OpenID authentification (#170)

* openid authentification

* openid middleware

* openId login

* tidied login page

* removed useless email text field

server/openid/middleware.go

@@ -0,0 +1,20 @@
+package openid
+
+import "net/http"
+
+func Middleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		token, err := r.Cookie("oid-token")
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		if _, err := verifier.Verify(r.Context(), token.Value); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}