This is motivated by the Android app:
https://github.com/syncthing/syncthing-android/pull/1982#issuecomment-1752042554
The planned fix in response to basic auth behaviour changing in #8757
was to add the `Authorization` header when opening the WebView, but it
turns out the function used only applies the header to the initial page
load, not any subsequent script loads or AJAX calls. The
`basicAuthAndSessionMiddleware` checks for no-auth exceptions before
checking the `Authorization` header, so the header has no effect on the
initial page load since the `/` path is a no-auth exception. Thus the
Android app fails to log in when opening the WebView.
This changes the order of checks in `basicAuthAndSessionMiddleware` so
that the `Authorization` header is always checked if present, and a
session cookie is set if it is valid. Only after that does the
middleware fall back to checking for no-auth exceptions.
`api_test.go` has been expanded with additional checks:
- Check that a session cookie is set whenever correct basic auth is
provided.
- Check that a session cookie is not set when basic auth is incorrect.
- Check that a session cookie is not set when authenticating with an API
token (either via `X-Api-Key` or `Authorization: Bearer`).
And an additional test case:
- Check that requests to `/` always succeed, but receive a session
cookie when correct basic auth is provided.
I have manually verified that
- The new assertions fail if the `createSession` call is removed in
`basicAuthAndSessionMiddleware`.
- The new test cases in e6e4df4d70 fail
before the change in 0e47d37e73 is
applied.
Emil Lundberg