How can I prevent OAuth server from remembering user? - oauth

I have a webapp which asks user several questions and store answers. User logs in via OAuth using external provider, then I get user ID information from external SSO server.
I need my app to be used by several users at the same computer, so every time the form is submitted, I need to log out the user. I can do it easily in my app, but then I redirect user to OAuth server again. OAuth server remembers user, so it gives the code of previously logged user right away. I want users to log in again at OAuth server though, but how can I do it? Is it possible to ask OAuth server not to remember the user that had logged in previously?

From your question the actual flow is a bit unclear, however, there are two options:
The client needs to log out after initial log in. With this, a new session flow will be initiated in the next iteration, forcing the client to have to log in again.
The server needs to not remember consent ("Do you want to allow x on app y."), to ask the client for consent again.
Please be aware of the terms authentication, authorisation and consent have very specific meanings in this context.
You may want to share more details on the situation you are in, e.g. relevant code, the OAuth2 server you want to authorise with, including software, version and possibly url. Also, the client (as in rfc6749) is of importance here, did you implement the oauth flow yourself or did you rely on any library? If yes, which?

Related

Ways to skip user consent in OpenID Connect

In the Authentication Request, if users previously gave consent to some client (for a specific list of scopes) and because they might be prompted for the same authorization multiple times. ¿Could be acceptable to skip it?. ¿Works on both code and implicit flows?. ¿How much time remember the consent?.
I'm a little bit confused about the way to implement this. The Oauth2 draft say:
... and obtains an authorization decision
(by asking the resource owner or by
establishing approval via other means).
And OpenID draft say:
... this MAY be done through an interactive dialogue with the End-User
that makes it clear what is being consented to or by establishing
consent via conditions for processing the request or other means
(for example, via previous administrative consent).
Am working on an OpenID Provider implementation for Django.
https://github.com/juanifioren/django-openid-provider
Thanks for your time. Greetings.
Consent is a tricky business. There are different rules in different countries and even different interpretations within the same country. But that aside a common way of handling consent in SSO systems is to ask the user for consent the first time she appears from a specific client and then also ask if the choice should be remembered or if it should only be valid this once. Of course if the user says her consent should be remember she still should have the possibility to later redraw the consent but then outside the normal authorization flow.
You should ask for approval for a specific client only the first time that a user logs in to that client and then store it for later usage. In some use cases user consent is not required because it may be implicit, e.g. in an enterprise setting where users use internal clients.

Use OAuth 2.0 Tokens to login to Salesforce.com

Currently we are not using OAuth with our apps but we are working on making the shift, we have direct login and capture the user/pass that was entered and store those. We then turn around and use the stored credentials for a feature that allows the user to open a record within Salesforce.com, we pass the user/pass in to the login endpoint along with a starting URL to the specific record, this works great and is a well liked feature as it is a simple SSO from the App to Salesforce.com where the user can see all data that may not be visible within the app.
Moving to OAuth 2.0 and using the standard webflow, we no longer can capture the user/pass, which is actually a good thing as far as security is concerned. We would however like to keep this functionality, is there anyway of SSO'ing into Salesforce.com by passing along one of the OAuth tokens or some kind of sesson id?
After reading more and thinking about what OAuth accomplishes I feel like this probably isn't possible being that the tokens obtained are meant to be used only with the API and not with the front end system. I hope that I am wrong though and there is a way to login to the front end using these tokens.
EDIT
Ok I am editing to hopefully make this more clear. Currently user's authenticate using the login() API method with their user/pass, we store this user/pass locally (not ideal). We then sync a subset of data that the users can access anytime within the app, being that it is a subset, we have a feature to "SSO" to the Salesforce.com front-end. This simply opens Salesforce.com in a web-view (UIWebView) using the URL https://ns8.salesforce.com/?pw=PASSWORD&un=username#example.com&startURL=/recordId. This will log us in to Salesforce.com and open the specified record.
Moving forward we want to use OAuth 2.0 with the web flow so that we aren't handling the user/pass and so that we do not have to deal with Security Tokens or opening specific IP ranges to allow login without a Security Token.
With that said, is there anyway to use the tokens/credentials received from the OAuth authentication to open Salesforce.com, automatically log the user in, and goto a specific record?
I may have mis-used "single sign on" before, but in a sense, this simulates an SSO from our App to Salesforce.com, in that our users can touch a single button within the app and be logged in to the Salesforce.com web interface.
When you request an OAuth token, you can specify what scope it has, options include api only (the original type of tokens), or other options which include the ability to use the token with the UI pages. (see the scope parameter detail in the help). One of the still missing peices is a way to bootstrap the UI with that token when all you can do is tell a browser/webview to goto a URL, but a widely used (but unsupported) way is via frontdoor.jsp, e.g. you'd open https://{instance}/secur/frontdoor.jsp?sid={the_Access_token}&retURL={optional_relative_url_to_open} remember to URLEncode the 2 values.
So I think you are saying your application uses the SFDC username and password to just authenticate to retrieve a record from SFDC to display in your app?
IF this is correct - which I think it is - then you could just use the standard Salesforce Single Sign On system to authenticate. There is a guide here which outlines the process of setting up a SAML SSO system with Pat Patterson writing an interesting feature on how the security system works here. He has also written a great blog post on DeveloperForce here about the nitty details of OAuth in general for Force.com and not just the SAML setup. I have used the OAuth system in an iPad app against SFDC and it works quickly and easily. I can't see why your system should be unable to use the protocol as you desire.
Direct access into Salesforce is a key benefit of SSO and definitely provided. I'm not sure where you read that SSO in Salesforce is API only. From the SSO PDF pbattisson linked for you:
With single sign-on, users only need to memorize a single password to
access both network resources or external applications and Salesforce.
When accessing Salesforce from inside the corporate network, users are
logged in seamlessly, without being prompted to enter a username or
password. When accessing Salesforce from outside the corporate
network, users' corporate network login works to log them in. With
fewer passwords to manage, system administrators receive fewer
requests to reset forgotten passwords.
OAuth 1 & 2 are both supported, though I'm a fan of OAuth 2 since 1 has really finicky additional steps involving the order of parameters and their encoding sequences. I recently wrote an Apex-Twitter integration and quickly realized it wasn't going to be as easy as Facebook, which uses OAuth 2.0.
But in your case it sounds like you just want to provide users with the ability to actually login to Salesforce and go to a specific landing page once authenticated. This is definitely doable.
Good luck!

Design for Facebook authentication in an iOS app that also accesses a secured web service

Goal:
Allow a user to authentication with Facebook into an iOS application which requires access to a protected web service that I'm running.
Assumptions:
There is a native authentication (and registration) system in place for those users that opt not to use Facebook for sign in.
Details:
Assume we want to offer the option for a user to sign in with Facebook without creating a separate account/credential for our system.
Because we support our own native auth mechanism (username and password) we have our own user IDs and issue an authentication token that is used for subsequent interactions after the initial credential validation.
I'm surprised that Facebook doesn't have best practices for this in their developer documentation. All the existing documentation is either assuming you are building FB auth into a website, or a standalone mobile app with no service that requires authentication.
Here's my initial thoughts on how this would be designed but want validation on whether it's correct.
Client pops the Facebook iOS Login
UI User signs in with Facebook credentials and gets access token
iOS App passes access token to our server
Our server talks to FB graph API using access token to (a) validate the token and (b) get the FB user ID for that access token.
e.g. Our server would call https://graph.facebook.com/me/?access_token=XYZ which would return profile info in a JSON object
Assuming it's valid, our server extracts the User ID from the JSON object and checks whether the user already has an account. If so, we issue our own auth ticket to client to use for that session. If user doesn't have an account, we create a new one with the Facebook User ID, assign our own unique UserID and issue our auth ticket.
Client then passes auth ticket back on subsequent interactions that need authentication.
This seems like the right approach to me but not sure if I'm missing something insanely basic and going down the wrong (complicated) path.
I just dealt with this myself, and here's the part that bit me:
In your step 5... It's possible for a user to register for an account with you entirely separate from their Facebook ID, right? Then some other time they log in with Facebook.... And you just created them a second account and lost their first one.
There needs to be a way to be logged in to your web service, then log in to facebook, and capture the association between the facebook ID and the local account.
Apart from that, your plan sounds solid.
Update: Facebook has added a doc outlining such a scenario HERE
Use https to transmit the auth token to your server, as stated by Facebook
Sharing of Access Tokens
Our Data Policies explicitly prohibit any sharing of an Access Token
for your app with any other app. However, we do allow developers to
share Tokens between a native implementation and a server
implementation of the same App (ie. using the same App ID) as long as
the transfer takes place using HTTPS.
One problem I can see with this strategy, is that somebody can give you an access token obtained for a different facebook app. As far as I know, there's no way to verify that the access token is for your application, so you'll just go on and use it.
It doesn't sound very harmful, though. Generally people/apps try to protect the access tokens, rather than sharing them.
One possible exploit of this would be, for somebody to create their own site or mobile app, obtain access tokens for their users and try to authenticate them, using your API. If this succeeds (the user is has a facebook account in your site), the malicious site will be able to use your API impersonating the user.
It's a bit of a long shot, but I think it could work.
Edit: It looks like there is a way to validate the access token after all. See the answer by #Daaniel on question Get application id from user access token (or verify the source application for a token).
your solution totally works.
Maybe an alternative: why not just get the email on the client from the initial social service request and send to your web service? The web service could just store the email, and maybe a social_provider as well. I understand that your web service will not be able to validate where the email came from, but isn't there a high-trust relationship between your web service and your client? If there is, seems like you can depend on the email coming from the right place. Someone please let me know what obvious thing I'm missing that makes the email-based approach silly...

Twitter update access with OAuth and DotNetOpenAuth

I'm trying to use OAuth with .NET (DotNetOpenAuth) to send updates to a Twitter account via a web application. I understand the basic workflow of OAuth and Twitter.
Where I'm confused if is it useful in a server web application? I don't want any user interaction.
But how it seems after an application start, the request token needs to be recreated and also an access token. This involves user interaction.
What is the correct workflow for my case?
Storing the request token or access token in config file?
Or the easist way, using HTTP basic authentication?
Thanks
If I understand you correctly your application will not be interacting with Twitter on behalf of your users but will be acting as the Twitter account for your application.
In this case there are 2 main factors to consider.
1) Do you want "from API" attached to each status as will be if you use basic auth or your applications name will happen if you use OAuth.
2) Do you want to put in the extra effort to implement OAuth.
If you decide to go with OAuth you would store your apps consumer key/secret and the accounts access token in configuration just like you would store the accounts screenname/password.
Your "request token needs to be recreated" phrase suggests you might be running into the problem where every time your user visits you need to re-authorize to Twitter, and perhaps you're looking for a way to access the user's Twitter account while he's not at your web site, and how can you do this when their token isn't fresh from being re-authorized. Is that right?
If so, the user isn't supposed to have to re-authorize Twitter every time they visit your site. The token is supposed to last a long time, which would also allow your site to access their Twitter account when they are not directly interacting with your web site. The problem may be that you haven't implemented the IConsumerTokenManager interface, but are instead using the default InMemoryTokenManager, which is for sample use only, since this memory-only token manager loses tokens every time the web app is restarted. Your own implementation of this simple interface should store and read the tokens out of some persistent storage such as a database.

Twitter Oauth question

I've read through documentation where possible but unable to figure out this basic question. When using Oauth with Twitter in my web application, does it require the user to be logged into Twitter everytime?
For example, if a user authorises their account with my website, in future sessions, if they complete an action that posts to their twitter stream, will this occur without any problems, or would they need to re-sign in via Twitter?
Thanks guys!
The OAuth authorization actually allows your application to access their account whenever it wants. So the users do not even need to be there doing something with your web application to allow it to tweet something or such.
Your application is then able to use the key and token which it received in the authorization process to tell Twitter any time "hey, I am authorized to use this account" and basically works as the application's personal login credentials for that account.
No, they only need to be logged into Twitter when they go through the initial OAuth authorization. After that, your site talks directly to the Twitter API using tokens that it saved from earlier.
Ok I've setup a test-case and it looks like I was a bit wrong:
oauth_token, oauth_token_secret are unique for each user and they never change, so if you store them in your database you can reuse them. No matter if the user is logged in to twitter or not.
No, they will normally not need to re-authorize. If the token is revoked, however, they will, and your application needs to be able to handle this (by allowing them to do so). In general, this is true for any SSO system.
A twitter user can explicitly revoke an application's token at the provided page.

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