Microsoft O365 Introduction Part-1

1. Visual Studio 2013 with Update 3 or later; I am using the Community Edition, it is free and has most of the features.
   
   
2. Microsoft Office 365 API Tools version 1.4.50428.2.
   
   
3. Office 365 account mapped with an Azure subscription. (Requires an Office 365 business and linked Azure subscription MSDN subscription enterprise/ultimate. For development we can create a trial Office 365 and create a linked Azure subscription).
   
   
4. Knowledge of MVC though we will not use much of its features.

Let set up the Office 365 account

Go to Office 365 Dev Program and sign up for a new Office 365 account.



It will ask for your personal details and live id.

You also must link it to an Azure subscription. To activate an Azure subscription it will ask for your credit card details but the best part is Microsoft will not charge for the free trial subscription. These subscriptions will expire in one month.

For Authentication Office 365 uses 2-layer of filtration and for Authorization we must configure Office 365 services in the application and set the access levels.

Authentication

Let's see the following sequence diagram for authentication.



Authentication is the first step to access the Office 365 APIs and it has total 7 steps. Authentication is done using an Azure active directory. It has the two layers Authorization Endpoint and Token Endpoint. Let's see the entire flow one by one.

Step 1: When the user opens your website he/she will redirect to the Azure AD Authorization end points.

Step 2: Authorization endpoint sends a browser popup/redirect to the login.

Step 3: Once the user is verified in an Authorization Endpoint it sends an authentication code back to the user.

Step 4: Now the web application will use this code and request a Token Endpoint for the token.

Step 5: On success, the Token End point will return an Access token and refresh the token as a response.

Step 6: With the refresh Token and Access token the application will start using the Office 365 APIs.

Step 7: The API will start responding as a HTTP Response.

Authorization

Authorization is very important for an application because if we don't set any authorization, the application might provide access to all the services of Office 365 that may not be required. After setting up the authorization an application will use only the set resources. We can set the authorization using Visual Studio and the Azure Management Portal. The following is the procedure to add Authorization to an application using Visual Studio.

Note: The following is the procedure that gives the brief details of how to add Office 365 to our application. In the future series, I will provide a detailed procedure and we will create a working example. For now assume we have a hello world application that uses an Office 365 service.

Step 1

Open Visual Studio and create a web application project.

Step 2

Right-click on the project and Select Connected services. Here the user must login with their Office 365 credentials.





Step 3

Once the user has logged in successfully, the user can select the services and set their access level (read, read and write and so on). This will configure the application to use only those services and their access rights.



Once the user has set up the permission, the user will see something similar to the following:



Step 4

To save the settings click OK. It will add all the necessary packages and templates.

You can see the packages and DLLs being added in the Output window.



Once you see “Done” in the output window you can check the references window for the new packages added to the project.



This article rovided an introduction to Office 365, its Authentication and Authorization. In the next article I will show a demo application and the entire procedure required to implement it in an application. I will also the show implementation of the services one by one.

References

1. Microsoft Virtual Academy

2. Dev centers