Factor out the client max-version logic into a helper function.

Replace the comment with a clearer one and reimplement it much more tidily. The
mask thing was more complicated than was needed.

This slightly changes behavior on the DTLS_ANY_VERSION side in that, if only
one method is enabled, we no longer short-circuit to the version-locked method
early. This "optimization" seems unnecessary.

Change-Id: I571c8b60ed16bd4357c67d65df0dd1ef9cc5eb57
Reviewed-on: https://boringssl-review.googlesource.com/2451
Reviewed-by: Adam Langley <agl@google.com>
4 files changed