pwgen
(1)
名称
pwgen - generate pronounceable passwords
用法概要
pwgen [ OPTION ] [ pw_length ] [ num_pw ]
描述
User Commands PWGEN(1)
NAME
pwgen - generate pronounceable passwords
SYNOPSIS
pwgen [ OPTION ] [ pw_length ] [ num_pw ]
DESCRIPTION
The pwgen program generates passwords which are designed to
be easily memorized by humans, while being as secure as pos-
sible. Human-memorable passwords are never going to be as
secure as completely completely random passwords. In par-
ticular, passwords generated by pwgen without the -s option
should not be used in places where the password could be
attacked via an off-line brute-force attack. On the other
hand, completely randomly generated passwords have a ten-
dency to be written down, and are subject to being compro-
mised in that fashion.
The pwgen program is designed to be used both interactively,
and in shell scripts. Hence, its default behavior differs
depending on whether the standard output is a tty device or
a pipe to another program. Used interactively, pwgen will
display a screenful of passwords, allowing the user to pick
a single password, and then quickly erase the screen. This
prevents someone from being able to "shoulder surf" the
user's chosen password.
When standard output (stdout) is not a tty, pwgen will only
generate one password, as this tends to be much more conve-
nient for shell scripts, and in order to be compatible with
previous versions of this program.
In addition, for backwards compatibility reasons, when std-
out is not a tty and secure password generation mode has not
been requested, pwgen will generate less secure passwords,
as if the -0A options had been passed to it on the command
line. This can be overriden using the -nc options. In the
future, the behavior when stdout is a tty may change, so
shell scripts using pwgen should explicitly specify the -nc
or -0A options. The latter is not recommended for security
reasons, since such passwords are far too easy to guess.
OPTIONS
-0, --no-numerals
Don't include numbers in the generated passwords.
-1 Print the generated passwords one per line.
-A, --no-capitalize
Don't bother to include any capital letters in the gen-
erated passwords.
pwgen version 2.05 Last change: January 2006 1
User Commands PWGEN(1)
-a, --alt-phonics
This option doesn't do anything special; it is present
only for backwards compatibility.
-B, --ambiguous
Don't use characters that could be confused by the user
when printed, such as 'l' and '1', or '0' or 'O'. This
reduces the number of possible passwords significantly,
and as such reduces the quality of the passwords. It
may be useful for users who have bad vision, but in
general use of this option is not recommended.
-c, --capitalize
Include at least one capital letter in the password.
This is the default if the standard output is a tty
device.
-C Print the generated passwords in columns. This is the
default if the standard output is a tty device.
-N, --num-passwords=num
Generate num passwords. This defaults to a screenful
if passwords are printed by columns, and one password.
-n, --numerals
Include at least one number in the password. This is
the default if the standard output is a tty device.
-H, --sha1=/path/to/file[#seed]
Will use the sha1's hash of given file and the optional
seed to create password. It will allow you to compute
the same password later, if you remember the file,
seed, and pwgen's options used. ie: pwgen -H
~/your_favorite.mp3#your@email.com gives a list of pos-
sibles passwords for your pop3 account, and you can ask
this list again and again.
WARNING: The passwords generated using this option are
not very random. If you use this option, make sure the
attacker can not obtain a copy of the file. Also, note
that the name of the file may be easily available from
the ~/.history or ~/.bash_history file.
-h, --help
Print a help message.
-s, --secure
Generate completely random, hard-to-memorize passwords.
These should only be used for machine passwords, since
otherwise it's almost guaranteed that users will simply
write the password on a piece of paper taped to the
monitor...
pwgen version 2.05 Last change: January 2006 2
User Commands PWGEN(1)
-v, --no-vowels
Generate random passwords that do not contain vowels or
numbers that might be mistaken for vowels. It provides
less secure passwords to allow system administrators to
not have to worry with random passwords accidentally
contain offensive substrings.
-y, --symbols
Include at least one special character in the password.
AUTHOR
This version of pwgen was written by Theodore Ts'o
<tytso@alum.mit.edu>. It is modelled after a program origi-
nally written by Brandon S. Allbery, and then later exten-
sively modified by Olaf Titz, Jim Lynch, and others. It
was rewritten from scratch by Theodore Ts'o because the
original program was somewhat of a hack, and thus hard to
maintain, and because the licensing status of the program
was unclear.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | crypto/pwgen |
+---------------+------------------+
|Stability | Committed |
+---------------+------------------+
SEE ALSO
passwd(1)
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from http://source-
forge.net/projects/pwgen/files/pwgen/2.06/pwgen-2.06.tar.gz
Further information about this software can be found on the
open source community website at http://source-
forge.net/projects/pwgen/.
pwgen version 2.05 Last change: January 2006 3