API keys are now only visible when first created. After that, only the first four characters are stored in the database for identification, along with an sha256 hash of the full key. This makes key usage easier to audit, and ensures attackers would not have access to the live site in the event of a database leak.
This makes the merge lower risk, because we have some time to revert if needed. Once the change is confirmed to be working, we will add a second commit to drop the `key` column.
This change both speeds up specs (less strings to allocate) and helps catch
cases where methods in Discourse are mutating inputs.
Overall we will be migrating everything to use #frozen_string_literal: true
it will take a while, but this is the first and safest move in this direction
David Taylor
Sam Saffron
Robin Ward