PWQCHECK(1) BSD General Commands Manual PWQCHECK(1)
NAME
pwqcheck -- Check passphrase quality
SYNOPSIS
pwqcheck [options]
DESCRIPTION
The pwqcheck program checks passphrase quality using the libpasswdqc library. By default, it expects to read 3 lines from standard input:
first line is a new password,
second line is an old password, and
third line is either an existing account name or a passwd(5) entry.
There are a number of supported options, which can be used to control the pwqcheck behavior.
pwqcheck prints OK on success. Scripts invoking pwqcheck are suggested to check for both a zero exit status and the OK line.
OPTIONS
min=N0,N1,N2,N3,N4
(default: min=disabled,24,11,8,7) The minimum allowed password lengths for different kinds of passwords/passphrases. The keyword
disabled can be used to disallow passwords of a given kind regardless of their length. Each subsequent number is required to be no
larger than the preceding one.
N0 is used for passwords consisting of characters from one character class only. The character classes are: digits, lower-case let-
ters, upper-case letters, and other characters. There is also a special class for non-ASCII characters, which could not be classi-
fied, but are assumed to be non-digits.
N1 is used for passwords consisting of characters from two character classes that do not meet the requirements for a passphrase.
N2 is used for passphrases. Note that besides meeting this length requirement, a passphrase must also consist of a sufficient number
of words (see the passphrase option below).
N3 and N4 are used for passwords consisting of characters from three and four character classes, respectively.
When calculating the number of character classes, upper-case letters used as the first character and digits used as the last charac-
ter of a password are not counted.
In addition to being sufficiently long, passwords are required to contain enough different characters for the character classes and
the minimum length they have been checked against.
max=N (default: max=40) The maximum allowed password length. This can be used to prevent users from setting passwords that may be too long
for some system services. The value 8 is treated specially: if max is set to 8, passwords longer than 8 characters will not be
rejected, but will be truncated to 8 characters for the strength checks and the user will be warned. This is to be used with the
traditional DES-based password hashes, which truncate the password at 8 characters.
It is important that you do set max=8 if you are using the traditional hashes, or some weak passwords will pass the checks.
passphrase=N
(default: passphrase=3) The number of words required for a passphrase.
match=N
(default: match=4) The length of common substring required to conclude that a password is at least partially based on information
found in a character string, or 0 to disable the substring search. Note that the password will not be rejected once a weak substring
is found; it will instead be subjected to the usual strength requirements with the weak substring partially discounted.
The substring search is case-insensitive and is able to detect and remove a common substring spelled backwards.
config=FILE
Load config FILE in the passwdqc.conf format. This file may define any options described in passwdqc.conf(5), but only the min, max,
passphrase, match, and config options are honored by pwqcheck.
-1 Read just 1 line (new passphrase). This is needed to use pwqcheck as the passwordcheck program on OpenBSD - e.g., with ":password-
check=/usr/bin/pwqcheck -1:" in the "default" section in /etc/login.conf.
-2 Read just 2 lines (new and old passphrases).
--multi
Check multiple passphrases (until EOF). This option may be used on its own or along with the -1 or -2 options. pwqcheck will read
1, 2, or 3 lines and will output one line per passphrase to check. The lines will start with either OK or a message explaining why
the passphrase did not pass the checks, followed by a colon and a space, and finally followed by the passphrase. The explanatory
message is guaranteed to not include a colon. With this option, the exit status of pwqcheck depends solely on whether there were any
errors preventing the strength of passphrases from being fully checked or not. A primary use for this option is to test different
policies and/or different versions of passwdqc on large passphrase lists.
--version
Output pwqcheck program version and exit.
-h, --help
Output pwqcheck help text and exit.
EXIT STATUS
pwqcheck exits with non-zero status when it encounters invalid config file, invalid option, invalid parameter value, invalid data in standard
input, and in any case when it fails to check passphrase strength. Without the --multi option, pwqcheck also exits with non-zero status when
it detects a weak passphrase.
FILES
/etc/passwdqc.conf.
SEE ALSO
pwqgen(1), passwd(5), passwdqc.conf(5), pam_passwdqc(8).
http://www.openwall.com/passwdqc/
AUTHORS
The pam_passwdqc module was written for Openwall GNU/*/Linux by Solar Designer. The pwqcheck program was originally written for ALT
GNU/*/Linux by Dmitry V. Levin, indirectly reusing code from pam_passwdqc (via libpasswdqc). This manual page (derived from the pam_passwdqc
documentation) was written for Openwall GNU/*/Linux by Dmitry V. Levin.
Openwall Project March 15, 2010 Openwall Project