Re: storing an explicit nonce

On Tue, Oct 5, 2021 at 1:24 PM Robert Haas <robertmhaas@gmail.com> wrote:
> On Mon, Oct 4, 2021 at 10:00 PM Stephen Frost <sfrost@snowman.net> wrote:
> > I do want to point out, as I think I did when we discussed this but want
> > to be sure it's also captured here- I don't think that temporary file
> > access should be forced to be block-oriented when it's naturally (in
> > very many cases) sequential.  To that point, I'm thinking that we need a
> > temp file access API through which various systems work that's
> > sequential and therefore relatively similar to the existing glibc, et
> > al, APIs, but by going through our own internal API (which more
> > consistently works with the glibc APIs and provides better error
> > reporting in the event of issues, etc) we can then extend it to work as
> > an encrypted stream instead.
>
> Regarding this, would it use block-oriented access on the backend?
>
> I agree that we need a better API layer through which all filesystem
> access is routed. One of the notable weaknesses of the Cybertec patch
> is that it has too large a code footprint,

(sent too soon)

...precisely because PostgreSQL doesn't have such a layer.

But I think ultimately we do want to encrypt and decrypt in blocks, so
if we create such a layer, it should expose byte-oriented APIs but
combine the actual I/Os somehow. That's also good for cutting down the
number of system calls, which is a benefit unto itself.

-- 
Robert Haas
EDB: http://www.enterprisedb.com