Re: QGIS Seem To Bypass PostgreSQL/PostGIS User Privileges/Permissions

While I do not know QGIS, I'm wondering if it's similar to some of our
applications where they always use the same system login for the database
while each user provides a unique login to the application. Have you ever
set log_connections in your postgresql.conf file? That would show you which
user is connecting during your attempts, and they might very well be
something you're not expecting. As far as I know, there is no way for any
application to bypass PostgreSQL's internal security model.

On Fri, Mar 17, 2017 at 11:43 AM, Osahon Oduware <oduwareosahon(at)gmail(dot)com>
wrote:

> Hi Giuseppe,
>
> Thanks for the response. I have provided the GRANTS and other PostgreSQL
> setup scripts below as it includes what you have suggested:
>
> ROLE
> ---------
> CREATE ROLE <role_name> WITH NOLOGIN NOSUPERUSER INHERIT NOCREATEDB
> NOCREATEROLE NOREPLICATION;
>
> USER
> ----------
> CREATE USER <username> WITH PASSWORD '<password>'
>
> REVOKES
> ----------------
> REVOKE ALL PRIVILEGES ON DATABASE <database_name> FROM PUBLIC;
> REVOKE ALL PRIVILEGES ON DATABASE postgres FROM PUBLIC;
>
> GRANTS
> -------------
> GRANT CONNECT ON DATABASE <database_name> TO <role_name>;
> GRANT USAGE ON SCHEMA <schema_name> TO <role_name>;
> GRANT SELECT ON ALL TABLES IN SCHEMA <schema_name> TO <role_name>;
> GRANT <role_name> TO <username>;
>
> I cannot but wonder why these privileges are working when tested in
> pgAdmin/pgsql, but not in QGIS with the same user/schema/table/database.
>
> On Fri, Mar 17, 2017 at 4:16 PM, Giuseppe Broccolo <giuseppe.broccolo@
> 2ndquadrant.it> wrote:
>
>> Hi Osahon,
>>
>> 2017-03-17 15:54 GMT+01:00 Osahon Oduware <oduwareosahon(at)gmail(dot)com>:
>>
>>> Hi All,
>>>
>>> I created a "Read-only" User in PostgreSQL via a Role with "SELECT" ONLY
>>> privilege on all tables in a schema as shown below:
>>>
>>> GRANT SELECT ON ALL TABLES IN SCHEMA [schema_name] TO [role_name]
>>> GRANT [role_name] TO [user_name]
>>>
>>
>> I'd have done this as followed:
>>
>> REVOKE ALL ON SCHEMA [schema_name] FROM PUBLIC;
>> GRANT USAGE ON SCHEMA [schema_name] TO [role_name];
>> GRANT SELECT ON ALL TABLES IN SCHEMA [schema_name] TO [role_name];
>> GRANT [role_name] TO [user_name];
>>
>>
>>>
>>> Next, I test this by trying to UPDATE a column in a table (same schema
>>> as above) with pgAdmin/psql and this works fine by giving a response that
>>> the user has no permission - 'ERROR: permission denied for relation
>>> <table_name>.'
>>>
>>> Next, I connect with the same user in QGIS and add a layer from the same
>>> table (same schema as above). I open the attribute table for the layer,
>>> turn on editing mode (by clicking on the pencil-like icon), and edit the
>>> same field/column above. To my surprise, the edit was saved successfully
>>> without any permission error prompt.
>>>
>>> Next, I check the value of the field/column (same table/schema as above)
>>> in pgAdmin/psql and it is having the new (edited) value from QGIS. This is
>>> rather strange as it seems QGIS is bypassing the permissions set for the
>>> same user in the PostgreSQL/PostGIS database.
>>>
>>> I will be glad if someone can help me unravel this mystery.
>>>
>>
>> Check which user is used the first time you connect to the database
>> through QGIS, and if you switch the user to [user_name] in a second moment.
>> I'm wondering if you are keeping some privileges from a previous session.
>>
>> All the best,
>> Giuseppe.
>>
>> --
>> Giuseppe Broccolo - 2ndQuadrant Italy
>> PostgreSQL & PostGIS Training, Services and Support
>> giuseppe(dot)broccolo(at)2ndQuadrant(dot)it | www.2ndQuadrant.it
>>
>
>