How to configure Custom Attributes in SP metadata

Question

I came to know that in any SSO Solution if SP needs any additional attributes it can publish them in its metadata using AttributeConsumingService argument. The required attributes can now be added like as below:

<md:AttributeConsumingService index="0"
xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">
<md:ServiceName xml:lang="en">ABC</md:ServiceName>
<md:ServiceDescription xml:lang="en">ABC</md:ServiceDescription>
<md:RequestedAttribute isRequired="true"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
Name="urn:oid:2.5.4.42"
FriendlyName="FirstName"/>
</md:AttributeConsumingService>

Now, if I want to add a custom attribute in my SP metadata, lets say "Role" of a user, how should I add it in the metadata? I mean, what would be its Name(this is what I'm unable to find!), NameFormat(is it urn:oasis:names:tc:SAML:2.0:attrname-format:uri?) and FriendlyName(can I give it as "Role" here?). I've not found anything related to this in the SAML2Core document.

Any suggestions please!

Thanks,

Abhilash

Answer 1

There is no universal answer as it depends on which IDP/federation you use and what is supported by it.

Generally, the friendly name is just a human-readable identifier for the attribute and the value can be freely defined.

The NameFormat and Name are defined based on Attribute Profile used by your IDP (e.g. Basic profile, X.500/LDAP Profile, ...). The expected values can be found in SAML 2.0 profiles document chapter 8.

You can find an example of how this is employed in practice for e.g. inCommon federation in their documentation.