Horton

Re: storing an explicit nonce

Andres Freund <andres@anarazel.de>

View thread
From: Andres Freund <andres@anarazel.de>
To: Bruce Momjian <bruce@momjian.us>
Cc: Stephen Frost <sfrost@snowman.net>, Robert Haas <robertmhaas@gmail.com>, 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: 2021-05-27T00:11:24Z
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.

Hi,

On 2021-05-25 17:12:05 -0400, Bruce Momjian wrote:
> If we used a block cipher instead of a streaming one (CTR), this might
> not work because the earlier blocks can be based in the output of
> later blocks.

What made us choose CTR for WAL & data file encryption? I checked the
README in the patchset and the wiki page, and neither seem to discuss
that.

The dangers around nonce reuse, the space overhead of storing the nonce,
the fact that single bit changes in the encrypted data don't propagate
seem not great?  Why aren't we using something like XTS? It has obvious
issues as wel, but CTR's weaknesses seem at least as great. And if we
want a MAC, then we don't want CTR either.

Greetings,

Andres Freund