A lot of us have been waiting for OWASP to publish a new set of top 10. Now that APIs are key in every solution, OWASP published the Top 10 Most Critical API Security Risks! It is worth the time to read it through. You don’t want to be in the news for the wrong reasons. #infosecurity #applicationsecurity
Yesterday I was wondering if Microsoft support middleware packages for Java to allow the typical resource provider actions in an access_token or id_tokens, similarly to what the OWIN NuGet packages do or the PassportJS libraries for NodeJS. These last two libraries act as middlewares intercepting the HTTP requests. They allow to, programmatically, parse the Authorization headers to extract Bearer tokens, validate the tokens, extract claims from the tokens etc, etc.
The libraries I had found so far, and that I was familiar with, were the MSAL set of libaries and the ADAL set of libraries. These are client side libraries, meant for applications acting or APIs acting as OAuth2 Clients (not as Resource Providers)
Microsoft does not maintain a Java middleware library similar to OWIN or Passport. The development team is using Spring and will use Azure Active Directory as the Identity Provider, they could use Spring Boot Starter for AAD: https://github.com/microsoft/azure-spring-boot/tree/master/azure-spring-boot-starters/azure-active-directory-spring-boot-starter
Spring Boot is a wrapper of Spring Framework libraries packaged with preconfigured components.
They can also work with AAD and Spring Security, but there aren’t many articles out there related to that framework and how to use it when AAD is the IdP providing JWT tokens except for this one:
Article and related links: https://azure.microsoft.com/en-us/blog/spring-security-azure-ad/
There is also this old blog post with some sample code(using spring framework security, however the example is for illustration purposes only, and uses an access_token issued for a SPA client application in order to request access to an API, which is not exaclty the case of the application we’re trying to modernize (multi-page JSP web application)
Microsoft identity providers work with two types of libraries:
- Server middleware libraries: Web apps use server middleware libraries for user sign-in. Web APIs use server middleware libraries to validate tokens that are sent by native clients or by other servers.
Microsoft developers produce and maintains two client Open Source libraries for Java that work with Microsoft identity providers => ADAL and MSAL
They support the industry standards OAuth2.0 and OpenID Connect 1.0
Client Libraries and Microsoft IDP versions
|IDP (Identity Provider)||Client Library|
|AAD v2||MSAL Java (also known as MSAL4J)|
|AAD B2C||MSAL Java (also known as MSAL4J)|
MSAL Java Project Entry point in GitHub https://github.com/AzureAD/microsoft-authentication-library-for-java
MSAL Java sample applications https://github.com/AzureAD/microsoft-authentication-library-for-java/tree/dev/src/samples
ADAL is an older library, used to communicate with identity providers such as ADFS and older versions of AAD v1 token and authorize endpoints
Project source code in GitHub https://github.com/AzureAD/azure-activedirectory-library-for-java
Sample Java application https://github.com/Azure-Samples/active-directory-java-webapp-openidconnect
There is also an oauth2-oidc-sdk for Java that contain the namespaces needed for token deserialization, token validation(s) and processing of claims, which is typically done server side, when the web app or api receives a bearer token in the HTTP(S) Security Authorization Header.
To my knowledge, this SDK is not maintained by Microsoft.
Note: Server side validation of the token, specifically, the decryption of the token digital signature and the comparison of the decrypted hash vs. the calculated hash is critical to ensure the token claims weren’t tampered in transit and that the IdP wasn’t spoofed. There are other token validations, but this one in particular guarantees the integrity of the information and the source of the token.
This needs a good POC!
Azure AD B2C is one of the most fast growing Identity Providers in the world. When this type of tenant was created for social identities and digital citizens, the Microsoft Identity team didn’t anticipate its massive growth. Over 1 billion of users authenticate to their apps, and apps to apis, using this type of Azure directory or tenant. When privacy norms such as GDPR in the European Union and CCPA in California, USA, came about, the flexibility provided by custom policies; the white label customization of the html/css and the Identity Experience Framework, allowed solutions where the end users have more control of their data, including the ability to remove the personal data that applications collect from them (profile information, credentials, user attributes and permissions). Microsoft Graph also provides one of the first RESTful APIs that allow application developers to programatically perform CRUD operations on user accounts and principals associated to applications and services.
This month the Microsoft Identity team has published a number of public articles to guide developers on the automation steps with Azure AD B2C: