108 lines
2.4 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package main
import (
"bytes"
"encoding/base64"
"math/rand"
"net/http"
"strings"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/events"
"github.com/syncthing/syncthing/lib/sync"
"github.com/syncthing/syncthing/lib/util"
"golang.org/x/crypto/bcrypt"
)
var (
sessions = make(map[string]bool)
sessionsMut = sync.NewMutex()
)
func emitLoginAttempt(success bool, username string) {
events.Default.Log(events.LoginAttempt, map[string]interface{}{
"success": success,
"username": username,
})
}
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 := util.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)
})
}