Move auth_token_state from multi to key_state

Move auth_token_state from multi to key_state

The auth-token check is tied to the username/password that is coming
via a specific SSL session, so keep the state also in the key_state
structure.

This also ensures the auth_token_state is always set to 0 on a new
session since we clear the key_state object at the start of a new
SSL session.

This is a prerequisite patch to fix 2020-15078 in the following two
commits.

This also applies the changes to the auth_token_test.c. The change of
tls_session to a pointer is necessary since before that we had tls_session
not tied to the multi and had two tls_session used in the test. One
implicitly in tls_multi and one explicit one. Merge these to one.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210520151148.2565578-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22415.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>