Due to a (soon to happen) change of laws here in Germany, I had to remove one package from my repository 
They have changed §202 StGB so that it is considered illegal now to manufacture, code, give away, spread or try to get software which can be considered as usefull on cracking or hacking machines/passwords/...
There is still a chance that this law will be revoked, but we'll have to wait at least until june.
As I cannot tell, if ophCrack will be used by someone this way, I choose to remove it before someone tries to sue me for this 
If you are searching for it, maybe they are still on some mirror I have no control off, who knows?
If you want to build it yourself (or even take over building the package and publishing it in a country where it is still allowed) you can download the last spec for building (2.3.4) from here: ophcrack.spec
I really hate having to do this...