Phalcon: Non-constant-time HMAC verification in `Encryption\Crypt::decrypt` (timing side-channel)

Summary Phalcon\Encryption\Crypt provides authenticated encryption: when useSigning is enabled the default, encrypt appends an HMAC tag and decrypt verifies it before returning the plaintext. The verification compares the attacker-supplied tag against the freshly computed HMAC using PHP/Zephir...