Horton

Re: storing an explicit nonce

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Stephen Frost <sfrost@snowman.net>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Masahiko Sawada <sawada.mshk@gmail.com>, Tom Kincaid <tomjohnkincaid@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL Development <pgsql-hackers@postgresql.org>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
Date: 2021-05-27T16:44:40Z
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 Thu, May 27, 2021 at 12:28:39PM -0400, Robert Haas wrote:
> On Thu, May 27, 2021 at 12:01 PM Andres Freund <andres@anarazel.de> wrote:
> > What prevents us from using something like XTS? I'm not saying that that
> > is the right approach, due to the fact that it leaks information about a
> > block being the same as an earlier version of the same block. But right
> > now we are talking about using CTR without addressing the weaknesses CTR
> > has, where a failure to increase the nonce is fatal (the code even
> > documents known cases where that could happen!), and where there's no
> > error propagation within a block.
> 
> I spent some time this morning reading up on XTS in general and also
> on previous discussions on this list on the list. It seems like XTS is
> considered state-of-the-art for full disk encryption, and what we're
> doing seems to me to be similar in concept. The most useful on-list
> discussion that I found was on this thread:
> 
> https://www.postgresql.org/message-id/flat/c878de71-a0c3-96b2-3e11-9ac2c35357c3%40joeconway.com#19d3b7c37b9f84798f899360393584df
> 
> There are a lot of things that people said on that thread, but then
> Bruce basically proposes CBC and/or CTR and I couldn't clearly
> understand the reasons for that choice. Maybe there was some off-list
> discussion of this that wasn't captured in the email traffic?

There was no other discussion about XTS that I know of.

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

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