Fix DTLS handling when receiving a no_renegotiation alert
no_renegotiation is a warning alert sent from the server when it is not
prepared to accept a renegotiation attempt. In TLS we abort the connection
when we receive one of these - which is a reasonable response. However,
in DTLS we incorrectly ignore this and keep trying to renegotiate.
We bring the DTLS handling of a no_renegotiation alert into line with
how TLS handles this. In versions prior to 3.2 handling of a warning
alert in DTLS was mishandled resulting in a failure of the connection,
which ends up being the right thing to do "by accident" in the case of
"no_renegotiation". From 3.2 this mishandling was fixed, but exposed this
latent bug.
Fixes #27419
Reviewed-by: Frederik Wedel-Heinen <fwh.openssl@gmail.com> Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27591)