middleware.go

// Copyright 2020 Vladimir Osintsev <osintsev@gmail.com>
//
// This file is part of Tornote.
//
// Tornote is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Tornote is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package tornote

import (
	"fmt"
	"net/http"
	"strings"
)

func RedirectToHTTPSMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
		proto := req.Header.Get("x-forwarded-proto")
		if !strings.EqualFold("https", proto) {
			http.Redirect(res, req, fmt.Sprintf("https://%s%s", req.Host, req.URL), http.StatusPermanentRedirect)
			return
		}
		next.ServeHTTP(res, req)
	})
}