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PWQCHECK(1) | General Commands Manual | PWQCHECK(1) |
NAME¶
pwqcheck
—
SYNOPSIS¶
pwqcheck [options] |
DESCRIPTION¶
Thepwqcheck
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 letters, upper-case letters, and other characters. There is also a special class for non-ASCII characters, which could not be classified, 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 character 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: ifmax
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 themin
,max
,passphrase
,match
, andconfig
options are honored bypwqcheck
. -1
- Read just 1 line (new passphrase). This is needed to use
pwqcheck
as the passwordcheck program on OpenBSD - e.g., with ":passwordcheck=/usr/bin/pwqcheck -1:\" (without the quotes, but with the trailing backslash) 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 ofpwqcheck
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 (not read unless this suggested file location is specified with theconfig=/etc/passwdqc.conf
option).
SEE ALSO¶
pwqgen(1), passwd(5), passwdqc.conf(5), pam_passwdqc(8).AUTHORS¶
The pam_passwdqc module was written for Openwall GNU/*/Linux by Solar Designer. Thepwqcheck
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.
December 9, 2019 | Openwall Project |