apgbfm

APGBFM(1)                         User Manual                        APGBFM(1)



NAME
       apgbfm - APG Bloom filter management program


SYNOPSIS
       apgbfm -f filter -n numofwords [-q]
       apgbfm -f filter -d dictfile [-q]
       apgbfm -f filter -a word [-q]
       apgbfm -f filter -A dictfile [-q]
       apgbfm -f filter -c word [-q]
       apgbfm -f filter -C dictfile [-q]
       apgbfm [-v] [-h]

DESCRIPTION
       apgbfm is used to manage Bloom filter that is used to restrict password
       generation in APG pasword generation software. Usage of the Bloom
       filter allows to speed up password check for large dictionaries and has
       some other benefits.

       The idea to use Bloom filter for that purpose is came from the
       description of the OPUS project OPUS: Preventing Weak Password Choices
       Purdue Technical Report CSD-TR 92-028 writen by Eugene H. Spafford.

       You can obtain this article from:
       http://www.cerias.purdue.edu/homes/spaf/tech-reps/9128.ps
       It has very nice description of Bloom filter and it's advantages for
       password checking systems.

       In simple words, apgbfm generates n hash values for every word and sets
       corresponding bits in filter file to 1. To check the word apgbfm
       generates the same hash functions for that word and if all n
       corresponding bits in filter file are set to 1 then it suppose that
       word exists in dicionary.  apgbfm uses SHA-1 as a hash function.

       apgbfm can be used as standalone utility, not only with apg, or apgd.

       WARNING !!!
              This is the first release of apgbfm and filter file format can
              be changed in the future. I'll try to make file formats
              compatible but i can not guaranty this.

       WARNING !!!
              apgbfm may slow down your computer during filter creation.

OPTIONS
       -f filter
              use filter as the name for Bloom filter filename.

       -n numofwords
              create new empty filter for numofwords number of words. Useful
              when you want to fill filter dynamicaly.

       -d dictfile
              create new filter from dictfile. It may take a lot of time to
              generate filter from a big dictionary. In that dictionary you
              may place words (one per line) that should not appear as
              generated passwords.  For example: user names common words, etc.
              You even can use one of the dictionaries that come with
              dictionary password crackers.  This check is case sensitive. For
              example, if you want to reject word 'root', you should insert in
              dictfile words: root, Root, RoOt, ... , ROOT.  To indicate that
              program is working apgbfm prints dot for every 100 words added
              in dictionary.

       -a word
              add word to the filter.

       -A dictfile
              add all words from dictfile to the filter. To indicate that
              program is working apgbfm prints dot for every 100 words added
              in dictionary.

       -c word
              check word for appearance in the filter.

       -C dictfile
              check every word from dictfile for appearance in the filter.

       -q     quiet mode.

       -v     print version information.

       -h     print help information.

EXIT CODE
       On successful completion of its task, apgbfm will complete with exit
       code 0.  An exit code of -1 indicates an error occurred.  Textual
       errors are written to the standard error stream.

FILES
       None.

BUGS
       None.  If you've found one, please send bug description to the author.

       This man page is Alpha too.

SEE ALSO
       apgd(8), apg(1)

AUTHOR
       Adel I. Mirzazhanov, <a-del@iname.com>
       Project home page: http://www.adel.nursat.kz/apg/



Automated Password Generator      2002 Jun 12                        APGBFM(1)