Re: [TLS] Let's remove gmt_unix_time from TLS

mrex@sap.com (Martin Rex) Tue, 10 December 2013 03:57 UTC

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To: Nick Mathewson <nickm@torproject.org>
Date: Tue, 10 Dec 2013 04:57:16 +0100 (CET)
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From: mrex@sap.com (Martin Rex)
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Subject: Re: [TLS] Let's remove gmt_unix_time from TLS
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Nick Mathewson wrote:
> 
> One caveat here is that a server could tell different clients that it
> had different skew values, thereby creating yet another way to set
> stealth cookies.  You'd need to be sure not to share your view of
> server-local time across anonymous sessions, while roaming in a
> privacy-conscious way, and so on.

The server could also return client-specific session IDs in ServerHello,
or it could generate client-specific (EC)DHE public keys.

They is probably little you could do against a server that is
either subverted by some three-letter-agency or malicious all by itself.

-Martin