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Re: [TLS] RFC 6066 - Max fragment length negotiation

Joseph Birr-Pixton <jpixton@gmail.com> Sat, 18 March 2017 09:18 UTC

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From: Joseph Birr-Pixton <jpixton@gmail.com>
Date: Sat, 18 Mar 2017 09:17:31 +0000
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Subject: Re: [TLS] RFC 6066 - Max fragment length negotiation
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On 17 March 2017 at 16:01, Hannes Tschofenig <hannes.tschofenig@gmx.net> wrote:
> Here are my 5 cents: we implement this extension in our mbed TLS stack

With the greatest of respect, mbedtls *doesn't* implement
max_fragment_length[1], because it doesn't fragment handshake messages
as required by the spec. Attempts to use it with a conforming peer
will fail to handshake.

When I came across this a year or so ago, I concluded that nobody
could have actually deployed max_fragment_length using mbedtls.

Cheers,
Joe

[1] https://github.com/ARMmbed/mbedtls/issues/387

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