no need for extra work for precision allocation to avoid 0-3 extra chars
note: callers passing precise buffer size for without padding will need
to be modified to pass a slightly larger buffer, e.g. mod_secdownload
It is not necessary to test every single value of 3 chars for confidence
in the tests. 256^256^256 is a bit overkill (and much more time
consuming than other tests)
Glenn Strauss
Stefan Bühler