| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101 |
- pam_listfile — deny or allow services based on an arbitrary file
- ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
- DESCRIPTION
- pam_listfile is a PAM module which provides a way to deny or allow services
- based on an arbitrary file.
- The module gets the item of the type specified -- user specifies the username,
- PAM_USER; tty specifies the name of the terminal over which the request has
- been made, PAM_TTY; rhost specifies the name of the remote host (if any) from
- which the request was made, PAM_RHOST; and ruser specifies the name of the
- remote user (if available) who made the request, PAM_RUSER -- and looks for an
- instance of that item in the file=filename. filename contains one line per item
- listed. If the item is found, then if sense=allow, PAM_SUCCESS is returned,
- causing the authorization request to succeed; else if sense=deny, PAM_AUTH_ERR
- is returned, causing the authorization request to fail.
- If an error is encountered (for instance, if filename does not exist, or a
- poorly-constructed argument is encountered), then if onerr=succeed, PAM_SUCCESS
- is returned, otherwise if onerr=fail, PAM_AUTH_ERR or PAM_SERVICE_ERR (as
- appropriate) will be returned.
- An additional argument, apply=, can be used to restrict the application of the
- above to a specific user (apply=username) or a given group (apply=@groupname).
- This added restriction is only meaningful when used with the tty, rhost and
- shell items.
- Besides this last one, all arguments should be specified; do not count on any
- default behavior.
- No credentials are awarded by this module.
- OPTIONS
- item=[tty|user|rhost|ruser|group|shell]
- What is listed in the file and should be checked for.
- sense=[allow|deny]
- Action to take if found in file, if the item is NOT found in the file, then
- the opposite action is requested.
- file=/path/filename
- File containing one item per line. The file needs to be a plain file and
- not world writable.
- onerr=[succeed|fail]
- What to do if something weird happens like being unable to open the file.
- apply=[user|@group]
- Restrict the user class for which the restriction apply. Note that with
- item=[user|ruser|group] this does not make sense, but for item=[tty|rhost|
- shell] it have a meaning.
- quiet
- Do not treat service refusals or missing list files as errors that need to
- be logged.
- EXAMPLES
- Classic 'ftpusers' authentication can be implemented with this entry in /etc/
- pam.d/ftpd:
- #
- # deny ftp-access to users listed in the /etc/ftpusers file
- #
- auth required pam_listfile.so \
- onerr=succeed item=user sense=deny file=/etc/ftpusers
- Note, users listed in /etc/ftpusers file are (counterintuitively) not allowed
- access to the ftp service.
- To allow login access only for certain users, you can use a /etc/pam.d/login
- entry like this:
- #
- # permit login to users listed in /etc/loginusers
- #
- auth required pam_listfile.so \
- onerr=fail item=user sense=allow file=/etc/loginusers
- For this example to work, all users who are allowed to use the login service
- should be listed in the file /etc/loginusers. Unless you are explicitly trying
- to lock out root, make sure that when you do this, you leave a way for root to
- log in, either by listing root in /etc/loginusers, or by listing a user who is
- able to su to the root account.
- AUTHOR
- pam_listfile was written by Michael K. Johnson <johnsonm@redhat.com> and Elliot
- Lee <sopwith@cuc.edu>.
|
