[Nachtjager]

personally I don't think that Hitler wanted any of his non-SS guys to know about the holocaust, because besides the evil people doing that stuff, many german soldiers and generals were good men either doing their job or fighting for what they beleived in, but had they completely known about the death camps, chances are Hitler would have seen a lot of resignations or even upriseings to help the jews. It doesn't surprise me one bit to hear wermacht or even some SS fighters to say that they didn't know about the holocaust.
Then again there were plenty of men who were officers or guards at the death camps who had to have told people about what was going on, and rumors run rampant in this world, so many generals and what not had to have known that something was going on.