PAM_SSS(8) SSSD Manual pages PAM_SSS(8)
NAME
pam_sss - PAM module for SSSD
SYNOPSIS
pam_sss.so [quiet] [forward_pass] [use_first_pass] [use_authtok]
[retry=N] [ignore_unknown_user] [ignore_authinfo_unavail]
[domains=X] [allow_missing_name] [prompt_always]
[try_cert_auth] [require_cert_auth]
DESCRIPTION
pam_sss.so is the PAM interface to the System Security Services daemon
(SSSD). Errors and results are logged through syslog(3) with the
LOG_AUTHPRIV facility.
OPTIONS
quiet
Suppress log messages for unknown users.
forward_pass
If forward_pass is set the entered password is put on the stack for
other PAM modules to use.
use_first_pass
The argument use_first_pass forces the module to use a previous
stacked modules password and will never prompt the user - if no
password is available or the password is not appropriate, the user
will be denied access.
use_authtok
When password changing enforce the module to set the new password
to the one provided by a previously stacked password module.
retry=N
If specified the user is asked another N times for a password if
authentication fails. Default is 0.
Please note that this option might not work as expected if the
application calling PAM handles the user dialog on its own. A
typical example is sshd with PasswordAuthentication.
ignore_unknown_user
If this option is specified and the user does not exist, the PAM
module will return PAM_IGNORE. This causes the PAM framework to
ignore this module.
ignore_authinfo_unavail
Specifies that the PAM module should return PAM_IGNORE if it cannot
contact the SSSD daemon. This causes the PAM framework to ignore
this module.
domains
Allows the administrator to restrict the domains a particular PAM
service is allowed to authenticate against. The format is a
comma-separated list of SSSD domain names, as specified in the
sssd.conf file.
NOTE: If this is used for a service not running as root user, e.g.
a web-server, it must be used in conjunction with the
“pam_trusted_users” and “pam_public_domains” options. Please see
the sssd.conf(5) manual page for more information on these two PAM
responder options.
allow_missing_name
The main purpose of this option is to let SSSD determine the user
name based on additional information, e.g. the certificate from a
Smartcard.
The current use case are login managers which can monitor a
Smartcard reader for card events. In case a Smartcard is inserted
the login manager will call a PAM stack which includes a line like
auth sufficient pam_sss.so allow_missing_name
In this case SSSD will try to determine the user name based on the
content of the Smartcard, returns it to pam_sss which will finally
put it on the PAM stack.
prompt_always
Always prompt the user for credentials. With this option
credentials requested by other PAM modules, typically a password,
will be ignored and pam_sss will prompt for credentials again.
Based on the pre-auth reply by SSSD pam_sss might prompt for a
password, a Smartcard PIN or other credentials.
try_cert_auth
Try to use certificate based authentication, i.e. authentication
with a Smartcard or similar devices. If a Smartcard is available
and the service is allowed for Smartcard authentication the user
will be prompted for a PIN and the certificate based authentication
will continue
If no Smartcard is available or certificate based authentication is
not allowed for the current service PAM_AUTHINFO_UNAVAIL is
returned.
require_cert_auth
Do certificate based authentication, i.e. authentication with a
Smartcard or similar devices. If a Smartcard is not available the
user will be prompted to insert one. SSSD will wait for a Smartcard
until the timeout defined by p11_wait_for_card_timeout passed,
please see sssd.conf(5) for details.
If no Smartcard is available after the timeout or certificate based
authentication is not allowed for the current service
PAM_AUTHINFO_UNAVAIL is returned.
MODULE TYPES PROVIDED
All module types (account, auth, password and session) are provided.
If SSSD's PAM responder is not running, e.g. if the PAM responder
socket is not available, pam_sss will return PAM_USER_UNKNOWN when
called as account module to avoid issues with users from other sources
during access control.
RETURN VALUES
PAM_SUCCESS
The PAM operation finished successfully.
PAM_USER_UNKNOWN
The user is not known to the authentication service or the SSSD's
PAM responder is not running.
PAM_AUTH_ERR
Authentication failure. Also, could be returned when there is a
problem with getting the certificate.
PAM_PERM_DENIED
Permission denied. The SSSD log files may contain additional
information about the error.
PAM_IGNORE
See options ignore_unknown_user and ignore_authinfo_unavail.
PAM_AUTHTOK_ERR
Unable to obtain the new authentication token. Also, could be
returned when the user authenticates with certificates and multiple
certificates are available, but the installed version of GDM does
not support selection from multiple certificates.
PAM_AUTHINFO_UNAVAIL
Unable to access the authentication information. This might be due
to a network or hardware failure.
PAM_BUF_ERR
A memory error occurred. Also, could be returned when options
use_first_pass or use_authtok were set, but no password was found
from the previously stacked PAM module.
PAM_SYSTEM_ERR
A system error occurred. The SSSD log files may contain additional
information about the error.
PAM_CRED_ERR
Unable to set the credentials of the user.
PAM_CRED_INSUFFICIENT
The application does not have sufficient credentials to
authenticate the user. For example, missing PIN during smartcard
authentication or missing factor during two-factor authentication.
PAM_SERVICE_ERR
Error in service module.
PAM_NEW_AUTHTOK_REQD
The user's authentication token has expired.
PAM_ACCT_EXPIRED
The user account has expired.
PAM_SESSION_ERR
Unable to fetch IPA Desktop Profile rules or user info.
PAM_CRED_UNAVAIL
Unable to retrieve Kerberos user credentials.
PAM_NO_MODULE_DATA
No authentication method was found by Kerberos. This might happen
if the user has a Smartcard assigned but the pkint plugin is not
available on the client.
PAM_CONV_ERR
Conversation failure.
PAM_AUTHTOK_LOCK_BUSY
No KDC suitable for password change is available.
PAM_ABORT
Unknown PAM call.
PAM_MODULE_UNKNOWN
Unsupported PAM task or command.
PAM_BAD_ITEM
The authentication module cannot handle Smartcard credentials.
FILES
If a password reset by root fails, because the corresponding SSSD
provider does not support password resets, an individual message can be
displayed. This message can e.g. contain instructions about how to
reset a password.
The message is read from the file pam_sss_pw_reset_message.LOC where
LOC stands for a locale string returned by setlocale(3). If there is no
matching file the content of pam_sss_pw_reset_message.txt is displayed.
Root must be the owner of the files and only root may have read and
write permissions while all other users must have only read
permissions.
These files are searched in the directory
/etc/sssd/customize/DOMAIN_NAME/. If no matching file is present a
generic message is displayed.
SEE ALSO
sssd(8), sssd.conf(5), sssd-ldap(5), sssd-krb5(5), sssd-simple(5),
sssd-ipa(5), sssd-ad(5), sssd-files(5), sssd-sudo(5), sssd-session-
recording(5), sss_cache(8), sss_debuglevel(8), sss_obfuscate(8),
sss_seed(8), sssd_krb5_locator_plugin(8), sss_ssh_authorizedkeys(8),
sss_ssh_knownhostsproxy(8), sssd-ifp(5), pam_sss(8). sss_rpcidmapd(5)
sssd-systemtap(5)
AUTHORS
The SSSD upstream - https://github.com/SSSD/sssd/
SSSD 06/07/2024 PAM_SSS(8)
Generated by dwww version 1.14 on Mon Feb 3 13:50:29 CET 2025.