Does all HTTP traffic go through HTTP.SYS on Windows?

Question

I know Microsoft created HTTP.SYS to increase the performance of IIS. My question though is does HTTP.SYS handle HTTP traffic for all apps? What about a JVM for instanc

Answer 1

Applications can choose to use http.sys. They can choose to implement their own HTTP protocol handlers.

It is strongly recommended that applications use http.sys for security reasons - the HTTP server implemented by http.sys is fairly well hardened and other HTTP servers may introduce security defects.

As far as I know, HTTP.SYS talks to the TCP stack, not NDIS (otherwise it would have to implement all of TCP internally and that doesn't make a lot of sense).

Answer 2

Winsock is socket level, below HTTP, so I would not think it goes through Http.Sys.

Internet Explorer uses Wininet for HTTP communication, which at up through Vista did not use Http.sys.

edit I think the book "Windows Internals" will answer your question.