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Portal authorization (was: Re: multiplexing -- don't do it)

From: Martin J. Dürst <duerst@it.aoyama.ac.jp>
Date: Tue, 10 Apr 2012 10:31:05 +0900
Message-ID: <4F838D59.50304@it.aoyama.ac.jp>
To: Jamie Lokier <jamie@shareable.org>
CC: Nicolas Mailhot <nicolas.mailhot@laposte.net>, "William Chan (陈智昌)" <willchan@chromium.org>, ietf-http-wg@w3.org
Hello Jamie, others,

Mark had a draft on this, 
http://tools.ietf.org/html/draft-nottingham-http-portal-02. I'm not sure 
why it didn't move forward.

Regards,   Martin.

On 2012/04/10 0:12, Jamie Lokier wrote:
> Nicolas Mailhot wrote:
>>
>> Le Sam 7 avril 2012 21:29, Jamie Lokier a écrit :
>>> Nicolas Mailhot wrote:
>>
>>>> The proposal has been made many times in browser bug trackers. It's always
>>>> basically:
>>>> 1. web client requests a web page
>>>> 2. gateway responds web client is not authorized (or authorized anymore) to
>>>> access this url, and specifies the address of its authentication page
>>>> 3. web client displays this address (if it's a dumb client like curl) or
>>>> renders it (if it's a browser)
>>>> 4. user authenticates
>>>> 5. web client retries its first request and now it works
>>>>
>>>> Happiness ensues as the user gets its page, the admin is not yelled at, and
>>>> corporate filtering is enforced.
>>>
>>> That's quite broken if the request is an AJAX update or something
>>> like that from an existing page on their browser, such as a page
>>> they've kept open from before, or resumed from a saved session, or as
>>> you say not authorized any more (presumably were earlier).
>>
>> No that's not quite broken that's the only way it can work.
>>
>> Please admit that on restricted networks access to some external sites
>> requires authorization. That this authorization won't be eternal for basic
>> security reasons. That due to hibernation/resume/client mobility/plain
>> equipment maintenance this authorization will need to be acquired or
>> reacquired at any point in the web client browsing.
>
> I'm not arguing against the authorization requirement.
>
> I'm only saying that your "happiness ensues" conclusion is false, as
> you did say the proposal is always basically the same, and in my
> personal experience as an end user, it's horrible already.
>
>> That means yes you do need to handle ajax updates,
>> mid-of-tls-interruptions, and all the difficult use cases. The user
>> is not going to oblige you by restricting himself to the simple use
>> cases when auth needs reacquiring Because if web clients don't
>> handle those, the gateway will always have the option to block the
>> access. And make no mistake it will and does exercise it.
>
> Right.  But the web client _can't_ handle those cases, because the
> gateway is injecting a fake redirect, the gateway doesn't know what
> it's interrupting, and the result is just like a normal page, not an
> error page or special signal to the browser asking for authorization.
>
>> The refusal to handle those cases so far has resulted in :
>> 1. broken hotel/conference captive portals
>> 2. widespread availability of TLS interception in proxy manufacturer catalogs
>> 3. corporations getting stuck on old insecure browser versions because the
>> newer ones 'security' hardening broke their proxies
>> 4. corporations hand-patching newer browser releases to restore the old
>> 'redirection on https works' behaviour
>>
>> And in all those cases, who were the first to suffer? The users. If you'd poll
>> them the vast majority would care *nothing* about the https cleanliness model,
>> privacy, etc. Not as long that means they have a broken browsing experience
>> everyday long.
>
> Here's what happens in the old style: I connect to
> corporate/hotel/cafe network.  Then I dread starting Firefox because
> my last 50 open tabs will start up and _all_ redirect to the portal's
> Wifi login page.  I get 50 stupid login pages, and lose the original
> state.
>
> If I'm paying attention, I start Firefox _before_ connecting to the
> network, wait for it to start in offline mode and load the 50 tabs
> correctly, and then connect to the network.
>
> But still, those pages which are using AJAX polling start doing random
> things, as their Javascript gets something random it wasn't expecting.
>
> These days I resort to running w3m (a Lynx-like text-only browser) to
> go the proxy's login page first.  But that's increasingly broken too,
> as some Wifi login pages have stopped being normal forms, and only
> work in a fully fledged graphical browser with Javascript enabled, to
> "simulate" form fieleds.  Don't ask me why.  All I know is the model
> you are pushing is broken enough with HTTP.
>
> So my objection to the classical approach to authorization by
> redirecting everything has nothing to do with security, or even HTTPS,
> and everything to do with the user experience.
>
> What would work much is if the browser got a response meaning "you
> will need to authorize before the original request can proceed - open
> [URL] to present an authorization page", and do not consider the
> original request to have completed yet.
>
> Intercepting proxies could do that with HTTP or HTTPS or HTTP/2.0 if
> there's a standard signal for it, *without* having to break the
> security model or mislead any users.  It would be a nicer experience
> for everyone.
>
> -- Jamie
>
>
Received on Tuesday, 10 April 2012 01:31:41 GMT

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