Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Tue, 24 Jul 2012 12:06:05 +0200
From: Frank Dittrich <>
Subject: Confusing --mem-file-size=SIZE description

The parameter --mem-file-size is mentioned in the usage output:
--mem-file-size=SIZE      size threshold for wordlist preload (default 5 MB)

It is also mentioned in doc/OPTIONS.
--mem-file-size=SIZE      max. size of wordlist to preload into memory.

The unit is not mentioned in the description, so I assume it is in bytes.
That means, to change the value from default 5 MB to 100 MB, I would
have to use --mem-file-size=100000000. Is that correct?
It would be nice to clarify this in doc/OPTIONS.

The parameter --mem-file-size is also mentioned in doc/README.mpi.
Here, the special SIZE values 0, 1, 2 are mentioned.
Apparently, for MPI this parameter is mis-used for something completely
different. Especially the --mem-file-size=0 meaning in MPI mode is
unfortunate, since without MPI, this means: load the complete file into
memory. If you have enough memory, this is usually what you want.
But for MPI that means, the sequence of password candidates tried will
not be optimal for wordlists with candidates sorted by popularity.

Is this documentation still correct?

If yes, should a new (possibly hidden) parameter replace this obscure
meaning of --mem-file-size?
This parameter could be disabled for non-MPI builds.


Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.