User Secrets in your .NET Project

Genarally, we need to include some sensitive data in our appsettings.json file, like a connection string that content a username and password or a something kind of private key:

{
  "ConnectionStrings": {
    "MongoDb": "mongodb://mongoadmin:secret@127.0.0.1:27017/aurora/?authSource=admin"
  }
}

However, the exposure of these credentials is not safe and is not a good practice either. And, when a developer get your repository, maybe they need to do adjust your docker images or change the sensitive data/connection strings to attend the project.

Let's see how can we solve this! 🤓

User Secrets

This is a way that allows us to manage sensitive data for .NET on local development.

So, to configure it in your project, you'll need something like below in your Startup/Program class:

WebApplication 
    .CreateBuilder(args)
    .Host
    .ConfigureAppConfiguration((context, configurationBuilder) =>
    {
        configurationBuilder
            .AddUserSecrets(Assembly.GetExecutingAssembly())
            .AddEnvironmentVariables();
    })

Now, we need to configure our secrets, right?
First, let's open the startup project folder and, next open the terminal, and follow the commands below:

• To enable secret storage:
  dotnet user-secrets init

• To add a secret:
  dotnet user-secrets set "ConnectionStrings:MongoDb" "[YOUR CONNECTION]"

• To add a secret in a list:
  dotnet user-secrets set "PrivateKey[0]" "[YOUR KEY]"
dotnet user-secrets set "PrivateKey[1]" "[YOUR KEY]"

• To list the secrets:
  dotnet user-secrets list

• To remove a secret:
  dotnet user-secrets remove "ConnectionStrings:MongoDB"

Conclusion

• Never store passwords or other sensitive data in source code
• Production/Staging/Development should not be used for local test/development
• Sensitive data should not be deployed with the app
• You should store sensitive data in a protected environment/tool, like Azure Key Vault

References

• https://learn.microsoft.com/en-us/aspnet/core/security/app-secrets?view=aspnetcore-7.0&tabs=windows