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SCIM Definitions, Overview, and Flows
draft-ietf-scim-use-cases-06

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Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 7642.
Authors Phil Hunt , Bhumip Khasnabish , Anthony Nadalin , Kepeng Li , Zachary Zeltsan
Last updated 2015-04-23 (Latest revision 2015-04-14)
RFC stream Internet Engineering Task Force (IETF)
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Stream WG state Submitted to IESG for Publication
Document shepherd Morteza Ansari
Shepherd write-up Show Last changed 2015-03-12
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draft-ietf-scim-use-cases-06
SCIM WG                                                          P. Hunt
Internet-Draft                                                    Oracle
Intended status: Informational                             B. Khasnabish
Expires: October 15, 2015                                  ZTE (TX) Inc.
                                                              A. Nadalin
                                                               Microsoft
                                                              K. LI, Ed.
                                                           Alibaba Group
                                                              Z. Zeltsan
                                                              Individual
                                                          April 13, 2015

                 SCIM Definitions, Overview, and Flows
                      draft-ietf-scim-use-cases-06

Abstract

   This document provides definitions and an overview of the System for
   Cross-domain Identity Management (SCIM).  It lays out the system's
   models and flows, and includes user scenarios, use cases, and
   requirements.

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 October 15, 2015.

Copyright Notice

   Copyright (c) 2015 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

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   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 . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  SCIM User Scenarios  . . . . . . . . . . . . . . . . . . . . .  4
     2.1.  Background & Context . . . . . . . . . . . . . . . . . . .  4
     2.2.  Model Concepts . . . . . . . . . . . . . . . . . . . . . .  4
       2.2.1.  Triggers . . . . . . . . . . . . . . . . . . . . . . .  4
       2.2.2.  Actors . . . . . . . . . . . . . . . . . . . . . . . .  5
       2.2.3.  Modes & Flows  . . . . . . . . . . . . . . . . . . . .  6
       2.2.4.  Bulk & Batch Operational Semantics . . . . . . . . . .  7
     2.3.  Cloud Service Provider to Cloud Service Provider Flows
           (CSP->CSP) . . . . . . . . . . . . . . . . . . . . . . . .  7
       2.3.1.  CSP->CSP - Create Identity (Push)  . . . . . . . . . .  7
       2.3.2.  CSP->CSP - Update Identity (Push)  . . . . . . . . . .  7
       2.3.3.  CSP->CSP - Delete Identity (Push)  . . . . . . . . . .  8
       2.3.4.  CSP->CSP - SSO Trigger (Push)  . . . . . . . . . . . .  8
       2.3.5.  CSP->CSP - SSO Trigger (Pull)  . . . . . . . . . . . .  8
       2.3.6.  CSP->CSP - Password Reset (Push) . . . . . . . . . . .  8
     2.4.  Enterprise Cloud Subscriber to Cloud Service Provider
           Flows(ECS->CSP)  . . . . . . . . . . . . . . . . . . . . .  9
       2.4.1.  ECS->CSP - Create Identity (Push)  . . . . . . . . . .  9
       2.4.2.  ECS ->CSP - Update Identity (Push) . . . . . . . . . .  9
       2.4.3.  ECS ->CSP - Delete Identity (Push) . . . . . . . . . .  9
       2.4.4.  ECS ->CSP - SSO Pull . . . . . . . . . . . . . . . . . 10
   3.  SCIM Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 10
     3.1.  Change of the ownership of a file  . . . . . . . . . . . . 10
     3.2.  Migration of the identities  . . . . . . . . . . . . . . . 11
     3.3.  Single Sign-On (SSO) Service . . . . . . . . . . . . . . . 12
     3.4.  Provisioning of the user accounts for a Community of
           Interest (CoI) . . . . . . . . . . . . . . . . . . . . . . 13
     3.5.  Transfer of attributes to a relying party web site . . . . 14
     3.6.  Change notification  . . . . . . . . . . . . . . . . . . . 15
   4.  Security considerations  . . . . . . . . . . . . . . . . . . . 16
   5.  IANA considerations  . . . . . . . . . . . . . . . . . . . . . 17
   6.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 17
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 17
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17

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1.  Introduction

   This document provides the SCIM definitions, models, flows, scenarios
   and use cases.  It also provides a list of the requirements derived
   from the use cases.  The document's objective is to help with
   understanding of the design and applicability of SCIM schema
   [I-D.ietf-scim-core-schema] and SCIM protocol [I-D.ietf-scim-api].

1.1.  Terminology

   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 [RFC2119] when they
   appear in ALL CAPS.  These words may also appear in this document in
   lower case as plain English words, absent their normative meanings.

   Here is a list of acronyms and abbreviations used in this document:

   o  COI: Community Of Interest

   o  CRM: Customer Relationship Management

   o  CRUD: Create Read Update Delete

   o  CSP: Cloud Service Provider

   o  CSU: Cloud Service User

   o  ECS: Enterprise Cloud Subscriber

   o  IaaS: Infrastructure as a Service

   o  JIT: Just In Time

   o  PaaS: Platform as a Service

   o  SaaS: Software as a Service

   o  SAML: Security Assertion Markup Language

   o  SCIM: System for Cross-domain Identity Management

   o  SSO: Single-Sign On

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2.  SCIM User Scenarios

2.1.  Background & Context

   The System for Cross-domain Identity Management (SCIM) specification
   is designed to make managing user identity in cloud based
   applications and services easier.  The specification suite seeks to
   build upon experience with existing schemas and deployments, placing
   specific emphasis on simplicity of development and integration, while
   applying existing authentication, authorization, and privacy models.
   It's intent is to reduce the cost and complexity of user management
   operations by providing a common user schema and extension model, as
   well as binding documents to provide patterns for exchanging this
   schema using standard protocols.  In essence, make it fast, cheap,
   and easy to move users in to, out of, and around the cloud.

   The SCIM scenarios are overview user stories designed to help clarify
   the intended scope of the SCIM effort.

2.2.  Model Concepts

2.2.1.  Triggers

   Quite simply, triggers are actions or activities that start SCIM
   flows.  Triggers may not be relevant at the protocol or the schema,
   they really serve to help identify the type or activity that resulted
   in a SCIM protocol exchange.  Triggers make use of the traditional
   provisioning C.R.U.D (Create Read Update & Delete) operations but add
   additional use case contexts like "SSO" (Single-Sign On) as it is
   designed to capture a class of use case that makes sense to the actor
   requesting it rather than to describe a protocol operation.

   o  Create SCIM Identity Resource - Service On-boarding Trigger: A
      "create SCIM identity resource" trigger is a service on-boarding
      activity in which a business action such as a new hire or new
      service subscription is initiated by one of the SCIM Actors.  In
      the protocol itself, service on-boarding may well be implemented
      via the same resource PUT method as a service change.  This is
      particular to the implementation, and not to the use cases that
      drive that implementation.

   o  Update SCIM Identity Resource - Service Change Trigger: An "update
      SCIM identity resource" trigger is a service change activity as a
      result of an identity moving or changing its service level.  An
      "update SCIM identity" trigger might be the result of a change in
      a service subscription level or a change to key identity data used
      to denote a service subscription level.  Password changes are
      specifically called out from other more general identity attribute

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      changes as they are considered to have specific use case
      differences.

   o  Delete SCIM Identity Resource - Service Termination Trigger: A
      "delete SCIM identity resource" trigger represents a specific and
      deliberate action to remove an identity from a given SCIM service
      point.  At this stage it is unclear if the SCIM protocol needs to
      identify separate protocol exchange for a service suspension
      actions.  This may be relevant as target services usually
      differentiate between these result and may require separate
      resource representations as a result.

   o  Single-Sign On (SSO) Trigger - Real-time Service Access Request: A
      "Single-Sign On" trigger is a special class of activity in which a
      Create or Update trigger is initiated during an SSO operational
      flow.  The implication here is that as the result of a real-time
      service access request by the end user (SSO), defined SCIM
      protocol exchanges can be used to initiate SCIM resource CRUD
      somewhere in the service cloud.

2.2.2.  Actors

   Actors are the operating parties that take part in both sides of a
   SCIM protocol exchange, and help identify the source of a given
   Trigger.  So far, we have identified the following SCIM Actors:

   o  Cloud Service Provider (CSP): A CSP is the entity operating a
      given cloud service.  In a SaaS scenario this is simply the
      application provider.  In an IaaS or PaaS scenario, the CSP may be
      the underlying IaaS/PaaS infrastructure provider or the owner of
      the application running on that platform.  In all cases, the CSP
      is the thing that holds the identity information being operated
      upon.  Put another way, the CSP really is the service that the
      end-end user interacts with.

   o  Enterprise Cloud Subscriber (ECS): An ECS represents a middle-tier
      of aggregation for related identity records.  In one of our sample
      enterprise SaaS scenarios, the ECS is "FooBar.Inc" that subscribes
      to a cloud based CRM service service "SaaS-CRM.Inc" (the CSP) for
      all of its sales staff.  The actual Cloud Service Users (CSUs) are
      the FooBar.Inc. sales staff.  The ECS actor is identified to help
      capture use cases in which a single entity is given administrative
      responsibility for other identity accounts.  SCIM may not address
      the configuration and setup of an ECS within the CSP, but it does
      address use cases in which SCIM identity resources are grouped
      together and administers as part of some broader agreement or
      operational exchange.

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   o  Cloud Service User (CSU): A CSU represents the real cloud service
      end user - the "person logging into and using the cloud service".
      As described above, and ECS will typically own or manage multiple
      CSU identities where as the CSU represents the FooBar.Inc.
      employee using the cloud service to manage their CRM process.

                             +---------------------+
                             |   Cloud Service     |
                             |   Provider (CSP)    |
                             +---------------------+
                                        |
                      +--------------------------------+
                      |                                |
                      v                                v
              +----------------+              +----------------+
              |Enterprise Cloud|              |Enterprise Cloud|
              |Subscriber (ECS)|              |Subscriber (ECS |
              +----------------+              +----------------+
                      |                                |
              +----------------+              +----------------+
              |                |              |                |
              v                v              v                v
      +-------------+ +-------------+   +-------------+ +-------------+
      |Cloud Service| |Cloud Service|   |Cloud Service| |Cloud Service|
      |  User (CSU) | |  User (CSU) |   |  User (CSU) | |  User (CSU) |
      +-------------+ +-------------+   +-------------+ +-------------+

                           Figure 1: SCIM Actors

2.2.3.  Modes & Flows

   Modes identify the functional intent of a data-flow initiated in a
   SCIM scenario.  The modes identified so far are 'push' and 'pull'
   referring to the fact of pushing data to, or pulling data from an
   authoritative identity data store.

   In the SCIM scenarios, Modes are often used in the context of a flow
   between two Actors.  For example, one might refer to a Cloud-to-Cloud
   Pull exchange.  Here one Cloud Service Provider (CSP) is pulling
   identity information from another CSP.  Commonly referenced flows
   are:

   o  Cloud Service Provider to Cloud Service Provider (CSP->CSP)

   o  Enterprise Cloud Subscriber to Cloud Service Provider (ECS-CSP)

   Modes & flows simply help us understand what is taking place; they

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   are likely to be technically meaningless at the protocol level, but
   again they help the reader follow the SCIM scenarios and apply them
   to real world use cases.

2.2.4.  Bulk & Batch Operational Semantics

   It is assumed that each of the triggers action outlined in this
   document may be part of the larger bulk or batch operation.
   Individual SCIM actions should be able to be collected together to
   create single protocol exchanges.

   The initial focus of SCIM scenarios is on identifying base flows and
   single operations.  The specific complexity of full bulk and batch
   operations is left to a later version of the scenarios or to the main
   specification.

2.3.  Cloud Service Provider to Cloud Service Provider Flows (CSP->CSP)

   These scenarios represent flows between two Cloud Service Providers
   (CSPs).  It is assumed that each CSP maintains an Identity Data Store
   for its Cloud Service Users (CSUs).  These scenarios address various
   joiner, mover, leaver and JIT triggers, resulting in push and pull
   data exchanges between the CSPs.

2.3.1.  CSP->CSP - Create Identity (Push)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User
   (CSU) accounts.  CSP-1 receives a Create Identity trigger action from
   its Enterprise Cloud Subscriber (ECS-1).  CSP-1 creates a local user
   account for the new CSU.  CSP-1 then pushes the new CSU joiner push
   request down-stream to CSU-2 and gets confirmation that the account
   was successfully created.  After receiving the confirmation from
   CSP-2, CSP-1 sends an acknowledgement to the requesting ECS.

2.3.2.  CSP->CSP - Update Identity (Push)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User
   (CSU) accounts.  The Enterprise Cloud Subscriber (ECS-1) has already
   created an account with CSP-1 and supplied a critical attribute
   "department" that is used by CSP-1 to drive service options.  CSP-1
   then receives an Update Identity trigger action from its Enterprise
   Cloud Subscriber (ECS).  CSP-1 updates its local directory account
   with the new department value.  CSP-1 then initiates a separate SCIM
   protocol exchange to push the mover change request down-stream to
   CSP-2.  After receiving the confirmation from CSP-2, CSP-1 sends an
   acknowledgment to ECS-1.

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2.3.3.  CSP->CSP - Delete Identity (Push)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User
   (CSU) accounts.  CSP-1 receives a Delete Identity trigger action from
   its Enterprise Cloud Subscriber (ECS-1).  CSP-1 suspends the local
   directory account for the specified CSU account.  CSP-1 then pushes a
   termination request for the specified CSU account down-stream to
   CSP-2 and gets confirmation that the account was successfully
   removed.  After receiving the confirmation from CSP-2, CSP-1
   finalizes the deletion operation and sends an acknowledgment to the
   requesting ECS.

   This use case highlights how different CSPs may implement different
   operational semantics behind the same SCIM operation.  Note CSP-1
   suspends the account representation for its service where as CPS-2
   implements a true delete operation.

2.3.4.  CSP->CSP - SSO Trigger (Push)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User
   (CSU) accounts.  However, rather than pre-provisioning accounts from
   CSP-1 to CSP-2, CSP-1 waits for a service access request from the end
   Cloud Service User (CSU-1) before issuing account creation details to
   CSP-2.  When the CSU completes a SSO transaction from CSP-1 to CSP-2,
   CSP-2 then creates an account for the CSU based on information pushed
   to it from CSP-1.

   At the protocol level, this class of scenarios may result in the use
   of common protocol exchange patters between CSP-1 & CSP-2.

2.3.5.  CSP->CSP - SSO Trigger (Pull)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User
   (CSU) accounts.  However, rather than pre-provisioning accounts from
   CSP-1 to CSP-2, CSP-2 waits for a service access request from the
   Cloud Service User (CSU-1) before initiating a Pull request to gather
   information about the CSU sufficient to create a local account.

   At the protocol level, this class of scenarios may result in the use
   of common protocol exchange patterns between CSP-2 & CSP-1.

2.3.6.  CSP->CSP - Password Reset (Push)

   In this scenario two CSPs (CSP-1 & CSP-2) have a shared service
   agreement in place that requires the exchange of Cloud Service User

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   (CSU) accounts.  CSP-1 wants to change the password for a specific
   Cloud Service User (CSU-1).  CSP-1 sends a request to CSP-2 to reset
   the password value for CSU-1.

   At the protocol level, this scenario may result in the same protocol
   exchange as any other attribute change request.

2.4.  Enterprise Cloud Subscriber to Cloud Service Provider
      Flows(ECS->CSP)

   These scenarios represent flows between an Enterprise Cloud
   Subscriber (ECS) and a Cloud Service Providers (CSP).  It is assumed
   that both the ECS and the CSP maintains an LDAP service for the
   relevant Cloud Service Users (CSUs).  These scenarios address various
   joiner, mover, leaver and JIT triggers, resulting in push and pull
   data exchanges between the ECS and the CSP.

   Many of these scenarios are very similar to those defined in the
   Cloud Service Provider to Cloud Service Provider section above.  They
   are identified separately here so that we may explore any differences
   and might emerge.

2.4.1.  ECS->CSP - Create Identity (Push)

   In this scenario an Enterprise Cloud Subscriber (ECS-1) maintains a
   service with a Cloud Service Provider (CSP-1) that requires the
   sharing of various Cloud Service User (CSU) accounts.  A new user
   joins ECS-1 and so ECS-1 pushes an account creation request to CSP-1,
   supplying all required base SCIM schema attribute values and
   additional extended SCIM schema values as required.

2.4.2.  ECS ->CSP - Update Identity (Push)

   In this scenario an Enterprise Cloud Subscriber (ECS-1) maintains a
   service with Cloud Service Provider (CSP-1) that drives service
   definition from a key account schema attribute called Department.
   ECS-1 wishes to move a given CSU from Department A to Department B
   and so it pushes an attribute update request to the CSP.

2.4.3.  ECS ->CSP - Delete Identity (Push)

   In this scenario an Enterprise Cloud Subscriber (ECS-1) maintains a
   service with a Cloud Service Provider (CSP-1).  Upon termination of
   one of its employees' employment agreement, ECS-1 sends a suspend
   account request to CSP-1 (Figure 1.4.3-1).  One week later the ECS
   wishes to complete the process by fully removing the Cloud Service
   User (CSU) account and so it sends a terminate account request to
   CSP-1.

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2.4.4.  ECS ->CSP - SSO Pull

   In this scenario an Enterprise Cloud Subscriber (ECS-1) maintains a
   service with a Cloud Service Provider (CSP-1).  No accounts are
   created or exchanged in advance.  However, rather than pre-
   provisioning accounts from ECS-1 to CSP-1, CSP-1 waits for a service
   access request from the Cloud Service User (CSU-1) under the control
   domain of ECS-1, before issuing an account Pull request to ECS-1.

3.  SCIM Use Cases

   This section lists the SCIM use cases.

3.1.  Change of the ownership of a file

   Description:

   Bob - an employee of the company SomeEnterprise - creates a file,
   which is located at the cloud provided by SomeCSP.  After Bob leaves
   SomeEnterprise, SomeCSP on a request from SomeEnterprise terminates
   Bob's rights to the file and transfers his former rights to Bill -
   another employee of SomeEnterprise.

   Pre-conditions:

   o  SomeCSP is a cloud service provider for SomeEnterprise.

   o  With permission of SomeEnterprise, Bob had created a file at the
      cloud provided by SomeCSP.

   o  Bob has left SomeEnterprise.

   o  SomeEnterprise terminates Bob's rights to the file and, possibly,
      decommissions Bob's identity.

   o  SomeEnterprise communicates the changes to Bob's rights to
      SomeCSP.

   o  SomeCSP enforces the changes made by SomeEnterprise.

   o  SomeEnterprise requests SomeCSP to transfer Bob's former rights to
      Bill.

   Post-conditions:

   o  Bob does not have the rights to the file at the cloud provided by
      SomeCSP.

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   o  Bill has the rights to the file that Bob had.

   Requirements:

   o  SomeEnterprise can securely communicate to SomeCSP all changes
      regarding its employee's identity.

   o  SomeCSP can enforce the requested changes.

   o  SomeCSP shall be able to log all changes regarding a
      SomeEnterprise employee's identity.

   o  The logs should be secure and available for auditing.

3.2.  Migration of the identities

   Description:

   A company SomeEnterprise runs an application ManageThem that relies
   on the identity information about its employees (e.g., identifiers,
   attributes).  The identity information is stored at the cloud
   provided by SomeCSP.  SomeEnterprise has decided to move identity
   information to the cloud of a different provider - AnotherCSP.  In
   addition, SomeEnterprise has purchased a second application
   ManageThemMore, which also relies on the identity information.
   SomeEnterprise is able to move identity information to AnotherCSP
   without changing the format of identity information.  The application
   ManageThemMore is able to use the identity information.

   Pre-conditions:

   o  SomeCSP is a cloud service provider for SomeEnterprise.

   o  SomeCSP has a known attribute name and value for the Enterprise
      used for managing and transferring data.

   o  AnotherCSP is a new cloud service provider for SomeEnterprise.

   o  All involved cloud service providers and applications support the
      same standard specifying the format for and actions on the user
      (e.g., employee) identity information.

   Post-conditions:

   o  SomeEnterprise has moved its employees' identity information from
      SomeCSP to AnotherCSP without making any changes to representation
      of identity information.

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   o  Application ManageThemMore is able to use the identity
      information.

   Requirements:

   o  SomeEnterprise, the applications ManageThem and ManageThemMore,
      the providers SomeCSP and AnotherCSP support a common standard for
      identity information, which specifies the following:

      *  Format (or schema) for representing user identity information

      *  Interfaces and protocol for managing user identity information

   o  Cloud providers shall be able to log all actions related to
      SomeEnterprise employees' identities.

   o  The logs should be secure and available for auditing.

3.3.  Single Sign-On (SSO) Service

   Description:

   Bob has an account with application hosted by a cloud service
   provider SomeCSP.  SomeCSP has federated its user identities with a
   cloud service provider AnotherCSP.  Bob requests a service from an
   application running on AnotherCSP.  The application running on
   AnotherCSP, relying on Bob's authentication by SomeCSP and using
   identity information provided by SomeCSP, serves Bob's request.

   Pre-conditions:

   o  Bob's identity information is stored on SomeCSP.

   o  SomeCSP and AnotherCSP have established trust and federated their
      user identities.

   o  SomeCSP is able to authenticate Bob.

   o  SomeCSP is able to securely provide the authentication results to
      AnotherCSP.

   o  SomeCSP is able to securely provide Bob's identity information
      (e.g., attributes) to AnotherCSP.

   o  AnotherCSP is able to verify information provided by SomeCSP.

   o  SomeCSP is able to process the identity information received from
      AnotherCSP.

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   Post-conditions:

   Bob has received the requested service from an application running on
   AnotherCSP without having to authenticate to that application
   explicitly.

   Requirements:

   o  Bob must have an account with SomeCSP.

   o  SomeCSP and AnotherCSP must establish trust and federate their
      user identities.

   o  SomeCSP must be able to authenticate Bob.

   o  SomeCSP must be able to securely provide the authentication
      results to AnotherCSP.

   o  SomeCSP must be able to securely provide Bob's identity
      information (e.g., attributes) to AnotherCSP.

   o  AnotherCSP must be able to verify the identity information
      provided by SomeCSP.

   o  SomeCSP must be able to process the identity information received
      from AnotherCSP.

   o  SomeCSP and AnotherCSP must log information generated by Bob's
      actions according to their policies and the trust agreement
      between them.

3.4.  Provisioning of the user accounts for a Community of Interest
      (CoI)

   Description:

   Organization YourHR provides Human Resources (HR) services to a
   Community of Interest (CoI) YourCoI.  The HR services are offered as
   Software-as-a-Service (SaaS) on public and private clouds.  YourCoI's
   offices are located all over the world.  Their Information Technology
   (IT) systems may be composed of the combinations of the applications
   running on Private and Public clouds along with the traditional IT
   systems.  The local YourCoI offices are responsible for collecting
   personal information(i.e. user identities and attributes).  YourHR
   services provide means for provisioning and distributing the employee
   identity information across all YourCoI offices.  YourHR also enables
   the individual users (e.g., employees) to manage their personal
   information that they are responsible for (e.g., update of an address

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   or a telephone number).

   Pre-conditions:

   o  YourCoI has a complex infrastructure composed of the large number
      of local offices that rely on the diverse IT systems.

   o  YourCoI has contracted YourHR to provide the HR services.

   o  Each local office has a right to establish a personal account for
      an employee.

   Post-conditions:

   o  All personal accounts are globally available to any authorized
      user or application across the YourCoI system through the services
      provided by YourHR.

   o  The employees have ability to manage the part of personal
      information that is in their responsibility.

   Requirements:

   o  YourHR must ensure that the personal information generated by the
      local offices is timely available in a globally-accessible
      database.

   o  Identity management of the personal data must be protected against
      unauthorised access and remain confidential to only authorised
      parties.

   o  All operation with identity data must be securely logged.

   o  The logs should be available for auditing.

3.5.  Transfer of attributes to a relying party web site

   Description:

   An end user has an account in a directory service A with one or more
   attributes.  That user then visits relying party web site B, and the
   user authorizes the transfer of data via authorization protocols
   (e.g.  OAuth, SAML), so selected attributes of the user are
   transferred from the user's account in directory service A to the web
   site B at the time of the user's first visit to that site.

   Pre-conditions:

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   o  User has an account in a directory service A.

   o  User has one or more attributes.

   o  User visits web site of a relying party B.

   Post-conditions:

   Selected attributes of the user are transferred from the user's
   account in directory service A to the web site B at the time of the
   user's first visit to that site.

   Requirements:

   o  Relying party B must be able to authenticate the end user.

   o  Relying party B must be able to securely provide the
      authentication results to directory service A.

   o  Directory service A must be able to securely provide end user's
      identity information (e.g., attributes) to relying party B.

   o  Relying parties have to be aware of changes to their cached copy,
      as these would potentially cause a state change in other relying
      parties.

   o  A maximum period should be set for the relying party to cache the
      information.

3.6.  Change notification

   Description:

   An end user has an account in a directory service A with one or more
   attributes.  That user then visits relying party web site B. Relying
   party web site B queries directory service A for attributes
   associated with that user, and related resources.

   The attributes of the user change later in directory service A. For
   example, the attributes might change if the user changes their name,
   has their account disabled, or terminates their relationship with
   directory service A. Furthermore, other resources and their
   attributes might also change.  The directory service A then wishes to
   notify relying party web site B of these changes, as relying party B
   might (or might not) have a cache of those attributes, and if the
   relying party B were aware of these changes to their cached copy,
   would potentially cause a state change in relying party B.

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   The volume of changes, however, might be substantial, and only some
   of the changes may be of interest to relying party B, so directory
   service A does not wish to "push" all the changes to B. Instead,
   directory service A wishes to notify B that there are changes
   potentially of interest, such that B can at an appropriate time
   subsequently contact directory service A and retrieve just the subset
   of changes of interest to B.

   Note that the user must authorize the directory service A to transfer
   data to the web site, and the user must authorize the directory
   service A to notify the web site.

   Pre-conditions:

   o  User has an account in a directory service A.

   o  User has one or more attributes.

   o  User visits relying party web site B.

   o  The resource being updated is at the web site.

   Post-conditions:

   Directory service A is able to notify relying party B that there are
   changes potentially of interest.

   Requirements:

   o  Relying party B must be able to authenticate the end user.

   o  Relying party B must be able to securely provide the
      authentication results to directory service A.

   o  Directory service A must be able to securely provide end user's
      changed identity information (e.g., attributes) to relying party
      B.

   o  Relying party B must be able at an appropriate time to
      subsequently contact directory service A and retrieve just the
      subset of changes of interest to relying party B.

4.  Security considerations

   Authentication and authorization must be guaranteed for the SCIM
   operations, to ensure that only authenticated entities can perform
   the SCIM requests and the requested SCIM operations are authorized.

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   SCIM resources (e.g., Users and Groups) can contain sensitive
   information.  Thus, data confidentiality MUST be guaranteed at the
   transport layer.

   Detailed security considerations are specified in section 7 of SCIM
   protocol [I-D.ietf-scim-api] and section 9 of SCIM schema
   [I-D.ietf-scim-core-schema].

5.  IANA considerations

   This Internet Draft includes no request to IANA.

6.  Acknowledgements

   Authors would like to thank Ray Counterman, Richard Fiekowsky, Bert
   Greevenbosch, Barry Leiba, Kelly Grizzle, Magnus Nystrom, Dapeng Liu
   and Jun Li for their reviews and comments.

   Also thanks to Darran Rolls and Patrick Harding, the SCIM user
   scenarios section is taken from them.

7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

7.2.  Informative References

   [I-D.ietf-scim-api]
              Hunt, P., Grizzle, K., Ansari, M., Wahlstroem, E., and C.
              Mortimore, "System for Cross-Domain Identity Management:
              Protocol", draft-ietf-scim-api-16 (work in progress),
              March 2015.

   [I-D.ietf-scim-core-schema]
              Hunt, P., Grizzle, K., Wahlstroem, E., and C. Mortimore,
              "System for Cross-Domain Identity Management: Core
              Schema", draft-ietf-scim-core-schema-17 (work in
              progress), March 2015.

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Authors' Addresses

   Phil Hunt
   Oracle

   Email: phil.hunt@oracle.com

   Bhumip Khasnabish
   ZTE (TX) Inc.
   55 Madison Ave, Suite 302
   Morristown, New Jersey  07960
   USA

   Phone: +001-781-752-8003
   Email: vumip1@gmail.com, bhumip.khasnabish@ztetx.com
   URI:   http://tinyurl.com/bhumip/

   Anthony Nadalin
   Microsoft

   Email: tonynad@microsoft.com

   Kepeng LI (editor)
   Alibaba Group
   Wenyixi Road, Yuhang District
   Hangzhou, Zhejiang  311121
   China

   Email: kepeng.lkp@alibaba-inc.com

   Zachary Zeltsan
   Individual

   Email: Zachary.Zeltsan@gmail.com

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