SAML2.0 request attribute name format

Question

Is it part of the SAML2.0 specification to request which attribute name format you want for the SAML response?

So back from Office365 SAML2.0 I get

<Attribute Name="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress">
   <AttributeValue>[email protected]</AttributeValue>
</Attribute>

Clearly the attribute name format seems to be NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri"

I want the name format to be (basic) NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"

So that OFfice365 responds with the ff instead

<Attribute Name="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress">
   <AttributeValue>[email protected]</AttributeValue>
</Attribute>

I know i can make these changes to the response on Office365 but i want to know if requesting such a response is a thing in SAML2.0

Answer 1

Yes. you can find the documentation under Section 8.2 Attribute Name Format Identifiers of SAML v2.0 OASIS Standard.

8.2 Attribute Name Format Identifiers The following identifiers MAY be used in the NameFormat attribute defined on the AttributeType complex type to refer to the classification of the attribute name for purposes of interpreting the name.

8.2.1 Unspecified URI: urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified The interpretation of the attribute name is left to individual implementations.

8.2.2 URI Reference URI: urn:oasis:names:tc:SAML:2.0:attrname-format:uri The attribute name follows the convention for URI references [RFC 2396], for example as used in XACML [XACML] attribute identifiers. The interpretation of the URI content or naming scheme is applicationspecific. See [SAMLProf] for attribute profiles that make use of this identifier.

8.2.3 Basic URI: urn:oasis:names:tc:SAML:2.0:attrname-format:basic The class of strings acceptable as the attribute name MUST be drawn from the set of values belonging to the primitive type xs:Name as defined in [Schema2] Section 3.3.6. See [SAMLProf] for attribute profiles that make use of this identifier.