Tag Archives: OAuth2

Implementing secure Microsoft Graph application clients in ASP.NET Core

The article looks at the different way a Microsoft Graph application client can be implemented and secured in an ASP.NET Core application or a .NET application. This type of client is intended for applications or application logic where no user is involved. Code: https://github.com/damienbod/MicrosoftGraphAppToAppSecurity Accessing Microsoft Graph can be initialized for app-to-app (application permissions) security […]

Implement the OAUTH 2.0 Token Exchange delegated flow between an Azure AD API and an API protected using OpenIddict

This article shows how to implement the OAUTH 2.0 Token Exchange RFC 8693 delegated 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 OAUTH 2.0 Token Exchange RFC 8693 delegated flow to get a new OpenIddict delegated […]

Azure AD Multi tenant Azure App registration consent

This article looks at Azure Active directory and consent with multi-tenant Azure App registrations. Consent works different depending on the user type, the tenant policies and the required permissions. It is sometimes hard to understand why a user cannot login or where the consent has to be given for a specific Azure App registration which […]

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 […]

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 […]

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 […]

Secure ASP.NET Core GRPC API hosted in a Linux kestrel Azure App Service

This article shows how to implement a secure GRPC API service implemented in ASP.NET Core and hosted on an Azure App Service using Linux and kestrel. An application Azure App registration is used to implement the security together with Microsoft.Identity.Web. A client credentials flow is used to acquire an application access token and the GRPC […]

Add Fido2 MFA to an OpenIddict identity provider using ASP.NET Core Identity

This article shows how to add Fido2 multi-factor authentication to an OpenID Connect identity provider using OpenIddict and ASP.NET Core Identity. OpenIddict implements the OpenID Connect standards and ASP.NET Core Identity is used for the user accounting and persistence of the identities. Code: https://github.com/damienbod/AspNetCoreOpeniddict I began by creating an OpenIddict web application using ASP.NET Core […]