4 ms·

A lot of websites now offer SSL by default, or as an option - is this more of an obstacle or can ISPs use some sort of MITM technique to defeat the SSL for snoo

by revjx 14y ago

A lot of websites now offer SSL by default, or as an option - is this more of an obstacle or can ISPs use some sort of MITM technique to defeat the SSL for snooping purposes? Forgive my ignorance, I'm very curious about this as a UK citizen.

Udo 14y ago
They can MITM SSL/TLS if they manage to forge the certificates in question, or on both endpoints by having a snooping backdoor in place on either the server or the client. Other than that there are no known weaknesses in the encryption websites use but there is a multitude of things that can and do go wrong without anybody noticing.
majke 14y ago
SSL does encrypt the traffic, but requested domain name is still transferred in plain text during the SSL handshake. I guess for tracking purposes remote IP and domain name would are more than enough.
rmc 14y ago
They can MITM attack SSL only if they have root/superuser access to your computer. They'd have to install a new SSL root cert. Or ISPs can put up a fake cert and hope that people ignore/click through the warnings (which lots do). Or if they have a contact with a corrupt SSL root cert signer, they could get their own fake cert signed.
4ad 14y ago
Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection or they could just be a CA themselves (any CA can MITM the whole internet). Here's the best talk I know of this subject: BlackHat USA 2011: SSL And The Future Of Authenticity: http://www.youtube.com/watch?v=Z7Wl2FW2TcA http://www.youtube.com/watch?v=Z7Wl2FW2TcA
- andyjohnson0 14y ago
  I find this hard to believe. "Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection" A business can buy their own SSL keys, but to MITM any SLL connection those keys would have to be trusted and installed at both ends of the connection and used to generate the SSL session key. "any CA can MITM the whole internet" Again, the CA's keys would have to be trusted and installed by the communicating parties. Or have I misunderstood your point?
  - 4ad 14y ago
    You did not misunderstand me, but you misunderstand how SSL in the context of HTTP is used and what CAs offer for sale. Please see the video I linked in my original post.
    - andyjohnson0 14y ago
      I don't have the time or opportunity to watch a 50 minute video right now, but I found a summary of the talk on the presenter's blog [1]. Interesting stuff! He references a paper [2] that discusses a "compelled assistance" attach, where a government can use the law to compel a CA to hand-over a certificate that would certainly be usable for a MITM attack. Bruce Schneier also mentioned this [3]. But this is far from "Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection". Businesses can't invoke CALEA (or the UK RIPA[4] law, since we're talking about UK government surveillance) - only governments can do that. And the keys are not really being sold or bought. And I don't see how a government could compel a CA in a different legal jurisdiction anyway. "any CA can MITM the whole internet" No. A CA has access to keys that can be used to MITM a connection that is secured by keys issued by them. Thats not the "whole internet". [1] http://blog.thoughtcrime.org/ssl-and-the-future-of-authenticity http://blog.thoughtcrime.org/ssl-and-the-future-of-authentic... [2] http://files.cloudprivacy.net/ssl-mitm.pdf http://files.cloudprivacy.net/ssl-mitm.pdf [3] http://www.schneier.com/blog/archives/2010/04/man-in-the-midd_2.html http://www.schneier.com/blog/archives/2010/04/man-in-the-mid... [4] http://en.wikipedia.org/wiki/Key_disclosure_law#United_Kingdom http://en.wikipedia.org/wiki/Key_disclosure_law#United_Kingd...

by revjx 14y ago

Udo 14y ago

They can MITM SSL/TLS if they manage to forge the certificates in question, or on both endpoints by having a snooping backdoor in place on either the server or the client. Other than that there are no known weaknesses in the encryption websites use but there is a multitude of things that can and do go wrong without anybody noticing.

majke 14y ago

SSL does encrypt the traffic, but requested domain name is still transferred in plain text during the SSL handshake. I guess for tracking purposes remote IP and domain name would are more than enough.

rmc 14y ago

They can MITM attack SSL only if they have root/superuser access to your computer. They'd have to install a new SSL root cert. Or ISPs can put up a fake cert and hope that people ignore/click through the warnings (which lots do). Or if they have a contact with a corrupt SSL root cert signer, they could get their own fake cert signed.

4ad 14y ago

Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection or they could just be a CA themselves (any CA can MITM the whole internet). Here's the best talk I know of this subject: BlackHat USA 2011: SSL And The Future Of Authenticity: http://www.youtube.com/watch?v=Z7Wl2FW2TcA http://www.youtube.com/watch?v=Z7Wl2FW2TcA

andyjohnson0 14y ago
I find this hard to believe. "Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection" A business can buy their own SSL keys, but to MITM any SLL connection those keys would have to be trusted and installed at both ends of the connection and used to generate the SSL session key. "any CA can MITM the whole internet" Again, the CA's keys would have to be trusted and installed by the communicating parties. Or have I misunderstood your point?
- 4ad 14y ago
  You did not misunderstand me, but you misunderstand how SSL in the context of HTTP is used and what CAs offer for sale. Please see the video I linked in my original post.
  - andyjohnson0 14y ago
    I don't have the time or opportunity to watch a 50 minute video right now, but I found a summary of the talk on the presenter's blog [1]. Interesting stuff! He references a paper [2] that discusses a "compelled assistance" attach, where a government can use the law to compel a CA to hand-over a certificate that would certainly be usable for a MITM attack. Bruce Schneier also mentioned this [3]. But this is far from "Businesses (and governments) can legitimately buy root keys that allow MITMing any SSL connection". Businesses can't invoke CALEA (or the UK RIPA[4] law, since we're talking about UK government surveillance) - only governments can do that. And the keys are not really being sold or bought. And I don't see how a government could compel a CA in a different legal jurisdiction anyway. "any CA can MITM the whole internet" No. A CA has access to keys that can be used to MITM a connection that is secured by keys issued by them. Thats not the "whole internet". [1] http://blog.thoughtcrime.org/ssl-and-the-future-of-authenticity http://blog.thoughtcrime.org/ssl-and-the-future-of-authentic... [2] http://files.cloudprivacy.net/ssl-mitm.pdf http://files.cloudprivacy.net/ssl-mitm.pdf [3] http://www.schneier.com/blog/archives/2010/04/man-in-the-midd_2.html http://www.schneier.com/blog/archives/2010/04/man-in-the-mid... [4] http://en.wikipedia.org/wiki/Key_disclosure_law#United_Kingdom http://en.wikipedia.org/wiki/Key_disclosure_law#United_Kingd...