This may sound surprising but: consider writing your own in Go. The net/http package contains both the server and client parts. Your handler can do whatever checks you need, create a new outgoing request and copy the data. This can be as short as, say, 20 lines of code. The resulting binary is fast and memory-safe. Google itself is running such servers in production, so it's not a toy.
Benny.
I am looking for a proxy web server designed to be sure, with minimal
security bugs.
I don't need especial features as cache, performance, etc. I want to
be it simple
HTTP and HTTPS is enough, and it will be used mainly for download
patches (yum, etc)
I tried http-gw from the toolkit of TIS, but it seems that it isn't
available anymore and the license is restrictive. It is for give
service on a hosted server of a customer.
It would be nice that it is in pkgsrc, but other options are good.