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This page shows some sample Shibboleth configurations that leverage the Registered By InCommon Category.

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IdP Uses of the Registered By InCommon Category

Typically, an IdP will use the registered-by-incommon entity attribute (if it uses it all) to constrain its attribute release policy. A number of sample policy rules are illustrated in the subsections below.

Do not filter SP metadata!

An interoperable IdP consumes all the SP metadata in the world, no exceptions. Consequently, an IdP does not filter metadata. Instead an interoperable IdP implements a rational set of attribute release rules, subject to local policy.

Releasing the Essential Attribute Bundle

A Shibboleth IdP uses type basic:ANY to activate a policy for any requester. For example, here's a default attribute release policy that releases the Essential Attribute Bundle to all SPs:

A Shib IdP config that releases attributes to ALL SPs
<afp:AttributeFilterPolicy id="releaseEssentialAttributeBundle">

  <!-- this policy is active for ANY requester -->
  <afp:PolicyRequirementRule xsi:type="basic:ANY"/>

  <!-- the Essential Attribute Bundle -->
 
  <afp:AttributeRule attributeID="eduPersonPrincipalName">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>
  <afp:AttributeRule attributeID="email">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>
  <afp:AttributeRule attributeID="displayName">
    <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:AttributeFilterPolicy>

A default policy (such as the previous policy) takes on a different meaning in the presence of eduGAIN metadata. For various reasons, some IdPs will want to retain the semantics of their current default policy, at least for a time. This is why the Registered By InCommon Category was created.

Here's how an instance of Shibboleth IdP V2 can leverage the registered-by-incommon entity attribute to retain its current default policy:

A Shib IdP V2 rule that releases attributes to all SPs registered by InCommon
<!-- this policy is active for a requester with the following entity attribute -->
<!-- (for Shib IdP V3, use type saml:EntityAttributeExactMatch instead)        -->
<afp:PolicyRequirementRule xsi:type="saml:AttributeRequesterEntityAttributeExactMatch"
    attributeName="http://macedir.org/entity-category"
    attributeValue="http://id.incommon.org/category/registered-by-incommon"/>

An instance of Shibboleth IdP V3 will either leverage the registered-by-incommon entity attribute (as above) or the <mdrpi:RegistrationInfo> element directly, as shown in the following example:

A Shib IdP V3 rule that releases attributes to all SPs registered by InCommon
<!-- this policy is active for a requester whose registrar has the given ID -->
<afp:PolicyRequirementRule xsi:type="saml:RegistrationAuthority"
    registrars="https://incommon.org"/>

The value of the registrars XML attribute above is the globally unique ID for the InCommon registrar.

Releasing the R&S Attribute Bundle

Most of the Research & Scholarship (R&S) IdPs in the InCommon Federation are configured with a policy rule that releases attributes to R&S SPs tagged with the legacy InCommon R&S entity attribute value:

A Shib IdP V2 rule that releases attributes to legacy R&S SPs
<afp:PolicyRequirementRule xsi:type="saml:AttributeRequesterEntityAttributeExactMatch"
    attributeName="http://macedir.org/entity-category"
    attributeValue="http://id.incommon.org/category/research-and-scholarship"/>

An IdP configuration SHOULD NOT rely on the incommon.org R&S tag in SP metadata

Use of the legacy incommon.org R&S tag to configure attribute release policy at the IdP is deprecated. Eventually this tag will be removed from all SP metadata although a timeline for doing so has not yet been determined.

R&S IdPs should instead be configured with a policy that releases the R&S Attribute Bundle to all R&S SPs, including R&S SPs in other federations:

A Shib IdP config that releases the R&S bundle to ALL R&S SPs
<afp:AttributeFilterPolicy id="releaseRandSAttributeBundle">

  <!-- for Shib IdP V3, use type saml:EntityAttributeExactMatch instead -->
 
  <afp:PolicyRequirementRule xsi:type="saml:AttributeRequesterEntityAttributeExactMatch"
      attributeName="http://macedir.org/entity-category"
      attributeValue="http://refeds.org/category/research-and-scholarship"/>

  <!-- a fixed subset of the Research & Scholarship Attribute Bundle -->
 
  <afp:AttributeRule attributeID="eduPersonPrincipalName">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>

  <!-- if your deployment of ePPN is non-reassigned, release of ePTID is OPTIONAL -->
  <afp:AttributeRule attributeID="eduPersonTargetedID">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>

  <afp:AttributeRule attributeID="email">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>

  <!-- either displayName or (givenName and sn) is REQUIRED but all three are RECOMMENDED -->
  <afp:AttributeRule attributeID="displayName">
    <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>

  <!-- release of ePSA is OPTIONAL -->
  <afp:AttributeRule attributeID="eduPersonScopedAffiliation">
    <afp:PermitValueRule xsi:type="basic:ANY"/>
  </afp:AttributeRule>

</afp:AttributeFilterPolicy>

To facilitate the migration suggested by the previous examples, all R&S SPs registered by InCommon have a multivalued R&S entity attribute in metadata.

It is thought that some R&S IdPs will want to retain their current attribute release policy for a time. An instance of Shibboleth IdP V2 may leverage the Registered By InCommon Category to retain its current attribute release policy but without relying on the legacy InCommon R&S entity attribute value:

A Shib IdP V2 rule that releases attributes to R&S SPs registered by InCommon
<!-- for Shib IdP V3, use type saml:EntityAttributeExactMatch instead -->
 
<afp:PolicyRequirementRule xsi:type="basic:AND">
  <basic:Rule xsi:type="saml:AttributeRequesterEntityAttributeExactMatch"
      attributeName="http://macedir.org/entity-category"
      attributeValue="http://refeds.org/category/research-and-scholarship"/>
  <basic:Rule xsi:type="saml:AttributeRequesterEntityAttributeExactMatch"
      attributeName="http://macedir.org/entity-category"
      attributeValue="http://id.incommon.org/category/registered-by-incommon"/>
</afp:PolicyRequirementRule>

An instance of Shibboleth IdP V3 will either leverage the registered-by-incommon entity attribute (as above) or the <mdrpi:RegistrationInfo> element directly, as shown in the following example:

A Shib IdP V3 rule that releases attributes to R&S SPs registered by InCommon
<afp:PolicyRequirementRule xsi:type="basic:AND">
  <basic:Rule xsi:type="saml:EntityAttributeExactMatch"
      attributeName="http://macedir.org/entity-category"
      attributeValue="http://refeds.org/category/research-and-scholarship"/>
  <basic:Rule xsi:type="saml:RegistrationAuthority"
      registrars="https://incommon.org"/>
</afp:PolicyRequirementRule>

For more information about configuring an IdP for Research & Scholarship, consult the R&S Attribute Bundle Config topic in the wiki.

SP Uses of the Registered By InCommon Category

SPs typically leverage entity attributes up front when metadata is consumed. The registered-by-incommon entity attribute may be used to customize the discovery interface, or in some special circumstances, to filter metadata altogether.

See the Shibboleth Metadata Config topic for a complete example of a MetadataProvider. At most one of the following MetadataFilter elements may be added to that MetadataProvider.

Filtering Untrusted Metadata

To filter all but InCommon metadata, add the following MetadataFilter to your SP's MetadataProvider:

Filter all metadata not registered by InCommon
<!-- consume only InCommon metadata -->
<MetadataFilter type="Whitelist" matcher="EntityAttributes">
  <saml:Attribute
      Name="http://macedir.org/entity-category"
      NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
    <saml:AttributeValue>http://id.incommon.org/category/registered-by-incommon</saml:AttributeValue>
  </saml:Attribute>
</MetadataFilter>

The above policy is severe but sometimes warranted. A more relaxed policy will simply filter the metadata from the discovery interface, as shown in the next section.

Customizing Discovery Interfaces

To show all IdPs with the registered-by-incommon entity attribute, add the following MetadataFilter to your SP's MetadataProvider:

Show only InCommon IdPs on the discovery interface
<!-- Show all IdPs with the registered-by-incommon entity attribute -->
<DiscoveryFilter type="Whitelist" matcher="EntityAttributes"
    attributeName="http://macedir.org/entity-category"
    attributeNameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
    attributeValue="http://id.incommon.org/category/registered-by-incommon"/>

Keep in mind that hiding an IdP from the discovery interface does not prevent the SP from accepting an assertion from that IdP.

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