Re: feedback requested regarding deprecation of TLS 1.0/1.1

[Jacob Bachmeyer <jcb62281 () gmail com>]

Peter Gutmann wrote:
> Jacob Bachmeyer <jcb62281 () gmail com> writes:
>   
> > The AtE mode has problems, but is still supported in TLS1.2.  (Why was EtA
> > not also introduced in TLS1.2?)
> >     
>
> It was:
>
> https://datatracker.ietf.org/doc/html/rfc7366
>
> So you don't need any new modes, just an extension to signal its presence and
> swapping the order of the processing operations if present.
>   

I see.  TLS1.2 supports *both* AtE and EtA.

My question (here expressed yet another way) still stands unanswered:  
excluding cipher suites (and the use of concatenated SHA1+MD5) what, if 
any, parts of TLS1.0/1.1 are not also required to implement TLS1.2?

Removing support for TLS1.0/1.1 has definite costs in compatibility, 
costs that hit particularly hard with legacy embedded devices for which 
no updates will be available.  Given that TLS1.2 is to remain supported, 
what benefits to maintainability are to be had?  How much of the 
TLS1.0/1.1 support does *not* overlap with the TLS1.2 support?  How much 
of it *should* overlap if the code were to be optimally refactored?


-- Jacob