Google Calendar API in iOS and Cross Client Authorization - ios

We have an iOS app that uses Google oAuth to ask a users permission for Google calendar using embedded browser. User logs in via the app and grants permission to their calendar(s), the oAuth authorization's refresh token and calendar id's are stored in an encrypted database.
Using this refresh token and calendar id's - their calendar items would then be displayed on a separate web application (without having to request for clients credentials again). This worked great until Google authorization requests in embedded browsers were blocked on April 20 this year. Until this time we used a single oAuth client id and used the client id & secret in both the iOS and the Web app. However, after April 20th, we had to create a separate iOS client key. The issue now is that although within the iOS app we are able to ask for users calendar permissions using this code:
OIDAuthorizationRequest *request = [[OIDAuthorizationRequest alloc] initWithConfiguration:configuration
clientId:GoogleCustomKey
scopes:#[OIDScopeOpenID,
OIDScopeProfile, OIDScopeEmail, #"https://www.googleapis.com/auth/calendar",
#"https://www.googleapis.com/auth/calendar.readonly",
#"https://www.googleapis.com/auth/tasks",
#"https://www.googleapis.com/auth/tasks.readonly"]
redirectURL:[NSURL URLWithString:GoogleRedirectUri]
responseType:OIDResponseTypeCode
additionalParameters:nil];
However now we are no longer able to display the users calendars using the refresh token on the web application. Within the web application, we get "Unauthorized access" error when we debug the web application code. But according to Google's documentation cross client authorization is permitted https://developers.google.com/identity/protocols/CrossClientAuth.
We are not sure what we are missing? Thanks.

Related

How can I get the token and simultaneously hide api credentials for google drive?

I am writing a google drive desktop application and I am using OAuth 2 to get credentials. I can get creds for just reading, but not changing files. As it is a desktop application, there is no site. It is written in https://developers.google.com/identity/protocols/oauth2/native-app, that I need to "supply a local redirect URI to handle responses from Google's authorization server". So, should the client also be a server and listening on some port locally? If I want to have the app verified, I need to provide Authorized domains and other stuff, but it is a desktop application, again. Or maybe there is a way to allow users to use the app, but with a warning on a consent screen for example for development purposes.
Also how to hide the credentials, that I use to get the token? If I publish the app with the credentials, everybody can just steal them and use them
In order to develop a desktop application which will use the Drive API you will have to use credentials of the web app type for which you will later provide the appropriate redirect URI.
By using OAuth 2.0 in your application, you are the only one who has access to the credentials for the application - unless you share them.
According to the Google OAuth 2.0 documentation:
You start by obtaining the OAuth 2.0 client credentials from the Google API Console. Then your client application requests an access token from the Google Authorization Server, extracts a token from the response, and sends the token to the Google API that you want to access.
For the login process, when the users will log-in to your application, they will use their own credentials and then they will have to authorize the application you have built in order to be able to use the Drive API.
Reference
OAuth 2.0 for Mobile & Desktop Apps;
Using OAuth 2.0 to Access Google APIs;

Redirect user from mobile application to mobile web browser for donate

I'm currently working on a mobile application in which we make donations.
Apple guidelines does not allow payment directly in application for donations.
I would like to redirect my users from my mobile application to their web browser on their devices.
How can i authenticate the user without force him to enter his credentials ?
What i've done so far is that i created a "ActionToken" in my database. When the user click on pay on the mobile application, a call to the database is done to generate a token (a simple GUID), and save it in database.
After that, the application redirect to the web page who read the token and retreive the associated user.
What i would like is to eliminate the generation of the token before redirecting to the browser.
Thank you !
When using the authentication in Azure App Service, a JSON web token (JWT) would be presented in the x-zumo-auth request header when the mobile client interacts with the azure mobile app. More details you could refer to Authentication and authorization in Azure App Service.
Per my understanding, you could leverage the authenticationToken generated by your mobile app backend and pass it as the query string with your payment url, then you could send ajax request against your mobile app endpoint (e.g. custom Web API,etc.) with the x-zumo-auth header. For the payment Web API in your mobile app backend, you could refer to adrian hall's book Custom HTTP Endpoints and How to: Retrieve authenticated user information.
For retrieving the value for x-zumo-auth header, you could access MobileServiceClient.CurrentUser.MobileServiceAuthenticationToken after you invoked MobileServiceClient.LoginAsync in your mobile client. More details about adding authentication to the iOS app, you could refer to here.

Google Sign In iOS and Web

I'm building a system with a web and a iOS app. The web part require authentication that can be used on the mobile part and vice versa.
I want to add support for google sign in on the web and on the mobile part. For test i've used the code from
https://developers.google.com/identity/sign-in/ios/start-integrating
for iOS and
https://developers.google.com/identity/sign-in/web/
for the web part.
scope are the same on Application and web (email, profile)
Expected flow
User sign in with google and grant access from mobile (or web)
user go to web site (or application)
user sign in with google
no need to grant permission again
What i got
User sign in with google and grant access from mobile
user go to web site
user sign in with google
same permission are asked again
How can i avoid asking permission again? from the documentation (https://developers.google.com/identity/sign-in/web/cross-platform-sign-in)
seems to be possible to obtain the expected flow but in practice i am unable to obtain it. iOS and Web are in the same google developer project.
I've made this work as expected following this guides: https://developers.google.com/identity/protocols/CrossClientAuth
https://developers.google.com/identity/sign-in/ios/offline-access
what you have to do is the following:
first add
[GIDSignIn sharedInstance].serverClientID = #"SERVER_CLIENT_ID";
in your iOS appDelegate. When the user authenticate through the app you can now retrive a token valid for your server_client_id via serverAuthCode attribute of your GIDGoogleUser object.
Send the token to the server and validate it on the token endpoint (/oauth2/v3/token) redirect_uri must be empty while grant_type must be authorization_codeotherwise you will have a 400 response.
Your server is now authenthicate and when the user will log on the website permission will not be asked again.

Twitter oauth refresh token

I have watched some videos on authenticating using oauth and have gotten the authentication part going but I have the following of questions.
Q1- Do access tokens expire?
Q2 -Do I have to make the user go through the whole user authentication process (with user authenticating the app again) once the twitter access token expires?
Q3-Is offline access to user's content possible once we have the access token
Ok so just to give some more context this is the scenario I have. Basically our mobile app is looking to integrate with twitter and there is a server side to it which needs to munch user's twitter feeds. And this is how we are thinking of doing it. Once the user authenticates our app using the mobile platform, we want to store this user access token in our server, poll his feeds at regular intervals and do some data munching on his feeds. For that we need
-Offline access to user's data
-Get a new access token without user's intervention if the previous one expires preferrably on the server side.
We don't want to have to go through user authenticating our app again.
The OAuth 2 spec is written in such a way that expired access tokens are a supported use case. Search for "expire" in https://www.rfc-editor.org/rfc/rfc6749 for example.
That said, the Twitter OAuth FAQ states:
We do not currently expire access tokens. Your access token will be invalid if a user explicitly rejects your application from their settings or if a Twitter admin suspends your application. If your application is suspended there will be a note on your application page saying that it has been suspended.
To clarify, Twitter's use of OAuth is much more basic than Facebook's or Google's. For details and further help, Google is your friend. ;-)

For a hybrid SSO scenario using the Facebook iOS SDK, what's the best way generating a password/key for our own custom user records?

So my intention is to have a login in my iOS app that allows for either our standard email/pwd registration, or login with Facebook. We are also creating rest services to get application info for a given user, e.g. https://url/getPosts/[userId]?userPwd=foo
I've implemented SSO with fb in a web application before but I have some concerns about the security of authentication in a iOS client scenario. The key difference from what I've done before is that in a web app, I was making a server to server call to Facebook to get the access token so I was reasonably assured that the user was authenticated and the web server made privileged calls to the database. In the iOS case, I have the mobile client app making the Facebook iOS authentication request itself and the server has to somehow trust that this user from the client app is indeed authenticated against the matching user record in our database.
My question is how do I generate a durable and secret unique key from the iOS SDK so that I can create and associate a matching user record in our database for users that authenticate only with Facebook. I want this to be seamless so the user would not have to manually fill out another form, and we would just automatically create this matching user record in our db.
I could insert a record into my own users table when they fbDidLogin with Facebook, using the Facebook Id as the unique identifier, and the fb access token as the pseudo password/key for my own user record. I would have to validate the access token with Facebook to make sure it's valid before saving it as a password for the user (the user would never see this password, it would just be passed by the client app during api calls). That way when the user makes a call to our own rest api via the iPhone app we can authenticate and authorize using this secret/pwd/key.
An alternative that would make this whole question moot is to just handle the authorization logic on the client app, and check that there is a valid fb session before making calls to our own apis which I secure with just a single application-wide secret, but that doesn't seem as secure since getting that one secret gives authorization to data on all users. I'd rather authorize at an individual user level. Is that the right choice? Am I being paranoid about iOS security?
The fb access token expires so that might not seem durable, however if I enable offline access that token won't expire but creates a scarier looking oauth dialog window. An alternative to the access token is to hash the fb Id with an application secret key on the iOS client, and use that as the Facebook user's password in our db. However, that again is a single secret key that could perhaps be reverse compiled from the iOS client app?
Design for Facebook authentication in an iOS app that also accesses a secured web service
This post helped me undesrtand it more. If I am not mistaken, the flow goes like this:
User authenticates in iOS app
iOS app takes auth token, sends it to the rails app
Rails app takes auth token and sends it to graph.facebook.com/?auth_token=XXX to get back the user if authentication was successful.
Rails app takes the user info and matches/creates user in own database table. Sends some kind of authentication key back to iOS app.
iOS app saves the authentication key so it can use it to communicate with the rails app.
Let me know if I am missing anything.
Have you looked at the iOS docs for Single Sign On (SSO)? https://developers.facebook.com/docs/guides/mobile/#ios
You can share an app ID across mobile, canvas and web site and the same user auth works for each environment.
Check out: https://developers.facebook.com/docs/authentication/
Facebook Platform provides a number of ways to use the above OAuth flows in different app types, including Websites, Apps on Facebook.com, Mobile and Desktop Apps.
You just need to insert users Facebook key to your database to know if its authenticated with Facebook. Use OAuth at ios side authenticate user take users secret key send it to your rest web-service and save it with users other info.

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