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Re: [TLS] PR for anti-downgrade mechanism

"Yngve N. Pettersen" <yngve@spec-work.net> Fri, 09 October 2015 13:02 UTC

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From: "Yngve N. Pettersen" <yngve@spec-work.net>
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Subject: Re: [TLS] PR for anti-downgrade mechanism
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On Fri, 09 Oct 2015 12:48:38 -0000, Karthikeyan Bhargavan  
<karthik.bhargavan@gmail.com> wrote:

> - We note that RSA ciphersuites already provide a version downgrade  
> mitigation,
>   although it has itself caused many headaches due to bleichenbacher  
> attacks.
>   But if a server implements good side-channel resistance to  
> bleichenbacher attacks,
>   TLS 1.3 can be protected from downgrades to both RSA and (EC)DHE  
> ciphersuites in
>   older protocol versions.

For reference, the version field in the TLS premaster secret is not  
checked by many servers, IIRC some of them have large market shares.

-- 
Sincerely,
Yngve N. Pettersen

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