Distributed computing is an awesome approach to distribute workload of huge tasks and easily outsource them, if needed. It makes computing tasks scalable and cheap, as cloud computing is involved. Computing time can be rent, which is mostly cheaper compared to buying the necessary hardware. However, outsourcing into foreign networks comes with the advantages and drawbacks of public infrastructure. Public networks cannot be trusted, therefore, traffic should be encrypted and connections should be authorized, which sounds easier than it is when using Python frameworks such as Dispy, Celery or Twisted.
Although implemented in the core of the frameworks I used, security is optional, sometimes flawed (e.g asynchronous cryptography in Dispy which uses the same private as well as public key on client as well as on server side, otherwise it will not work) and often with lack of good documentation.
The main priority of official tutorials is to make it work, period – so developers test the shown code and use it, without bothering about further security steps. Tutorials showing working code with all needed encryption and authorization steps are rare. Often framework developers are showing the needed parts separated, but not the complete setup. So developers have to spend a lot of time puzzling all needed steps together. Security should be implemented by default, which unfortunately is not often the case in official framework tutorials. It was therefore not easy to find documented literature to implement the frameworks in a secure way. Sometimes, the frameworks did not even offer complete secure solutions. Let us have look at a framework called Twisted in combination with a JSON-RPC server and how to secure it. There is still room for improvement, but I hope this blog-post will help developers hardening and securing their software a little bit more.
The example code can be found here.