PostgreSQL permission reports and checks

This extension allows you to review object permissions on a PostgreSQL database.

Cookbook

First, you have to install the extension in the database:

CREATE EXTENSION pg_permissions SCHEMA public;

Then you need to add entries to permission_target that correspond to your desired permissions.

Let's assume we have a schema appschema, and appuser should have SELECT, UPDATE, DELETE and INSERT permissions on all tables and views in that schema:

INSERT INTO public.permission_target
   (role_name, permissions,
    object_type, schema_name)
VALUES
   ('appuser', '{SELECT,INSERT,UPDATE,DELETE}',
    'TABLE', 'appschema');
INSERT INTO public.permission_target
   (role_name, permissions,
    object_type, schema_name)
VALUES
   ('appuser', '{SELECT,INSERT,UPDATE,DELETE}',
    'VIEW', 'appschema');

Of course, the user will need the USAGE privilege on the schema:

INSERT INTO public.permission_target
   (role_name, permissions,
    object_type, schema_name)
VALUES
   ('appuser', '{USAGE}',
    'SCHEMA', 'appschema');

The user also needs USAGE privileges on the appseq sequence in that schema:

INSERT INTO public.permission_target
   (role_name, permissions,
    object_type, schema_name, object_name)
VALUES
   ('appuser', '{USAGE}',
    'SEQUENCE', 'appschema', 'appseq');

Now we can review which permissions are missing and which additional permissions are granted:

SELECT * FROM public.permission_diffs();

 missing | role_name | object_type | schema_name | object_name | column_name | permission
---------+-----------+-------------+-------------+-------------+-------------+------------
 f       | laurenz   | VIEW        | appschema   | appview     |             | SELECT
 t       | appuser   | TABLE       | appschema   | apptable    |             | DELETE
(2 rows)

That means that appuser is missing the DELETE privilege on appschema.apptable which should be granted, while user laurenz has the additional SELECT privilege on appschema.appview (missing is FALSE).

To review the actual permissions on an object, we can use the *_permissions views:

SELECT * FROM schema_permissions
   WHERE role_name = 'appuser' AND schema_name = 'appschema';

 object_type | role_name | schema_name | object_name | column_name | permissions | granted
-------------+-----------+-------------+-------------+-------------+-------------+---------
 SCHEMA      | appuser   | appschema   |             |             | USAGE       | t
 SCHEMA      | appuser   | appschema   |             |             | CREATE      | f
(2 rows)

Usage

Views

The extension provides a number of views:

• database_permissions: permissions granted on the current database

• schema_permissions: permissions granted on schemas

• table_permissions: permissions granted on tables

• view_permissions: permissions granted on views

• column_permissions: permissions granted on table and view columns

• function_permissions: permissions granted on functions

• sequence_permissions: permissions granted on sequences

• all_permissions: permissions on all objects (UNION of the above)

All views have the same columns; a column is NULL if it has no meaning for the current view.

These views can be used to examine the currently granted permissions on database objects.

The granted column of these views can be updated, which causes the appropriate GRANT or REVOKE command to be executed.

Note: Superusers are not shown in the views, as they automatically have all permissions.

Tables

The extension provides a table permission_target with which you can describe the permissions that should be granted on database objects.

If you set a relevant column in permission_target to NULL (e.g., the object_name and column_name columns in a TABLE entry), the meaning is that the entry refers to all possible objects (in the example above, all tables in the schema).

Functions

The table function permission_diffs() checks the desired permissions in permission_target against the actually granted permissions in the views of the extension and returns a table of differences.

If the first column missing is TRUE, the result is a permission that should be there but isn't; if missing is FALSE, the result row is a permission that is there even though it is not defined in permission_target (an extra permission).

Installation

Make sure the PostgreSQL extension building infrastructure is installed. If you installed PostgreSQL with installation packages, you usually need to install the "development"-Package.

Make sure that pg_config is on your PATH. Then type

make install

Then connect to the database where you want to run pg_permissions and use

CREATE EXTENSION pg_permissions;

To upgrade from an older version of the extension, run

ALTER EXTENSION pg_permissions UPDATE;

You need CREATE privileges on the schema where you install the extension.

Installation without the extension building infrastructure

This is also what Windows users will have to do because there is no extension building infrastructure for Windows.

Find out where your PostgreSQL share directory is:

pg_config --sharedir

Then copy pg_permissions.control and the SQL files to the extension subdirectory of that directory, e.g.

copy pg_permissions.control *.sql "C:\Program Files\PostgreSQL\10\share\extension"

You still have to run CREATE EXTENSION as described above.

Support

Open an issue on GitHub if you have problems or questions.

For professional support, please contact Cybertec.