Devlog #5

I’m currently on vacation, but I’m trying to stay productive by working on some software projects.

OAuth2.0 Token Management + EF Core SQLite Setup + HTTPClient/DPAPI

The past few days, I’ve been working on setting up some basic OAuth functionality for Google and Google Drive. I thought it would be very simple at first, but perhaps since I’m new to C# and on vacation, it took me a bit to get used to the C#/ASP.NET features and development patterns, such as dependency injection.

Additionally, there’s plenty more to using OAuth 2.0 that I was not aware of at first. Step 1) involved acquiring ClientId and Clientsecret values from the Google Dev Console page. These were stored in User Secrets in Visual Studio along with the project.

For desktop clients, clients use the provider’s OAuth API link to apply for a long-lived Refresh Token. This Refresh Token, once encrypted and stored securely, is used to continuously request for short-lived Access Tokens, which is what is actually used for Google’s API services, like the Google Drive API.

Encryption was setup using the .NET data protection API, DPAPI. I created two classes: a GoogleDriveProvider to manage Google-specific OAuth setup and Drive API calls, and a generic TokenManager that handles the refresh-access token exchange for all OAuth-related providers, including ones I will add in the future such as OneDrive and Dropbox.

For the HTTPClients used to make the web requests, I decided to add an HTTPClient to GoogleDriveProvider using builder.Services.AddHttpClient().

Finally, all pertinent information to the app is stored within an SQLite database using EF Core. Refresh Tokens are stored within an object called CloudTokens.

I have the basic functionality for the OAuth setup, so my next steps will just be to test it out and debug for any errors.

Below are some snapshots from the code I wrote.