Description
Expected Behavior
Attributes should be untouched and specified by their Name (which is a required attribute). As FriendlyName is an optional attribute, one cannot rely on that and must-not as specified by the specification.
Section 2.7.3.1, § FriendlyName, line 1271
This attribute's value MUST NOT be used as a basis for formally identifying SAML attributes
Convertion from Name to FriendlyName should be explicit and handled by the user.
Current Behavior
Internally pysaml2 converts attribute names to friendly names and uses the latter for most operations, like filtering, metadata generation (RequestedAttributes element), creation of class members, etc. This is achieved through the AttributeConverter class, the helper functions defined in attribute_converter module and the attributemaps files. These allows for some control over the conversion process.
Possible Solution
Only depend on attribute Name. It is the only way to guarantee robustness and is required to be in line with the specification. This questions the value of attribute_converter module; whether it is needed at all. The user of the library (the application) should be responsible for such a conversion, which most probably would be used to present an interface where friendly-names could be used in place of the non-descriptive name identifiers.