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Re: [TLS] Quest for Unified Solution to TLS Renegotiation

Yoav Nir <ynir@checkpoint.com> Thu, 26 November 2009 06:24 UTC

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From: Yoav Nir <ynir@checkpoint.com>
To: Michael D'Errico <mike-list@pobox.com>
Date: Thu, 26 Nov 2009 08:24:20 +0200
Thread-Topic: [TLS] Quest for Unified Solution to TLS Renegotiation
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Cc: TLS Working Group <tls@ietf.org>
Subject: Re: [TLS] Quest for Unified Solution to TLS Renegotiation
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What David-Sarah said, but you could XOR it with the master_secret as input to the PRF, or even better, use it instead of the finished_label.

This way, you don't have to worry about where to put it in the handshake message stream, just keep it from the previous session.

On Nov 26, 2009, at 5:50 AM, Michael D'Errico wrote:

>> Eric Rescorla wrote:
>> 
>>>>   3) Incorporate previous verify_data into Finished calc.
>>> 
>>> I'm not happy with this, actually.
> 
> Would this work:
> 
>      Finished  =  verify_data  XOR  previous_verify_data
> 
> 
> Not sure if anyone has suggested that already....
> 
> Does it work if you renegotiate twice or more times?
> 
> Also how to handle if renegotiation changes TLS version (SSLv3
> verify_data is 36 bytes long).
>

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