Implement in-app logic for a deep link to Connect My Computer

[ravicious]

• The deep link should open or log in to a relevant workspace and then open the Connect My Computer tab.
• The deep link should include the cluster address (so that we know which cluster to connect to) and the action (so that we can support other actions in the future).
• Look at implementations of custom protocols in other apps to ensure the URL scheme we pick is extensible enough to use it with other actions in the future.
• The deep link should prefill the login form, but it shouldn't perform any actions for the user.
  • If the cluster was not already added in Connect, the deep link should not add it automatically but merely prefill the cluster address. See Slack thread 1 and Slack thread 2.
• See these two articles about the security concerns around custom protocols:
  • https://textslashplain.com/2019/08/29/web-to-app-communication-app-protocols/
  • https://parsiya.net/blog/2021-03-17-attack-surface-analysis-part-2-custom-protocol-handlers/

TODO:

• Read custom URL from event / app start.
  • Since the custom URI is always passed as the first command-line arg, look for it at a specific position rather than scanning through all argv items.
• Check how URL encoding works in different browsers.
  • "Another behavior to be aware of is that some callers will decode or encode URLs before passing them along to the target program." source, test website
  • Check @ and other signs that are likely to be included in cluster addresses and usernames.
• Parse it / validate it with whatwg-url.
  • Check if it matches the protocol.
  • Check if the pathname matches any of the supported URIs.
  • Extract and pass just the pathname + query string (our URI).
• Pass it to the frontend app.
• Implement flow in the frontend app after receiving the custom protocol event.

Buttons for testing