Re: [TLS] What does "renegotiation_info" mean?

Martin Thomson <martin.thomson@gmail.com> Wed, 13 June 2018 20:03 UTC

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From: Martin Thomson <martin.thomson@gmail.com>
Date: Wed, 13 Jun 2018 13:03:19 -0700
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Subject: Re: [TLS] What does "renegotiation_info" mean?
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Hi Rich,

I think that the Qualys interpretation might be safer.  That is, you
probably should send R-I always. See Karthik's response to my
suggestion that it might be OK to omit R-I in some cases:

https://mailarchive.ietf.org/arch/msg/tls/TfiUa3M390augtvUoxH2D7L5LGM
On Wed, Jun 13, 2018 at 12:47 PM Salz, Rich
<rsalz=40akamai.com@dmarc.ietf.org>; wrote:
>
> It seems that the semantics of the "renegotiation_info" extension are slightly muddy. Qualys understands it to mean that the server will not perform insecure renegotiation, full stop. But OpenSSL further understands it to mean that the server *will* perform secure negotiation. OpenSSL therefore makes it difficult to simultaneously simultaneously satisfy both of Qualys's expectations, since disabling all renegotiation will cause it not to send the "renegotiation_info" extension. Popular open source web servers implement a workaround which achieves Qualys's desired behavior.  Comments?
>
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