SCIM Directory Services
draft-hunt-scim-directory-01

Abstract

This document describes a directory server that implements the SCIM protocol and schema [, its capabilities and access control model], and optional support for LDAPv3 protocol. This specification extends SCIM from provisioning to a general purpose access protocol in support of data management applications (e.g. self-service systems) and RESTful clients that need read/write access to a directory on the Internet, between domains, or within a cloud.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on February 02, 2014.

Copyright Notice

Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

• 1. Introduction
• 1.1. Applications and Directories
• 1.2. Requirements Language
• 2. Data Models
• 2.1. SCIM Model
• 2.1.1. Object Model
• 2.1.2. Attributes
• 2.1.3. Directory SCIM Schema Extensions
• 2.2. LDAP Model
• 2.2.1. Syntax Support
• 2.2.2. Object Classes
• 2.2.3. Attributes
• 2.2.3.1. Attribute Type Mapping
• 2.2.3.2. Complex Attributes
• 2.2.3.3. Multi-Valued Attributes
• 2.2.3.4. Attribute Name Mapping
• 2.2.4. LDAP Operations
• 2.2.5. LDAP Controls
• 3. Server Topology
• 4. SCIM API Support
• 5. Authentication & Access Control
• 5.1. Authentication
• 5.2. Access Control
• 6. IANA Considerations
• 7. Security Considerations
• 8. References
• 8.1. Normative References
• 8.2. Informative References
• Appendix A. Acknowledgements
• Appendix B. Document History
• Author's Address

1. Introduction

SCIM is a protocol[I-D.scim-api] and schema[I-D.scim-core-schema] designed for provisioning applications and repositories. SCIM was intended to be implemented by applications to enable a common standard protocol for provisioning. This document describes a SCIM Directory, a general purpose RESTful server that can be used by applications as a repository for shared identity information. Specifically, this document reframes the concepts of a directory server as expressed in [RFC2251], and describes how a "SCIM Directory" may simultaneously support LDAPv3 protocol.

For a directory servers supporting both SCIM and LDAPv3, the document describes how SCIM schema, in particular complex attributes is mapped to the LDAPv3 Data Model. The dual-protocol objective of this specification enables eased migration to RESTful Identity Services and avoids the need to run parallel SCIM and LDAPv3 server infrastructures.

This document will describe the following components:

• Data model for a SCIM Directory
• The basic feature set of a SCIM Directory.
• The access control requirements for a SCIM Directory[TBD].
• [OPTIONAL] support for LDAPv3 clients accessing a directory implementing the SCIM Data Model

[TBD: Directory replication. Access control - data layer vs. http layer]

1.1. Applications and Directories

For the purpose of this document, two different types of SCIM Provider (or server) are implied: being "application providers" and "directory providers". Whereas an "application" implements the SCIM API and Core Schema specifications, a "directory" has further requirements detailed in this document.

1.2. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

2. Data Models

This specification bases the SCIM data model upon that of the SCIM Core Schema specification[I-D.scim-core-schema]. It further extends and defines how an LDAP Model can be applied within a SCIM Directory in order to provide dual protocol (LDAPv3 and SCIM) support.

2.1. SCIM Model

The SCIM Protocol defines a schema suitable for exchange using JSON data objects exchanged over a REST API. SCIM Core Schema provides minimal core schema for representing resources such as users and groups encompassing common attributes used by cloud providers, PortableContacts, and LDAP directory services. Further and most importantly, SCIM Core Schema provides an extension model upon which more resource types may be defined.

2.1.1. Object Model

A SCIM Directory stores objects based on an extension model where objects of different types extend a parent object type to create specialized objects such as Users and Groups. As defined in the SCIM Core Schema, all objects are extensions of the SCIM Resource object.

                              +----------+*id,meta
                ------------->| Resource |<----------
               /              |__________|           \
              /                     ^                 \
             /                      | *externalId      \
+-----------+-----------+  +--------+---------+   +-----+----+
| ServiceProviderConfig |  |   CoreResource   |   |  Schema  |
|_______________________|  |__________________|   |__________|
                              ^           ^
                              |           |
                           +--+---+   +---+---+
                           | User |   | Group |
                           |______|   |_______|
                              ^
                              |
                     +--------+--------+
                     | Enterprise User |
                     |_________________|