Jose\Algorithm\KeyEncryption\RSA::encryptKey PHP Method

    public function encryptKey(JWKInterface $key, $cek, array $complete_headers, array &$additional_headers)
    {
        $this->checkKey($key);
        $pub = RSAKey::toPublic(new RSAKey($key));
        if (self::ENCRYPTION_OAEP === $this->getEncryptionMode()) {
            $encrypted = JoseRSA::encrypt($pub, $cek, $this->getHashAlgorithm());
            Assertion::string($encrypted, 'Unable to encrypt the data.');
            return $encrypted;
        } else {
            $res = openssl_public_encrypt($cek, $encrypted, $pub->toPEM(), OPENSSL_PKCS1_PADDING | OPENSSL_RAW_DATA);
            Assertion::true($res, 'Unable to encrypt the data.');
            return $encrypted;
        }
    }