ParagonIE_Sodium_Crypto32::box_seal( string $message, string $publicKey ): string

448    public static function box_seal($message, $publicKey)449    {450        /** @var string $ephemeralKeypair */451        $ephemeralKeypair = self::box_keypair();452 453        /** @var string $ephemeralSK */454        $ephemeralSK = self::box_secretkey($ephemeralKeypair);455 456        /** @var string $ephemeralPK */457        $ephemeralPK = self::box_publickey($ephemeralKeypair);458 459        /** @var string $nonce */460        $nonce = self::generichash(461            $ephemeralPK . $publicKey,462            '',463            24464        );465 466        /** @var string $keypair - The combined keypair used in crypto_box() */467        $keypair = self::box_keypair_from_secretkey_and_publickey($ephemeralSK, $publicKey);468 469        /** @var string $ciphertext Ciphertext + MAC from crypto_box */470        $ciphertext = self::box($message, $nonce, $keypair);471        try {472            ParagonIE_Sodium_Compat::memzero($ephemeralKeypair);473            ParagonIE_Sodium_Compat::memzero($ephemeralSK);474            ParagonIE_Sodium_Compat::memzero($nonce);475        } catch (SodiumException $ex) {476            $ephemeralKeypair = null;477            $ephemeralSK = null;478            $nonce = null;479        }480        return $ephemeralPK . $ciphertext;481    }