openssl-nonblock

Ruby recently added a bunch of non-blocking operations to its core socket
classes, like connect_nonblock, read_nonblock, etc. There are plans to add
similar methods to the SSL library of future versions of Ruby. However,
there’s no reason you can’t have these methods today.

With a bit of crazy C hackery, this module will patch existing versions of
Ruby, including 1.8.6, 1.8.7, and 1.9.1 to include non-blocking SSL support.

Usage

Once the openssl-nonblock gem has been installed, use:

to include non-blocking SSL support in your program. This will also pull in
the ‘openssl’ library if you haven’t required it already.

Additional methods

The openssl-nonblock gem adds four new methods to the OpenSSL::SSL::SSLSocket
class. These methods are:

• connect_nonblock: connect to an SSL server
• accept_nonblock: accept an SSL connection
• read_nonblock(length): read up to the given length, but don’t block
• write_nonblock(data): write as much of the given data as possible without blocking

Exceptions

The openssl-nonblock adds two new exception objects which are needed for
correct I/O behavior when using this module. Any of the *_nonblock versions
of the SSL methods added by this module will require proper handling of these
exceptions:

• OpenSSL::SSL::ReadAgain: this means OpenSSL needs to read more data to
  complete the given request. You should wait until the underlying IO object
  becomes readable again before retrying the request.
• OpenSSL::SSL::WriteAgain: similar to above, except OpenSSL is trying to write
  data to the IO object, and the IO object is not presently writable. You
  should wait until the object becomes writable again before retrying the request.

Possible compatibility problems

ruby-core is officially trying to add nonblocking SSL support, however at the
present time it is insufficient for full non-blocking SSL support. Please be
aware that this extension may conflict with future versions of Ruby.

Problems?

openssl-nonblock is a subcomponent of Rev, an event library for Ruby. Please
address any questions about openssl-ruby to the rev-talk mailing list at:

https://rubyforge.org/mailman/listinfo/rev-talk

Additional information about Rev is available at:

https://rev.rubyforge.org