AVideo Unauthenticated Stream Credential Disclosure via Forgeable Token

AVideo (current commit e01e41ecc and earlier) exposes stream credentials through the plugin/Live/view/Live_restreams/getLiveKey.json.php endpoint. Supplying a 'token' request parameter waives both the Live::canRestream() access gate and the restream ownership check, causing the endpoint to return any restream's stream_key and stream_url (credentials for external platforms such as YouTube, Facebook, and Twitch) without authentication. The token is merely encryptString() of an integer id with no user binding, expiry, or authentication tag. Because encryption uses AES-256-CBC with a deterministic IV and no MAC, and because intval() accepts any string beginning with a digit, an unauthenticated attacker can forge valid tokens using the public encryption oracle in view/url2Embed.json.php, disclosing arbitrary users' stream credentials.