diff options
Diffstat (limited to 'pwgen.1')
| -rw-r--r-- | pwgen.1 | 83 |
1 files changed, 62 insertions, 21 deletions
@@ -1,4 +1,4 @@ -.TH PWGEN 1 "July 2002" "pwgen version 2.02" +.TH PWGEN 1 "June 2005" "pwgen version 2.04" .SH NAME pwgen \- generate pronounceable passwords .SH SYNOPSIS @@ -13,9 +13,19 @@ pwgen \- generate pronounceable passwords .I num_pw ] .SH DESCRIPTION +The +.B pwgen +program generates passwords which are designed to be easily memorized by +humans, while being as secure as possible. Human-memorable passwords +are never going to be as secure as completely completely random +passwords. In particular, passwords generated by .B pwgen -generates passwords which are designed to be easily memorized by humans, -while being as secure as possible. +without the +.B \-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 tendency to be written down, +and are subject to being compromised in that fashion. .PP The .B pwgen @@ -31,16 +41,39 @@ being able to "shoulder-surf" the user's chosen password. When standard output is not a tty, .B pwgen will only generate one password, as this tends to be much more convenient -for shell scripts. This also assures that +for shell scripts, and in order to be +compatible with previous versions of this program. In addition, for +backwards compatibility reasons, .B pwgen -is compatible with a previous version of this program. +will not use upper case letters or numbers by default in this mode, +although this can be overriden using the +.B \-n +and +.B \-c +options. .B .SH OPTIONS .TP +.B \-0, \--no-numerals +Don't include numbers in the generated passwords. +.TP +.B \-1 +Print the generated passwords one per line. +.TP +.B \-A, \--no-capitalize +Don't bother to include any capital letters in the generated passwords. +.TP .B \-a, --alt-phonics This option doesn't do anything special; it is present only for backwards compatibility. .TP +.B \-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 signficantly, 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. +.TP .B \-c, --capitalize Include at least one capital letter in the password. This is the default if the standard output is a tty device. @@ -49,33 +82,41 @@ if the standard output is a tty device. Print the generated passwords in columns. This is the default if the standard output is a tty device. .TP -.B \-n, --numerals -Include at least one number in the password. This is the default -if the standard output is a tty device. -.TP -.B \--no-numerals -Don't include a number in the generated passwords. -.TP -.B \--no-capitalize -Don't bother to include any capital letters in the generated passwords. -.TP .B \-N, --num-passwords=\fInum Generate .I num passwords. This defaults to a screenful if passwords are printed by columns, and one password. .TP +.B \-n, --numerals +Include at least one number in the password. This is the default +if the standard output is a tty device. +.TP +.B \-H, --sha1=\fI/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_favourite.mp3#your@email.com gives +a list of possibles passwords for your pop3 account, and you can +ask this list again and again. +.IP +.B 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. +.TP +.B \-h, --help +Print a help message. +.TP .B \-s, --secure -Generate completely random, hard-to-memorize paswords. These should +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... .TP -.B \-h, --help -Print a help message. -.TP -.B \-1 -Print the generated passwords one per line. +.B \-y, --symbols +Include at least one special character in the password. .SH AUTHOR This version of .B pwgen |