understanding the SSL I/O model

[Christian Parpart]

Hey all,

I've got a question I could not actually google for it.
Somebody recently told me, that an SSL write or read operation may also
result in not just a write for write, or read for read, but also, that a
write could also require a read and vice versa.
I have absolutely no idea when and why, except (maybe) for the
rehandshake-part which *seems* to be allowed to be ignored and hope, that
the other side accepts it.

A handshake *will* require read and write operations.
A write operation *will* require sending the plain text encrypted, though,
a write operation at least. but *can* it result into a read?
Same for the read operation.

At what moments should I handle those rehandshake requests from the other
side (and why would he want to rehandshake anyways?)?
Are there any other unexpected events than the rehandshake-request that I
*should* handle during an SSL session?

Many many thanks,
Christian Parpart.