pam_pwhistory(8)

1PAM_PWHISTORY(8)               Linux-PAM Manual               PAM_PWHISTORY(8)
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NAME

6       pam_pwhistory - PAM module to remember last passwords
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SYNOPSIS

9       pam_pwhistory.so [debug] [use_authtok] [enforce_for_root] [remember=N]
10                        [retry=N] [authtok_type=STRING]
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DESCRIPTION

13       This module saves the last passwords for each user in order to force
14       password change history and keep the user from alternating between the
15       same password too frequently.
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17       This module does not work together with kerberos. In general, it does
18       not make much sense to use this module in conjunction with NIS or LDAP,
19       since the old passwords are stored on the local machine and are not
20       available on another machine for password history checking.
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OPTIONS

23       debug
24           Turns on debugging via syslog(3).
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26       use_authtok
27           When password changing enforce the module to use the new password
28           provided by a previously stacked password module (this is used in
29           the example of the stacking of the pam_passwdqc module documented
30           below).
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32       enforce_for_root
33           If this option is set, the check is enforced for root, too.
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35       remember=N
36           The last N passwords for each user are saved in
37           /etc/security/opasswd. The default is 10. Value of 0 makes the
38           module to keep the existing contents of the opasswd file unchanged.
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40       retry=N
41           Prompt user at most N times before returning with error. The
42           default is 1.
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44       authtok_type=STRING
45           See pam_get_authtok(3) for more details.
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MODULE TYPES PROVIDED

48       Only the password module type is provided.
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RETURN VALUES

51       PAM_AUTHTOK_ERR
52           No new password was entered, the user aborted password change or
53           new password couldn't be set.
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55       PAM_IGNORE
56           Password history was disabled.
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58       PAM_MAXTRIES
59           Password was rejected too often.
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61       PAM_USER_UNKNOWN
62           User is not known to system.
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EXAMPLES

65       An example password section would be:
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67           #%PAM-1.0
68           password     required       pam_pwhistory.so
69           password     required       pam_unix.so        use_authtok
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72       In combination with pam_passwdqc:
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74           #%PAM-1.0
75           password     required       pam_passwdqc.so    config=/etc/passwdqc.conf
76           password     required       pam_pwhistory.so   use_authtok
77           password     required       pam_unix.so        use_authtok
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FILES

82       /etc/security/opasswd
83           File with password history
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AUTHOR

89       pam_pwhistory was written by Thorsten Kukuk <kukuk@thkukuk.de>
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93Linux-PAM Manual                  09/03/2021                  PAM_PWHISTORY(8)