package home import ( "crypto/sha256" "encoding/binary" "encoding/hex" "encoding/json" "fmt" "math/rand" "net/http" "strings" "sync" "time" "github.com/AdguardTeam/golibs/log" "go.etcd.io/bbolt" "golang.org/x/crypto/bcrypt" ) const cookieTTL = 365 * 24 // in hours const sessionCookieName = "agh_session" type session struct { userName string expire uint32 // expiration time (in seconds) } /* expire byte[4] name_len byte[2] name byte[] */ func (s *session) serialize() []byte { var data []byte data = make([]byte, 4+2+len(s.userName)) binary.BigEndian.PutUint32(data[0:4], s.expire) binary.BigEndian.PutUint16(data[4:6], uint16(len(s.userName))) copy(data[6:], []byte(s.userName)) return data } func (s *session) deserialize(data []byte) bool { if len(data) < 4+2 { return false } s.expire = binary.BigEndian.Uint32(data[0:4]) nameLen := binary.BigEndian.Uint16(data[4:6]) data = data[6:] if len(data) < int(nameLen) { return false } s.userName = string(data) return true } // Auth - global object type Auth struct { db *bbolt.DB sessions map[string]*session // session name -> session data lock sync.Mutex users []User sessionTTL uint32 // in seconds } // User object type User struct { Name string `yaml:"name"` PasswordHash string `yaml:"password"` // bcrypt hash } // InitAuth - create a global object func InitAuth(dbFilename string, users []User, sessionTTL uint32) *Auth { log.Info("Initializing auth module: %s", dbFilename) a := Auth{} a.sessionTTL = sessionTTL a.sessions = make(map[string]*session) rand.Seed(time.Now().UTC().Unix()) var err error a.db, err = bbolt.Open(dbFilename, 0644, nil) if err != nil { log.Error("Auth: open DB: %s: %s", dbFilename, err) if err.Error() == "invalid argument" { log.Error("AdGuard Home cannot be initialized due to an incompatible file system.\nPlease read the explanation here: https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#limitations") } return nil } a.loadSessions() a.users = users log.Info("Auth: initialized. users:%d sessions:%d", len(a.users), len(a.sessions)) return &a } // Close - close module func (a *Auth) Close() { _ = a.db.Close() } func bucketName() []byte { return []byte("sessions-2") } // load sessions from file, remove expired sessions func (a *Auth) loadSessions() { tx, err := a.db.Begin(true) if err != nil { log.Error("Auth: bbolt.Begin: %s", err) return } defer func() { _ = tx.Rollback() }() bkt := tx.Bucket(bucketName()) if bkt == nil { return } removed := 0 if tx.Bucket([]byte("sessions")) != nil { _ = tx.DeleteBucket([]byte("sessions")) removed = 1 } now := uint32(time.Now().UTC().Unix()) forEach := func(k, v []byte) error { s := session{} if !s.deserialize(v) || s.expire <= now { err = bkt.Delete(k) if err != nil { log.Error("Auth: bbolt.Delete: %s", err) } else { removed++ } return nil } a.sessions[hex.EncodeToString(k)] = &s return nil } _ = bkt.ForEach(forEach) if removed != 0 { err = tx.Commit() if err != nil { log.Error("bolt.Commit(): %s", err) } } log.Debug("Auth: loaded %d sessions from DB (removed %d expired)", len(a.sessions), removed) } // store session data in file func (a *Auth) addSession(data []byte, s *session) { name := hex.EncodeToString(data) a.lock.Lock() a.sessions[name] = s a.lock.Unlock() if a.storeSession(data, s) { log.Debug("Auth: created session %s: expire=%d", name, s.expire) } } // store session data in file func (a *Auth) storeSession(data []byte, s *session) bool { tx, err := a.db.Begin(true) if err != nil { log.Error("Auth: bbolt.Begin: %s", err) return false } defer func() { _ = tx.Rollback() }() bkt, err := tx.CreateBucketIfNotExists(bucketName()) if err != nil { log.Error("Auth: bbolt.CreateBucketIfNotExists: %s", err) return false } err = bkt.Put(data, s.serialize()) if err != nil { log.Error("Auth: bbolt.Put: %s", err) return false } err = tx.Commit() if err != nil { log.Error("Auth: bbolt.Commit: %s", err) return false } return true } // remove session from file func (a *Auth) removeSession(sess []byte) { tx, err := a.db.Begin(true) if err != nil { log.Error("Auth: bbolt.Begin: %s", err) return } defer func() { _ = tx.Rollback() }() bkt := tx.Bucket(bucketName()) if bkt == nil { log.Error("Auth: bbolt.Bucket") return } err = bkt.Delete(sess) if err != nil { log.Error("Auth: bbolt.Put: %s", err) return } err = tx.Commit() if err != nil { log.Error("Auth: bbolt.Commit: %s", err) return } log.Debug("Auth: removed session from DB") } // CheckSession - check if session is valid // Return 0 if OK; -1 if session doesn't exist; 1 if session has expired func (a *Auth) CheckSession(sess string) int { now := uint32(time.Now().UTC().Unix()) update := false a.lock.Lock() s, ok := a.sessions[sess] if !ok { a.lock.Unlock() return -1 } if s.expire <= now { delete(a.sessions, sess) key, _ := hex.DecodeString(sess) a.removeSession(key) a.lock.Unlock() return 1 } newExpire := now + a.sessionTTL if s.expire/(24*60*60) != newExpire/(24*60*60) { // update expiration time once a day update = true s.expire = newExpire } a.lock.Unlock() if update { key, _ := hex.DecodeString(sess) if a.storeSession(key, s) { log.Debug("Auth: updated session %s: expire=%d", sess, s.expire) } } return 0 } // RemoveSession - remove session func (a *Auth) RemoveSession(sess string) { key, _ := hex.DecodeString(sess) a.lock.Lock() delete(a.sessions, sess) a.lock.Unlock() a.removeSession(key) } type loginJSON struct { Name string `json:"name"` Password string `json:"password"` } func getSession(u *User) []byte { // the developers don't currently believe that using a // non-cryptographic RNG for the session hash salt is // insecure salt := rand.Uint32() //nolint:gosec d := []byte(fmt.Sprintf("%d%s%s", salt, u.Name, u.PasswordHash)) hash := sha256.Sum256(d) return hash[:] } func (a *Auth) httpCookie(req loginJSON) string { u := a.UserFind(req.Name, req.Password) if len(u.Name) == 0 { return "" } sess := getSession(&u) now := time.Now().UTC() expire := now.Add(cookieTTL * time.Hour) expstr := expire.Format(time.RFC1123) expstr = expstr[:len(expstr)-len("UTC")] // "UTC" -> "GMT" expstr += "GMT" s := session{} s.userName = u.Name s.expire = uint32(now.Unix()) + a.sessionTTL a.addSession(sess, &s) return fmt.Sprintf("%s=%s; Path=/; HttpOnly; Expires=%s", sessionCookieName, hex.EncodeToString(sess), expstr) } func handleLogin(w http.ResponseWriter, r *http.Request) { req := loginJSON{} err := json.NewDecoder(r.Body).Decode(&req) if err != nil { httpError(w, http.StatusBadRequest, "json decode: %s", err) return } cookie := Context.auth.httpCookie(req) if len(cookie) == 0 { log.Info("Auth: invalid user name or password: name='%s'", req.Name) time.Sleep(1 * time.Second) http.Error(w, "invalid user name or password", http.StatusBadRequest) return } w.Header().Set("Set-Cookie", cookie) w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, proxy-revalidate") w.Header().Set("Pragma", "no-cache") w.Header().Set("Expires", "0") returnOK(w) } func handleLogout(w http.ResponseWriter, r *http.Request) { cookie := r.Header.Get("Cookie") sess := parseCookie(cookie) Context.auth.RemoveSession(sess) w.Header().Set("Location", "/login.html") s := fmt.Sprintf("%s=; Path=/; HttpOnly; Expires=Thu, 01 Jan 1970 00:00:00 GMT", sessionCookieName) w.Header().Set("Set-Cookie", s) w.WriteHeader(http.StatusFound) } // RegisterAuthHandlers - register handlers func RegisterAuthHandlers() { http.Handle("/control/login", postInstallHandler(ensureHandler("POST", handleLogin))) httpRegister("GET", "/control/logout", handleLogout) } func parseCookie(cookie string) string { pairs := strings.Split(cookie, ";") for _, pair := range pairs { pair = strings.TrimSpace(pair) kv := strings.SplitN(pair, "=", 2) if len(kv) != 2 { continue } if kv[0] == sessionCookieName { return kv[1] } } return "" } // nolint(gocyclo) func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { if r.URL.Path == "/login.html" { // redirect to dashboard if already authenticated authRequired := Context.auth != nil && Context.auth.AuthRequired() cookie, err := r.Cookie(sessionCookieName) if authRequired && err == nil { r := Context.auth.CheckSession(cookie.Value) if r == 0 { w.Header().Set("Location", "/") w.WriteHeader(http.StatusFound) return } else if r < 0 { log.Debug("Auth: invalid cookie value: %s", cookie) } } } else if strings.HasPrefix(r.URL.Path, "/assets/") || strings.HasPrefix(r.URL.Path, "/login.") { // process as usual // no additional auth requirements } else if Context.auth != nil && Context.auth.AuthRequired() { // redirect to login page if not authenticated ok := false cookie, err := r.Cookie(sessionCookieName) if glProcessCookie(r) { log.Debug("Auth: authentification was handled by GL-Inet submodule") ok = true } else if err == nil { r := Context.auth.CheckSession(cookie.Value) if r == 0 { ok = true } else if r < 0 { log.Debug("Auth: invalid cookie value: %s", cookie) } } else { // there's no Cookie, check Basic authentication user, pass, ok2 := r.BasicAuth() if ok2 { u := Context.auth.UserFind(user, pass) if len(u.Name) != 0 { ok = true } else { log.Info("Auth: invalid Basic Authorization value") } } } if !ok { if r.URL.Path == "/" || r.URL.Path == "/index.html" { if glProcessRedirect(w, r) { log.Debug("Auth: redirected to login page by GL-Inet submodule") } else { w.Header().Set("Location", "/login.html") w.WriteHeader(http.StatusFound) } } else { w.WriteHeader(http.StatusForbidden) _, _ = w.Write([]byte("Forbidden")) } return } } handler(w, r) } } type authHandler struct { handler http.Handler } func (a *authHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { optionalAuth(a.handler.ServeHTTP)(w, r) } func optionalAuthHandler(handler http.Handler) http.Handler { return &authHandler{handler} } // UserAdd - add new user func (a *Auth) UserAdd(u *User, password string) { if len(password) == 0 { return } hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost) if err != nil { log.Error("bcrypt.GenerateFromPassword: %s", err) return } u.PasswordHash = string(hash) a.lock.Lock() a.users = append(a.users, *u) a.lock.Unlock() log.Debug("Auth: added user: %s", u.Name) } // UserFind - find a user func (a *Auth) UserFind(login string, password string) User { a.lock.Lock() defer a.lock.Unlock() for _, u := range a.users { if u.Name == login && bcrypt.CompareHashAndPassword([]byte(u.PasswordHash), []byte(password)) == nil { return u } } return User{} } // GetCurrentUser - get the current user func (a *Auth) GetCurrentUser(r *http.Request) User { cookie, err := r.Cookie(sessionCookieName) if err != nil { // there's no Cookie, check Basic authentication user, pass, ok := r.BasicAuth() if ok { u := Context.auth.UserFind(user, pass) return u } return User{} } a.lock.Lock() s, ok := a.sessions[cookie.Value] if !ok { a.lock.Unlock() return User{} } for _, u := range a.users { if u.Name == s.userName { a.lock.Unlock() return u } } a.lock.Unlock() return User{} } // GetUsers - get users func (a *Auth) GetUsers() []User { a.lock.Lock() users := a.users a.lock.Unlock() return users } // AuthRequired - if authentication is required func (a *Auth) AuthRequired() bool { if GLMode { return true } a.lock.Lock() r := (len(a.users) != 0) a.lock.Unlock() return r }