box_seal example

if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
            throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
        }

        if (self::useNewSodiumAPI()) {
            return (string) sodium_crypto_box_seal($plaintext, $publicKey);
        }
        if (self::use_fallback('crypto_box_seal')) {
            return (string) call_user_func('\\Sodium\\crypto_box_seal', $plaintext, $publicKey);
        }
        if (PHP_INT_SIZE === 4) {
            return ParagonIE_Sodium_Crypto32::box_seal($plaintext, $publicKey);
        }
        return ParagonIE_Sodium_Crypto::box_seal($plaintext, $publicKey);
    }

    /** * Opens a message encrypted with crypto_box_seal(). Requires * the recipient's keypair (sk || pk) to decrypt successfully. * * This validates ciphertext integrity. * * @param string $ciphertext Sealed message to be opened * @param string $keypair Your crypto_box keypair * @return string The original plaintext message * @throws SodiumException * @throws TypeError * @psalm-suppress MixedArgument * @psalm-suppress MixedInferredReturnType * @psalm-suppress MixedReturnStatement */