
## Why Use SAML SSO in Decoupled .NET Applications? {#Why Use SAML SSO in Decoupled .NET Applications?}

**Centralized Authentication**

Eliminate multiple logins—authenticate once and access all connected apps securely without additional credentials.

**Cross-Platform Compatibility**

Seamless integration with ASP.NET, ASP.NET Core, and microservices-based .NET applications.

**Tailored for Decoupled Apps**

Use our plugins to integrate SAML SSO into your decoupled .NET apps effortlessly.

**Compliance & Security**

Built on SAML 2.0 standards, ensuring encrypted communication and enterprise-grade security.

## How SAML SSO Works for Decoupled .NET Applications (Frontend + Backend) {#How SAML SSO Works for Decoupled .NET Applications}

A decoupled .NET application consists of independent apps (API, front-end, back-end) that need a unified authentication mechanism. Here’s how miniOrange makes it work:


 ![Working of Decoupled .NET Architecture](/blog/assets/2025/asp-net-decoupled-architecture.webp)

 **1. User Starts Login**

 When **User A** visits your frontend app, the app checks if the user is already logged in. If not, it starts the SSO process.

 **2. Frontend Redirects to Backend**

 The frontend passes the login request to the .NET backend to handle authentication.

 **3. Backend Sends SAML Request to Identity Provider (IdP)**

 The backend sends a SAML request to the Identity Provider (IdP) (like Azure AD, Okta, etc.) to ask for user authentication.

 **4. IdP Authenticates the User**

 The IdP checks the user's credentials. If everything is valid, it sends back a SAML response confirming the user's identity.

 **5. Backend Logs the User In**

 The backend reads the SAML response, logs in the user, and sets a claims cookie. Then it redirects the user back to the frontend.

 **6. Frontend Asks for a Token**

 After being redirected, the frontend sends a request to the backend to get a JWT token (a secure login token).

 **7. Backend Sends the JWT Token**

 The backend checks the request and sends a signed JWT token back to the frontend. The frontend now uses this token to make secure API calls.

 ## Use Case: SAML SSO for Angular, Vue.js & React Frontends with .NET Backend

 **Scenario:**

 Organizations are increasingly adopting decoupled apps, using modern frontends like Angular, Vue.js, or React that communicate with a centralized ASP.NET (.NET Core/Web API) backend. While this setup offers flexibility and scalability, it presents a challenge when implementing SAML Single Sign-On (SSO).

 **Challenge:**

 **SAML Incompatibility with Modern Frontends:**

 SAML depends on browser-based redirects, which don’t play well with frontend   frameworks like React, Angular, or Vue. 

 **Disjointed Authentication Experience:**

 The absence of a centralized login system leads to inconsistent user experiences and adds complexity and time to the development process.

**Unauthorized API Access:**

Unable to allow only authenticated users to access your .NET APIs. Implementing JWT could help prevent unauthorized data exposure.

**Lack of Role-Based Access:**

User roles (e.g., admin, viewer) needed to be enforced at the backend, keeping them hidden from the frontend and reducing security risks.

**No Frontend Code Modifications:**

The organization prefers not to alter frontend code—whether due to the risk of introducing bugs or the complexity of deployment pipelines.

**Solution:**

**Backend-Handled SAML Authentication:**

By introducing a .NET-based SAML Identity Broker, all SAML requests and responses are handled at the backend.

**Multi-IdP Support:**

With support for multiple Identity Providers like Azure AD, Okta, ADFS, and Google Workspace, organizations can centralize authentication across different systems.

**Secure Token Exchange + API Access:**

After successful SAML authentication, the backend issues a JWT or session token. Frontend apps use this token to make secure API calls, ensuring only authenticated users can access your .NET APIs.

**Role & Attribute Mapping:**

The backend fetches user roles and attributes (like email, department, and permissions) from the IdP and applies RBAC policies. This keeps role enforcement off the frontend, improving security.

**Outcome:**

By implementing the miniOrange SAML SSO solution for decoupled frontend-backend apps, organizations benefit in the following key ways:

**Centralized & Secure Authentication:**

Centralized SAML authentication ensures secure login, better control, and prevents token mishandling on the client side.

**Better User Experience Across Frontends:** 

Users on Angular, Vue.js, or React apps experience smooth, SSO-based login flows without redirects breaking the UI or interrupting sessions.

**Efficient Token-Based API Communication:**

 Post-authentication, JWT tokens are issued by the backend, enabling frontend apps to securely call APIs. 

**Granular Access Control with RBAC:**  

Fine-grained authorization logic that can enforce access restrictions at both the API and feature levels—without exposing role logic in the frontend.

**Support for Multiple Identity Providers:** 

miniOrange SAML SSO integrates with any SAML-compliant IdP—allowing organizations to manage multiple login sources from a single backend integration point.

## Why Choose miniOrange for SAML SSO in Decoupled .NET Apps? {#Why Choose miniOrange for SAML SSO in Decoupled .NET Apps?}

**Seamless Integration with .NET Backend**

Works with ASP.NET Core, Web API, and microservices. Ensure smooth and secure communication between .NET apps.

**Secure Token-Based Authentication**

Ensures safe API access using industry-standard JWTs. Prevent unauthorized access and maintain data integrity.

**Supports Multiple IdPs**

Authenticate your users using a variety of Identity Providers (IdPs) such as Okta, Azure AD, ADFS, Google Workspace, and more.

**Flexible Role & Attribute Mapping**

Go beyond basic authentication with custom role and attribute mapping. 

&nbsp;

## Resources {#more resources}
- [What is Single Sign-On (SSO)?](https://www.miniorange.com/products/single-sign-on-sso)
- [What is ASP.NET SAML Single Sign-On (SSO)?](https://plugins.miniorange.com/asp-net-saml-single-sign-on-sso)
- [Steps to Configure the ASP.NET SAML 2.0 Module](https://plugins.miniorange.com/asp-dot-net-saml-2-0-single-sign-sso-connector)
- [Setup Steps for ASP.NET SAML SSO Module](https://plugins.miniorange.com/asp-net-saml-sso-setup-guides)


Simplify Authentication Across Your .NET Applications.Eliminate repeated logins with SAML Single Sign-On (SSO) built for decoupled .NET apps. Let users log in once and securely access all your applications—streamlining access while ensuring enterprise-grade security and a seamless user experience.

Secure Your Decoupled .NET Apps with SAML SSO


### How to use Single Sign-On for your ASP.NET MVC application? {#how to use single-sign-on for ASP.NET MVC application}

There may come a time when you need to implement [Single Sign-On onto your ASP.NET MVC application](https://plugins.miniorange.com/asp-net-saml-single-sign-on-sso). It allows you to integrate your app with other systems and helps them work together as if they are one unified application.

Some of the benefits of doing this are an improved user experience, increased security, and reduction in costs. Users will be able to seamlessly access pages on any of these applications or systems after signing in only once.

Or, if you want to migrate your application, rather than having to rewrite it entirely, you can migrate it one service at a time. Implementing SSO between the two applications helps you effectively link them together as if they were one, after which you can migrate your app with ease. There are even more advantages discussed later in this article.

To understand how you can implement [ASP.NET MVC Single Sign On](https://plugins.miniorange.com/asp-net-saml-single-sign-on-sso), let us first understand what its components mean.

### What is ASP.NET MVC? {#what is ASP.NET MVC}

ASP.NET MVC is composed of two parts: ASP.NET and MVC. The first is an open-source web application framework that can be used to produce dynamic web pages, applications, and services. The second is MVC, which stands for Model View Controller. It is an architectural pattern that is meant to achieve separation of concerns. 

Together, they form a web application framework that eliminates the drawbacks of web forms like slow response times, issues in unit testing, and HTML customization.

Designing your application using the ASP.NET MVC framework allows you to benefit from both its components’ advantages. However, you still need to make it easier for users to sign in to your application and avail of its services in a hassle-free manner. Let’s see how we can do that.

 ### What is SSO? {#what is SSO}

 When a user wants to access secured services on your application, they have to enter their username and password once to authenticate themselves. In a situation where they want to access similar services over multiple applications connected or related to each other, they would be required to enter either the same or different usernames and passwords multiple times.

 ![what-is-single-sign-on-and-how-sso-works-4](/blog/assets/2023/what-is-single-sign-on-and-how-sso-works-4.webp)

 Single Sign-On (SSO) makes this process easier by using the same authentication ID and authorizing the user across multiple services. Because of SSO, as the name suggests, the user is required to sign in only once in a certain time window before the authentication token expires.

 ### What are the types of SSO protocols? {#what are the types of SSO protocols}

 For SSO to work, Service Providers (SP) and Identity Providers (IDP) must decide on an open standard protocol for how they will choose to exchange identity and authentication information with one another over the relevant applications.

 Here are a few examples of these protocols: 

 **OAuth**: This is an open standard for token-based authentication and authorization, which is used to provide Single Sign-On (SSO). It allows an end user’s account information to be used by third-party services without exposing the user’s password. It serves as an intermediary on behalf of the end-user, providing the service with an access token that authorizes specific account information to be shared.

 **OpenID**: This is one of the most popular authentication protocols, used by the likes of Google and Facebook. It is open standard and decentralized. Third-party Identity Providers (IdP) are used to authenticate users to Relying Parties (RP). It serves as an identity layer on top of OAuth, thereby functioning as an extension to it.

 **SAML**: SAML uses session cookies in a browser that allows a user to access certain pages. It gives more control to enterprises to keep their SSO logins more secure. You can find a detailed explanation of SAML below.


### Let’s take an in-depth look at SAML {#in-depth look at SAML}

SAML stands for Security Assertion Markup Language. Its main purpose in online security is to enable you to access multiple web applications using one set of credentials. It works by passing authenticated credentials between two parties: an Identity Provider (IDP) and a Service Provider (SP). Doing so makes the user experience simpler while also providing better security.

 ![saml-diagram-2](/blog/assets/2023/saml-diagram-2.webp)

 ### Where can we use SAML SSO? {#where can we use SAML SSO}

The primary attribute of SAML is that it is used for authentication, not authorization. This means that a variety of applications, websites, and services that could be used to access and edit data from the service provider need to form a trusted relationship with the SSO website.


Now, when a user tries to access data from the service provider’s app, they’ll need to be authenticated at least once by entering a username and password before they can read or write onto this data. If, however, they have already done this once, then they will be granted access more directly. A SAML request will be generated by the application, asking to authenticate the user, to which the identity provider will respond with a SAML response.


This is particularly useful in situations where the service provider is offering their services across a wide range of applications. It inadvertently also increases the scope of the product by allowing a variety of third-party applications to offer their unique services using the same data.

For example:
- Data-driven statistics websites and applications for online multiplayer games.
- Social media applications and bulletin boards designed around the same topic.
- Online video streaming services with features for viewer engagement.
- Online software marketplaces like Steam that offer user analytics and metadata.

### What are the benefits of using ASP.NET MVC Single Sign On? {#benefits of using ASP.NET MVC Single Sign On}

**Shorter development time**: Using ASP.NET MVC Single Sign-On reduces development time by providing developers with a common authentication framework. It takes even more load off of them if the mechanism is independent.

**Reduction in costs**: Besides the fact that development time is reduced, support requests for forgotten passwords and IT help desk calls also go down, thereby lowering the overall costs.

**Increased security**: An important benefit of SSO is that it reduces the chance of users falling prey to phishing attacks. This is because the user is not trained to mindlessly enter their username and password everywhere. Furthermore, SSO systems usually force users to use secure communication channels. This means that only one place of authentication receives their credentials. The applications, however, don’t receive any specific information besides whether they should let the user in or not. This happens only once, resulting in a minimum transfer of sensitive information, which is naturally favorable.

**Streamlined administration**: The burden on the administrative system to manage user accounts is massively reduced with the implementation of SSO. Keep note, however, that SSO only takes care of authentication. The authorization of users based on their access privileges still needs to be set up separately.

**Improved user experience**: With ASP.NET MVC Single Sign On enabled, users don’t have to enter their usernames and passwords multiple times to access the same service across multiple applications and browsers.

### Additional Sources: {#Additional sources}
- [What is Single Sign-On (SSO)?](https://www.miniorange.com/products/single-sign-on-sso)
- [What is ASP.NET SAML Single Sign-On (SSO)?](https://plugins.miniorange.com/asp-net-saml-single-sign-on-sso)
- [Steps to Configure the ASP.NET SAML 2.0 Module](https://plugins.miniorange.com/asp-dot-net-saml-2-0-single-sign-sso-connector#steps)
- [Setup Steps for ASP.NET SAML SSO Module](https://plugins.miniorange.com/asp-net-saml-sso-setup-guides)





How to use Single Sign-On for your ASP.NET MVC application?