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
       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  Pur-
       due 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 dic-
	      tionary.

       -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/

Automated Password Generator					    2003 Jun 19 							 APGBFM(1)