refactor(jwr): better middlewares

jwt/jwt.go

@@ -116,7 +116,7 @@ func (s Secret) VerifyToken(tokenString string) (*Claims, error) {
 	return nil, fmt.Errorf("invalid token")
 }
 
-// Middleware is an authentication guard for HTTP servers.
+// Middleware is a middleware that inject the JWT in the context for HTTP servers.
 func (jwt Secret) Middleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// Get the JWT token from the request header
@@ -139,6 +139,19 @@ func (jwt Secret) Middleware(next http.Handler) http.Handler {
 	})
 }
 
+// Deny is an authentication guard for HTTP servers.
+func Deny(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, ok := GetClaimsFromRequest(r)
+		if !ok {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}
+
 // GetClaimsFromRequest is a helper function to fetch the JWT session token from an HTTP request.
 func GetClaimsFromRequest(r *http.Request) (claims Claims, ok bool) {
 	claims, ok = r.Context().Value(claimsContextKey{}).(Claims)

main.go

@@ -242,6 +242,7 @@ var app = &cli.App{
 				http.Error(w, err.Error(), http.StatusInternalServerError)
 			}
 		}
+		r.With(jwt.Deny).Get("/counter", renderFn)
 		r.Get("/*", renderFn)
 		r.Handle("/static/*", http.FileServer(http.FS(static)))