depthq - ccm|mac

If you want to check to ensure your SSL or non-SSL ports in PostgreSQL are working properly, read further to find out how.

For SSL support, you need to setup your PostgreSQL to work with SSL properly. Just turn on the ssl flag in postgresql.conf and then make sure you've setup the server.crt as mentioned in PostgreSQL docs about Secure TCP/IP Connections with SSL.

If you want force psql to use non-SSL for the connection, you need to set the PGSSLMODE environment variable. If you're using bash, do something like this:

export PGSSLMODE=disable

And then try to run the psql to connect to the server. I would suggest that you be explicit in your pg_hba.conf to specify that you want hostnossl, so that the server will not accept SSL connections.

If you got things configured correctly, it should work without problems. On the other hand, you can force it to use SSL, like this:

export PGSSLMODE=require

You should see a fatal error message from psql, stating that there is no pg_hba.conf entry for SSL on. You can use the same method to test for SSL-only connections by using hostssl instead in pg_hba.conf.

This environment variable works not only for psql but also for any library or tool that uses libpq. For example, I include the console output for testing the psycopg library. I have already set up the PostgreSQL to work with SSL only.

silviana:~ cheeming$ export PGSSLMODE=disable
silviana:~ cheeming$ python2.4
Python 2.4.5 (#1, Jul 15 2008, 23:37:00) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import psycopg
>>> psycopg.__version__
'1.1.21'
>>> psycopg.connect('host=127.0.0.1 dbname=mydatabase')
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
psycopg.OperationalError: FATAL:  no pg_hba.conf entry for host "127.0.0.1", 
    user "cheeming", database "mydatabase", SSL off
>>> psycopg.connect('host=127.0.0.1 dbname=mydatabase sslmode=require')
<connection object at 0x6a180>
>>> 
silviana:~ cheeming$ export PGSSLMODE=require
silviana:~ cheeming$ python2.4
Python 2.4.5 (#1, Jul 15 2008, 23:37:00) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import psycopg
>>> psycopg.connect('host=127.0.0.1 dbname=mydatabase')
<connection object at 0x6a1d8>

As I tried out using the environment variable way, I realised that you can also change the data source name to include sslmode=require, the same like the PGSSLMODE environment variable. I have updated the console listing above to show that as well.

Oh by the way, I heard a rumour that psycopg 1 doesn't support SSL. I am not 100% sure about it. Its quite hard to find out for sure (as I have tried on google, maybe I am not RTFM-ing enough) other than just testing it. The only info I found indicating this is some guy complaining about ssl not being supported in Windows.

Looking at the psycopg source code shows that there is support for something called sslmode. And in the ChangeLog file, its stated as follows:

2004-01-10  Federico Di Gregorio  <fog@debian.org>

    * module.c (psyco_connect): added "sslmode" parameter.

There are more environment variables that you can tweak to change the behaviour of the libpq C library and its stated here.

Hope this is useful for future PostgreSQL bug hunters!