kadmind_selinux (8) - Linux Manuals
kadmind_selinux: Security Enhanced Linux Policy for the kadmind processes
NAME
kadmind_selinux - Security Enhanced Linux Policy for the kadmind processesDESCRIPTION
Security-Enhanced Linux secures the kadmind processes via flexible mandatory access control.
The kadmind processes execute with the kadmind_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
For example:
ps -eZ | grep kadmind_t
ENTRYPOINTS
The kadmind_t SELinux type can be entered via the kadmind_exec_t file type.
The default entrypoint paths for the kadmind_t domain are the following:
/usr/(kerberos/)?sbin/kadmind, /usr/(kerberos/)?sbin/_kadmind, /usr/kerberos/sbin/kadmin.local
PROCESS TYPES
SELinux defines process types (domains) for each process running on the systemYou can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux kadmind policy is very flexible allowing users to setup their kadmind processes in as secure a method as possible.
The following process types are defined for kadmind:
kadmind_t
Note: semanage permissive -a kadmind_t can be used to make the process type kadmind_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
BOOLEANS
SELinux policy is customizable based on least access required. kadmind policy is extremely flexible and has several booleans that allow you to manipulate the policy and run kadmind with the tightest access possible.
If you want to allow all daemons to write corefiles to /, you must turn on the daemons_dump_core boolean. Disabled by default.
setsebool -P daemons_dump_core 1
If you want to enable cluster mode for daemons, you must turn on the daemons_enable_cluster_mode boolean. Enabled by default.
setsebool -P daemons_enable_cluster_mode 1
If you want to allow all daemons to use tcp wrappers, you must turn on the daemons_use_tcp_wrapper boolean. Disabled by default.
setsebool -P daemons_use_tcp_wrapper 1
If you want to allow all daemons the ability to read/write terminals, you must turn on the daemons_use_tty boolean. Disabled by default.
setsebool -P daemons_use_tty 1
If you want to deny any process from ptracing or debugging any other processes, you must turn on the deny_ptrace boolean. Enabled by default.
setsebool -P deny_ptrace 1
If you want to allow all domains to use other domains file descriptors, you must turn on the domain_fd_use boolean. Enabled by default.
setsebool -P domain_fd_use 1
If you want to allow all domains to have the kernel load modules, you must turn on the domain_kernel_load_modules boolean. Disabled by default.
setsebool -P domain_kernel_load_modules 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 enable reading of urandom for all domains, you must turn on the global_ssp boolean. Disabled by default.
setsebool -P global_ssp 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
MANAGED FILES
The SELinux process type kadmind_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.
anon_inodefs_t
cluster_conf_t
cluster_var_lib_t
cluster_var_run_t
kadmind_log_t
kadmind_tmp_t
kadmind_var_run_t
krb5kdc_conf_t
krb5kdc_lock_t
krb5kdc_principal_t
root_t
security_t
FILE CONTEXTS
SELinux requires files to have an extended attribute to define the file type.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 kadmind policy is very flexible allowing users to setup their kadmind processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the kadmind, 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 kadmind_var_run_t '/srv/mykadmind_content(/.*)?'
restorecon -R -v /srv/mykadmind_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for kadmind:
kadmind_exec_t
- Set files with the kadmind_exec_t type, if you want to transition an executable to the kadmind_t domain.
- Paths:
-
/usr/(kerberos/)?sbin/kadmind, /usr/(kerberos/)?sbin/_kadmind, /usr/kerberos/sbin/kadmin.local
kadmind_log_t
- Set files with the kadmind_log_t type, if you want to treat the data as kadmind log data, usually stored under the /var/log directory.
kadmind_tmp_t
- Set files with the kadmind_tmp_t type, if you want to store kadmind temporary files in the /tmp directories.
- Paths:
-
/var/tmp/kadmin_0, /var/tmp/kiprop_0
kadmind_var_run_t
- Set files with the kadmind_var_run_t type, if you want to store the kadmind files under the /run or /var/run 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.
COMMANDS
semanage fcontext can also be used to manipulate default file context mappings.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 settings.