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=72) 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 wordlist=FILE
95 Deny passwords that are based on lines of the tiny external text
96 FILE, which can reasonably be e.g. a list of a few thousand com‐
97 mon passwords. Common dictionary words may also reasonably be
98 included, especially in a local language other than English, or
99 longer yet common English words. (passwdqc includes a list of a
100 few thousand common English words of lengths from 3 to 6 built
101 in. Any word list possibly specified with this option is used in
102 addition to the built-in word list.)
103 Substring matching and discounting will be used if the match set‐
105 ting above is non-zero. Please note that this is very ineffi‐
106 cient, and isn't to be used with large wordlists.
107 denylist=FILE
109 Deny passwords or passphrases directly appearing in the tiny ex‐
110 ternal text FILE. That file can reasonably be e.g. a list of
111 common passwords if only a relaxed policy is desired and stricter
112 checks are thus disabled (using their separate options). Such
113 policy would only be somewhat effective against online/remote at‐
114 tacks, but not against offline attacks on hashed passwords.
115 filter=FILE
117 Deny passwords or passphrases directly appearing in a maybe huge
118 binary filter FILE created with pwqfilter. This is very effi‐
119 cient, needing at most two random disk reads per query. A filter
120 created from millions of leaked passwords can reasonably be used
121 on top of passwdqc's other checks to further reduce the number of
122 passing yet weak passwords without causing unreasonable inconve‐
123 nience (as e.g. higher minimum lengths and character set require‐
124 ments could).
125 random=N[,only]
127 (default: random=47) The size of randomly-generated passphrases
128 in bits (24 to 136), or 0 to disable this feature. Any
129 passphrase that contains the offered randomly-generated string
130 will be allowed regardless of other possible restrictions.
131 The only modifier can be used to disallow user-chosen passwords.
133
135 enforce=none|users|everyone
136 (default: enforce=everyone) The PAM module can be configured to
137 warn of weak passwords only, but not actually enforce strong
138 passwords. The users setting is like everyone for all PAM ser‐
139 vices except chpasswd and passwd. For these two PAM services
140 users will enforce strong passwords for invocations by non-root
141 users only.
142 non-unix
144 Normally, the PAM module uses getpwnam(3) to obtain the user's
145 personal login information and use that during the password
146 strength checks. This behavior can be disabled with the non-unix
147 option.
148 retry=N
150 (default: retry=3) The number of times the PAM module will ask
151 for a new password if the user fails to provide a sufficiently
152 strong password and enter it twice the first time.
153 ask_oldauthtok[=update]
155 Ask for the old password as well. Normally, the PAM module
156 leaves this task for subsequent modules. With no argument, the
157 ask_oldauthtok option will cause the PAM module to ask for the
158 old password during the preliminary check phase. If the
159 ask_oldauthtok option is specified with the update argument, the
160 PAM module will do that during the update phase.
161 check_oldauthtok
163 This tells the PAM module to validate the old password before
164 giving a new password prompt. Normally, this task is left for
165 subsequent modules.
166 The primary use for this option is when ask_oldauthtok=update is
168 also specified, in which case no other module gets a chance to
169 ask for and validate the password. Of course, this will only
170 work with UNIX passwords.
171 use_first_pass, use_authtok
173 Use the new password obtained by other modules stacked before the
174 PAM module. This disables user interaction within the PAM mod‐
175 ule. The only difference between use_first_pass and use_authtok
176 is that the former is incompatible with ask_oldauthtok.
177 noaudit
179 If audit is enabled at build time, the PAM module logs audit
180 events once user tries to change their credentials. This option
181 disables that audit logging.
182
184 /etc/passwdqc.conf (not read unless this suggested file location is spec‐
185 ified with the config=/etc/passwdqc.conf option).
186
188 getpwnam(3), libpasswdqc(3), pam_passwdqc(8).
189 https://www.openwall.com/passwdqc/
191
193 The pam_passwdqc module was written for Openwall GNU/*/Linux by Solar
194 Designer <solar at openwall.com>. This manual page was derived from
195 pam_passwdqc(8). The latter, derived from the author's documentation, was
196 written for the FreeBSD Project by ThinkSec AS and NAI Labs, the Security
197 Research Division of Network Associates, Inc. under DARPA/SPAWAR contract
198 N66001-01-C-8035 (“CBOSS”), as part of the DARPA CHATS research program.
199Openwall Project March 10, 2021 Openwall Project