pam_userdb(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | MODULE TYPES PROVIDED | RETURN VALUES | EXAMPLES | SEE ALSO | AUTHOR | COLOPHON

PAM_USERDB(8)               Linux-PAM Manual               PAM_USERDB(8)

NAME         top

       pam_userdb - PAM module to authenticate against a db database

SYNOPSIS         top

       pam_userdb.so db=/path/database [debug] [crypt=[crypt|none]]
                     [icase] [dump] [try_first_pass] [use_first_pass]
                     [unknown_ok] [key_only]

DESCRIPTION         top

       The pam_userdb module is used to verify a username/password pair
       against values stored in a Berkeley DB database. The database is
       indexed by the username, and the data fields corresponding to the
       username keys are the passwords.

OPTIONS         top

       crypt=[crypt|none]
           Indicates whether encrypted or plaintext passwords are stored
           in the database. If it is crypt, passwords should be stored
           in the database in crypt(3) form. If none is selected,
           passwords should be stored in the database as plaintext.

       db=/path/database
           Use the /path/database database for performing lookup. There
           is no default; the module will return PAM_IGNORE if no
           database is provided. Note that the path to the database file
           should be specified without the .db suffix.

       debug
           Print debug information.

       dump
           Dump all the entries in the database to the log. Don't do
           this by default!

       icase
           Make the password verification to be case insensitive (ie
           when working with registration numbers and such). Only works
           with plaintext password storage.

       try_first_pass
           Use the authentication token previously obtained by another
           module that did the conversation with the application. If
           this token can not be obtained then the module will try to
           converse. This option can be used for stacking different
           modules that need to deal with the authentication tokens.

       use_first_pass
           Use the authentication token previously obtained by another
           module that did the conversation with the application. If
           this token can not be obtained then the module will fail.
           This option can be used for stacking different modules that
           need to deal with the authentication tokens.

       unknown_ok
           Do not return error when checking for a user that is not in
           the database. This can be used to stack more than one
           pam_userdb module that will check a username/password pair in
           more than a database.

       key_only
           The username and password are concatenated together in the
           database hash as 'username-password' with a random value. if
           the concatenation of the username and password with a dash in
           the middle returns any result, the user is valid. this is
           useful in cases where the username may not be unique but the
           username and password pair are.

MODULE TYPES PROVIDED         top

       The auth and account module types are provided.

RETURN VALUES         top

       PAM_AUTH_ERR
           Authentication failure.

       PAM_AUTHTOK_RECOVERY_ERR
           Authentication information cannot be recovered.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CONV_ERR
           Conversation failure.

       PAM_SERVICE_ERR
           Error in service module.

       PAM_SUCCESS
           Success.

       PAM_USER_UNKNOWN
           User not known to the underlying authentication module.

EXAMPLES         top

           auth  sufficient pam_userdb.so icase db=/etc/dbtest

SEE ALSO         top

       crypt(3), pam.conf(5), pam.d(5), pam(8)

AUTHOR         top

       pam_userdb was written by Cristian Gafton >gafton@redhat.com<.

COLOPHON         top

       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 2021-08-27.  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 to man-pages@man7.org

Linux-PAM Manual               04/01/2016                  PAM_USERDB(8)