Reverse proxy deep dive: Why HTTP parsing at the edge is harder than it looks (startwithawhy.com)

Oh, and it can get messy and lead to exploits really quick.

Incorrect parsing and parsing differences between libraries can lead to exciting exploits.

Like what do you do when there is multiple of the same headers with odd line breaks?

GET /example HTTP/1.1 Host: bad-stuff-here Host: vulnerable-website.com

I've been building out a very large network of reverse proxies the last year. Very fun, and your article is very relatable. Go has been my friend. Been spending the last couple months testing trying to figure out all the weird things that can happen and its quite a bit.