On Wed, Mar 28, 2018 at 7:16 PM, Andres Freund <andres@anarazel.de> wrote:
> +analysis of whether that's safe to do from a cryptographic POV. There's a reason compression has been disabled for
justabout all SSL/TLS libraries.
As I understand it on a brief review of the Google search
results^W^W^Wliterature, the reason that was done was to prevent
things like the CRIME attack, which apparently involves Javascript
running in your browser from deducing information that it shouldn't be
able to get, like the Cookies that are sent along with the requests it
initiates. No similar attack should be possible against PostgreSQL
because there's no similar kind of privilege separation. Your PG
driver doesn't have untrusted Javascript running inside of it, we
hope.
In general, I'd expect compressing data to be beneficial for the
security of encryption because it should increase the entropy of the
encrypted bytes, but obviously it's not hard to hypothesize cases
where the opposite is true for one reason or another.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company