On Wed, 25 Oct 2017 18:57:05 -0400
Viktor Dukhovni <[email protected]> wrote:

> Which is different from
> requiring that clients or servers reject weaker options, but given
> such a server requirement, it would not be too unreasonable for STS
> clients to in fact require at least TLS 1.2 and its MIT ciphersuites
> from STS servers.

The MTI cipher in TLS 1.2 is
TLS_RSA_WITH_AES_128_CBC_SHA

Which doesn't support forward secrecy and is affected by two major
cryptographic flaws (Vaudenay padding oracle and Bleichenbacher million
message attack) that are hard to avoid in implementations.

I don't want to discuss here how it happened that the TLS 1.2 authors
decided to declare such a cipher as "MTI", but I think it would be
actively harmful to require a cipher in any modern standard that I'd
argue should be deprecated better sooner than later.

-- 
Hanno Böck
https://hboeck.de/

mail/jabber: [email protected]
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