Registered By InCommon Category

Currently all entity metadata in the InCommon production aggregate were registered by the InCommon registrar and therefore every entity descriptor contains the following extension element:

<md:Extensions xmlns:mdrpi="urn:oasis:names:tc:SAML:metadata:rpi">
  <mdrpi:RegistrationInfo registrationAuthority="https://incommon.org"/>
</md:Extensions>

The value of the registrationAuthority XML attribute in the previous extension element is the ID of the InCommon registrar. Every metadata registrar has such a globally unique identifier. As other metadata (such as eduGAIN metadata) is imported into the InCommon aggregate, the <mdrpi:RegistrationInfo> element will become a distinguishing characteristic of entity metadata.

Since the <mdrpi:RegistrationInfo> element is not widely supported in software, every occurrence of mdrpi:RegistrationInfo/@registrationAuthority="https://incommon.org/" in metadata is replicated as a fixed entity attribute. This makes it easier for consumers to determine whether the registrar of a given entity descriptor is the InCommon registrar. This is the sole purpose of the Registered By InCommon Category.

<md:Extensions
    xmlns:mdrpi="urn:oasis:names:tc:SAML:metadata:rpi"
    xmlns:mdattr="urn:oasis:names:tc:SAML:metadata:attribute">
  <mdrpi:RegistrationInfo registrationAuthority="https://incommon.org"/>
  <mdattr:EntityAttributes xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">
    <saml:Attribute
        NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
        Name="http://macedir.org/entity-category">
      <saml:AttributeValue>
        http://id.incommon.org/category/registered-by-incommon
      </saml:AttributeValue>
    </saml:Attribute>
  </mdattr:EntityAttributes>
</md:Extensions>

Note that the Registered By InCommon entity category applies to both SPs and IdPs. The semantics of the registered-by-incommon entity attribute are identical to mdrpi:RegistrationInfo/@registrationAuthority="https://incommon.org".

Practically speaking, the registered-by-incommon entity attribute is used by SP and IdP deployments to reverse the effects of importing eduGAIN entities into the InCommon production aggregate.