ParagonIE_Sodium_Crypto::box_seal_open( string $message, string $keypair ): string

495    public static function box_seal_open($message, $keypair)496    {497        /** @var string $ephemeralPK */498        $ephemeralPK = ParagonIE_Sodium_Core_Util::substr($message, 0, 32);499 500        /** @var string $ciphertext (ciphertext + MAC) */501        $ciphertext = ParagonIE_Sodium_Core_Util::substr($message, 32);502 503        /** @var string $secretKey */504        $secretKey = self::box_secretkey($keypair);505 506        /** @var string $publicKey */507        $publicKey = self::box_publickey($keypair);508 509        /** @var string $nonce */510        $nonce = self::generichash(511            $ephemeralPK . $publicKey,512            '',513            24514        );515 516        /** @var string $keypair */517        $keypair = self::box_keypair_from_secretkey_and_publickey($secretKey, $ephemeralPK);518 519        /** @var string $m */520        $m = self::box_open($ciphertext, $nonce, $keypair);521        try {522            ParagonIE_Sodium_Compat::memzero($secretKey);523            ParagonIE_Sodium_Compat::memzero($ephemeralPK);524            ParagonIE_Sodium_Compat::memzero($nonce);525        } catch (SodiumException $ex) {526            $secretKey = null;527            $ephemeralPK = null;528            $nonce = null;529        }530        return $m;531    }