When configuring a Shibboleth SP for step-up authentication, please refer to:
Requesting an IAQ

To populate the <samlp:RequestedAuthnContext> element in the SP's requests, the AuthnContextClassRef content setting can be used.

Content settings are properties that can be set in a number of places in the SP to associate settings with resources, commonly via the Apache ShibRequestSetting command or the<RequestMap> in shibboleth2.xml, or by passing them as parameters to "/Shibboleth.sso/Login" if the SP's lazy session feature is being used to generate requests.

Currently, this mechanism only allows for a single IAQ to be requested. To include multiple values in a request, the AuthnRequest "template" mechanism described in the SessionInitiator documentation can be used.

NB: voor een algemene beschrijving van het koppelen van een Shibboleth SP aan SURFconext, zie:
An example Apache configuration snippet where a request for a specific URL triggers a SAML request with a higher LoA:
<Location /secure>
        AuthType shibboleth
        ShibRequestSetting requireSession 1
        ShibRequestSetting authnContextClassRef http://suaas.example.com/assurance/loa2
        require valid-user
The resulting subset of environment variables:
[Shib-Application-ID] => default
[Shib-Session-ID] => _77421bdf5f17e10c70efb9a89aa3737e
[Shib-Identity-Provider] => http://suaas-gw.surfnet.nl/metadata
[Shib-Authentication-Instant] => 2013-10-29T22:08:46Z
[Shib-Authentication-Method] => http://suaas.example.com/assurance/loa3
[Shib-AuthnContext-Class] => http://suaas.example.com/assurance/loa3 [Shib-Session-Index] => c8a493e33432686feb5cc683a9fd0c7c
[persistent-id] => http://suaas-gw.surfnet.nl/metadata!https://suaas-sp.surfnet.nl/shibboleth!urn:collab:person:surfnet.nl:jodi