How to log in to same web application from different computer?

Question

So here is my scenario. I have multiple machines/devices which I use to log in to a particular web application using my Google account. From my laptop, iPhone, iPod, iPad, and ANY OTHER DEVICE I can log in to my app just fine. However, when I try to log in to the same web app from my home computer, it fails.

When I look at my authorized accounts here: https://accounts.google.com/IssuedAuthSubTokens it shows the same app listed twice which I find odd. I have been working with the app developer to trouble shoot this issue. What he sees is that when I attempt to log in from my home computer Google is sending back a different id from all the other devices I use.

Does anyone have any idea as to what the problem may be?

Update: I have already tried to revoke access to both the apps listed in my Google Account and then re-authenticate. However this does not resolve the issue.

Also, from what I understand, Google provides a unique OpenId identifier for each application that is requesting authentication. This would lead me to believe that Google thinks the app requesting authentication from my home computer is somehow different from the app doing the same request on the other devices.

Answer 1

Ok, so here is what was going on. The application in question was using Google's OpenId API for authentication. Google implements something called "directed identity" and basically what that does is returns a different OpenId for every domain that is requesting authentication. That is understandable but how does that explain the issue I was seeing? Well, when you try to authenticate from "www.myapp.com" from one machine and "myapp.com" from another Google sees those as two different domains and as a result sends back two different OpenId results.

So as long as I was using "myapp.com" from all my devices things were fine. The developer actually fixed this in the app so that no matter what you may have entered in the address bar, Google would always receive the request from the same domain and authenticate the user.