1PASSWDQC.CONF(5) BSD File Formats Manual PASSWDQC.CONF(5)
2
4 passwdqc.conf — libpasswdqc configuration file
5
7 libpasswdqc is a simple password strength checking library. In addition
8 to checking regular passwords, it offers support for passphrases and can
9 provide randomly generated ones. A passwdqc.conf configuration file may
10 be used to override default libpasswdqc settings.
11
13 A passwdqc.conf file consists of 0 or more lines of the following format:
14 option=value
15 Empty lines and lines beginning with “#” are ignored. Whitespace charac‐
17 ters between the option, “=”, and value are not allowed.
18
20 config=FILE
21 Load the specified configuration FILE in the passwdqc.conf for‐
22 mat. This file may define any options described in this manual,
23 including load of yet another configuration file, but loops are
24 not allowed.
25
27 min=N0,N1,N2,N3,N4
28 (default: min=disabled,24,11,8,7) The minimum allowed password
29 lengths for different kinds of passwords/passphrases. The key‐
30 word disabled can be used to disallow passwords of a given kind
31 regardless of their length. Each subsequent number is required
32 to be no larger than the preceding one.
33 N0 is used for passwords consisting of characters from one char‐
35 acter class only. The character classes are: digits, lower-case
36 letters, upper-case letters, and other characters. There is also
37 a special class for non-ASCII characters, which could not be
38 classified, but are assumed to be non-digits.
39 N1 is used for passwords consisting of characters from two char‐
41 acter classes that do not meet the requirements for a passphrase.
42 N2 is used for passphrases. Note that besides meeting this
44 length requirement, a passphrase must also consist of a suffi‐
45 cient number of words (see the passphrase option below).
46 N3 and N4 are used for passwords consisting of characters from
48 three and four character classes, respectively.
49 When calculating the number of character classes, upper-case let‐
51 ters used as the first character and digits used as the last
52 character of a password are not counted.
53 In addition to being sufficiently long, passwords are required to
55 contain enough different characters for the character classes and
56 the minimum length they have been checked against.
57 max=N (default: max=40) The maximum allowed password length. This can
59 be used to prevent users from setting passwords that may be too
60 long for some system services. The value 8 is treated specially:
61 if max is set to 8, passwords longer than 8 characters will not
62 be rejected, but will be truncated to 8 characters for the
63 strength checks and the user will be warned. This is to be used
64 with the traditional DES-based password hashes, which truncate
65 the password at 8 characters.
66 It is important that you do set max=8 if you are using the tradi‐
68 tional hashes, or some weak passwords will pass the checks.
69 passphrase=N
71 (default: passphrase=3) The number of words required for a
72 passphrase, or 0 to disable the support for user-chosen
73 passphrases.
74 match=N
76 (default: match=4) The length of common substring required to
77 conclude that a password is at least partially based on informa‐
78 tion found in a character string, or 0 to disable the substring
79 search. Note that the password will not be rejected once a weak
80 substring is found; it will instead be subjected to the usual
81 strength requirements with the weak substring partially dis‐
82 counted.
83 The substring search is case-insensitive and is able to detect
85 and remove a common substring spelled backwards.
86 similar=permit|deny
88 (default: similar=deny) Whether a new password is allowed to be
89 similar to the old one. The passwords are considered to be simi‐
90 lar when there is a sufficiently long common substring and the
91 new password with the substring partially discounted would be
92 weak.
93 random=N[,only]
95 (default: random=47) The size of randomly-generated passphrases
96 in bits (24 to 85), or 0 to disable this feature. Any passphrase
97 that contains the offered randomly-generated string will be
98 allowed regardless of other possible restrictions.
99 The only modifier can be used to disallow user-chosen passwords.
101
103 enforce=none|users|everyone
104 (default: enforce=everyone) The PAM module can be configured to
105 warn of weak passwords only, but not actually enforce strong
106 passwords. The users setting will enforce strong passwords for
107 invocations by non-root users only.
108 non-unix
110 Normally, the PAM module uses getpwnam(3) to obtain the user's
111 personal login information and use that during the password
112 strength checks. This behavior can be disabled with the non-unix
113 option.
114 retry=N
116 (default: retry=3) The number of times the PAM module will ask
117 for a new password if the user fails to provide a sufficiently
118 strong password and enter it twice the first time.
119 ask_oldauthtok[=update]
121 Ask for the old password as well. Normally, the PAM module
122 leaves this task for subsequent modules. With no argument, the
123 ask_oldauthtok option will cause the PAM module to ask for the
124 old password during the preliminary check phase. If the
125 ask_oldauthtok option is specified with the update argument, the
126 PAM module will do that during the update phase.
127 check_oldauthtok
129 This tells the PAM module to validate the old password before
130 giving a new password prompt. Normally, this task is left for
131 subsequent modules.
132 The primary use for this option is when ask_oldauthtok=update is
134 also specified, in which case no other module gets a chance to
135 ask for and validate the password. Of course, this will only
136 work with UNIX passwords.
137 use_first_pass, use_authtok
139 Use the new password obtained by other modules stacked before the
140 PAM module. This disables user interaction within the PAM mod‐
141 ule. The only difference between use_first_pass and use_authtok
142 is that the former is incompatible with ask_oldauthtok.
143
145 /etc/passwdqc.conf.
146
148 getpwnam(3), pam_passwdqc(8).
149 http://www.openwall.com/passwdqc/
151
153 The pam_passwdqc module was written for Openwall GNU/*/Linux by Solar
154 Designer <solar at openwall.com>. This manual page was derived from
155 pam_passwdqc(8). The latter, derived from the author's documentation, was
156 written for the FreeBSD Project by ThinkSec AS and NAI Labs, the Security
157 Research Division of Network Associates, Inc. under DARPA/SPAWAR contract
158 N66001-01-C-8035 (“CBOSS”), as part of the DARPA CHATS research program.
159Openwall Project March 13, 2010 Openwall Project