pam_krb5(8) System Administrator's Manual pam_krb5(8)
pam_krb5 - Kerberos 5 authentication
auth required /lib/security/pam_krb5.so
session optional /lib/security/pam_krb5.so
account sufficient /lib/security/pam_krb5.so
password sufficient /lib/security/pam_krb5.so
pam_krb5.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), and Kerberos IV ticket file grabbing. Its main use is as an authentication mod-
ule, but it also supplies the same functions as a session-management module to better sup-
port poorly-written applications, and a couple of other workarounds as well. It also sup-
ports account management 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. When the application subsequently requests deletion
of credentials or closing of the session, the module deletes the ticket files.
debug turns on debugging via syslog(3). Debugging messages are logged with priority
tells pam_krb5.so to obtain credentials without address lists. This may be neces-
sary if your network uses NAT, and should otherwise not be used.
tells pam_krb5.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 out-
ward-facing address here should allow Kerberos authentication to succeed.
tells pam_krb5.so how to identify itself when users attempt to change their pass-
tells pam_krb5.so which directory to use for storing credential caches.
tells pam_krb5.so that credentials it obtains should be forwardable.
tells pam_krb5.so the location of a keytab to use when validating credentials
obtained from KDCs.
tells pam_krb5.so to obtain Kerberos IV credentials for users, in addition to Ker-
beros 5 credentials.
tells pam_krb5.so to ignore authentication attempts by users with UIDs below the
tells pam_krb5.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.
tells pam_krb5.so that credentials it obtains should be proxiable.
overrides the default realm set in /etc/krb5.conf, which pam_krb5.so will attempt to
authenticate users to.
sets the default renewable lifetime for credentials.
tells pam_krb5.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.
sets the default lifetime for credentials.
tells pam_krb5.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
tells pam_krb5.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.
tells pam_krb5.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
tells pam_krb5.so to verify that the TGT obtained from the realm's servers has not
Probably, but let's hope not. If you find any, please email the author.
Nalin Dahyabhai <email@example.com>
Red Hat Linux 2002/02/15 pam_krb5(8)