class ActiveStorage::VerifiedKeyWithExpiration class_attribute :verifier class << self def encode(key, expires_in: nil) verifier.generate([ key, expires_at(expires_in) ]) end def decode(encoded_key) key, expires_at = verifier.verified(encoded_key) key if key && fresh?(expires_at) end private def expires_at(expires_in) expires_in ? Time.now.utc.advance(seconds: expires_in) : nil end def fresh?(expires_at) expires_at.nil? || Time.now.utc < expires_at end end end