[squid-users] Squid config Teams add-on in Outlook

[Amos Jeffries]

On 7/07/23 00:32, Alessandro Baritello wrote:
> Hello, I need help with a Squid ver. 4.15 used with kerberos 
> authentication to windows, whitelists and cache_peers to McAfee Web 
> Gateway appliances.


Squid 6.1 was released a few days ago and 4.x have reached their 
official EOS. You may want to try a newer version now.
  There have been numerous changes to CONNECT tunnel handling since 4.15 
which may help with your issue. Better debugging and logging of tunnel 
activities at very least may be useful to you.

> 
> Everything works, except for a teams add-on integrated in Outlook, i.e. 
> when a teams meeting is created from Outlook it does not open Teams 
> correctly, and therefore the relative part with the Teams Meeting ID is 
> not seen in the email.
> 
> Consulting access.log you can see numerous TCP_DENIED/407 errors even if 
> previously there was TCP_TUNNEL/200 with the connect.

Status 407 means the TCP connection which is being used has not yet been 
authenticated, OR the credentials given for it are not permitted to 
perform the action requested.

You will need to check:
  * whether those status 200 were using the same TCP connection (likely 
not), and
  * whether credentials were provided on the TCP connection (in the 
current HTTP request headers, or any prior HTTP request on that 
connection), and
  * what type of authentication is happening. The MS schemes have some 
peculiar and annoying impacts on HTTP.


HTH
Amos