Horton

Re: Key management with tests

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Stephen Frost <sfrost@snowman.net>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
Date: 2021-01-12T18:46:53Z
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, Jan 12, 2021 at 01:15:44PM -0500, Bruce Momjian wrote:
> On Tue, Jan 12, 2021 at 01:11:29PM -0500, Stephen Frost wrote:
> > I don't think there's any doubt that we need to make sure that the IV is
> > distinct and advancing the LSN to get a new one when needed for this
> > case seems like it's probably the way to do that.  Hint bit change
> > visibility to users isn't really at issue here- we can't use the same IV
> > multiple times.  The two options that we have are to either not actually
> > update the hint bit in such a case, or to make sure to change the
> > LSN/IV.  Another option would be to, if we're able to make a hole to put
> > the GCM tag on to the page somewhere, further widen that hole to include
> > an additional space for a counter that would be mixed into the IV, to
> > avoid having to do an XLOG NOOP.
> 
> Well, we have eight unused bits in the IV, so we could just increment
> that for every hint bit change that uses the same LSN, and then force a
> dummy WAL record when that 8-bit counter overflows --- that seems
> simpler than logging hint bits.

Sorry, I was incorrect.  The IV is 16 bytes, made up of the LSN (8
bytes), and the page number (4 bytes).  That leaves 4 bytes unused or
2^32 values for hint bit changes before we have to generate a dummy LSN
record.

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

  The usefulness of a cup is in its emptiness, Bruce Lee