I've researched that there is an overall HTTP request size limit, and read this is normally a restriction set by Apache. But considering there's a bunch of other headers I could send through, that I'm not, I highly doubt I'm reaching the overall request size limit.
All I'm doing, is HTTP Basic authentication for a REST API, sending an API Key and API Secret, which are both 30 characters in length. And this seems to just fall over and fail. Nothing happens.
However, if I shorten the API Key and API Secret to 28 characters each, it works.
I find it hard to believe, that for something like authentication, there is a hard limit of 28 characters for the "username" and "password"?