Changes

dtls.c: add check for valid handshake message type when version is 1.0.

Fixes issue #209.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls_debug.h: explicitly cast macro parameter to size_t.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls-server.c: check for left cli-arguments.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls-client.c: accept options after arguments.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls-client.c: apply option for local port.

The previous version ignores the option for the local port. That may be
caused by issues using the same default local port for the server and
client.
This enables the use of an specific local port and changes the default
to an ephemeral free port, similar to quite a lot of other UDP clients.
The DEFAULT_PORT is therefore only used for the destination.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

Add client dtls connection ID.

Simple client side implementation indicates support and uses the cid of
the server, when negotiated by that.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls-client.c: add support_cid option.

Signed-off-by: Achim Kraus <achim.kraus@cloudcoap.net>

dtls.c: Handle DTLS1.3 ClientHello when calculating cookie

Do not calculate the cookie using the Extensions as these are
different between DTLS1.2 and DTLS1.3

https://datatracker.ietf.org/doc/html/rfc6347#section-4.2.1

When responding to a HelloVerifyRequest, the client MUST use the same
parameter values (version, random, session_id, cipher_suites,
compression_method) as it did in the original ClientHello.  The
server SHOULD use those values to generate its cookie and verify that
they are correct upon cookie receipt.

https://www.rfc-editor.org/rfc/rfc9147.html#section-5.3

The ClientHello up to, but not including the Extensions is the same for
DTLS1.2 and DTLS1.3

Signed-off-by: Jon Shallow <supjps-libcoap@jpshallow.com>