Multiple secure sites per IP address

vanderkerkoff · 09-30-2009, 05:36 AM

Hello there

I've recently had the need to run two sites on the same machine with https.

My first site a.com I registered the certificate, no probs.

The second site, b.com, I registered, then when I ran it it spewed an error hostname mismatch, as expected. I wasn't aware of this limitation at the time but do now :-)

I then asked a colleague who said if I run the second site on a non standard port, say 8443, then the second security certificate will validate.

Can anyone explain how that works to me? Also, is it a good idea?

Thanks in advance

bathory · 09-30-2009, 06:34 AM

Hi,

Your colleague is partially right. Until now it was not possible to have to 2 SSL servers running on the same IP and listening on the same port.
This is now possible using the new SNI extension. Read this for details and for an explanation why it was not possible before.

Regards

vanderkerkoff · 09-30-2009, 06:50 AM

Thanks Bathory, I'm looking into SNI now, looks good. I'm using nginx though so I'm asking about on their IRC to see if there is an equivalent in nginx.

Out of interest, how does the certificate work if I run the second site on another port?

Thanks again

Quote:

Originally Posted by bathory

Hi,

Your colleague is partially right. Until now it was not possible to have to 2 SSL servers running on the same IP and listening on the same port.
This is now possible using the new SNI extension. Read this for details and for an explanation why it was not possible before.

Regards

bathory · 09-30-2009, 07:03 AM

For apache you have to define something like that:

Code:

Listen 443
Listen 8443
<VirtualHost _default_:443>
  ServerName server1.domain.com
  ...
  ...
  SSLEngine On
  SSLCertificateKeyFile /path/to/certificate1.key
  SSLCertificateFile /path/to/certificate1.crt
</VirtualHost>

<VirtualHost _default_:8443>
  ServerName server2.domain.com
  ...
  ...
  SSLEngine On
  SSLCertificateKeyFile /path/to/certificate2.key
  SSLCertificateFile /path/to/certificate2.crt
</VirtualHost>

zhjim · 09-30-2009, 07:06 AM

Quote:

Originally Posted by vanderkerkoff

Out of interest, how does the certificate work if I run the second site on another port?

The answer is a bit hidden in the text bathory linked to

Code:

The ordinary behavior, then, is that the SSL connection is set up using the configuration in the default virtual host for the address where the connection was received.

As the webserver uses its default vhost it will always use the same certificate despite the configured certificate for the vhost.
If you use a different port you have a different default configuration so the right certificate is used.

vanderkerkoff · 09-30-2009, 07:15 AM

Thanks everyone

I can see how it is working on port 8443 now, and also that SNI would be a much better solution.

On this video on how to get it working on nginx, http://www.ehow.com/video_5204262_co...ation-sni.html

Art mentions that this will not work on any browser running on an XP box as it's not in the XP network stack. Does this mean that whatever web server I choose, apache or nginx, when I'm using SNI any browser on an XP box will not handle it properly?

Thanks again