What Is SAML Authentication?
SAML (Security Assertion Markup Language) is a protocol that allows authentication information to be securely exchanged between systems.
The SAML protocol is used in many systems during the authentication process. You can think of authentication simply as the user signing in and having their identity verified.
SAML stands for Security Assertion Markup Language.
Thanks to this protocol, a user’s identity information can be securely passed from one system to another.
How Does SAML Work?
With SAML, a user:
- Signs in to System A
- Gets authenticated
- Doesn’t need to sign in again when moving to System B
This mechanism is generally known as Single Sign-On (SSO).
As a result:
- The user experience improves
- The user doesn’t have to log in repeatedly
- Identity is shared securely between systems
SAML typically carries the following information between systems:
- Username
- Email address
- First name
- Last name
- Other identity attributes belonging to the user
The Technical Structure of SAML
SAML is an XML-based protocol.
Authentication information is transmitted between systems as a SAML Assertion, an XML-formatted structure.
The SAML standard was developed and published by OASIS (Organization for the Advancement of Structured Information Standards).
SAML Components
SAML’s architecture has two core components.
Service Provider (SP)
The Service Provider is the application the user wants to access.
For example:
- A web application
- A SaaS platform
- An internal corporate panel
The user ultimately wants to sign in to this system.
Identity Provider (IdP)
The Identity Provider is the system that authenticates users.
This service:
- Authenticates the user
- Generates identity information
- Sends this information to the Service Provider as a SAML Assertion
Examples of Identity Providers:
- Okta
- Azure AD
- Keycloak
- Auth0
My Sample SAML Service Provider (SP) Repo
Below I’m sharing a screenshot and GitHub repo link for a simple Service Provider (SP) I built using SAML.
This app lets you quickly test SAML integration against various Identity Provider (IdP) services.
I built it with Node.js. To make setup easier, I moved it to a Docker container architecture and published it on GitHub.
You can clone the project and have it running in just a few minutes to run your own SAML integration tests.
Features
- A simple SAML Service Provider implementation
- Test against different Identity Provider services
- Built with Node.js
- Quick setup with Docker
- Easy to spin up a test environment