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: 2021-10-13T15:00:22Z
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 Wed, Oct 13, 2021 at 09:16:37AM -0400, Stephen Frost wrote:
> Greetings,
> 
> * Ants Aasma (ants@cybertec.at) wrote:
> > On Wed, 13 Oct 2021 at 02:20, Bruce Momjian <bruce@momjian.us> wrote:
> > > On Wed, Oct 13, 2021 at 12:48:51AM +0300, Ants Aasma wrote:
> > > > On Wed, 13 Oct 2021 at 00:25, Bruce Momjian <bruce@momjian.us> wrote:
> > > >
> > > >     On Tue, Oct 12, 2021 at 11:21:28PM +0300, Ants Aasma wrote:
> > > >     > Page encrypting to all zeros is for all practical purposes
> > > impossible to
> > > >     hit.
> > > >     > Basically an attacker would have to be able to arbitrarily set the
> > > whole
> > > >     > contents of the page and they would then achieve that this page
> > > gets
> > > >     ignored.
> > > >
> > > >     Uh, how do we know that valid data can't produce an encrypted
> > > all-zero
> > > >     page?
> > > >
> > > >
> > > > Because the chances of that happening by accident are equivalent to
> > > making a
> > > > series of commits to postgres and ending up with the same git commit
> > > hash 400
> > > > times in a row.
> > >
> > > Yes, 256^8192 is 1e+19728, but why not just assume a page LSN=0 is an
> > > empty page, and if not, an error?  Seems easier than checking if each
> > > page contains all zeros every time.
> > >
> > 
> > We already check it anyway, see PageIsVerifiedExtended().
> 
> Right- we check the LSN along with the rest of the page there.

Very good.  I have not looked at the Cybertec patch recently.

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

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