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A more secure Planet PostgreSQL

Today, Planet PostgreSQL was switched over from http to https. Previously, https was only used for the logged in portions for blog owners, but now the whole site uses it. If you access the page with the http protocol, you will automatically be redirected to https.

As part of this, the RSS feeds have also changed address from http to https (the path part of the URLs remain unchanged). If your feed reader does not automatically follow redirects, this will unfortunately make it stop updating until you have changed the URL.

In a couple of days we will enable HTTP Strict Transport Security on the site as well.

We apologize for the inconvenience for those of you who have to reconfigure your feeds, but we hope you agree the change is for the better.

www.postgresql.org is now https only

We've just flipped the switch on www.postgresql.org to be served on https only. This has been done for a number of reasons:

  • In response to popular request
  • Google, and possibly other search engines, have started to give higher scores to sites on https, and we were previously redirecting accesses to cleartext
  • Simplification of the site code which now doesn't have to keep track of which pages need to be secure and which does not
  • Prevention of evil things like WiFi hotspot providers injecting ads or javascript into the pages

We have not yet enabled HTTP Strict Transport Security, but will do so in a couple of days once we have verified all functionality. We have also not enabled HTTP/2 yet, this will probably come at a future date.

Please help us out with testing this, and let us know if you find something that's not working, by emailing the pgsql-www mailinglist.

There are still some other postgresql.org websites that are not available over https, and we will be working on those as well over the coming weeks or months.

A few short notes about PostgreSQL and POODLE

The POODLE attack on https (the attack is about https, the vulnerability in SSL, an important distinction) has received a lot of media attention lately, so I figured a (very) short writeup was necessary.

The TL;DR; version is, you don't have to worry about POODLE for your PostgreSQL connections when using SSL.

The slightly longer version can be summarized by:

  • The PostgreSQL libpq client in all supported versions will only connect with TLSv1, which is not vulnerable.
  • The PostgreSQL server prior to the upcoming 9.4 version will however respond in SSLv3 (which is the vulnerable version) if the client insists on it (which a third party client can do).
  • To exploit POODLE, you need a client that explicitly does out-of-protocol downgrading. Something that web browsers do all the time, but very few other clients do. No known PostgreSQL client library does.
  • To exploit POODLE, the attacker needs to be able to modify the contents of the encrypted stream - it cannot be passively broken into. This can of course happen if the attacker can control parameters to a SQL query for example, but the control over the data tends to be low, and the attacker needs to already control the client. In the https attack, this is typically done through injecting javascript.
  • To exploit POODLE, there needs to be some persistent secret data at a fixed offset in each connection. This is extremely unlikely in PostgreSQL, as the protocol itself has no such data. There is a "cancel key" at the same location in each stream, but it is not reused and a new one is created for each connection. This is where the https attack typically uses the session cookie which is both secret and fixed location in the request header.

For a really good writeup on the problem, see this post from PolarSSL, or this one from GnuTLS.

PostgreSQL and the OpenSSL Heartbleed vulnerability

Is your PostgreSQL installation vulnerable to the Heartbleed bug in OpenSSL? The TL;DR; version is "maybe, it depends, you should read this whole thing to find out". If you are vulnerable, it is a high risk vulnerability!

The slightly longer version is that it will be vulnerable if you are using SSL, and not vulnerable if you are not. But the situation is not quite that easy, as you may be using SSL even without planning to. PostgreSQL also not provide any extra protection against the bug - if you are using SSL, you are vulnerable to the bug just as with any other service.

As the bug is in OpenSSL, however, what you need to get patched is your OpenSSL installation and not PostgreSQL itself. And of course, remember to restart your services (this includes both PostgreSQL and any other services using SSL on your system). You will then have to consider in your scenario if you have to replace your SSL keys or not - the same rules apply as to any other service.

It depends on if SSL is enabled

PostgreSQL by default ships with SSL turned off on most platforms. The most notable exception is Debian and derivatives (such as Ubuntu), which enable SSL by default.

If SSL is disabled globally, your installation is not vulnerable.

The easiest way to check this is to just use a simple SQL query:


postgres=# show ssl;
 ssl 
-----
 off
(1 row)

If this parameter returns off, you are not vulnerable. If it returns on, you are.

If you do not need SSL, the easiest fix is to turn this off and restart PostgreSQL. This also brings additional benefits of not paying the overhead of encryption if you don't need it. If you actually use SSL, this is of course not an option.

It depends on your installation

If you have installed PostgreSQL using a package based system, such as yum (from redhat/fedora or from yum.postgresql.org), apt (from debian/ubuntu/etc or from apt.postgresql.org), FreeBSD ports etc, it is up to your operating system to provide a patch. Most major distributions have already done this - you just need to to install it (and restart your services!). If your distribution has not yet updated, you need to convince them to do so ASAP.

If you are using a PostgreSQL installation package that bundles OpenSSL, you need an updated version of this package. The most common example of this is the EnterpriseDB Graphical Installers primarily used on Windows and Mac. We expect a new version of these installers to be released within a day or a few.

Postgres.app is also vulnerable and needs an update, but is normally not used for servers.

The OpenSCG separate download packages are also vulnerable.

For each of these you will have to wait for an updated package to show up in the next couple of days. All package maintainers have been notified, so it's only a matter of time.

Per the www.postgresql.org download pages we do recommend that you always use the "package manager" system for any platform where this is supported, which means most modern Linux or BSD distributions. If you are currently using one of the above installers on these platforms, a quick fix before the packages are out would be to switch to one of the "package manager" platforms that rely on the operating system update process. This may or may not be an option of course, depending on the complexity of the installation.

If you are using a platform where this is not available (such as Windows), your only option is to wait.

pg_hba does not protect you

In PostgreSQL, the SSL negotiation happens before pg_hba.conf is matched. And the vulnerability in OpenSSL is in the negotiation phase. For this reason, even if you have restricted access to your server using pg_hba.conf IP filter rules, or your pg_hba.conf specifies only hostnossl records, this does not protect you.

Obviously, if you have an IP level firewall, either at the host or on the network, that will protect you. But pg_hba does not.

Usage in pgcrypto

The pgcrypto module in PostgreSQL uses OpenSSL to provide encryption functions when available. Since the vulnerability is specifically in the protocol negotiation, use in pgcrypto is not vulnerable to this issue.

pgcon, 1st talk day

We're now up to the third day of pgcon, the first one of the actual conference - the previous ones being dedicated to tutorials. The day started with Selena, me and Dave doing a semi-improvised keynote. Well, it started with Dan saying welcome and going through some details, but he doesn't count... I doubt we actually spread any knowledge with that talk, but at least we got to plug some interesting talks at the conference, and show pictures of elephants.

Missed the start of the Aster talk on Petabyte databases using standard PostgreSQL, but the parts I caught sounded very interesting. I'm especially excited to hear they are planning to contribute a whole set of very interesting features back to core PostgreSQL. This makes a lot of sense since they're building their scaling on standard PostgreSQL and not a heavily modified one like some other players in the area, and it's very nice to see that they are realizing this.

After this talk, it was time for my own talk on PostgreSQL Encryption. I had a hard time deciding the split between pgcrypto and SSL when I made the talk, but I think it came out fairly well. Had a number of very good questions at the end, so clearly some people were interested. Perhaps even Bruce managed to learn something...

After this we had lunch, and I'm now sitting in Greg Smiths talk about benchmarking hardware. This is some very low level stuff compared to what you usually see around database benchmarking, but since this is what sits underneath the database, it's important stuff. And very interesting.

The rest of the day has a lineup of some very nice talks, I think. So there'll be no sitting around in the hallway! And in the evening there is the EnterpriseDB party, of course!

Yesterday had the developer meeting, where a bunch (~20) of the most active developers that are here in Ottawa sat down together for the whole day to discuss topics around the next version of PostgreSQL, and how our development model works. Got some very important discussions started, and actually managed to get agreement on a couple of issues that have previously been going in circles. All in all, a very useful day.

Conferences

I speak at and organize conferences around Open Source in general and PostgreSQL in particular.

Upcoming

SCALE+PGDays
Mar 2-5, 2017
Pasadena, California, USA
Open Source Infrastructure @ SCALE
Mar 2, 2017
Pasadena, California, USA
Confoo Montreal 2017
Mar 8-10, 2017
Montreal, Canada
Nordic PGDay 2017
Mar 21, 2017
Stockholm, Sweden
pgDay.paris 2017
Mar 23, 2017
Paris, France
PGCon 2017
May 23-26, 2017
Ottawa, Canada

Past

FOSDEM + PGDay 2017
Feb 2-4, 2017
Brussels, Belgium
PGConf.Asia 2016
Dec 2-3, 2016
Tokyo, Japan
Berlin PUG
Nov 17, 2016
Berlin, Germany
PGConf.EU 2016
Nov 1-4, 2016
Tallinn, Estonia
Stockholm PUG 2016/5
Oct 25, 2016
Stockholm, Sweden
More past conferences