Security-Enhanced Linux secures the gssd processes via flexible mandatory access control.
If you want to allow gssd to read temp directory. For access to kerberos tgt, you must turn on the gssd_read_tmp boolean.
setsebool -P gssd_read_tmp 1
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd serve for the gssd_t, you must turn on the authlogin_nsswitch_use_ldap boolean.
setsebool -P authlogin_nsswitch_use_ldap 1
If you want to allow confined applications to run with kerberos for the gssd_t, you must turn on the kerberos_enabled boolean.
setsebool -P kerberos_enabled 1
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux gssd policy is very flexible allowing users to setup their gssd processes in as secure a method as possible.
The following file types are defined for gssd:
gssd_exec_t
- Set files with the gssd_exec_t type, if you want to transition an executable to the gssd_t domain.
gssd_keytab_t
- Set files with the gssd_keytab_t type, if you want to treat the files as kerberos keytab files.
gssd_tmp_t
- Set files with the gssd_tmp_t type, if you want to store gssd temporary files in the /tmp directories.
Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels.
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux gssd policy is very flexible allowing users to setup their gssd processes in as secure a method as possible.
The following process types are defined for gssd:
gssd_t
Note: semanage permissive -a PROCESS_TYPE can be used to make a process type permissive. Permissive process types are not denied access by SELinux. AVC messages will still be generated.
The SELinux user type gssd_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.
auth_cache_t
/var/cache/coolkey(/.*)?
gssd_tmp_t
krb5_host_rcache_t
/var/cache/krb5rcache(/.*)?
/var/tmp/nfs_0
/var/tmp/host_0
/var/tmp/imap_0
/var/tmp/HTTP_23
/var/tmp/HTTP_48
/var/tmp/ldap_55
/var/tmp/ldap_487
/var/tmp/ldapmap1_0
user_tmp_t
/var/run/user(/.*)?
/tmp/gconfd-.*
var_lib_nfs_t
/var/lib/nfs(/.*)?
xdm_tmp_t
/tmp/.X11-unix(/.*)?
/tmp/.ICE-unix(/.*)?
/tmp/.X0-lock
semanage permissive can also be used to manipulate whether or not a process type is permissive.
semanage module can also be used to enable/disable/install/remove policy modules.
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy setting