Security-Enhanced Linux secures the denyhosts processes via flexible mandatory access control.
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd serve for the denyhosts_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 denyhosts_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 denyhosts policy is very flexible allowing users to setup their denyhosts processes in as secure a method as possible.
The following file types are defined for denyhosts:
denyhosts_exec_t
- Set files with the denyhosts_exec_t type, if you want to transition an executable to the denyhosts_t domain.
denyhosts_initrc_exec_t
- Set files with the denyhosts_initrc_exec_t type, if you want to transition an executable to the denyhosts_initrc_t domain.
denyhosts_var_lib_t
- Set files with the denyhosts_var_lib_t type, if you want to store the denyhosts files under the /var/lib directory.
denyhosts_var_lock_t
- Set files with the denyhosts_var_lock_t type, if you want to treat the files as denyhosts var lock data, stored under the /var/lock directory
denyhosts_var_log_t
- Set files with the denyhosts_var_log_t type, if you want to treat the data as denyhosts var log data, usually stored under the /var/log directory.
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 denyhosts policy is very flexible allowing users to setup their denyhosts processes in as secure a method as possible.
The following process types are defined for denyhosts:
denyhosts_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 denyhosts_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.
denyhosts_var_lib_t
/var/lib/denyhosts(/.*)?
denyhosts_var_lock_t
/var/lock/subsys/denyhosts
net_conf_t
/etc/ntpd?.conf.*
/etc/hosts[^/]*
/etc/yp.conf.*
/etc/denyhosts.*
/etc/hosts.deny.*
/etc/resolv.conf.*
/etc/ntp/step-tickers.*
/etc/sysconfig/networking(/.*)?
/etc/sysconfig/network-scripts(/.*)?
/etc/sysconfig/network-scripts/.*resolv.conf
/etc/ethers
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.
system-config-selinux is a GUI tool available to customize SELinux policy settings.