Old format available?
I'm wondering if I can use this type : 3910 md5(md5($pass).md5($salt)) in hashcat?

md5(md5($pass).$salt) would work too...

if so, how? In hashcat 3.0 it doesnt seem to work...
It's pretty close to old vBulletin format, but vbulletin has a salt lenght fixed which doesnt work with what I need...

BTW.. I know salts.. im not bruteforcing any of those.
There's no algorithm that you can use out of the box to do that. You need to patch a kernel.