Integrate a SAML 2.0 service provider with an identity provider

Steps

1. Generate your SP metadata XML containing your entity ID, AssertionConsumerService URL, and your SP's signing certificate (refer to it as a PEM-encoded certificate in configuration); share this with the IdP administrator
2. Obtain the IdP metadata XML (or configure issuer, SSO URL, and IdP signing certificate manually) and load it into your SAML library
3. On a login attempt, generate an AuthnRequest, sign it with your SP private key, and redirect the user to the IdP SSO URL via HTTP-Redirect or HTTP-POST binding
4. Receive the SAMLResponse at your ACS URL; base64-decode and XML-parse it, then verify the XML signature against the IdP's certificate
5. Extract the NameID and attribute statements from the assertion; validate the Conditions element (NotBefore, NotOnOrAfter, AudienceRestriction must include your entity ID)
6. Implement one-time-use tracking for the InResponseTo ID to prevent replay attacks, then create or update the local user session