I have an ASP.NET MVC application which uses Google+ sign-in to authenticate the user. The flow is as follows;
User accesses controller action decorated with [Authorize]
attribute, forms authentication is configured so the user is
forwarded to the log in page.
User clicks the Sign In with Google+ button and the server side flow is initiated as per guide
Server receives the Google tokens which are used to authenticate the user, logging them in and returning the standard asp.net auth cookie in the response. The user can then access the site with the cookie.
Now, if I go through the usual asp.net forms log out process of clearing the user's cookie/session there's a problem. If they attempt to access the application after they've logged out but are still signed into a Google product in another tab, they'll be re-directed to my login page. The Google+ sign-in button will automatically sign them back in again initiating the whole sign in process and getting a brand new asp.net cookie!! The only way to truly sign out is to ensure you are not signed into any Google products still and then attempt to sign out. Not exactly user friendly. I guess the same thing happens with all Google products, if I'm signed into Gmail and open Docs, I'll get signed in automagically. The difference being if you sign out of one, you'll sign out of all Google products. I think.
There is currently not a supported means of logging the user out from your site. What you can do is force the user to click the Google+ Sign-In Button before they will be authorized unless you have set a cookie on their client indicating they are signed in (or enrolled, if you want to distinguish between the sign-in action and being signed-in). You can look at this question:
how do i sign user out of my app?
or this question:
Preventing automatic sign-in when using Google+ Sign-In
for discussions on this topic on stack overflow and answers to similar questions.
Related
If I register with Facebook (x#x.com) and later log in with Google (y#y.com), but I do not have the same email address on both providers, there are 2 users created. How can I handle this situation?
Linking is typically used in three cases:
Automatically requested by the backend for security reasons: when a user signs in to google for example with email x#x and then logs out and tries to sign in with a new facebook account x#x. In this case the backend will not complete the second sign in without verifying that the second user is the same as the first user (since both use the same email). So in this case, the user has to sign to the google account and then link the second facebook account to the initial one.
Manually triggered by the developer: One common case here is that the user signs in to google with email x#x and remains signed in. The developer wants access to the user's facebook friends. So the developer will ask the user to link their facebook account to the already logged in google user.
Upgrading an anonymous user: Developer could automatically sign in users initially as anonymous and then prompt them to upgrade to a registered user. In this case you can call link on the anonymous user.
So auth.currentUser.link can be made on all kinds of users as long as the account you are linking is new and not already linked.
You'll want to use the Account Linking APIs to authenticate multiple providers for the same account. Docs for Web, Android, and iOS are available.
I need to refresh the user linkedin access token without them having to go through the initial authorization process all over again. I have also looked at this documentation http://developer.linkedin.com/documents/exchange-jsapi-tokens-rest-api-oauth-tokens, but It doesn't work because my users authorize the app through regular OAuth and the article uses the JS OAuth. (Not sure, if there is a difference between two processes, and if there is a difference between access tokens received from each process). Even though, I'm already logged in another tab on the same browser,
it always prompts me to login to LinkedIn.
If I try IN.User.isAuthorized() it returns false though I'm logged in into LinkedIn and I can't seem to be able to refresh the token.
If I pass the user LinkedIn access token from my server to the JS and the user LinkedIn id IN.User.isAuthorized() always returns true even when I'm not logged in
So what I'm trying to ask is, is there a way to refresh the user linkedin oauth token thorguh JS when the user is logged in to linkedin on the same broswer like we are able do for facebook ? and what is it ?
You cannot refresh the token without the member being at your application.
If you want to refresh the token, the member needs to be there and you need to direct them through the authorization page. If they're signed in to LinkedIn, this will be a seamless refresh and we'll redirect page to your application.
I'm developing a Sina Weibo integration and I'm doing the oauth correctly but I have a problem with authorization page. When I click on enter, I accept authorization page and I can loggin correctly but if I log off and I try to clic another time enter, I can only see a login page, but no an authorization page.
How can I force that an authorization page shows always?
The correct login flow consists of the following:
1. redirect user to the authorize page with the app's client id
2. client logs in to weibo (authentication)
3. client grants the application requested permissions (authorization)
4. client is redirected to your app page.
I believe the step you are asking about is #3. Once a user has granted your application permissions, this will be stored on their weibo account. The user will no longer be prompted to grant permissions every time the user logs in. The exception is when the user has removed your application from their weibo account. Thus there is no way for your application to force the user to reauthorize your app every time. It is unclear under what circumstances this would ever be required/beneficial.
As a side note:
If a user is already logged in, #2 is skipped by default. The user can be forced to relogin with the forcelogin parameter described in the docs: http://open.weibo.com/wiki/2/oauth2/authorize/en
I want to enable Facebook authentication and the FB-Graph in my website, which already has forms authentication. Using http://multitiered.wordpress.com/2010/08/05/getting-started-with-the-facebook-c-sharp-sdk/, I was able to figure out how to login server-side.
However, the problem with this approach is that a secure cookie will not be created, since the call returns the authentication code in the querystring via a callback. This means that the user will have to login every time.
I can see two ways around this:
Store the access token in a secure cookie manually
Instead of the above approach, use the FB JS API to login - this stores a secure cookie with the access token automatically
I would prefer not to use the second approach, as I would like the login code to be server-side.
Which would be the better approach? Am I missing something?
I use the JavaScript method to first authenticate the user, the JS SDK then writes an encrypted cookie (called "fbs_[YourAppID]") when a connected user hits your page; using one of the many Facebook c# SDKs, this cookie can be decoded using your application secret giving you the user ID, oAuth token, expiry date etc.
Then I hook into the AuthenticateRequest event of my .NET application, check the presence of the cookie, decode if it found, and then find a user who has been assigned this facebook ID (your user table must have a extra field for storing the ID of their facebook account).
If a match is found, I write a normal forms authentication cookie for this user, then .NET will recognise them for all future requests. If no user is found, then this is a brand new user who has just connected. Use the SDK again to query the graph API using their oAuth token, get things like their name/email etc and create a new account, then issue a authentication token as normal.
By writing a normal authetication cookie, the user will stay logged into to your site for all requests, just as if they were a normal user.
One side point, when using email address, check for duplicates, and check for the facebook cookie in all requests. For example, an existing registered logged in user may have just connected.
What is the right way to find out if a user has logged in to Flickr? I have an iframe in my application which lets user's download their images from Flickr. But if the user is not logged into flickr, then flickr redirects me OUT of the iframe to the yahoo home page.
I would like to do the following:
- Check if the user has logged into flickr, if he has, then download his images in the iframe.
- Else, open a new browser window which will let the user enter his flickr login credentials.
Any suggestions from the experts?
You should use the Flikr API. You need to setup proper flikr authentication in your app. According to the docs, the authentication should flow like this:
Our web based app has the api key
'1234567890'. It has already
registered a callback url for this key
- 'http://viewr.com/auth.php'.
User visits http://viewr.com/ and clicks on the 'login' link.
This link points to http://flickr.com/services/auth/?api_key=1234567890&perms=read&api_sig=2f3870be274f6c49b3e31a0c6728957f.
The user is already logged in to flickr - they are asked if they wish
to allow the application to have
'read' permissions to their photos.
The user clicks 'yes' and flickr updates it's auth database.
The user is redirected to http://viewr.com/auth.php?frob=abcxyz.
-The app makes a background call to flickr.auth.getToken:
http://flickr.com/services/rest/?method=flickr.auth.getToken&api_key=1234567890&frob=abcxzy&api_sig=3f3870be274f6c49b3e31a0c6728957f.
The call returns an auth token '334455'.
The application stores the auth token and creates a session for the
user with a cookie which points to the
user's auth token.
The application makes a background request to the flickr.people.getInfo
to return information about the user,
by calling
http://flickr.com/services/rest/?method=flickr.people.getInfo&api_key=1234567890&auth_token=334455&api_sig=4f3870be274f6c49b3e31a0c6728957f.