Proxy-Authenticate scope

[mnot]

P-A is defined as:

The "Proxy-Authenticate" header field consists of at least one challenge that indicates the authentication scheme(s) and parameters applicable to the proxy for this effective request URI (Section 5.5).

This seems really odd -- P-A is not generally used in a way that's specific to a single target URI.

[mnot]

I think it's scoped to the request; i.e., if the client retries the same request with appropriate credentials, it's likely to succeed; we can't say much more than that.

[reschke]

FTR, the text we have is inherited from https://greenbytes.de/tech/webdav/rfc2616.html#header.proxy-authenticate.