Re: Internal key management system

On Fri, 20 Mar 2020 at 01:38, Bruce Momjian <bruce@momjian.us> wrote:
>
> On Fri, Mar 20, 2020 at 12:50:27AM +0900, Masahiko Sawada wrote:
> > On Fri, Mar 20, 2020 at 0:35 Bruce Momjian <bruce@momjian.us> wrote:
> >     Well, the issue is if the user can control the user key, there is might be
> >     a way to make the user key do nothing.
> >
> > Well I meant ‘USER_KEY:’ is a fixed length string for the key used for wrap and
> > unwrap SQL interface functions. So user cannot control it. We will have another
> > key derived by, for example, HKDF(MK, ‘TDE_KEY:’ || system_identifier) for
> > block encryption.
>
> OK, yes, something liek that might make sense.
>

Attached the updated version patch. The patch introduces KDF to derive
a new key from the master encryption key. We use the derived key for
pg_wrap and pg_unwrap SQL functions, instead of directly using the
master encryption key. In the future, we will be able to have a
separate derived keys for block encryption. As a result of using KDF,
the minimum version of OpenSSL when enabling key management is 1.1.0.

Regards,

--
Masahiko Sawada            http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services