[secdir] Secdir review of draft-ietf-scim-core-schema-18

["Brian Weis (bew)" <[e-mail]>]

I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

For the security area directions, I consider this document to be "Ready with nits”.

This document documents resources a JSON scheme for Cross-Domain Identity Management, a standard definition of attributes representing users and groups, and a set of named schemas incorporating these attributes. The goal of the document  is to make identity management in cloud based applications and services easier. This is used when identity information needs to be shared between services.

The Security Considerations (Section 9) in version 18 is reasonably clear in the first two sub-sections that there are risks to sensitive information defined in the schema, these sub-sections point to helpful text in draft-ietf-scim. It is much improved over version 17. I have a couple of comments suggesting clarification be added to the document.

Section 9.3 begins by stating the schema “defines attributes that MAY contain personally identifiable information as well as other sensitive data”. I don’t understand the “MAY”. Just about every attribute described in this document is arguably personally identifiable information (PII), since transporting PII between services seems to be the actual need for development of the schema. It seems more accurate to say “defines attributes that contain personally identifiable information as well as other sensitive data”. (Also “MAY” is intended to declare a part of the standard that is optional for an implementation, and I don’t see how that could apply here.)

Section 4.1.1 defines the “password” attribute as a “clear text password”. It is much safer to store and pass a salted and hashed password. Do none of the services using this schema support a method of hashing a user password to see if it matches a given hashed value ? Or could this be an option in the scheme definition? If so, it would be worth describing that here and in the Security Considerations section.

 Brian