Very sensitive subject actually. During the Algerian war in the 50s, the French army did use torture against some prisoners (the technique based on electrical shocks, or "gégéne", became infamous), which triggered very negative reactions (as it should). That behaviour has been remembered and mentioned in the following tensions with northern African countries, and helps build a picture of France as "bad ennemy" to different extremist groups.
I don't think there have been open cases of French torture since (not major enough to become common knowledge anyway), but using torture now would definitely be the worst idea you could imagine. More than fanning the flames, it would be pouring napalm on it.