APGBFM(1)                         User Manual                        APGBFM(1)



NAME
       apgbfm - APG Bloom filter management program


SYNOPSIS
       apgbfm -f filter -n numofwords [-q] [-s]
       apgbfm -f filter -d dictfile [-q] [-s]
       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 -i filter
       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  fil-
       ter  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 descrip-
       tion  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 gener-
       ates  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 !!!
              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.

       -i filter
              print information about filter.

       -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 gener-
              ated 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 dic-
              tionary.

       -a word
              add word to the filter.

       -A dictfile
              add all words from dictfile to the filter. To indicate that pro-
              gram  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.

       -s     create new filter in case-insensitive 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      2003 Jun 19                        APGBFM(1)
