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APG(1) User Manual APG(1)
NAME
apg - generates several random passwords
SYNOPSIS
apg [-a algorithm] [-M mode] [-E char_string] [-n num_of_pass] [-m
min_pass_len] [-x max_pass_len] [-r dictfile] [-b filter_file] [-p
min_substr_len] [-s] [-c cl_seed] [-d] [-y] [-l] [-t] [-k] [-q] [-h]
[-v]
DESCRIPTION
apg generates several random passwords. It uses several password
generation algorithms (currently two) and a built-in pseudo random
number generator.
Default algorithm is pronounceable password generation algorithm
designed by Morrie Gasser and described in A Random Word Generator For
Pronounceable Passwords National Technical Information Service (NTIS)
AD-A-017676. The original paper is very old and had never been put
online, so I have to use NIST implementation described in FIPS-181.
Another algorithm is simple random character generation algorithm, but
it uses four user-defined symbol sets to produce random password. It
means that user can choose type of symbols that should appear in
password. Symbol sets are: numeric symbol set (0,...,9) , capital
letters symbol set (A,...,Z) , small letters symbol set (a,...,z) and
special symbols symbol set (#,@,!,...).
Built-in pseudo random number generator is an implementation of
algorithm described in Appendix C of ANSI X9.17 or RFC1750 with
exception that it uses CAST or SHA-1 instead of Triple DES. It uses
local time with precision of microseconds (see gettimeofday(2)) and
/dev/random (if available) to produce initial random seed.
apg also have the ability to check generated password quality using
dictionary. You can use this ability if you specify command-line
options -r dictfile or -b filtername where dictfile is the dictionary
file name and filtername is the name of Bloom filter file. 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. Bloom filter file should be created with apgbfm(1) utility
included in apg distribution. In future releases I plan to implement
some other techniques to check passwords (like pattern check) just to
make life easier.
OPTIONS
Password generation modes options
-a algorithm
use algorithm for password generation.
0 - (default) pronounceable password generation
1 - random character password generation
-n num_of_pass
generate num_of_pass number of passwords. Default is 6.
-m min_pass_len
generate password with minimum length min_pass_len. If
min_pass_len > max_pass_len then max_pass_len = min_pass_len.
Default minimum password length is 8.
-x max_pass_len
generate password with maximum length max_pass_len. If
min_pass_len > max_pass_len then max_pass_len = min_pass_len.
Default maximum password length is 10.
-M mode
Use symbolsets specified with mode for password generation.
mode is a text string consisting of characters S, s, N, n, C, c,
L, l. Where:
S generator must use special symbol set for every generated
password.
s generator should use special symbol set for password
generation.
N generator must use numeral symbol set for every generated
password.
n generator should use numeral symbol set for password
generation.
C generator must use capital symbol set for every generated
password.
c generator should use capital symbol set for password
generation.
L generator must use small letters symbol set for every
generated password (always present if pronounceable
password generation algorithm is used).
l generator should use small letters symbol set for
password generation.
R,r not supported any more. Use -E char_string option
instead.
mode can not be more than 4 characters in length.
Note:
Usage of L, S, N, C will slow down password generation process.
Examples:
-M sncl or -M SNCL or -M Cn
-E char_string
exclude characters in char_string from password generation
process (in pronounceable password generation mode you can not
exclude small letters). To include special symbols that can be
recognized by shell (apostrophe, quotes, dollar sign, etc.) in
char_string use the backslashed versions.
Examples:
Command apg -a 1 -M n -n 3 -m 8 -E 23456789 will generate a set
of passwords that will look like this
10100110
01111000
11011101
Command apg -a 1 -M nc -n 3 -m 26 -E GHIJKLMNOPQRSTUVWXYZ will
generate a set of passwords that will look like this
16A1653CD4DE5E7BD9584A3476
C8F78E06944AFD57FB9CB882BC
8C8DF37CD792D36D056BBD5002
Password quality control options
-k check every generated password using cracklib. To use this
ability you must enable cracklib support during programm
building.
-r dictfile
check generated passwords for their appearance in dictfile
-b filter_file
check generated passwords for their appearance in filter_file.
filter_file should be created with apgbfm(1) utility.
-p min_substr_len
this option tells apg(1) to check every substring of the
generated password for appearance in filter_file. If any of such
substrings would be found in the filter_file then generated
password would be rejected and apg(1) will generate another one.
min_substr_len specifies minimum substring length to check.
This option is active only if -b option is defined.
Pseudo random number generator options
-s ask user for random sequence for password generation
-c cl_seed
use cl_seed as a random seed for password generation. I use it
when i have to generate passwords in a shell script.
Password output options
-d do NOT use any delimiters between generated passwords. I use it
when i have to generate passwords in a shell script.
-y print generated passwords and crypted passwords (see man
crypt(3))
-q quiet mode (do not print warnings)
-l spell generated passwords. Useful when you want to read
generated password by telephone.
WARNING: Think twice before read your password by phone.
-t print pronunciation for generated pronounceable password
-h print help information and exit
-v print version information and exit
DEFAULT OPTIONS
apg -a 0 -M sncl -n 6 -x 10 -m 8 (new style)
If you want to generate really secure passwords, you should use option
-s. To simplify apg usage, you can write a small shell script. For
example:
[begin]----> pwgen.sh
#!/bin/sh
/usr/local/bin/apg -m 8 -x 12 -s
[ end ]----> pwgen.sh
EXIT CODE
On successful completion of its task, apg will complete with exit code
0. An exit code of -1 indicates an error occurred. Textual errors are
written to the standard error stream.
DIAGNOSTICS
If /dev/random is not available, apg will display a message about it.
FILES
None.
BUGS
None. If you've found one, please send bug description to the author.
SEE ALSO
apgd(8), apgbfm(1)
AUTHOR
Adel I. Mirzazhanov, <a-del@iname.com>
Project home page: http://www.adel.nursat.kz/apg/
Automated Password Generator 2003 Aug 04 APG(1)