Author Archives: damienbod

Sharing Microsoft Graph permissions and solution Azure App Registrations

This article looks at using Microsoft Graph permissions in Azure App registrations and whether you should use Graph in specific Azure App registrations types and if it is ok to expose these with other scopes and roles. Is it ok to expose Graph permissions in public Azure App registrations? Using Graph with public applications As […]

Use multiple Azure AD access tokens in an ASP.NET Core API

This article shows how to setup an ASP.NET Core application to authorize multiple access tokens from different Azure AD App registrations. Each endpoint can only accept a single AAD access token and it is important that the other access tokens do not work on the incorrect API. ASP.NET Core Schemes and Policies are used to […]

Create Azure App Registration for API using Powershell

This post shows how to setup an Azure App registration using Powershell for an application access token using an application role. In Azure roles are used for App only, scopes are used for delegated flows (Or roles for users). The Azure App registration uses OAuth2 with the client credentials flow. A secret and a client_id […]

Switch tenants in an ASP.NET Core app using Azure AD with multi tenants

This article shows how to switch between tenants in an ASP.NET Core multi-tenant application using a multi-tenant Azure App registration to implement the identity provider. Azure roles are added to the Azure App registration and this can be used in the separate enterprise applications created from the multi-tenant Azure App registration to assign users and […]

Is scanning QR Codes for authentication safe?

This article explains why cross device authentication has security issues as it is subject to phishing attacks unless further authentication is used in the client. Scanning QR Codes for authentication does not protect against phishing and leaves the users open to having their session stolen. Phishing There a many forms of phishing and this is […]

Force phishing resistant authentication in an ASP.NET Core application using Azure AD

This article shows how to force a phishing resistant authentication for an ASP.NET Core application using Azure AD and a conditional access policy which forces a phishing resistant authentication using a conditional access authentication context. The ASP.NET Core application forces this by requiring the acrs claim in the id_token with the value of c4 which […]

Implement the On Behalf Of flow between an Azure AD protected API and an API protected using OpenIddict

This article shows how to implement the On Behalf Of flow between two APIs, one using Azure AD to authorize the HTTP requests and a second API protected using OpenIddict. The Azure AD protected API uses the On Behalf Of flow (OBO) to get a new OpenIddict delegated access token using the AAD delegated access […]

ASP.NET Core Api Auth with multiple Identity Providers

This article shows how an ASP.NET Core API can be secured using multiple access tokens from different identity providers. ASP.NET Core schemes and policies can be used to set this up. Code: https://github.com/damienbod/AspNetCoreApiAuthMultiIdentityProvider The ASP.NET Core API has a single API and needs to accept access tokens from three different identity providers. Auth0, OpenIddict and […]

Setup application client in Azure App Registration with App roles to use a web API

In Azure AD, a client application with no user (daemon client) which uses an access token to access an API protected with Microsoft Identity needs to use an Azure API Registration with App Roles. Scopes are used for delegated flows (with a User and a UI login). This is Azure AD specific not OAuth2. This […]

Implement a GRPC API with OpenIddict and the OAuth client credentials flow

This post shows how to implement a GRPC service implemented in an ASP.NET Core kestrel hosted service. The GRPC service is protected using an access token. The client application uses the OAuth2 client credentials flow with introspection and the reference token is used to get access to the GRPC service. The GRPC API uses introspection […]