TLS v1.3 extensions in TLS v1.2 handshake

[Severin Gehwolf]

CC'ing jdk8u-dev list.

Fridrich, is this an 8u-only problem you are observing? Would you have
some details about the problem so that I can file a bug for you?

Thanks,
Severin

On Tue, 2021-05-25 at 07:12 +0200, Fridrich Strba wrote:
> Hello, good people,
> 
> The java 11 implementation of TLS v1.3 was backported into java 8
> since some CPUs and it results sometimes in new handshake failures
> with hard-to-updage-firmware devices whose shell life might be still
> long.
> 
> We somehow debugged those failures and some devices bomb because of 
> TLSv1.2 handshake containing the signature_algorihms_cert and 
> supported_versions extensions.
> 
> TLSv1.3 handshake still contains both extensions as it should. This 
> could solve the differences of Java 8 behaviour between different
> update 
> numbers.
> 
> Please, have a look and comment
> 
> Cheers
> 
> Fridrich
>