The goal of the needed Shibb IdP config mentioned below can be simply stated as this:
"If the IdP receives a SAML authentication request with 'https://refeds.org/profile/mfa' set as the only authenticationContextClassRef, then it MUST force the user to login with MFA. Optionally, if the IdP receives 'https://refeds.org/profile/mfa' in a list of multiple allowed authentication contexts, it MAY ask the user if they would like to authenticate with MFA."
The InCommon Cert Service SSO/MFA flow works like this:
User clicks federated login link.
User selects IdP from discovery service
IdP receives SAML authenticationRequest with 'Password', 'PasswordProtectedTransport', 'http://id.incommon.org/assurance/base-level', and 'https://refeds.org/profile/mfa' set as the allowed/requested SAML authenticationContextClassRef values.
IdP optionally asks user if they want to use MFA authentication
SP/app receives SAML assertion with user's ePPN.
SP/app looks up user's invitation and determines if the user is an RAO.
If the user is an RAO, then the SAML authenticationContextClassRef in the received assertion is checked.
If the RAO user did not authenticate with MFA, they are sent back to the IdP with only 'https://refeds.org/profile/mfa' set as the allowed/requested SAML authenticationContextClass (since the user was identified as an RAO). Otherwise, the user is a DRAO and they are logged in.
Both eppn and email address are required.
EduPersonPrincipalName [eppn] (SAML: urn:oid:184.108.40.206.4.1.59220.127.116.11.6)
Email address [mail] (SAML: urn:oid:0.9.2342.19200300.100.1.3)
First and last name are optional.
First name [givenName] (SAML: urn:oid:18.104.22.168)
Last name [sn] (SAML: urn:oid:22.214.171.124)
For the initial invitation, the email address asserted by the IdP must match the email address in the invited user’s CCM profile. At that point, the user’s eppn is stored in their CCM profile.
Thereafter, only a match on eppn is required to bind the user to their CCM profile.
The user’s eppn can be edited directly in CCM.
After the initial login, values for email address, first name, and last name received from the IdP will be used to update the related values in the user’s CCM profile
Once logged into CCM, here’s how to onboard existing RAOs/DRAOs in your org:
Change in general-authn.xml-- Add new 2fa supported principal to both authn/Duo, and authn/MFA: <bean parent="shibboleth.SAML2AuthnContextClassRef" c:classRef="https://refeds.org/profile/mfa" /> ...and then just add a release rule. <afp:AttributeFilterPolicy id="Incommon_Certmanager"> <afp:PolicyRequirementRule xsi:type="basic:AttributeRequesterString" value="https://cert-manager.com/shibboleth" /> <afp:AttributeRule attributeID="email"> <afp:PermitValueRule xsi:type="basic:ANY" /> </afp:AttributeRule> <afp:AttributeRule attributeID="givenName"> <afp:PermitValueRule xsi:type="basic:ANY" /> </afp:AttributeRule> <afp:AttributeRule attributeID="surname"> <afp:PermitValueRule xsi:type="basic:ANY" /> </afp:AttributeRule> <afp:AttributeRule attributeID="eduPersonPrincipalName"> <afp:PermitValueRule xsi:type="basic:ANY" /> </afp:AttributeRule> </afp:AttributeFilterPolicy>