ParagonIE_Sodium_Compat::crypto_kx_client_session_keys( string $keypair, string $serverPublicKey ): array{0:

2128    public static function crypto_kx_client_session_keys(2129        #[\SensitiveParameter]2130        $keypair,2131        $serverPublicKey2132    ) {2133        ParagonIE_Sodium_Core_Util::declareScalarType($keypair, 'string', 1);2134        ParagonIE_Sodium_Core_Util::declareScalarType($serverPublicKey, 'string', 2);2135 2136        $keypair = (string) $keypair;2137        $serverPublicKey = (string) $serverPublicKey;2138 2139        if (ParagonIE_Sodium_Core_Util::strlen($keypair) !== self::CRYPTO_KX_KEYPAIRBYTES) {2140            throw new SodiumException('keypair should be SODIUM_CRYPTO_KX_KEYPAIRBYTES bytes');2141        }2142        if (ParagonIE_Sodium_Core_Util::strlen($serverPublicKey) !== self::CRYPTO_KX_PUBLICKEYBYTES) {2143            throw new SodiumException('public keys must be SODIUM_CRYPTO_KX_PUBLICKEYBYTES bytes');2144        }2145 2146        $sk = self::crypto_kx_secretkey($keypair);2147        $pk = self::crypto_kx_publickey($keypair);2148        $h = self::crypto_generichash_init(null, self::CRYPTO_KX_SESSIONKEYBYTES * 2);2149        self::crypto_generichash_update($h, self::crypto_scalarmult($sk, $serverPublicKey));2150        self::crypto_generichash_update($h, $pk);2151        self::crypto_generichash_update($h, $serverPublicKey);2152        $sessionKeys = self::crypto_generichash_final($h, self::CRYPTO_KX_SESSIONKEYBYTES * 2);2153        return array(2154            ParagonIE_Sodium_Core_Util::substr(2155                $sessionKeys,2156                0,2157                self::CRYPTO_KX_SESSIONKEYBYTES2158            ),2159            ParagonIE_Sodium_Core_Util::substr(2160                $sessionKeys,2161                self::CRYPTO_KX_SESSIONKEYBYTES,2162                self::CRYPTO_KX_SESSIONKEYBYTES2163            )2164        );2165    }