chkpwd_selinux - Man Page

Security-Enhanced Linux secures the chkpwd processes via flexible mandatory access control.

The chkpwd processes execute with the chkpwd_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 chkpwd_t

The chkpwd_t SELinux type can be entered via the chkpwd_exec_t file type.

The default entrypoint paths for the chkpwd_t domain are the following:

/usr/bin/validate, /usr/bin/unix_chkpwd, /usr/bin/unix_verify, /usr/libexec/chkpwd/tcb_chkpwd

SELinux defines process types (domains) for each process running on the system

You can see the context of a process using the -Z option to psbP

Policy governs the access confined processes have to files. SELinux chkpwd policy is very flexible allowing users to setup their chkpwd processes in as secure a method as possible.

The following process types are defined for chkpwd:

chkpwd_t

Note: semanage permissive -a chkpwd_t can be used to make the process type chkpwd_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.

SELinux policy is customizable based on least access required.  chkpwd policy is extremely flexible and has several booleans that allow you to manipulate the policy and run chkpwd with the tightest access possible.

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 Apache to use mod_auth_pam, you must turn on the httpd_mod_auth_pam boolean. Disabled by default.

setsebool -P httpd_mod_auth_pam 1

If you want to allow nagios/nrpe to call sudo from NRPE utils scripts, you must turn on the nagios_run_sudo boolean. Disabled by default.

setsebool -P nagios_run_sudo 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

The SELinux process type chkpwd_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.

krb5_host_rcache_t

/var/tmp/krb5_0.rcache2
/var/cache/krb5rcache(/.*)?
/var/tmp/nfs_0
/var/tmp/DNS_25
/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

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 lsbP

Policy governs the access confined processes have to these files. SELinux chkpwd policy is very flexible allowing users to setup their chkpwd processes in as secure a method as possible.

STANDARD FILE CONTEXT

SELinux defines the file context types for the chkpwd, if you wanted to store files with these types in a different paths, you need to execute the semanage command to specify alternate labeling and then use restorecon to put the labels on disk.

semanage fcontext -a -t chkpwd_exec_t '/srv/chkpwd/content(/.*)?'
restorecon -R -v /srv/mychkpwd_content

Note: SELinux often uses regular expressions to specify labels that match multiple files.

The following file types are defined for chkpwd:

chkpwd_exec_t

- Set files with the chkpwd_exec_t type, if you want to transition an executable to the chkpwd_t domain.

Paths:

/usr/bin/validate, /usr/bin/unix_chkpwd, /usr/bin/unix_verify, /usr/libexec/chkpwd/tcb_chkpwd

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 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.

This manual page was auto-generated using sepolicy manpage .

selinux(8), chkpwd(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8)