Re: Handle HTTP error 511 Network Authentication Required (standard secure proxy authentification/captive portal detection)

On Sun, Feb 19, 2012 at 10:03:37PM +0100, Nicolas Mailhot wrote:

The IETF finally set up to fix this problem and defined a standard HTTP error
that lets access control equipments tell the web client authentication or
re-authentication is needed and where the authentication form is located.

http://tools.ietf.org/id/draft-nottingham-http-new-status-04.txt

→ <http://www.rfc-editor.org/queue2.html#draft-nottingham-http-new-status> (the
spec is approved and in the queue for publication as RFC)

Please add error 511 handling in git, so git users that try to access external
git repositories over http can authenticate on the corporate proxy

If I'm reading this right, the process works something like this:

  1. Git wants to make a request to http://example.com

  2. We make our request to a proxy server which is transparently
     proxying our traffic (i.e, a "captive portal").

  3. The proxy returns 511 along with some URL (e.g.,
     "http://login.corporatenetwork"), indicating that we need
     to go to that URL to complete some authentication.

As a non-browser client, what should git do? We can't make sense of the
content at http://login.corporatenetwork, which is most likely an HTML
form asking for credentials (or even money, if the captive portal is
something like a public wireless provider). The best we can probably do
is die and say "apparently you need to go http://login.corporatenetwork
in a browser before making your request".

Reading that rfc draft, the man impetus for non-browser clients seems
not to get them to do anything useful, but rather to return them a code
that is clearly not from the actual site (if it were a redirect, for
example, then we would think that example.com is redirecting is, which
is simply not true).

-Peff