Preemptive authentication does not work when only setting the host

[tommix000]

public void enablePreemptiveAuthentication(String hostname)

populates the AuthCache using the port numbers -1 and preemptive authentication does not happen when using the default ports 80/443.

It works by calling Sardine#enablePreemptiveAuthentication(host, 80, 443);

[kkofler]

Note that this also affects enablePreemptiveAuthentication(URL) when using a URL of the form https://dav.example.com as opposed to https://dav.example.com:443, see the implementation of enablePreemptiveAuthentication(URL) and the Javadoc for URL.getPort() (it returns -1 when not explicitly set).

[lookfirst]

There is also this in the documentation.

[lookfirst]

I'm going to close this. Not sure this is a real issue. If it is, we can reopen.

[kkofler]

Uh, this is definitely a real issue in production, which is why I found this issue report. We tried using a URL of the form https://dav.example.com/ without port in our code, and enablePreemptiveAuthentication with that URL had no effect, we still run into https://groups.google.com/g/sardine-dav/c/OF-DUlSZK1E (i.e., exactly what your documentation link says we need to enable preemptive authentication for). We are currently using the "call list first" workaround (because I have just started debugging the issue and found this issue report), but we will try passing an explicit port next to verify that it helps.

If it does (testing still pending here), enablePreemptiveAuthentication(String) and enablePreemptiveAuthentication(URL) need to be fixed to use an explicit default port instead of -1 if the port is not explicitly specified, and/or enablePreemptiveAuthentication(String, int, int) needs to translate -1 to 80/443 before passing it to the HttpHost constructor.

[lookfirst]

@kkofler Sounds good. Thanks for the update. Once you test and find a solution, a PR is much appreciated.

[lookfirst]

This is so old, I don't remember why we ended up with -1 there... it does seem like a huge amount of code smell to do that, but I have a feeling it was to work around some issue in HttpClient which may or may not be long resolved. Again, happy to accept a PR if you can figure this all out.

[kkofler]

It is possible that you might actually need to add cache entries both for -1 and for the real default port, though I hope not.

[kkofler]

We are going to try:

URL baseURL = …;
int port = baseURL().getPort();
sardine.enablePreemptiveAuthentication(baseURL.getHost(), port >= 0 ? port : 80, port >= 0 ? port : 443);

as a local workaround. If that works out, I will send a PR implementing this (the magic in the ternaries) within sardine.enablePreemptiveAuthentication(String, int, int); if not, I will keep you updated on our findings and we will see how to proceed.

[kkofler]

We have tested it: The sardine.enablePreemptiveAuthentication(baseURL.getHost(), port >= 0 ? port : 80, port >= 0 ? port : 443); workaround works indeed. So, as I suggested previously, sardine.enablePreemptiveAuthentication(String, int, int) should translate -1 to 80 resp. 443. I am going to submit a pull request.

[kkofler]

See PR #348, now with correct issue references.