order to use a default configuration:
 //   chargePoint := NewChargePoint("someUniqueId", nil, nil)
 //
-// It is recommended to use the default configuration, unless a custom networking / ocppj layer is required.
+// Additional networking parameters (e.g. TLS or proxy configuration) may be passed, by creating a custom client.
+// Here is an example for a client using TLS configuration with a self-signed certificate:
+//	cp := NewChargePoint("someUniqueId", nil, ws.NewTLSClient(func (dialer *websocket.Dialer) {
+//		certPool := x509.NewCertPool()
+//		data, err := ioutil.ReadFile("serverSelfSignedCertFilename")
+//		if err != nil {
+//			log.Fatal(err)
+//		}
+//		ok = certPool.AppendCertsFromPEM(data)
+//		if !ok {
+//			log.Fatal("couldn't parse PEM certificate")
+//		}
+//		dialer.TLSClientConfig = &tls.Config{
+//			RootCAs: certPool,
+//		}
+//	}))
+//
+// For more advanced options, or if a customer networking/occpj layer is required,
+// please refer to ocppj.ChargePoint and ws.WsClient.
 func NewChargePoint(id string, dispatcher *ocppj.ChargePoint, client ws.WsClient) ChargePoint {
 	if client == nil {
 		client = ws.NewClient()
@@ -824,11 +846,11 @@ func (cs *centralSystem) SetChargePointDisconnectedHandler(handler func(chargePo
 func (cs *centralSystem) SendRequestAsync(clientId string, request ocpp.Request, callback func(confirmation ocpp.Confirmation, err error)) error {
 	switch request.GetFeatureName() {
 	case ChangeAvailabilityFeatureName, ChangeConfigurationFeatureName, ClearCacheFeatureName, DataTransferFeatureName, GetConfigurationFeatureName, RemoteStartTransactionFeatureName, RemoteStopTransactionFeatureName, ResetFeatureName, UnlockConnectorFeatureName,
-	GetLocalListVersionFeatureName, SendLocalListFeatureName,
-	GetDiagnosticsFeatureName, UpdateFirmwareFeatureName,
-	ReserveNowFeatureName, CancelReservationFeatureName,
-	TriggerMessageFeatureName,
-	SetChargingProfileFeatureName, ClearChargingProfileFeatureName, GetCompositeScheduleFeatureName:
+		GetLocalListVersionFeatureName, SendLocalListFeatureName,
+		GetDiagnosticsFeatureName, UpdateFirmwareFeatureName,
+		ReserveNowFeatureName, CancelReservationFeatureName,
+		TriggerMessageFeatureName,
+		SetChargingProfileFeatureName, ClearChargingProfileFeatureName, GetCompositeScheduleFeatureName:
 	default:
 		return fmt.Errorf("unsupported action %v on central system, cannot send request", request.GetFeatureName())
 	}
@@ -993,6 +1015,9 @@ func (cs *centralSystem) handleIncomingError(chargePointId string, err *ocpp.Err
 //
 // It is recommended to use the default configuration, unless a custom networking / ocppj layer is required.
 // The default dispatcher supports all OCPP 1.6 profiles out-of-the-box.
+//
+// If you need a TLS server, you may use the following:
+//	cs := NewCentralSystem(nil, ws.NewTLSServer("certificatePath", "privateKeyPath"))
 func NewCentralSystem(dispatcher *ocppj.CentralSystem, server ws.WsServer) CentralSystem {
 	if server == nil {
 		server = ws.NewServer()

ocpp1.6_test/ocpp16_test.go

@@ -2,7 +2,6 @@ package ocpp16_test
 
 import (
 	"fmt"
-	"github.com/gorilla/websocket"
 	"github.com/lorenzodonini/ocpp-go/ocpp"
 	ocpp16 "github.com/lorenzodonini/ocpp-go/ocpp1.6"
 	"github.com/lorenzodonini/ocpp-go/ocppj"
@@ -20,7 +19,7 @@ type MockWebSocket struct {
 	id string
 }
 
-func (websocket MockWebSocket) GetId() string {
+func (websocket MockWebSocket) GetID() string {
 	return websocket.id
 }
 
@@ -73,7 +72,7 @@ type MockWebsocketClient struct {
 	MessageHandler func(data []byte) error
 }
 
-func (websocketClient *MockWebsocketClient) Start(url string, dialOptions ...func(websocket.Dialer)) error {
+func (websocketClient *MockWebsocketClient) Start(url string) error {
 	args := websocketClient.MethodCalled("Start", url)
 	return args.Error(0)
 }
@@ -383,7 +382,7 @@ func NewWebsocketServer(t *testing.T, onMessage func(data []byte) ([]byte, error
 			response, err := onMessage(data)
 			assert.Nil(t, err)
 			if response != nil {
-				err = wsServer.Write(ws.GetId(), data)
+				err = wsServer.Write(ws.GetID(), data)
 				assert.Nil(t, err)
 			}
 		}

ocppj/central_system.go

@@ -54,12 +54,12 @@ func (centralSystem *CentralSystem) Start(listenPort int, listenPath string) {
 	// Set internal message handler
 	centralSystem.server.SetNewClientHandler(func(ws ws.Channel) {
 		if centralSystem.newChargePointHandler != nil {
-			centralSystem.newChargePointHandler(ws.GetId())
+			centralSystem.newChargePointHandler(ws.GetID())
 		}
 	})
 	centralSystem.server.SetDisconnectedClientHandler(func(ws ws.Channel) {
 		if centralSystem.disconnectedChargePointHandler != nil {
-			centralSystem.disconnectedChargePointHandler(ws.GetId())
+			centralSystem.disconnectedChargePointHandler(ws.GetID())
 		}
 	})
 	centralSystem.server.SetMessageHandler(centralSystem.ocppMessageHandler)
@@ -135,7 +135,7 @@ func (centralSystem *CentralSystem) ocppMessageHandler(wsChannel ws.Channel, dat
 	message, err := centralSystem.ParseMessage(parsedJson)
 	if err != nil {
 		if err.MessageId != "" {
-			err2 := centralSystem.SendError(wsChannel.GetId(), err.MessageId, err.Code, err.Description, nil)
+			err2 := centralSystem.SendError(wsChannel.GetID(), err.MessageId, err.Code, err.Description, nil)
 			if err2 != nil {
 				return err2
 			}
@@ -146,15 +146,15 @@ func (centralSystem *CentralSystem) ocppMessageHandler(wsChannel ws.Channel, dat
 	switch message.GetMessageTypeId() {
 	case CALL:
 		call := message.(*Call)
-		centralSystem.requestHandler(wsChannel.GetId(), call.Payload, call.UniqueId, call.Action)
+		centralSystem.requestHandler(wsChannel.GetID(), call.Payload, call.UniqueId, call.Action)
 	case CALL_RESULT:
 		callResult := message.(*CallResult)
-		delete(centralSystem.clientPendingMessages, wsChannel.GetId())
-		centralSystem.confirmationHandler(wsChannel.GetId(), callResult.Payload, callResult.UniqueId)
+		delete(centralSystem.clientPendingMessages, wsChannel.GetID())
+		centralSystem.confirmationHandler(wsChannel.GetID(), callResult.Payload, callResult.UniqueId)
 	case CALL_ERROR:
 		callError := message.(*CallError)
-		delete(centralSystem.clientPendingMessages, wsChannel.GetId())
-		centralSystem.errorHandler(wsChannel.GetId(), ocpp.NewError(callError.ErrorCode, callError.ErrorDescription, callError.UniqueId), callError.ErrorDetails)
+		delete(centralSystem.clientPendingMessages, wsChannel.GetID())
+		centralSystem.errorHandler(wsChannel.GetID(), ocpp.NewError(callError.ErrorCode, callError.ErrorDescription, callError.UniqueId), callError.ErrorDetails)
 	}
 	return nil
 }

ocppj_test/ocppj_test.go

@@ -2,7 +2,6 @@ package ocppj_test
 
 import (
 	"fmt"
-	"github.com/gorilla/websocket"
 	"github.com/lorenzodonini/ocpp-go/ocpp"
 	"github.com/lorenzodonini/ocpp-go/ocppj"
 	"github.com/lorenzodonini/ocpp-go/ws"
@@ -19,7 +18,7 @@ type MockWebSocket struct {
 	id string
 }
 
-func (websocket MockWebSocket) GetId() string {
+func (websocket MockWebSocket) GetID() string {
 	return websocket.id
 }
 
@@ -72,7 +71,7 @@ type MockWebsocketClient struct {
 	MessageHandler func(data []byte) error
 }
 
-func (websocketClient *MockWebsocketClient) Start(url string, dialOptions ...func(websocket.Dialer)) error {
+func (websocketClient *MockWebsocketClient) Start(url string) error {
 	args := websocketClient.MethodCalled("Start", url)
 	return args.Error(0)
 }
@@ -148,7 +147,7 @@ func NewWebsocketServer(t *testing.T, onMessage func(data []byte) ([]byte, error
 			response, err := onMessage(data)
 			assert.Nil(t, err)
 			if response != nil {
-				err = wsServer.Write(ws.GetId(), data)
+				err = wsServer.Write(ws.GetID(), data)
 				assert.Nil(t, err)
 			}
 		}