#47 Allow bufferevent_openssl to target a BIO.

[Nick Mathewson]

OpenSSL has a generic IO interface; it is pretty easy, given all the openssl code we have already, to target it. Here's a partial patch to do that.

This is a potentially risky interface, since people using it might think
they're getting encryption when they aren't. This suggests that there should
be _another_ interface to creating one of these things that takes a BIO
rather than an fd or a bufferevent.

It needs testing and documentation.

The implementation of be_openssl_ctrl needs to get fixed.

Perhaps there should be a way to override the 'find the right bufferevent or
fd to use as our target' code.

see thread "libevent-2.0 and openssl filter" on libevent users, nov 2009.

[Nick Mathewson]

[Nick Mathewson]

Letting this languish until somebody needs it.