Two ways to integrate/federate applications with Azure AD:
Azure marketplace:
https://azure.microsoft.com/en-us/marketplace/active-directory/all/
check if the application exists:
The Microsoft Azure Marketplace is an online store that offers applications and services either built on or designed to integrate with Microsoft’s Azure public cloud.
Else, how to configure single sign-on to applications that are not in the Azure Active Directory application gallery: https://docs.microsoft.com/en-us/azure/active-directory/active-directory-saas-custom-apps
Authentication scenarios for Azure AD:
Applications integrated with Azure: the access via https://account.activedirectory.windowsazure.com/applications/default.aspx
Integrating applications with Azure AD: https://docs.microsoft.com/fr-fr/azure/active-directory/develop/active-directory-integrating-applications
Identity hybrid ports and protocols:
https://docs.microsoft.com/en-us/azure/active-directory/connect/active-directory-aadconnect-ports
Azure app gallery:
https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-app-gallery-listing
If not pre-packaged in Azure marketplace: Any app that supports SAML 2.0 can be integrated directly with an Azure AD tenant using these instructions to add a custom application.
Provide credentials for a test tenant or account with your application that can be used by the Azure AD team to test the integration.
Provide the SAML Sign-On URL, Issuer URL (entity ID), and Reply URL (assertion consumer service) values for your application, as described here. If you typically provide these values as part of a SAML metadata file, then please send that as well.
Provide a brief description of how to configure Azure AD as an identity provider in your application using SAML 2.0. If your application supports configuring Azure AD as an identity provider through a self-service administrative portal, then please ensure the credentials provided above include the ability to set this up.
Configuring single sign-on to applications that are not in the Azure Active Directory application gallery:
https://docs.microsoft.com/en-us/azure/active-directory/active-directory-saas-custom-apps
Note:
Sign On URL (SP-initiated only) – Where the user goes to sign-in to this application. If the application is configured to perform service provider-initiated single sign on, then when a user navigates to this URL, the service provider will do the necessary redirection to Azure AD to authenticate and log on the user in. If this field is populated, then Azure AD will use this URL to launch the application from Office 365 and the Azure AD Access Panel. If this field is ommited, then Azure AD will instead perform identity provider -initiated sign on when the app is launched from Office 365, the Azure AD Access Panel, or from the Azure AD single sign-on URL (copiable from the Dashboard tab).
Issuer URL – The issuer URL should uniquely identify the application for which single sign on is being configured. This is the value that Azure AD sends back to application as the Audience parameter of the SAML token, and the application is expected to validate it. This value also appears as the Entity ID in any SAML metadata provided by the application. Check the application’s SAML documentation for details on what it’s Entity ID or Audience value is. Below is an example of how the Audience URL appears in the SAML token returned to the application
Reply URL – The reply URL is where the application expects to receive the SAML token. This is also referred to as the Assertion Consumer Service (ACS) URL.
