ge_scalarmult example

if (self::strlen($p) !== 32) {
            throw new SodiumException('Point must be 32 bytes, ' . self::strlen($p) . ' given.');
        }
        $result = self::ristretto255_frombytes($p);
        if ($result['res'] !== 0) {
            throw new SodiumException('Could not multiply points');
        }
        $P = $result['h'];

        $t = self::stringToIntArray($n);
        $t[31] &= 0x7f;
        $Q = self::ge_scalarmult(self::intArrayToString($t), $P);
        $q = self::ristretto255_p3_tobytes($Q);
        if (ParagonIE_Sodium_Compat::is_zero($q)) {
            throw new SodiumException('An unknown error has occurred');
        }
        return $q;
    }

    /** * @param string $n * @return string * @throws SodiumException */