- Enhance the token exchange to check that the same client is used
compared to the client used during the original authorization and
token requests, and also check that the client has the token-exchange
grant type allowed in its configuration.
- Reduce the minimum required bcrypt cost for OIDCClient secrets
because 15 is too slow for real-life use, especially considering
that every login and every refresh flow will require two client auths.
- In unit tests, use bcrypt hashes with a cost of 4, because bcrypt
slows down by 13x when run with the race detector, and we run our
tests with the race detector enabled, causing the tests to be
unacceptably slow. The production code uses a higher minimum cost.
- Centralize all pre-computed bcrypt hashes used by unit tests to a
single place. Also extract some other useful test helpers for
unit tests related to OIDCClients.
- Add tons of unit tests for the token endpoint related to dynamic
clients for authcode exchanges, token exchanges, and refreshes.
