This module saves the last passwords for each user in order to force
password change history and keep the user from alternating between
the same password too frequently.
This module does not work together with kerberos. In general, it does
not make much sense to use this module in conjunction with NIS or
LDAP, since the old passwords are stored on the local machine and are
not available on another machine for password history checking.
Turns on debugging via syslog(3).
When password changing enforce the module to use the new password
provided by a previously stacked password module (this is used in
the example of the stacking of the pam_cracklib module documented
If this option is set, the check is enforced for root, too.
The last N passwords for each user are saved in
/etc/security/opasswd. The default is 10. Value of 0 makes the
module to keep the existing contents of the opasswd file
Prompt user at most N times before returning with error. The
default is 1.
See pam_get_authtok(3) for more details.
No new password was entered, the user aborted password change or
new password couldn't be set.
Password history was disabled.
Password was rejected too often.
User is not known to system.
This page is part of the linux-pam (Pluggable Authentication Modules
for Linux) project. Information about the project can be found at
⟨http://www.linux-pam.org/⟩. If you have a bug report for this manual
page, see ⟨//www.linux-pam.org/⟩. This page was obtained from the
tarball Linux-PAM-1.3.0.tar.bz2 fetched from
⟨http://www.linux-pam.org/library/⟩ on 2020-08-13. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
Linux-PAM Manual 04/01/2016 PAM_PWHISTORY(8)