[squid-dev] SSL-BUMP distinguish between mobile devices such as IOS or ANDROID vs PC request

[Alex Rousskov]

On 02/22/2018 11:56 AM, Eliezer Croitoru wrote:

> I was wondering about the options to distinguish mobile devices TLS\SSL
> requests compared to PC one's.

You need ACLs that can match various TLS Client Hello fields (mostly
message version, protocol version, and ciphers) and a knowledgebase of
typical Hellos for the devices/clients you are interested in. A
Hello-based solution cannot be 100% reliable, but I bet you can identify
many popular OS versions (and, as a consequence, even some physical
devices) with a good-enough probability (for most applications).

IIRC, Squid does not have ACLs that interrogate TLS Client Hello with
the exception of SNI (i.e., ssl::server_name --client_requested).
However, it should not be very difficult to add such ACLs and they would
be generally useful IMO.


Forward proxies can also examine CONNECT headers. That is already
supported AFAIK.


Examining TCP/IP packet headers would also be useful in many cases, but
that is harder to do directly in Squid.


HTH,

Alex.