Displaying secured images in an image tag

Step 1: Create a .NET Core Web API

Open Visual Studio or your preferred code editor. Create a new project and choose "ASP.NET Core Web API."

Step 2: Set Up JWT Authentication

Install the required NuGet packages:

1dotnet add package Microsoft.AspNetCore.Authentication.JwtBearer

In your Startup.cs, configure JWT authentication in the ConfigureServices and Configure methods:

1// ConfigureServices
2services.AddAuthentication(options =>
3{
4    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
5    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
6}).AddJwtBearer(options =>
7{
8    options.TokenValidationParameters = new TokenValidationParameters
9    {
10        ValidateIssuer = true,
11        ValidateAudience = true,
12        ValidIssuer = "your_issuer",
13        ValidAudience = "your_audience",
14        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("your_secret_key")),
15    };
16});

Add [Authorize] attribute to your API controllers or actions to secure them.

Step 3: Access Images from Blob Storage with SAS Tokens

Install the Azure.Storage.Blobs NuGet package:

1dotnet add package Azure.Storage.Blobs

In your controller, you can generate a SAS token for your blob and return it in the API response. For example, to generate a SAS token for a blob in an Azure Blob Storage container:

1using Azure.Storage.Blobs;
2using Azure.Storage.Blobs.Models;
3
4
5[Authorize]
6public string GetImageUrl(string fileName){
7    var blockBlob = BlobContainerClient.GetBlobClient(fileName);
8    var uri = blockBlob.GenerateSasUri(
9                Azure.Storage.Sas.BlobSasPermissions.Read,
10                DateTime.UtcNow.Add(timetoLive));
11    return uri.ToString();
12}

Step 4: Testing

Test your API using tools like Postman or by creating a client application to send JWT tokens when accessing the protected endpoints.

This is a high-level overview of creating a .NET Core Web API with JWT authorization and using SAS tokens for images from a blob in the response. You can expand on this structure to fit your specific requirements. If you have any specific questions or need more detailed code examples, feel free to ask!