PKLA-CHECK-AUTHORI(8) pkla-check-authorization PKLA-CHECK-AUTHORI(8)
NAME
pkla-check-authorization - Evaluate pklocalauthority authorization
configuration
SYNOPSIS
pkla-check-authorization [--help]
pkla-check-authorization [--paths paths] {user-name} {is-local}
{is-active} {action}
DESCRIPTION
pkla-check-authorization interprets non-JavaScript configuration files
described below to determine the response of polkit(8) to authorization
queries.
Note: Authorization decision evaluation is driven by JavaScript rules
as described in polkit(8). pkla-check-authorization is called by a
JavaScript rule file named 49-polkit-pkla-compat.rules; other
JavaScript rules with a higher priority may exist, so the
pkla-check-authorization configuration may not necessarily govern the
final polkit(8) authorization decision.
The ordering of the JavaScript rule files and the ordering of
pkla-check-authorization configuration files is not integrated and uses
different rules; the pkla-check-authorization configuration evaluation
is happens at a single point within the JavaScript rule evaluation
order.
pkla-check-authorization is an internal helper program of
pkla-polkit-compat. You shouldn't need to run it directly, except for
debugging purposes.
The arguments to pkla-check-authorization are, in order:
user-name
Name of the user account asking for authorization
is-local
Whether the attempted action is performed from a local login
session, true or false.
is-active
Whether the attempted action is performed from a currently active
session (e.g. currently active virtual console), true or false.
action
A string identifying the polkit(8) action.
If the configuration specifies an authorization decision,
pkla-check-authorization outputs the decision and a terminating
newline. If no decision is configured, the output is empty.
OPTIONS
-h, --help
Write a summary of the available options to standard output and
exit successfully.
-p, --paths=paths
Search for configuration files in semicolon-separated paths instead
of the default
/var/lib/polkit-1/localauthority;/etc/polkit-1/localauthority.
EXIT STATUS
pkla-check-authorization exits with 0 on success (even if there is no
decision configured), and a non-zero status on error.
DIRECTORY STRUCTURE
Files with .pkla extension are read from all directories located inside
the /etc/polkit-1/localauthority and /var/lib/polkit-1/localauthority
directories (or as specified using the --paths option). By default, the
following sub-directories are installed.
/etc/polkit-1/
`-- localauthority
|-- 10-vendor.d
|-- 20-org.d
|-- 30-site.d
|-- 50-local.d
`-- 90-mandatory.d
and
/var/lib/polkit-1/
`-- localauthority
|-- 10-vendor.d
|-- 20-org.d
|-- 30-site.d
|-- 50-local.d
`-- 90-mandatory.d
The /etc/polkit-1/localauthority hierarchy is intended for local
configuration and the /var/lib/polkit-1/localauthority is intended for
3rd party packages.
Each .pkla file contains one or more authorization entries. If the
underlying filesystem supports file monitoring, the Local Authority
will reload information whenever .pkla files are added, removed or
changed.
Each directory is intended for a specific audience
10-vendor.d
Intended for use by the OS vendor.
20-org.d
Intended for the organization deploying the OS.
30-site.d
Intended for the site deploying the system.
50-local.d
Intended for local usage.
90-mandatory.d
Intended for the organization deploying the OS.
and new directories can be added/removed as needed.
As to regards to the content, each .pkla file is a standard key file
and contains key/value pairs in one or more groups with each group
representing an authorization entry. A .pkla file MUST be named by
using a scheme to ensure that the name is unique, e.g. reverse DNS
notation or similar. For example, if the organization is "Acme Corp"
needs to modify policy for the product "Frobnicator", a name like
com.acme.frobnicator.pkla would be suitable.
AUTHORIZATION ENTRY
Each group in a .pkla file must have a name that is unique within the
file it belongs to. The following keys are recognized:
Identity
A semi-colon separated list of entries to match identities. Each
entry should start with unix-user: or unix-group: to specify
whether to match on a UNIX user name or a UNIX group name, and
continue with a glob matching the group or user name. Netgroups are
supported with the unix-netgroup: prefix, but cannot support glob
syntax. Finally, an entry "default" (with no prefix) can be used to
specify the default match.
Action
A semi-colon separated list of globs to match action identifiers.
ResultActive
The result to return for subjects in an active local session that
matches one or more of the given identities. Allowed values are
similar to what can be used in the defaults section of .policy
files used to define actions, e.g. yes, no, auth_self,
auth_self_keep, auth_admin and auth_admin_keep.
ResultInactive
Like ResultActive but instead applies to subjects in inactive local
sessions.
ResultAny
Like ResultActive but instead applies to any subject.
All keys specified above are required except that only at least one of
ResultAny, ResultInactive and ResultActive must be present.
EVALUATION ORDER
The authorization entries discussed above are consulted using the
following algorithm.
The authorization entries from all .pkla files are ordered using the
following rules. First all the basename of all sub-directories (e.g.
30-site.d) from both the /etc/polkit-1/localauthority and
/var/lib/polkit-1/localauthority directories are enumerated and sorted
(using the C locale). If a name exists in both /etc and /var, the one
in /etc takes precedence. Then all .pkla files are read in order from
this list of sub-directories. For each .pkla file, authorizations from
each file are appended in order resulting in an ordered list of
authorization entries.
For example, given the following files
/var/lib/polkit-1
localauthority
10-vendor.d
| 10-desktop-policy.pkla
20-org.d
30-site.d
50-local.d
55-org.my.company.d
| 10-org.my.company.product.pkla
90-mandatory.d
/etc/polkit-1
localauthority
10-vendor.d
| 01-some-changes-from-a-subvendor.pkla
20-org.d
30-site.d
50-local.d
55-org.my.company.d
| 10-org.my.company.product.pkla
90-mandatory.d
the evaluation order of the .pkla files is:
1. 10-desktop-policy.pkla
2. 01-some-changes-from-a-subvendor.pkla
3. 10-org.my.company.product.pkla (the /var one)
4. 10-org.my.company.product.pkla (the /etc one)
When the list of authorization entries has been calculated, the
authorization check can be made. First, the user of the Subject is
determined and the groups that the user belongs are looked up.
Then, authorization entries that include the "default" field value in
the Identity field are consulted in order. If the authorization entry
matches the data from the authorization check, then the authorization
result from RequireAny, RequireInactive or RequireActive is used.
Next, for each group identity, all authorization entries that contain a
matching group entry are again consulted in the same manner.
Finally, the authorization entries are consulted using the user
identity in the same manner.
Note that processing continues even after a match. This allows for so
called "negative authorizations", see the section called "EXAMPLE" for
further discussion.
EXAMPLE
The following .pkla file grants authorization to all users in the staff
group for actions matching the glob com.example.awesomeproduct.*
provided they are in an active session on the local console:
[Normal Staff Permissions]
Identity=unix-group:staff
Action=com.example.awesomeproduct.*
ResultAny=no
ResultInactive=no
ResultActive=yes
If the users homer and grimes are member of the staff group but policy
requires that an administrator needs to authenticate every time
authorization for any action matching com.example.awesomeproduct.* is
required, one would add
[Exclude Some Problematic Users]
Identity=unix-user:homer;unix-user:grimes
Action=com.example.awesomeproduct.*
ResultAny=no
ResultInactive=no
ResultActive=auth_admin
and make sure this authorization entry is after the first one.
The following entry modifies the default authorization decision (it is
overridden by any entry that matches using unix-user: or unix-group:,
but overrides any defaults set by the application author in an .action
file):
[Disable Access by Default]
Identity=default
Action=com.example.awesomeproduct.*
ResultAny=no
ResultInactive=no
ResultActive=no
FILES
/etc/polkit-1/localauthority, /var/lib/polkit-1/localauthority
Default directories containing decision configuration files.
AUTHOR
Written by David Zeuthen <davidz AT redhat.com> with a lot of help from
many others. Adapted by Miloslav Trma <mitr AT redhat.com>.
SEE ALSO
polkit(8)
polkit-pkla-compat May 2013 PKLA-CHECK-AUTHORI(8)