Author Archives: damienbod

Implement a Microsoft Entra ID external authentication method using ASP.NET Core and OpenIddict

The article shows how to implement a Microsoft Entra ID external authentication method (EAM) using ASP.NET Core, OpenIddict and FIDO2/passkeys. The application using ASP.NET Core Identity to manage the accounts and the passkeys. Code: https://github.com/damienbod/MfaServer The following flow diagram from the Microsoft docs explains how EAM works. Refer to the documentation for a full explanation. […]

Using SonarCloud with ASP.NET Core, Angular and github actions

This article demonstrates how to implement code analysis and Static Application Security Testing (SAST) using SonarCloud and GitHub Actions. The solution involves building a secure web application with ASP.NET Core for the backend and an Angular UI for the frontend, following a backend-for-frontend security architecture. Both the ASP.NET Core (C#) codebase and the Angular (TypeScript […]

Implement a secure Blazor Web application using OpenID Connect and security headers

This article shows how to implement a secure .NET 8 Blazor Web application using OpenID Connect and security headers with CSP nonces. The NetEscapades.AspNetCore.SecurityHeaders nuget package is used to implement the security headers and OpenIddict is used to implement the OIDC server. Code: https://github.com/damienbod/BlazorWebOidc OpenIddict is used as the identity provider and an OpenID connect […]

BFF secured ASP.NET Core application using downstream API and an OAuth client credentials JWT

This article shows how to implement a web application using backend for frontend security architecture for authentication and consumes data from a downstream API protected using a JWT access token which can only be accessed using an app-to-app access token. The access token is acquired using the OAuth2 client credentials flow and the API does […]

Create conditional access base policies for a Microsoft Entra ID tenant

This article shows some of the base conditional access policies which can be implemented for all Microsoft Entra ID tenants. Phishing resistant authentication should be required for all administration flows and some other user policies like sign-in risk MFA or terms of conditions. I recommend these base policies when implementing an Microsoft Entra ID tenant […]

Multi client blob storage access using ASP.NET Core with Entra ID authentication and RBAC

This article shows how to onboard different clients or organizations in an ASP.NET Core application to use separated Azure blob containers with controlled access using security groups and RBAC applied roles. Each user in a client group can only access a single blob storage and has no access to blob containers belonging to different clients. […]

Delegated read and application write access to blob storage using ASP.NET Core with Entra ID authentication

This article shows how an ASP.NET Core application can control the write access to an Azure blob storage container using an application app registration. Microsoft Entra ID is used to control the user access and to implement the authentication of the web application. Code: https://github.com/damienbod/AspNetCoreEntraIdBlobStorage Blogs in this series The solution provides a secure upload […]

Using a CSP nonce in Blazor Web

OLD, please refer to the blogs in the github repo. This article shows how to use a CSP nonce in a Blazor Web application using the InteractiveServer server render mode. Using a CSP nonce is a great way to protect web applications against XSS attacks and other such Javascript vulnerabilities. Code: https://github.com/damienbod/BlazorServerOidc Notes The code […]

Using Blob storage from ASP.NET Core with Entra ID authentication

This article shows how to implement a secure upload and a secure download in ASP.NET Core using Azure blob storage. The application uses Microsoft Entra ID for authentication and also for access to the Azure Blob storage container. Code: https://github.com/damienbod/AspNetCoreEntraIdBlobStorage Blogs in this series Security architecture The application is setup to store the file uploads […]

Secure an ASP.NET Core Blazor Web app using Microsoft Entra ID

This article shows how to implement an ASP.NET Core Blazor Web application using Microsoft Entra ID for authentication. Microsoft.Identity.Web is used to implement the Microsoft Entra ID OpenID Connect client. Code: https://github.com/damienbod/Hostedblazor8MeID Note: I based this implementation on the example provided by Tomás López Rodríguez and adapted it. Setup The Blazor Web application is an […]