Re: [TLS] CCS and key reset and renegotiation

Peter Gutmann <> Fri, 06 June 2014 08:00 UTC

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From: Peter Gutmann <>
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Thread-Topic: [TLS] CCS and key reset and renegotiation
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Date: Fri, 6 Jun 2014 08:00:42 +0000
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Subject: Re: [TLS] CCS and key reset and renegotiation
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Watson Ladd <> writes:

>Because the Certificate, Certificate Request, ServerKeyExchange, and some
>other messages in the handshake are optional, I don't see how a ladder
>diagram can encapsulate the protocol. 

... and yet somehow everyone who's ever tried to document it this way has

(Well, OK, that's a bit absolute, there may be thousands of people out there
who've tried to do this and given up that we don't know about, but somehow I
doubt it.  When I did SSL it was so obviously a ladder diagram that I just
ignored all the state-machine stuff in the spec and implemented the protocol
as such.  My implementation couldn't be made vulnerable to the recent OpenSSL
issue without rewriting half the code).