pam.conf(5) - NetBSD Manual Pages

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PAM.CONF(5)               NetBSD File Formats Manual               PAM.CONF(5)


NAME

     pam.conf -- Pluggable Authentication Modules configuration file


DESCRIPTION

     The pam.conf file specifies how Pluggable Authentication Modules (PAM)
     should operate.  For an overview of the Pluggable Authentication Modules
     framework, see pam(8).

     PAM may be configured using a single /etc/pam.conf configuration file or
     by using multiple configuration files, one for each PAM-aware service,
     located in the /etc/pam.d/ directory.  If /etc/pam.d/ exists,
     /etc/pam.conf will be ignored.  /etc/pam.d/ is the preferred method for
     configuring PAM.

     PAM's configuration is based on ``stacking'' different modules together
     to form a processing chain for the task.  A standard PAM configuration
     stanza is structured as follows:

           [service-name] module-type control-flag module-name [options]

     service-name is used only (and is mandatory) in /etc/pam.conf.  It speci-
     fies the PAM-aware service whose PAM behavior is being configured.  When
     /etc/pam.d/ is used, the name of the configuration file specifies the
     service.

     module-type specifies which of the four classes of PAM module functional-
     ity is being configured.  These four classes are account (account
     management), auth (authentication), password (password management), and
     session (session management).

     control-flag specifies the behavior of the processing chain upon success
     or failure of the PAM module's authentication task.  The following are
     valid values for control-flag:

     binding     If the module succeeds and no earlier module in the chain has
                 failed, the chain is immediately terminated and the request
                 is granted.  If the module fails, the rest of the chain is
                 executed, but the request is ultimately denied.

     requisite   If the module returns success, continue to execute the pro-
                 cessing chain.  If the module fails, immediately return the
                 error code from the first `required' failure.

     required    If the module returns success, continue to execute the pro-
                 cessing chain.  If the module fails, record as a `required'
                 failure and continue to execute the processing chain.  If
                 there are any `required' failures in the processing chain,
                 the chain will ultimately return failure.

     optional    If the module returns success, continue to execute the pro-
                 cessing chain.  If the module fails, record as an `optional'
                 failure and continue to execute the processing chain.

     sufficient  If the module returns success and there have been no recorded
                 `required' failures, immediately return success without call-
                 ing any subsequent modules in the processing chain.  If the
                 module fails, return as an `optional' failure and continue to
                 execute the processing chain.

     module-name specifies the module to execute for this stanza.  This is
     either an absolute path name or a path name relative to the default mod-
     ule location: /usr/lib/security.

     options are additional options that may be specified for the module.
     Refer to the individual modules' documentation for more information on
     available options.

     In addition to the standard configuration stanza format, there is an
     additional stanza format available when /etc/pam.d/ is used:

           module-type include service-name

     This stanza format provides a simple inheritance model for processing
     chains.


FILES

     /etc/pam.conf  monolithic PAM configuration file
     /etc/pam.d/    PAM service configuration file directory


EXAMPLES

     The following auth processing chain for the ``login'' service (located in
     /etc/pam.d/login) performs the following tasks: allows the login if the
     old user and new user are the same, verifies that logins are not disabled
     using the /var/run/nologin file, allows Kerberos 5 password authentica-
     tion, and requires standard UNIX password authentication if Kerberos 5
     failed:

           auth    sufficient      pam_self.so
           auth    required        pam_nologin.so
           auth    sufficient      pam_krb5.so
           auth    required        pam_unix.so


NOTES

     It is important to note that loading a chain will fail if any of the com-
     ponents of the chain fail to load or are not available.  A common situa-
     tion when this can happen is on a system that where components such as
     kerberos(1) or crypto(3) have not been installed.  In that situation
     pam_krb5(8), pam_ksu(8), or pam_ssh(8) might not be present in the sys-
     tem.  In order for a chain to load properly all non-present components
     must be removed from the chain.


SEE ALSO

     login(1), passwd(1), su(1), pam(3), pam(8)


HISTORY

     The pam.conf file format first appeared in NetBSD 3.0.

NetBSD 3.0.2                     March 8, 2005                    NetBSD 3.0.2