Add logout functionality and resolve some crashes

src/fs/auth.go

@@ -49,6 +49,12 @@ func (service *MercuryFsService) authenticate(writer http.ResponseWriter, reques
 	}
 }
 
+func (service *MercuryFsService) logout(w http.ResponseWriter, r *http.Request) {
+	authToken := r.Header.Get("Authorization")
+	service.Users.remove(authToken)
+	w.WriteHeader(http.StatusOK)
+}
+
 func (service *MercuryFsService) checkAuthHeader(w http.ResponseWriter, r *http.Request) (user *HdaUser) {
 	authToken := r.Header.Get("Authorization")
 	user = service.Users.find(authToken)
@@ -60,14 +66,19 @@ func (service *MercuryFsService) checkAuthHeader(w http.ResponseWriter, r *http.
 
 func (service *MercuryFsService) authMiddleware(pass http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		service.checkAuthHeader(w, r)
-		pass(w, r)
+		user := service.checkAuthHeader(w, r)
+		if user != nil {
+			pass(w, r)
+		}
 	}
 }
 
 func (service *MercuryFsService) shareReadAccess(pass http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		user := service.checkAuthHeader(w, r)
+		if user == nil {
+			return
+		}
 		shareName := r.URL.Query().Get("s")
 		if access, err := user.HasReadAccess(shareName); !access {
 			if err == nil {
@@ -84,6 +95,9 @@ func (service *MercuryFsService) shareReadAccess(pass http.HandlerFunc) http.Han
 func (service *MercuryFsService) shareWriteAccess(pass http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		user := service.checkAuthHeader(w, r)
+		if user == nil {
+			return
+		}
 		shareName := r.URL.Query().Get("s")
 		if access, err := user.HasWriteAccess(shareName); !access {
 			if err == nil {

src/fs/hda_users.go

@@ -88,6 +88,14 @@ func (users *HdaUsers) find(authToken string) *HdaUser {
 	return user
 }
 
+func (users *HdaUsers) remove(authToken string) {
+	if authToken != "" {
+		users.Lock()
+		delete(users.Users, authToken)
+		users.Unlock()
+	}
+}
+
 func (users *HdaUsers) revalidateSession(authToken string, user *HdaUser) (isValid bool, err error) {
 	dbconn, err := sql.Open("mysql", MYSQL_CREDENTIALS)
 	if err != nil {

src/fs/service.go

@@ -69,6 +69,7 @@ func NewMercuryFSService(rootDir, localAddr string) (service *MercuryFsService,
 	// set up API mux
 	apiRouter := mux.NewRouter()
 	apiRouter.HandleFunc("/auth", service.authenticate).Methods("POST")
+	apiRouter.HandleFunc("/logout", service.logout).Methods("POST")
 	apiRouter.HandleFunc("/shares", service.serveShares).Methods("GET")
 	apiRouter.HandleFunc("/files", use(service.serveFile, service.shareReadAccess)).Methods("GET")
 	apiRouter.HandleFunc("/files", use(service.deleteFile, service.shareWriteAccess)).Methods("DELETE")
@@ -272,10 +273,8 @@ func (service *MercuryFsService) serveFile(writer http.ResponseWriter, request *
 }
 
 func (service *MercuryFsService) serveShares(writer http.ResponseWriter, request *http.Request) {
-	authToken := request.Header.Get("Authorization")
-	user := service.Users.find(authToken)
+	user := service.checkAuthHeader(writer, request)
 	if user == nil {
-		http.Error(writer, "Authentication Failed", http.StatusUnauthorized)
 		return
 	}
 	var shares []*HdaShare