Horton

Re: storing an explicit nonce

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Stephen Frost <sfrost@snowman.net>
Cc: Ants Aasma <ants@cybertec.at>, Antonin Houska <ah@cybertec.at>, Robert Haas <robertmhaas@gmail.com>, Sasasu <i@sasa.su>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-10-12T13:14:12Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Rethink method for assigning OIDs to the template0 and postgres DBs.

  2. pg_upgrade: Preserve database OIDs.

  3. pg_upgrade: Preserve relfilenodes and tablespace OIDs.

  4. Fix for new Boolean node

  5. Improve error handling of HMAC computations

  6. Add macro RelationIsPermanent() to report relation permanence

  7. Enhance nbtree index tuple deletion.

On Tue, Oct 12, 2021 at 08:49:28AM -0400, Stephen Frost wrote:
> * Bruce Momjian (bruce@momjian.us) wrote:
> > I thought he was saying that when you extend a file, you might have to
> > extend it with all zeros, rather than being able to extend it with
> > an actual encrypted page of zeros.  For example, I think when a page is
> > corrupt in storage, it reads back as a fully zero page, and we would
> > need to handle that.  Are you saying we already have logic to handle
> > that so we don't need to change anything?
> 
> When we extend a file, it gets extended with all zeros.  PG already
> handles that case, PG w/ TDE would need to also recognize that case
> (which is what Ants was saying their patch does) and handle it.  In
> other words, we just need to realize when a page is all zeros and not
> try to decrypt it when we're reading it.  Ants' patch does that and my
> recollection is that it wasn't very complicated to do, and that seems
> much simpler than trying to figure out a way to ensure we do encrypt a
> zero'd page as part of extending a file.

Well, how do you detect an all-zero page vs a page that encrypted to all
zeros?  I am thinking a zero LSN (which is not encrypted) would be the
only sure way, but we then have to make sure unlogged relations always
get a fake LSN.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.