SAML2 Authentication - Unsolicited SSO

SAML2 IdP Unsolicited/SSO profile, also known as IdP Initiated, supports the following parameters:

Parameter Description
providerId Required. Entity ID of the service provider.
shire Optional. Response location (ACS URL) of the service provider.
target Optional. Relay state.
time Optional. Skew the authentication request.

A typical request to the CAS would look like this:

1
2
3
GET https://sso.example.org/cas/idp/profile/SAML2/Unsolicited/SSO \
    ?providerId=https://sp.example.org/saml2 \
    &shire=my-relay-state-here