TokenReplayGuard
Corex\Captcha\TokenReplayGuard · class · Add-ons layer
Prevents a single reCAPTCHA token from being accepted twice. State is a transient keyed on an HMAC fingerprint of the token — never the token itself — with a TTL a little longer than the token’s own validity window. The TTL is the bound and the cleanup: an entry that outlives the token’s expiry is harmless, because an expired token fails the age check first, so no separate pruning job or table is needed. Transients are shared across requests, so two simultaneous submissions of the same token cannot both win. consume() is check-and-set in one call: it returns true exactly once per token (the first caller records the fingerprint) and false thereafter.