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Re: [TLS] Premaster/Master convention

Juho Vähä-Herttua <juhovh@iki.fi> Wed, 30 July 2014 19:47 UTC

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From: Juho Vähä-Herttua <juhovh@iki.fi>
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Date: Wed, 30 Jul 2014 22:47:14 +0300
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To: "Gero, Charlie" <cgero@akamai.com>
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Subject: Re: [TLS] Premaster/Master convention
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> On 30.7.2014, at 18.02, "Gero, Charlie" <cgero@akamai.com> wrote:
> 
> We have a number of technologies at Akamai that utilize the fact that the PMS is split from the MS and that MS is produced in conjunction with the randoms.  It allows us to do splitting between machines that have keys and those that don't (machines in safe locales and those which are simply terminators).  I don't think we could use the same methods we use today without that sub step.  It would make it very difficult for Akamai to adopt 1.3.

Without going much into details, are you sure that you can still use these methods, or that these methods are still relevant, without the RSA key exchange?

With ephemeral (EC)DH only things done with the certificate private key is signing and verifying, and that doesn't involve the randoms. So I can't figure out how PMS->MS separation helps there, although I can see how it helps in the RSA key exchange. But I'll take your word for it if you say so.


Juho

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