Provided by: apg_2.2.3.dfsg.1-2_i386 bug

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
       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 !!!
              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
              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.

       -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

       apg(1)

AUTHOR

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