Slides from my guest lecture at Xamarin University on how to add Google Authentication to your Xamarin.Android application.

1. ▸ Lecture will begin shortly
Google+ Login - A
Primer

2. ❖ Overview
❖ How Does OAuth 2.0 Work?
❖ Setting up Project
❖ Google Play Services
Topics

3. Overview
❖ Sharing passwords
❖ No cross-federated authentication
❖ Everybody had their own username/
password

6. ❖ Provides authentication flows for web,
desktop, and mobile.
❖ User authentication is delegate to an
HTTP services such as Google.
❖ Relies on informed user consent and
tokens
OAuth 2.0 to the Rescue

7. User
Login
&
Consent
Request
Token
Mobile
App
Authorization
Code
Call
Google
API
with
Token
Access
Token
Refresh
Token
Exchange
Code
for
Token

8. Google has their own OAuth 2
Using Google Play Services

9. ❖ Nobody wants to create “Yet Another
Login”
❖ Hides a lot of the OAuth 2.0 details
❖ Provides a standard, native experience
❖ Authentication is a Hard Thing
❖ In other words, we’re lazy…
Why Use Google+ Login?

10. Creating an API Project
https://console.developers.google.com/project

11. SHA1 Fingerprint

12. Create a Google API Project

13. Enable the Google+ API

14. Create Client ID

15. Now For the Code
Adding Google+ Authentication to a Xamarin.Android App.

16. ① Add Google Play Services to the Android Project
② Update Android Permissions
③ Add Google+ Sign-in Button to UI
④ Initialize a GoogleApiClient
⑤ Respond to callbacks from the GoogleApiClient
Checklist

17. Show Me The Code!

18. ❖ Source Code
https://github.com/topgenorth/gplus-quickstart-xamarin.android
❖ Google Developer Console
https://console.developers.google.com/
❖ Start integrating Google+ into your Android app
https://developers.google.com/+/mobile/android/getting-started
❖ Google+ Sign-in for Android
https://developers.google.com/+/mobile/android/sign-in
❖ Google+ Platform Developer Policies
https://developers.google.com/+/policies
References

19. ❖ OAuth2 Crash Course
❖ Creating the Google API Project
❖ Examined Working Code
Summary