On 05/07/2014 10:55 AM, Pawel Mojski wrote:
W dniu 2014-05-07 15:40, Marcus Kool pisze:
[...]
certificate chain:
Certificate chain
0 s:/CN=*.gateway.messenger.live.com
i:/DC=com/DC=microsoft/DC=corp/DC=redmond/CN=MSIT Machine Auth CA 2
1 s:/DC=com/DC=microsoft/DC=corp/DC=redmond/CN=MSIT Machine Auth CA 2
i:/CN=Microsoft Internet Authority
2 s:/CN=Microsoft Internet Authority
i:/C=IE/O=Baltimore/OU=CyberTrust/CN=Baltimore CyberTrust Root
There is a misunderstanding here.
Skype does not use SSL, it only uses port 443 which is commonly used
by SSL,
but skype knows that there is a proxy and uses the CONNECT method to
get a tunnel from Squid.
Squid (without SSL-bump) than simply "tunnels" (i.e. passes everything
from the client to the server and back).
But _with_ ssl-bump Squid assumes that the CONNECT is for a SSL
connection and this assumption is wrong.
Sorry, but you are wrong. Skype *IS* using ssl like you can see on
example above.
That example was made on openssl -connect
ip.from.sniffing.my.own.skype:443 and as you can see, it's a proper SSL
connection.
But, no one of us have any idea what is the native protocol, all what we
can figure out it is SSL connection. This is some kind of protocol over SSL.
Skype starts connecting to a node so a Skype node is a critical component.
Lets look at a Skype node at 157.55.235.144 :
openssl s_client -connect 157.55.235.144:443
CONNECTED(00000003)
139691491997512:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown
protocol:s23_clnt.c:766:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 263 bytes
There is no SSL. So at least part of Skype uses port 443 for non-SSL traffic.
This observation matches the error messages in the original post:
2014/05/02 18:18:11 kid1| clientNegotiateSSL: Error negotiating SSL connection
on FD 166: error:1408F10B:SSL
so also Squid cannot negotiate an SSL connection because the server uses an
other protocol.
The design of Squid ssl-bump assumes that a CONNECT to a server always has an
SSL-based communication channel
and therefore any software that uses non-SSL traffic on port 443 fails to work
with ssl-bump.
Marcus
