Обсуждение: createdb but revoke dropdb

Hi,
In using 8.3. I'm trying to set up programmatic database creation but
is there a way that the user creating the databases can be restricting
from dropping them?

I have two roles, 'adminuser' with createdb permission, and 'dbuser' a
user with CRUD privileges.

adminuser is a member of the dbuser role, this seems to allow
adminuser to createdb databases for dbuser with:
createdb -U adminuser -O dbuser  new_database_name
Adding .pgpass to the linux user's home directory allows createdb to
work without additional user input.

But now it seems the linux user also has dropdb privileges. How can i
restrict this?
Perhaps there is a recommended method to disable dropdb? Can anyone
suggest?

The adminuser has no login privileges so by removing dropdb this
should remove the possibility for any hacker chaos other than creating
more databases?

Thanks in advance for any advice,
Ben

On 02/03/10 18:22, Ben Eliott wrote:
> I have two roles, 'adminuser' with createdb permission, and 'dbuser' a
> user with CRUD privileges.
>
> adminuser is a member of the dbuser role, this seems to allow adminuser
> to createdb databases for dbuser with:
> createdb -U adminuser -O dbuser new_database_name
> Adding .pgpass to the linux user's home directory allows createdb to
> work without additional user input.
>
> But now it seems the linux user also has dropdb privileges. How can i
> restrict this?
> Perhaps there is a recommended method to disable dropdb? Can anyone
> suggest?

 From the SQL reference page for "GRANT"
"The right to drop an object, or to alter its definition in any way, is
not treated as a grantable privilege; it is inherent in the owner, and
cannot be granted or revoked. (However, a similar effect can be obtained
by granting or revoking membership in the role that owns the object; see
below.) The owner implicitly has all grant options for the object, too."

Don't make "dbuser" the owner of the database, make "adminuser" the
owner, then grant whatever top-level privileges dbuser needs. Make sure
you don't have adminuser as an automatic login through .pgpass

> The adminuser has no login privileges so by removing dropdb this should
> remove the possibility for any hacker chaos other than creating more
> databases?

Or deleting/modifying all your data, presumably. If you don't trust the
linux user account, don't give it automatic login.

--
   Richard Huxton
   Archonet Ltd

Hi,

Thank-you for coming back and your advice. I understand what you mean.
However, in order to run the script without additional user
input, .pgpass is always needed. One way or another, which ever way i
try and twist this, something has to give on security.  Perhaps it
would be just about ok-ish if I could restrict the linux user to just
creating databases, but the privilege to add a database means the
privilege to drop them too. And ok-ish isn't great either.

So, rather than fight this  I think perhaps instead another approach -
to pre-prepare sets of databases ahead of time and then, rather than
create them programmatically, just assign them programmatically
instead. It doesn't exactly solve the original problem, but I think i
prefer it from a security standpoint anyhow.

Ben

On 3 Mar 2010, at 09:17, Richard Huxton wrote:

> On 02/03/10 18:22, Ben Eliott wrote:
>> I have two roles, 'adminuser' with createdb permission, and
>> 'dbuser' a
>> user with CRUD privileges.
>>
>> adminuser is a member of the dbuser role, this seems to allow
>> adminuser
>> to createdb databases for dbuser with:
>> createdb -U adminuser -O dbuser new_database_name
>> Adding .pgpass to the linux user's home directory allows createdb to
>> work without additional user input.
>>
>> But now it seems the linux user also has dropdb privileges. How can i
>> restrict this?
>> Perhaps there is a recommended method to disable dropdb? Can anyone
>> suggest?
>
> From the SQL reference page for "GRANT"
> "The right to drop an object, or to alter its definition in any way,
> is not treated as a grantable privilege; it is inherent in the
> owner, and cannot be granted or revoked. (However, a similar effect
> can be obtained by granting or revoking membership in the role that
> owns the object; see below.) The owner implicitly has all grant
> options for the object, too."
>
> Don't make "dbuser" the owner of the database, make "adminuser" the
> owner, then grant whatever top-level privileges dbuser needs. Make
> sure you don't have adminuser as an automatic login through .pgpass
>
>> The adminuser has no login privileges so by removing dropdb this
>> should
>> remove the possibility for any hacker chaos other than creating more
>> databases?
>
> Or deleting/modifying all your data, presumably. If you don't trust
> the linux user account, don't give it automatic login.
>
> --
>  Richard Huxton
>  Archonet Ltd