Absent, Unspecified or Malformed NameID in Response

[peppelinux]

a pySMAL2 SP seems to work properly even if get a Response with an unspecified NameID value, as follow

        <saml:Subject>
            <saml:NameID Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient" NameQualifier="">
            </saml:NameID>

We have the same behaviour even if the NameID statement would be absent.

For example, this trows a unhandled exception in djangosam2:

djangosaml2/backends.py", line 82, in _extract_user_identifier_params
    user_lookup_value = session_info['name_id'].text
AttributeError: 'NoneType' object has no attribute 'text'

We have the same behaviour even if the Response have a missing Format value in NameID statement

            <saml:NameID Format="" NameQualifier="https://that.url.org">
                    _e32052ed-bdda-4645-823c-7b92ee2c29c6       
            </saml:NameID>

even if the Format is malformed

            <saml:NameID Format="" NameQualifier="https://that.url">
                    _e32052ed-bdda-4645-823c-7b92ee2c29c6       
            </saml:NameID>

even if NameQualifier is absent or malformed

            <saml:NameID Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient" NameQualifier="">
                    _afb61c1f-08c2-4724-b15f-1af6447534c4
            </saml:NameID>