[Pharo-project] SSL/HTTPS - SecureSocketStream/SSLSession for Pharo/Squeak and other Smalltalk implementations

Sven Van Caekenberghe sven at beta9.be
Tue May 10 19:42:31 CEST 2011


SSL/HTTPS - SecureSocketStream/SSLSession for Pharo/Squeak and other Smalltalk implementations


HTTP client and server functionality has become an essential part of any Smalltalk implementation. There exist various open source solutions delivering this functionality.

Users quickly find out that HTTPS is not as readily available as HTTP. Although a solution exists in the form of SqueakSSL, it is not easily portable to Pharo and certainly not to other Smalltalk implementations. Furthermore, SqueakSSL is incomplete and more a working proof of concept than a high quality, high performance, maintainable piece of code, partially because of its dependence on the internals of SocketStream.

Hence, some people wanting HTTPS on Pharo as well as one organisation have come foreword with a bounty to force a solution. Here are the requirements, a plan of action and a number of steps to build such a solution.


First of all, it would be stupid not to start from the work already done for SqueakSSL. Any new solution should start from the existing plugin, from the existing set of primitives and from the current implementation of these primitives for the Windows, Mac OS X and Linux platforms. 

The Smalltalk part of the solution should be as platform independent as possible. We therefor need a new, clean implementation of SocketStream, with proper internal buffering and optimised versions of the bulk input and output primitives. The code should be time and space efficient. At first, only binary I/O is needed. Encoding/decoding is best done by wrapping the stream. Maybe a bivalent stream could be an option. The current ASCII support in quite limited. 

Next a SecureSocketStream can be implemented using this clean base combined with the SSLSession primitives. Here too, time and space efficiency are important although SSL will by definition be less efficient. 

Eventually, HTTP frameworks can then use this SecureSocketStream to actually implement HTTPS. Although the primary requirement is client functionality, server functionality should be provided as well. 

Next the existing issues with certificates need to be resolved, on all 3 platforms. 

Finally, the C code of the plugin for each of the 3 platforms needs to be cleaned up and improved where necessary. This requires contributions from developers who know and understand a platform as well as how SSL is supposed to work. Furthermore they have to understand and be motivated to work on Smalltalk plugins. Up to 3 different developers might be needed. 

The current implementation on Mac OS X does not seem to (directly) use the standard OpenSSL library from Linux although this library exists on Mac OS X. This could be an opportunity to reduce the number of implementations of the plugin to 2 API's. 

Needless to say the whole implementation should be open source licensed (MIT), be documented and have a number of units tests to cover it's main functionality as well edge cases encountered in the field.

Friendly cooperation with other open source projects in the Smalltalk world is a plus. This project should benefit the whole community.


The bounty should be split in different parts. 

The first part is setting up the new project, delivering the new SocketStream, SSLSession and SecureSocketStream, including the HTTPS client proof of concept. Traction within the community has to be developed. 

Next the issues with the plugin have to be identified. Then the work on the plugin code for each platform has to be defined and 3 more bounties could be offered.

The goal should be to include the plugin in VM's by default. 

With a proper solution to the plugin issues, SSL server functionality should be no problem. 


I offer to take on part one and help manage the coordination of this project. 

So is there anyone capable and willing to help out on the plugin on on one or more platforms for part of the bounty ?

Are there others who wish to raise the bounty ?

We will need a couple of good beta testers who understand this field as well.


Sven




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