How cookies are handled if you use a proxy between a client and server in HTTP

Question

How cookies are handled if you use a proxy between a client and server in HTTP

Answer 1

The proxy proxies them, just like it proxies everything else.

Answer 2

There is no particular issue with cookies. The Cookie request and Set-Cookie response headers are passed straight through proxies.

If you are worried about a page that depends on a cookie being cached by a proxy and served to a different user who shouldn't be able to see it, you should specify this case with the header:

Cache-Control: private

This should be done for any pages protected by a cookie-based login system.