Re: [squid-users] transparent https interception without mitm

On 07/11/2014 05:43 AM, James Harper wrote:

> Is it possible for squid to intercept and apply acl's to https
> without actually decrypting and generating certificates etc? The
> conversation would go something like:

> . Client makes connection to IP 1.2.3.4
> . Squid intercepts the connection (but doesn't respond yet)
> . Squid connects to 1.2.3.4 to obtain the hostname (CN or other identifier) of the certificate [1]
> . Squid applies ACL rules to the hostname [2]
> . If the ACL results in a deny then the client connection is dropped [3]
> . If the ACL results in an allow then a new connection is made to the 1.2.3.4 and squid just blindly proxies the TCP connection
>
> [1] I believe certificates can be valid for multiple hostnames, and wildcards, so this would have to be taken into account
> [2] stream is encrypted, so obviously no access to URL etc
> [3] dropped, because there isn't much else you can do with it, although maybe at this point a fake cert could be used to supply an "access denied" page?

I believe the above is one of the use cases that SSL Peek and Splice
project aims to address. Look for step2 "peek" and "terminate" actions
specifically:

  http://wiki.squid-cache.org/Features/SslPeekAndSplice

IIRC, both of those actions are supported in the experimental project
branch, but we have not polished the changes for the official submission
yet.

  https://code.launchpad.net/~measurement-factory/squid/peek-and-splice

HTH,

Alex.
Received on Fri Jul 11 2014 - 16:15:13 MDT