Make client request base64 encoding

This makes gotty-client still work.

webtty/codecs.go

@@ -0,0 +1,19 @@
+package webtty
+
+type Decoder interface {
+	Decode(dst, src []byte) (int, error)
+}
+
+type Encoder interface {
+	Encode(dst, src []byte) (int, error)
+}
+
+type NullCodec struct{}
+
+func (NullCodec) Encode(dst, src []byte) (int, error) {
+	return copy(dst, src), nil
+}
+
+func (NullCodec) Decode(dst, src []byte) (int, error) {
+	return copy(dst, src), nil
+}

webtty/message_types.go

@@ -13,6 +13,8 @@ const (
 	Ping = '2'
 	// Notify that the browser size has been changed
 	ResizeTerminal = '3'
+	// Change encoding
+	SetEncoding = '4'
 )
 
 const (

webtty/webtty.go

@@ -24,6 +24,7 @@ type WebTTY struct {
 	rows        int
 	reconnect   int // in seconds
 	masterPrefs []byte
+	decoder     Decoder
 
 	bufferSize int
 	writeMutex sync.Mutex
@@ -43,6 +44,7 @@ func New(masterConn Master, slave Slave, options ...Option) (*WebTTY, error) {
 		rows:        0,
 
 		bufferSize: 1024,
+		decoder:    &NullCodec{},
 	}
 
 	for _, option := range options {
@@ -177,9 +179,9 @@ func (wt *WebTTY) handleMasterReadEvent(data []byte) error {
 		}
 
 		var decodedBuffer = make([]byte, len(data))
-		n, err := base64.StdEncoding.Decode(decodedBuffer, data[1:])
+		n, err := wt.decoder.Decode(decodedBuffer, data[1:])
 		if err != nil {
-			return errors.Wrapf(err, "failed to write received data to slave")
+			return errors.Wrapf(err, "failed to decode received data")
 		}
 
 		_, err = wt.slave.Write(decodedBuffer[:n])
@@ -193,6 +195,14 @@ func (wt *WebTTY) handleMasterReadEvent(data []byte) error {
 			return errors.Wrapf(err, "failed to return Pong message to master")
 		}
 
+	case SetEncoding:
+		switch string(data[1:]) {
+		case "base64":
+			wt.decoder = base64.StdEncoding
+		case "null":
+			wt.decoder = NullCodec{}
+		}
+
 	case ResizeTerminal:
 		if wt.columns != 0 && wt.rows != 0 {
 			break

webtty/webtty_test.go

@@ -98,8 +98,8 @@ func TestWriteFromFrontend(t *testing.T) {
 	checkNextMsgType(t, mMaster.gottyToMasterReader, SetWindowTitle)
 	checkNextMsgType(t, mMaster.gottyToMasterReader, SetBufferSize)
 
-	// simulate input from frontend... ("hello" in base64)
-	message := []byte("1aGVsbG8=\n") // line buffered canonical mode
+	// simulate input from frontend...
+	message := []byte("1hello\n") // line buffered canonical mode
 	mMaster.masterToGottyWriter.Write(message)
 
 	// ...and make sure it makes it through to the slave intact
@@ -108,7 +108,7 @@ func TestWriteFromFrontend(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Unexpected error from Write(): %s", err)
 	}
-	if !bytes.Equal(readBuf[:n], []byte("hello")) {
+	if !bytes.Equal(readBuf[:n], message[1:]) {
 		t.Fatalf("Unexpected message received: `%s`", readBuf[:n])
 	}
 }