Files

91 lines
2.8 KiB
Go

package webui
import (
"encoding/base64"
"encoding/json"
"net/http"
)
// Flash mirrors one Flask flash() message: (message, category).
type Flash struct {
Category string `json:"c"`
Message string `json:"m"`
}
const flashCookieName = "flash"
// setFlash mirrors flask.flash(): appends one message to the flash cookie so it
// survives the redirect that (almost) always follows a form POST in this app.
// No signing: these are cosmetic toast notifications, not a trust boundary.
func setFlash(w http.ResponseWriter, category, message string) {
flashes := []Flash{{Category: category, Message: message}}
encoded, _ := json.Marshal(flashes)
http.SetCookie(w, &http.Cookie{
Name: flashCookieName,
Value: base64.URLEncoding.EncodeToString(encoded),
Path: "/",
HttpOnly: true,
SameSite: http.SameSiteLaxMode,
})
}
// popFlashes mirrors get_flashed_messages(with_categories=true): reads and clears the
// flash cookie so each message is shown exactly once, on the very next render.
func popFlashes(w http.ResponseWriter, r *http.Request) []Flash {
c, err := r.Cookie(flashCookieName)
if err != nil || c.Value == "" {
return nil
}
http.SetCookie(w, &http.Cookie{Name: flashCookieName, Value: "", Path: "/", MaxAge: -1})
raw, err := base64.URLEncoding.DecodeString(c.Value)
if err != nil {
return nil
}
var flashes []Flash
if err := json.Unmarshal(raw, &flashes); err != nil {
return nil
}
return flashes
}
// AppPasswordReveal carries a freshly-generated app password secret across the
// create->redirect hop, kept out of the toast-driven Flash system so it can render
// as its own centered modal (with a copy button) instead of a toast that's easy to
// miss and can't be copied without retyping.
type AppPasswordReveal struct {
Label string `json:"l"`
Secret string `json:"s"`
}
const appPasswordRevealCookieName = "app_pw_reveal"
// setAppPasswordReveal mirrors setFlash but for the one-time secret reveal.
func setAppPasswordReveal(w http.ResponseWriter, label, secret string) {
encoded, _ := json.Marshal(AppPasswordReveal{Label: label, Secret: secret})
http.SetCookie(w, &http.Cookie{
Name: appPasswordRevealCookieName,
Value: base64.URLEncoding.EncodeToString(encoded),
Path: "/",
HttpOnly: true,
SameSite: http.SameSiteLaxMode,
})
}
// popAppPasswordReveal mirrors popFlashes but for the one-time secret reveal.
func popAppPasswordReveal(w http.ResponseWriter, r *http.Request) *AppPasswordReveal {
c, err := r.Cookie(appPasswordRevealCookieName)
if err != nil || c.Value == "" {
return nil
}
http.SetCookie(w, &http.Cookie{Name: appPasswordRevealCookieName, Value: "", Path: "/", MaxAge: -1})
raw, err := base64.URLEncoding.DecodeString(c.Value)
if err != nil {
return nil
}
var reveal AppPasswordReveal
if err := json.Unmarshal(raw, &reveal); err != nil {
return nil
}
return &reveal
}