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Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP

Manuel Pégourié-Gonnard <mpg@polarssl.org> Fri, 05 September 2014 13:57 UTC

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Date: Fri, 05 Sep 2014 15:57:29 +0200
From: Manuel Pégourié-Gonnard <mpg@polarssl.org>
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Subject: Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP
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On 02/09/2014 17:23, Viktor Dukhovni wrote:
> Postfix supports authenticated NULL ciphers for communication
> between an MTA and local (127.0.0.1 or ::1) LMTP server.  Encrypting
> local IPC is just a waste of CPU.  Yes, this is a specialized use-case.
> 
I realise encrypting local communications looks like a waste, but I'm curious if
we can make this assertion more quantitative. With a typical workload, do you
have any idea how much more CPU would be used by starting to encrypt these
communications? (Eg with AES-GCM, both with and without hardware support.)

What would be an acceptable performance penalty?

Manuel.

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