Sending a Hot Potato to someone.
Words of warnings: This does not scale. There are Concurrency, Thread issues and risk of Raise Conditions. No data is persisted, only kept in memory so if the process restarts, the posted data is gone.
Why all these known drawbacks?
Too learn, one sometimes have to create problems to solve.
We have often seen sensitive information like passwords being sent over channels where the sender/receiver don't have full control over the integrity of the data. Sometime the helpdesk generates a random password like: summer2020 and a message saying: -Change at you first login. Which of course never happens. So it happens that passwords are the same for many people and stores in chats.
So I wanted to learn a bit more Rubyand play around with ways of handling the Problem.
Some of the problem areas identified are:
- Is it encrypted in transit?
- Is it encrypted at rest?
- How long is it stored?
- Can we be sure only the intended receiver reads it?
Simplified logical overview says there are two involved parties,
Sender and Receiver, and the do only two simple things Post or Get.
The Sender Post a hot_potato (aka some secret info) and a secret_password to encrypt/decrypt it.
The System returns a unique_id where the hot_potato can be retrieved.
Senders gives the ID and secret_password to the Receiver which unlocks and deletes the hot_potato.
The implementation is written as a Sinatra webapp with class PotatoCollection including Singleton to initialize a in-memory hash where the unique_id is the hash key and the values is another hash:
{msg: encrypted, salt: salt, iv: iv, ttl: end_of_life}The PotatoCollection initialize also starts a asynchronous SuckerPunch::Job background job which every 60 seconds calls the PotatoCollection.check_ttl method to delete all hot_potatoes where ttl has run out.
On the hotpotato.mccc.se deployment kamal-proxy handles TLS and ProxyPass traffic to puma running the Sinatra app.
Written using 3.4.1
Running GitHub Actions as defined in .github/workflows/ruby.yaml.
Should add the rspec tests, but have not made it run in GitHub.
It is scanned by standardrb app.rb and erb_lint views/*.