So my web app requires JWT authentication and I decided to make a mockup wrapper class for php-jwt before implementing it into my web app:class JWTWrapper{    public function newToken($issuedAt, $notBefore, $expire, $server, $sessionData){        $tokenId = base64_encode(mcrypt_create_iv(32));        $notBefore = $notBefore + $issuedAt;        $expire = $expire + $notBefore;        $data = [            'iat' => $issuedAt,            'jti' => $tokenId,            'iss' => $server,            'nbf' => $notBefore,            'exp' => $expire,            'data' => $sessionData        ];        $jwt = JWT::encode($data, PRIVATE_KEY, HS512);        return $jwt;    }    public function getToken($jwt){        if($jwt){            try{                $token = JWT::decode($jwt, PRIVATE_KEY, [HS512]);                return $token;            } catch(Exception $e){                return false;            }        } else{            return false;        }    }    public function getTokenData($jwt){        if($jwt){            try{                $token = JWT::decode($jwt, PRIVATE_KEY, [HS512]);                return $token->data;            } catch(Exception $e){                return false;            }        } else{            return false;        }    }}I've been reading over articles about JWT vulnerabilities such as so im really paranoid I might have made some sort of catastrophic mistake like this (even though its not apparent that I have...)
JWT with Firebase php-jwt
php;jwt