title: How to setup Authentication between Spring Security Web API and SSO Angular 9 App in Azure?
body: <p>so I am trying to get my Angular Spring Authentication working for like 3 weeks now and I am totally stuck. Here is what I am trying to do:</p>
  
  <p>I have an SSO Angular App, which uses the '@azure/msal-angular' dependency to authentication and authorize against my Azure Active Directory. That part is working completely fine at this point.</p>
  
  <p>In addition to my frontend, I have a Spring-boot backend-application as a Web API. What I am trying to do is, use the JWT Tokens that my frontend got from the Azure Authentication Process and use that token to authentication the Rest Call. </p>
  
  <p>I am not sure what the correct authentication flow is from here on.
  I have seen these 3 different example implementation which are all different:</p>
  
  <p><a href="https://github.com/Azure-Samples/ms-identity-java-webapp" rel="nofollow noreferrer">https://github.com/Azure-Samples/ms-identity-java-webapp</a> </p>
  
  <p><a href="https://github.com/microsoft/azure-spring-boot/tree/master/azure-spring-boot-starters/azure-active-directory-spring-boot-starter" rel="nofollow noreferrer">https://github.com/microsoft/azure-spring-boot/tree/master/azure-spring-boot-starters/azure-active-directory-spring-boot-starter</a></p>
  
  <p><a href="https://github.com/jdubois/spring-active-directory" rel="nofollow noreferrer">https://github.com/jdubois/spring-active-directory</a></p>
  
  <p>Not one of these implementations worked for my backend. 
  So the question is: What is the correct way to build this authentication flow? Is there a valid tutorial/example implementation that I have not seen yet?</p>