Add explicit login functionality

internal/server/pages.go

@@ -49,19 +49,18 @@ type indexPage struct {
 	MaxExpiry     string
 	DefaultExpiry string
 	AbsBase       string
-	TokenName     string // the remembered token's name, if there is one
 	AllowVanity   bool
-	Stale         bool // a remembered token that no longer exists
+	MaxSizeBytes  int64 // 0 when unlimited; the script checks against it
+	Stale         bool  // a login whose token no longer exists
 }
 
 func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 	// A remembered token is resolved server-side, so the page can show the real
 	// limits without the cookie ever being readable by a script.
-	remembered := cookieCredential(r)
-	lim, err := s.limitsFor(remembered)
+	lim, err := s.limitsFor(cookieCredential(r))
 	stale := false
 	if err != nil {
-		// The token was revoked or the file was edited; drop the cookie rather
+		// The token was revoked or the file was edited; end the session rather
 		// than leave the caller wondering why uploads fail.
 		s.forget(w, r)
 		lim, stale = auth.Anonymous(s.cfg), true
@@ -73,8 +72,8 @@ func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 		MaxExpiry:     config.FormatDuration(lim.MaxExpiry),
 		DefaultExpiry: config.FormatDuration(lim.DefaultExpiry),
 		AbsBase:       s.absBase(r),
-		TokenName:     lim.Name,
 		AllowVanity:   lim.AllowVanity,
+		MaxSizeBytes:  lim.MaxSize,
 		Stale:         stale,
 	})
 }