man 8 sssd_krb5_locator_plugin

SSSD_KRB5_LOCATOR_PL(8)        SSSD Manual pages       SSSD_KRB5_LOCATOR_PL(8)

NAME
       sssd_krb5_locator_plugin - Kerberos locator plugin

DESCRIPTION
       The Kerberos locator plugin sssd_krb5_locator_plugin is used by libkrb5
       to find KDCs for a given Kerberos realm. SSSD provides such a plugin to
       guide all Kerberos clients on a system to a single KDC. In general it
       should not matter to which KDC a client process is talking to. But
       there are cases, e.g. after a password change, where not all KDCs are
       in the same state because the new data has to be replicated first. To
       avoid unexpected authentication failures and maybe even account
       lockings it would be good to talk to a single KDC as long as possible.

       libkrb5 will search the locator plugin in the libkrb5 sub-directory of
       the Kerberos plugin directory, see plugin_base_dir in krb5.conf(5) for
       details. The plugin can only be disabled by removing the plugin file.
       There is no option in the Kerberos configuration to disable it. But the
       SSSD_KRB5_LOCATOR_DISABLE environment variable can be used to disable
       the plugin for individual commands. Alternatively the SSSD option
       krb5_use_kdcinfo=False can be used to not generate the data needed by
       the plugin. With this the plugin is still called but will provide no
       data to the caller so that libkrb5 can fall back to other methods
       defined in krb5.conf.

       The plugin reads the information about the KDCs of a given realm from a
       file called kdcinfo.REALM. The file should contain one or more DNS
       names or IP addresses either in dotted-decimal IPv4 notation or the
       hexadecimal IPv6 notation. An optional port number can be added to the
       end separated with a colon, the IPv6 address has to be enclosed in
       squared brackets in this case as usual. Valid entries are:

       o   kdc.example.com

       o   kdc.example.com:321

       o   1.2.3.4

       o   5.6.7.8:99

       o   2001:db8:85a3::8a2e:370:7334

       o   [2001:db8:85a3::8a2e:370:7334]:321

       SSSD's krb5 auth-provider which is used by the IPA and AD providers as
       well adds the address of the current KDC or domain controller SSSD is
       using to this file.

       In environments with read-only and read-write KDCs where clients are
       expected to use the read-only instances for the general operations and
       only the read-write KDC for config changes like password changes a
       kpasswdinfo.REALM is used as well to identify read-write KDCs. If this
       file exists for the given realm the content will be used by the plugin
       to reply to requests for a kpasswd or kadmin server or for the MIT
       Kerberos specific master KDC. If the address contains a port number the
       default KDC port 88 will be used for the latter.

NOTES
       Not all Kerberos implementations support the use of plugins. If
       sssd_krb5_locator_plugin is not available on your system you have to
       edit /etc/krb5.conf to reflect your Kerberos setup.

       If the environment variable SSSD_KRB5_LOCATOR_DEBUG is set to any value
       debug messages will be sent to stderr.

       If the environment variable SSSD_KRB5_LOCATOR_DISABLE is set to any
       value the plugin is disabled and will just return KRB5_PLUGIN_NO_HANDLE
       to the caller.

       If the environment variable SSSD_KRB5_LOCATOR_IGNORE_DNS_FAILURES is
       set to any value plugin will try to resolve all DNS names in kdcinfo
       file. By default plugin returns KRB5_PLUGIN_NO_HANDLE to the caller
       immediately on first DNS resolving failure.

SEE ALSO
       sssd(8), sssd.conf(5), sssd-ldap(5), sssd-ldap-attributes(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                              04/07/2025           SSSD_KRB5_LOCATOR_PL(8)