예제 #1
0
// Check for CSRF token on /rest/ URLs. If a correct one is not given, reject
// the request with 403. For / and /index.html, set a new CSRF cookie if none
// is currently set.
func csrfMiddleware(unique string, prefix string, cfg config.GUIConfiguration, next http.Handler) http.Handler {
	loadCsrfTokens()
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Allow requests carrying a valid API key
		if cfg.IsValidAPIKey(r.Header.Get("X-API-Key")) {
			next.ServeHTTP(w, r)
			return
		}

		// Allow requests for the front page, and set a CSRF cookie if there isn't already a valid one.
		if !strings.HasPrefix(r.URL.Path, prefix) {
			cookie, err := r.Cookie("CSRF-Token-" + unique)
			if err != nil || !validCsrfToken(cookie.Value) {
				httpl.Debugln("new CSRF cookie in response to request for", r.URL)
				cookie = &http.Cookie{
					Name:  "CSRF-Token-" + unique,
					Value: newCsrfToken(),
				}
				http.SetCookie(w, cookie)
			}
			next.ServeHTTP(w, r)
			return
		}

		if r.Method == "GET" {
			// Allow GET requests unconditionally, but if we got the CSRF
			// token cookie do the verification anyway so we keep the
			// csrfTokens list sorted by recent usage. We don't care about the
			// outcome of the validity check.
			if cookie, err := r.Cookie("CSRF-Token-" + unique); err == nil {
				validCsrfToken(cookie.Value)
			}
			next.ServeHTTP(w, r)
			return
		}

		// Verify the CSRF token
		token := r.Header.Get("X-CSRF-Token-" + unique)
		if !validCsrfToken(token) {
			http.Error(w, "CSRF Error", 403)
			return
		}

		next.ServeHTTP(w, r)
	})
}
예제 #2
0
func basicAuthAndSessionMiddleware(cookieName string, cfg config.GUIConfiguration, next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if cfg.IsValidAPIKey(r.Header.Get("X-API-Key")) {
			next.ServeHTTP(w, r)
			return
		}

		cookie, err := r.Cookie(cookieName)
		if err == nil && cookie != nil {
			sessionsMut.Lock()
			_, ok := sessions[cookie.Value]
			sessionsMut.Unlock()
			if ok {
				next.ServeHTTP(w, r)
				return
			}
		}

		httpl.Debugln("Sessionless HTTP request with authentication; this is expensive.")

		error := func() {
			time.Sleep(time.Duration(rand.Intn(100)+100) * time.Millisecond)
			w.Header().Set("WWW-Authenticate", "Basic realm=\"Authorization Required\"")
			http.Error(w, "Not Authorized", http.StatusUnauthorized)
		}

		hdr := r.Header.Get("Authorization")
		if !strings.HasPrefix(hdr, "Basic ") {
			error()
			return
		}

		hdr = hdr[6:]
		bs, err := base64.StdEncoding.DecodeString(hdr)
		if err != nil {
			error()
			return
		}

		fields := bytes.SplitN(bs, []byte(":"), 2)
		if len(fields) != 2 {
			error()
			return
		}

		username := string(fields[0])
		if username != cfg.User {
			emitLoginAttempt(false, username)
			error()
			return
		}

		if err := bcrypt.CompareHashAndPassword([]byte(cfg.Password), fields[1]); err != nil {
			emitLoginAttempt(false, username)
			error()
			return
		}

		sessionid := randomString(32)
		sessionsMut.Lock()
		sessions[sessionid] = true
		sessionsMut.Unlock()
		http.SetCookie(w, &http.Cookie{
			Name:   cookieName,
			Value:  sessionid,
			MaxAge: 0,
		})

		emitLoginAttempt(true, username)
		next.ServeHTTP(w, r)
	})
}