Security-Enhanced Linux secures the rshd processes via flexible mandatory access control.
The rshd processes execute with the rshd_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
ps -eZ | grep rshd_t
The rshd_t SELinux type can be entered via the rshd_exec_t file type.
The default entrypoint paths for the rshd_t domain are the following:
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux rshd policy is very flexible allowing users to setup their rshd processes in as secure a method as possible.
The following process types are defined for rshd:
Note: semanage permissive -a rshd_t can be used to make the process type rshd_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server, you must turn on the authlogin_nsswitch_use_ldap boolean. Disabled by default.
setsebool -P authlogin_nsswitch_use_ldap 1
If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.
setsebool -P fips_mode 1
If you want to allow confined applications to run with kerberos, you must turn on the kerberos_enabled boolean. Enabled by default.
setsebool -P kerberos_enabled 1
If you want to allow system to run with NIS, you must turn on the nis_enabled boolean. Disabled by default.
setsebool -P nis_enabled 1
If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.
setsebool -P nscd_use_shm 1
If you want to enable polyinstantiated directory support, you must turn on the polyinstantiation_enabled boolean. Disabled by default.
setsebool -P polyinstantiation_enabled 1
You can see the types associated with a port by using the following command:
semanage port -l
Policy governs the access confined processes have to these ports. SELinux rshd policy is very flexible allowing users to setup their rshd processes in as secure a method as possible.
The following port types are defined for rshd:
Default Defined Ports: tcp 514
The SELinux process type rshd_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.
all user tmp files
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 rshd policy is very flexible allowing users to setup their rshd processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the rshd, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t rshd_keytab_t '/srv/myrshd_content(/.*)?'
restorecon -R -v /srv/myrshd_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for rshd:
- Set files with the rshd_exec_t type, if you want to transition an executable to the rshd_t domain.
- Set files with the rshd_keytab_t type, if you want to treat the files as kerberos keytab files.
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.
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 port can also be used to manipulate the port definitions
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy settings.