On Fri, Aug 9, 2019 at 10:54:51PM -0400, Bruce Momjian wrote: > On Thu, Aug 8, 2019 at 10:17:53PM -0400, Sehrope Sarkuni wrote: > > On Thu, Aug 8, 2019 at 2:16 PM Bruce Momjian <br...@momjian.us> wrote: > > > > On Wed, Aug 7, 2019 at 08:56:18AM -0400, Sehrope Sarkuni wrote: > > > Simplest approach for derived keys would be to use immutable > > attributes > > of the > > > WAL files as an input to the key derivation. Something like HKDF(MDEK, > > "WAL:" | > > > > So, I am thinking we should use "WAL:" for WAL and "REL:" for heap/index > > files. > > > > > > Sounds good. Any unique convention is fine. Main thing to keep in mind is > > that > > they're directly tied to the master key so it's not possible to rotate them > > without changing the master key. > > A recent email talked about using two different encryption keys for > heap/index and WAL, which allows for future features, and allows for key > rotation of the two independently. (I already stated how hard key > rotation would be with WAL and pg_rewind.)
So, I just had an indea if we use separate encryption keys for heap/index and for WAL --- we already know we will have an offline tool that can rotate the passphrase or encryption keys. If we allow the encryption keys to be rotated independently, we can create a standby, and immediately rotate its heap/index encryption key. We can then start streaming replication. When we promote the standby to primary, we can then shut it down and rotate the WAL encryption key --- the new primary would then have no shared keys with the old primary. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription +
