pam_krb5afs
pam_krb5afs(8) System Administrator's Manual pam_krb5afs(8)
NAME
pam_krb5afs - Kerberos 5 authentication with AFS support
SYNOPSIS
auth required /lib/security/pam_krb5afs.so
session optional /lib/security/pam_krb5afs.so
account sufficient /lib/security/pam_krb5afs.so
password sufficient /lib/security/pam_krb5afs.so
DESCRIPTION
pam_krb5afs.so is designed to allow smooth integration of Kerberos 5
password- checking with applications built using PAM. It also supports
session-specific ticket files (which are neater), Kerberos IV ticket
file grabbing, and AFS token-grabbing. Its main use is as an authenti-
cation module, but it also supplies the same functions as a session-
management module to better support poorly-written applications, and a
couple of other workarounds as well. It also supports account manage-
ment and password-changing.
When a user logs in, the module's authentication function performs a
simple password check and, if possible, obtains Kerberos 5 and Kerberos
IV credentials, caching them for later use. When the application
requests initialization of credentials (or opens a session), the usual
ticket files are created and AFS tokens are obtained. When the appli-
cation subsequently requests deletion of credentials or closing of the
session, the module destroys the tokens for the current PAG and deletes
the ticket files.
Some applications (notably, wu-ftpd, wu-imapd, and Samba) neither cre-
ate credentials nor open sessions. For these applications, it's best
to use the tokens option to force token-grabbing during the password
check, which is usually the right thing to do for these server apps.
ARGUMENTS
debug turns on debugging via syslog(3). Debugging messages are logged
with priority LOG_DEBUG.
addressless
tells pam_krb5afs.so to obtain credentials without address
lists. This may be necessary if your network uses NAT, and
should otherwise not be used.
hosts=host
tells pam_krb5afs.so to obtain credentials using the address of
the given host in addition to the addresses of interfaces on the
local workstation. For example, if your workstation is behind a
masquerading firewall, specifying the firewall's outward-facing
address here should allow Kerberos authentication to succeed.
afs_cells=cell
tells pam_krb5afs.so to obtain tokens for users in the given
cell when they log in. The default is the current realm name
converted to lower case.
banner=Kerberos
tells pam_krb5afs.so how to identify itself when users attempt to
change their passwords.
ccache_dir=/tmp
tells pam_krb5afs.so which directory to use for storing credential
caches.
forwardable
tells pam_krb5afs.so that credentials it obtains should be for-
wardable.
keytab=/etc/krb5.keytab
tells pam_krb5afs.so the location of a keytab to use when validat-
ing credentials obtained from KDCs.
krb4_convert
tells pam_krb5afs.so to obtain Kerberos IV credentials for users,
in addition to Kerberos 5 credentials.
minimum_uid=0
tells pam_krb5afs.so to ignore authentication attempts by users
with UIDs below the specified number.
no_user_check
tells pam_krb5afs.so to not check if a user exists on the local
system, and to create ccache files owned by the current process's
UID. This is useful for situations where a non-privileged server
process needs to use Kerberized services on behalf of remote users
who may not have local access. Note that such a server should
have an encrypted connection with its client in order to avoid
allowing the user's password to be eavesdropped.
proxiable
tells pam_krb5afs.so that credentials it obtains should be proxi-
able.
realm=realm
overrides the default realm set in /etc/krb5.conf, which
pam_krb5afs.so will attempt to authenticate users to.
renew_lifetime=36000
sets the default renewable lifetime for credentials.
retain_after_close
tells pam_krb5afs.so to retain the ticket after the session has
been closed.
skip_first_pass
tells pam_krb5afs.so to not bother checking a password that has
been set by a module listed earlier in the stack. This option is
included mainly for completeness.
ticket_lifetime=36000
sets the default lifetime for credentials.
tokens
tells pam_krb5afs.so to get AFS tokens for the user immediately if
the password check succeeds. This is necessary for some programs
that never open sessions or attempt to initialize credentials
(PAM's credentials, not Kerberos's). If you have a server app
that requires access to the user's file space, you might need
this.
try_first_pass
tells pam_krb5afs.so to check the password as with use_first_pass,
but to prompt the user for another one if the previously-entered
one fails. This is the default mode of operation.
use_first_pass
tells pam_krb5afs.so to get the user's entered password as it was
stored by a module listed earlier in the stack, usually pam_unix
or pam_pwdb, instead of prompting the user for it.
use_authtok
tells pam_krb5afs.so to never prompt for passwords when changing
passwords. This is useful if you are using pam_cracklib.so to try
to enforce use of less-easy-to-guess passwords.
validate
tells pam_krb5afs.so to verify that the TGT obtained from the
realm's servers has not been spoofed.
FILES
/etc/krb5.conf
SEE ALSO
pam_krb5afs(5)
BUGS
Probably, but let's hope not. If you find any, please email the
author.
AUTHOR
Nalin Dahyabhai <nalin@redhat.com>
Red Hat Linux 2002/02/15 pam_krb5afs(8)
