home: improve checkSession

internal/home/auth.go

@@ -59,10 +59,10 @@ func (s *session) deserialize(data []byte) bool {
 // Auth - global object
 type Auth struct {
 	db         *bbolt.DB
-	sessions   map[string]*session // session name -> session data
-	lock       sync.Mutex
+	sessions   map[string]*session
 	users      []User
-	sessionTTL uint32 // in seconds
+	lock       sync.Mutex
+	sessionTTL uint32
 }
 
 // User object
@@ -223,23 +223,35 @@ func (a *Auth) removeSession(sess []byte) {
 	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 {
+// checkSessionResult is the result of checking a session.
+type checkSessionResult int
+
+// checkSessionResult constants.
+const (
+	checkSessionOK       checkSessionResult = 0
+	checkSessionNotFound checkSessionResult = -1
+	checkSessionExpired  checkSessionResult = 1
+)
+
+// checkSession checks if the session is valid.
+func (a *Auth) checkSession(sess string) (res checkSessionResult) {
 	now := uint32(time.Now().UTC().Unix())
 	update := false
 
 	a.lock.Lock()
 	defer a.lock.Unlock()
+
 	s, ok := a.sessions[sess]
 	if !ok {
-		return -1
+		return checkSessionNotFound
 	}
+
 	if s.expire <= now {
 		delete(a.sessions, sess)
 		key, _ := hex.DecodeString(sess)
 		a.removeSession(key)
-		return 1
+
+		return checkSessionExpired
 	}
 
 	newExpire := now + a.sessionTTL
@@ -256,7 +268,7 @@ func (a *Auth) CheckSession(sess string) int {
 		}
 	}
 
-	return 0
+	return checkSessionOK
 }
 
 // RemoveSession - remove session
@@ -389,8 +401,8 @@ func optionalAuthThird(w http.ResponseWriter, r *http.Request) (authFirst bool)
 		ok = true
 
 	} else if err == nil {
-		r := Context.auth.CheckSession(cookie.Value)
-		if r == 0 {
+		r := Context.auth.checkSession(cookie.Value)
+		if r == checkSessionOK {
 			ok = true
 		} else if r < 0 {
 			log.Debug("Auth: invalid cookie value: %s", cookie)
@@ -431,12 +443,13 @@ func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.Re
 			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 {
+				r := Context.auth.checkSession(cookie.Value)
+				if r == checkSessionOK {
 					w.Header().Set("Location", "/")
 					w.WriteHeader(http.StatusFound)
+
 					return
-				} else if r < 0 {
+				} else if r == checkSessionNotFound {
 					log.Debug("Auth: invalid cookie value: %s", cookie)
 				}
 			}