The following query parameters can be set in the URL when accessing spSSOInit.jsp:
AuthnContextClassRef or AuthnContextDeclRef: These properties specify one or more URI references identifying the provider's supported authentication context classes. If a value is not specified, the default is urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport.
AuthLevel: This parameter specifies the authentication level of the authentication context being used for authentication.
AuthComparison: This parameter specifies the method of comparison used to evaluate the requested context classes or statements. Accepted values include:
exact where the authentication context statement in the assertion must be the exact match of, at least, one of the authentication contexts specified.
minimum where the authentication context statement in the assertion must be, at least, as strong (as deemed by the identity provider) one of the authentication contexts specified.
maximum where the authentication context statement in the assertion must be no stronger than any of the authentication contexts specified.
better where the authentication context statement in the assertion must be stronger than any of the authentication contexts specified.
If the element is not specified, the default value is exact.
An example URL might be http://SP_host:SP_port/uri/spSSOInit.jsp?metaAlias=SP_MetaAlias&idpEntityID=IDP_EntityID&AuthnContextClassRef=PasswordProtectedTransport&AuthLevel=4&AuthComparision=minimum