Security Assertion Markup Language (SAML) defines a common XML framework for creating, requesting, and exchanging authentication and authorization data among entities known as Identity Providers (IdPs) and Service Providers (SPs). This exchange enables single sign-on among such entities.
In simple terms, an IdP is a claims producer and a service provider is a claims consumer. An IdP produces assertions about users, attesting to their identities. Service providers consume and validate assertions before providing access to resources.
SAML 2.0 is an OASIS open standard. The SAML core specification defines the structure and content of assertions.
SAML metadata specifies how configuration information is defined and shared between two communicating entities: a SAML Identity Provider (IdP) and a SAML service provider. Service provider metadata provides information about service provider requirements, such as whether the service provider requires a signed assertion, the protocol binding support for endpoints (AssertionConsumerService) and which certificates and keys to use for signing and encryption. IdP metadata provides information about IdP requirements, such as the protocol binding support for endpoints (SingleSignOnService), and which certificate to use for signing and encryption.
Configure a BIG-IP system as a SAML identity provider when you have one BIG-IP system and you want it to provide single sign-on authentication service for a group of external SAML service providers.
Configure a BIG-IP system as a SAML service provider when you have one BIG-IP system and you want it to protect services that are behind it, and direct users to an external SAML identity provider for authentication.
For security purposes, each SP should have a certificate from the IdP that manages identities for it; each IdP should have certificates from the SPs for which it manages identities.
Metadata normally includes a certificate. When you import metadata into a BIG-IP system from an external SP or an external IdP, the certificate that was included in the metadata is stored on the BIG-IP system. When you configure security-related settings on the BIG-IP system, you select certificates from the store.
If you do not have metadata that you can import from external SPs or IdPs, then you need to do one of the following:
To get a certificate from the BIG-IP system, you can export it. You can potentially also get a certificate from a BIG-IP system by exporting SAML metadata for use on the external system.
When you export metadata from a BIG-IP system, it includes a certificate. However, when an external system requires signed metadata, the external system must already have a certificate from the BIG-IP system to validate the metadata.