Re: [BUGS] BUG #14686: OpenSSL 1.1.0+ breaks PostgreSQL's sslcompression assumption, defaults to SSL_OP_NO_COMPRESSION - Mailing list pgsql-bugs

From Tom Lane
Subject Re: [BUGS] BUG #14686: OpenSSL 1.1.0+ breaks PostgreSQL's sslcompression assumption, defaults to SSL_OP_NO_COMPRESSION
Date
Msg-id 6829.1496457815@sss.pgh.pa.us
Whole thread Raw
In response to [BUGS] BUG #14686: OpenSSL 1.1.0+ breaks PostgreSQL's sslcompressionassumption, defaults to SSL_OP_NO_COMPRESSION  (greenreaper@hotmail.com)
Responses Re: [BUGS] BUG #14686: OpenSSL 1.1.0+ breaks PostgreSQL'ssslcompression assumption, defaults to SSL_OP_NO_COMPRESSION  (Laurence Parry <greenreaper@hotmail.com>)
List pgsql-bugs
greenreaper@hotmail.com writes:
> PostgreSQL is documented to compress data over SSL connections by default
> where possible:
> https://www.postgresql.org/docs/9.6/static/libpq-connect.html#LIBPQ-CONNECT-SSLCOMPRESSION

> PostgreSQL assumes that OpenSSL 0.9.8+ will compress with zlib if it can.
> However, OpenSSL 1.1.0+ - already in Manjaro, and the upcoming Debian 9
> 'Stretch', Fedora 26, and Tails 3.0 - sets SSL_OP_NO_COMPRESSION by default
> to discourage the CRIME attack:

So the actual issue here, which you've not addressed in this otherwise
extensive screed, is whether it's a wise thing for us to override that
decision.  Should we not just change sslcompression into a no-op?  Is
there some reason why PG data is immune to the CRIME attack?

We might in the future consider compressing the data for ourselves inside
the SSL stream, but (a) that would be a protocol break, with a pile of
unpleasant compatibility consequences, and (b) if compression by OpenSSL
itself makes the stream more decryptable, wouldn't app-provided
compression inside the stream also do that?

In short I'm wondering whether app-driven transport data compression
is an idea whose time has passed.
        regards, tom lane


--
Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-bugs

pgsql-bugs by date:

Previous
From: Shawn Doyle
Date:
Subject: Re: [BUGS] HP-UX 11.31 Itanium2 64bit again
Next
From: "Hans Buschmann"
Date:
Subject: Re: [BUGS] BUG #14684: pg_dump omits columns in inherited tables / psql -d shows deleted columns