Testing safe renegotiation is relatively complex, here is a summary of

what we test and what how we believe it should work.

srn0.c:

This tests that the safe renegotiation extension is negotiated

properly by default on initial connections and on rehandshaked

connections. Consequently, it also verifies that rehandshaked

connections work with the extension enabled.

srn4.c:

This tests that clients without support for safe renegotiation is

able to handshake properly against a default GnuTLS server, but

that rehandshake will be refused by the server.

srn5.c:

This tests that clients with support for safe renegotiation is able

to handshake properly against a server with no support for safe

renegotiation, but that the client will not be able to complete a

rehandshake.