This commit also addresses the side effect that additional messages have
an influence on the derivation of the application traffic secrets. Therefore,
key derivation is relocated after the server finished message has been sent,
so the additional messages from the client (Certificate, CertificateVerify)
don't affect the key derivation. Only the outbound key is switched there, the
inbound key remains in use until the client's finished message has been
processed.
There is no point proposing legacy (or future) cipher suites depending on
the proposed TLS versions. It was actually possible to negotiate and use
cipher suites only defined for TLS 1.2 with earlier TLS versions.
Only the tests with client authentication failed, the client accepted
the trusted self-signed certificate even when it was expired. On the
server the lookup (based on the pre-configured SAN) first found the ECDSA
cert, which it dismissed for the RSA authentication the client used, and
since only the first "pretrusted" cert is considered the following RSA
cert was verified more thoroughly.
The lookup on the client always uses the full DN of the server certificate
not the pre-configured identity so it found the correct certificate on
the first try.