added no-store headers to api responses

Signed-off-by: RonniSkansing <rskansing@gmail.com>

backend/app/administration.go

@@ -319,8 +319,9 @@ func setupRoutes(
 	// phishing server (app/server.go AssignRoutes), gated to a single global
 	// domain, so the admin port does not need public exposure for SCIM.
 
-	// all other admin routes are protected by the ip allowlist middleware
-	admin := r.Group("/", middleware.IPLimiter)
+	// ip allowlist on all admin routes; NoStore keeps API responses out of the
+	// browser disk cache. static assets are served off the group and stay cacheable.
+	admin := r.Group("/", middleware.IPLimiter, middleware.NoStore)
 	_ = admin
 
 	if !build.Flags.Production {

backend/app/middleware.go

@@ -15,6 +15,7 @@ type Middlewares struct {
 	LoginRateLimiter   gin.HandlerFunc
 	SessionHandler     gin.HandlerFunc
 	SoftSessionHandler gin.HandlerFunc
+	NoStore            gin.HandlerFunc
 }
 
 // NewMiddlewares creates a collection of middlewares
@@ -48,6 +49,7 @@ func NewMiddlewares(
 		LoginRateLimiter:   loginThrottle,
 		SessionHandler:     sessionHandler,
 		SoftSessionHandler: softSessionHandler,
+		NoStore:            middleware.NoStore(),
 	}
 }
 

backend/middleware/noStore.go

@@ -0,0 +1,12 @@
+package middleware
+
+import "github.com/gin-gonic/gin"
+
+// NoStore keeps responses out of the browser disk cache. A handler may set
+// its own Cache-Control afterwards to override it.
+func NoStore() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Header("Cache-Control", "no-store")
+		c.Next()
+	}
+}