The new V2ClientHello sniff asserts, for safety, that nothing else has
initialized the record layer before it runs. However, OpenSSL allows you to
avoid explicitly calling SSL_connect/SSL_accept and instead let
SSL_read/SSL_write implicitly handshake for you. This check happens at a fairly
low-level in the ssl3_read_bytes function, at which point the record layer has
already been initialized.
Add some tests to ensure this mode works.
(Later we'll lift the handshake check to a higher-level which is probably
simpler.)
Change-Id: Ibeb7fb78e5eb75af5411ba15799248d94f12820b
Reviewed-on: https://boringssl-review.googlesource.com/3334
Reviewed-by: Adam Langley <agl@google.com>
e0e7d0da68