I am not suggesting changing the entire spec, just dropping the request
token part.

This is what I'm getting at -->
https://oauth.pbwiki.com/Signed-Approval-URLs

On Sat, Apr 25, 2009 at 2:58 PM, J. Adam Moore <jadammo...@gmail.com> wrote:

>
> EDIT LAST POST: The second "consumer" I meant to say provider.
>
> On Apr 25, 12:55 pm, "J. Adam Moore" <jadammo...@gmail.com> wrote:
> > What I should have added was that using my solution, the consumer is
> > completely capable of being stupid and giving the consumer a redirect
> > that doesn't require a login on the consumer side, but they can also
> > take a gun and blow their brains out. You can't stop people from being
> > stupid and it's not the Providers job to even care if the redirect
> > they were given is secure.
> >
> > I'll say it again. I AM NOT CHANGING THE OAUTH MODEL. Everything works
> > exactly as before EXCEPT the request token HAPPENS AFTER
> > AUTHENTICATION ON THE PROVIDER SIDE. That is all. That fixes
> > everything. Triggering the authentication flow AS IT IS NOW from
> > behind a login ON THE PROVIDER SIDE. An attacker cannot generate a
> > reusable token or spoof/calculate an access token. Totally secure
> > would be the scenario I explained where both sites redirect behind a
> > login. It's simple. It's easy. Lets do it.
> >
> > On Apr 25, 12:41 pm, "J. Adam Moore" <jadammo...@gmail.com> wrote:
> >
> > > Logically I find that the only way to guarantee that two different
> > > users at two different sites are really the same person is to make
> > > them self authenticate BEFORE establishing a secure communication. By
> > > having both the Provider and Consumer redirect to a spot behind a
> > > login on both sites it fulfills this requirement without breaking the
> > > current model or people's brains. Making something simpler for the
> > > sake of simplicity is simply not a compelling argument against
> > > requiring habeas corpus at each end. I think too many people are
> > > trying to adjust the model instead of the implementation. The model is
> > > fine once you can prove (on each end) that it is the same user. Not
> > > caring what your login is on the consumer? What does that even mean?
> > > Either the redirect url is publicly accessible or it requires a login.
> > > I don't need to know WHO you are or care if you are logged in or not,
> > > but nothing is going to happen until you prove that you are who you
> > > are trying to associate with. This also leaves sites able to craft
> > > their redirect urls to contain either unique paths or unique tokens or
> > > both without breaking the protocol or damaging the current information
> > > exchange model. I still favor a solution that doesn't add or take away
> > > anything from the current model. Basically a protocol that reorders
> > > passing information to occur after user authentication and tightens
> > > rules on where redirects point.
> >
> > > On Apr 25, 12:12 pm, Josh Roesslein <jroessl...@gmail.com> wrote:
> >
> > > > We don't really need the user to be logged into the consumer to
> generate our
> > > > token. The service provider should not care what our login is on the
> > > > consumer.
> > > > All it cares about is authorizing a consumer access to our data. We
> log into
> > > > the provider and authorize the creation of an access token for the
> consumer.
> > > > We then visit this consumer and hand over our token (either manually
> for
> > > > desktop apps or by being redirect by a callback w/ token attached).
> > > > The consumer can now access our data. It is up to the consumer now on
> how to
> > > > store this token.  (Here is a link to the flow:
> http://pastie.org/pastes/457478)
> >
> > > > I don't think preventing middle attacks or phishing is really what
> oauth
> > > > should be doing. SSL does this well and it should be used for the
> transfer
> > > > of the token
> > > > from the provider to the consumer. This way an attacker can't
> intercept the
> > > > token and use it to log in to the consumer under their account and
> access
> > > > our data on our provider account.
> >
> > > > The user can't be easily phished since both URL's (authorization URL
> and
> > > > callback URL) are verifiable by SSL. Also the callback is either
> stored on
> > > > the service provider or signed in the authorization request by the
> consumer.
> >
> > > > On Sat, Apr 25, 2009 at 1:43 PM, J. Adam Moore <jadammo...@gmail.com>
> wrote:
> >
> > > > > The idea is that the communication between the Consumer and
> Provider
> > > > > sites consist of urls that are composed behind user logins ON BOTH
> > > > > SITES at the same time. I believe that this prevents simpler
> attacks
> > > > > like man in the middle or DNS or url tampering and allows secure
> token
> > > > > generation based on session authentication, which, when employed
> > > > > properly, cannot be spoofed from either end or the middle.
> >
> > > > > On Apr 25, 11:21 am, Josh Roesslein <jroessl...@gmail.com> wrote:
> > > > > > I don't really see the need for the double trip to the service
> provider
> > > > > to
> > > > > > perform the login and authorization.
> > > > > > This can be done in one single step like I have outlined in my
> proposal.
> > > > > > User logs into provider, grants access, and returns back with the
> token.
> > > > > > The less work we do in our flow the less likely an attacker can
> find a
> > > > > hole.
> > > > > > The double trip just creates a second chance for an attack.
> >
> > > > > > On Sat, Apr 25, 2009 at 12:33 PM, J. Adam Moore <
> jadammo...@gmail.com
> > > > > >wrote:
> >
> > > > > > > I'm writing a blog post to explain why I think I have a
> solution, but
> > > > > > > I believe it is as simple as moving the provider login to
> before the
> > > > > > > consumer token generation which is triggered by a provider-side
> > > > > > > redirect. This is simply playing keep-away with redirects, but
> it
> > > > > > > arguably works if your goal is web-based "sudo" permissions for
> an app
> > > > > > > or site.
> >
> > > > > > > 1) User clicks on Consumer site link to Provider (no tokens or
> > > > > > > anything, just a request for a protected area on the site that
> IDs the
> > > > > > > Consumer)
> > > > > > > 2) Link is protected, requires login. (This should generate
> your
> > > > > > > session/user identifier)
> > > > > > > 3) Once logged in user is redirected (with a unique identifier,
> > > > > > > encrypted or not) back to a Consumer redirect page
> > > > > > > 4) Consumer generates request token and automatically redirects
> back
> > > > > > > to Provider's user authorization page
> > > > > > > 5) User approves access, Provider automatically logs user out,
> > > > > > > callbacks are optional.
> > > > > > > 6) Desktop apps can use a one-time-only password-reset-style
> cut-n-
> > > > > > > paste token IN THE NORMAL PASSWORD FIELD to authenticate.
> >
> > > > > > > There are many suggestions that duplicate tokens, information,
> or
> > > > > > > steps in the process. If the initial association of the process
> with a
> > > > > > > user is the problem, then requiring a login first will ALWAYS
> be the
> > > > > > > solution. The flow is fine as it is, with the small exception
> that the
> > > > > > > provider-side login requirement needs to be moved up in the
> process.
> >
> > > > > > > The game of keep-away doesn't hinge on obfuscation of the
> McGuffin,
> > > > > > > but in passing it outside of the reach of the attacker. If an
> attacker
> > > > > > > can use redirects to jump into the position of a player, then
> we can
> > > > > > > use redirects to never pass the McGuffin to the same position
> with the
> > > > > > > same info.
> >
> > > > > > > As far as I can tell there was only one INSIGNIFICANT flaw with
> OAuth
> > > > > > > and that was the Provider login requirement happening too late.
> That's
> > > > > > > it. Once you do that you can check the session or user, send
> nonces or
> > > > > > > encrypted user_ids with the initial redirect, or just about any
> crazy
> > > > > > > security measure you can think up.
> >
> > > > > > > Steps 3,4,and 5 are invisible to the user and end with a token
> that
> > > > > > > can be used as a temporary password which triggers token
> authorization
> > > > > > > and association with a seamless manual option that appears to
> jump
> > > > > > > straight to step 6. Because all of this is happening behind a
> Provider
> > > > > > > login, it is as secure as you're going to get it without
> fundamentally
> > > > > > > changing the structure of the whole process.
> >
> >
> >
>

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