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Versions: 00                                                            
Network Working Group                                     M. Ansari, Ed.
Internet-Draft                                                     Cisco
Intended status: Standards Track                                 P. Hunt
Expires: September 10, 2015                                       Oracle
                                                           March 9, 2015


                            SCIM Soft Delete
                    draft-ansari-scim-soft-delete-00

Abstract

   The System for Cross-Domain Identity Management (SCIM) specification
   is an HTTP based protocol that makes managing identities in multi-
   domain scenarios easier to support through a standardized HTTP
   service.

   Among other operations, SCIM defines delete operation where upon
   successful completion of the call, the SCIM endpoint is supposed to
   delete the requested object and the object should not be available
   for future SCIM calls and not used in uniqueness criteria
   requirements.

   While this model is sufficient for a number of SCIM implementations,
   there are cases this simple definition of delete may not meet product
   or business requirements.  For example a service provider may require
   a user object to continue to exist as other objects/data is linked
   with it or for billing purposes, etc.  For example a cloud file
   storage mechanism may require to show basic information about who
   created a given file or modified one even if the user is de-
   provisioned from the system.

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 September 10, 2015.



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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
   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 and Overview . . . . . . . . . . . . . . . . . .   2
     1.1.  Notational Conventions  . . . . . . . . . . . . . . . . .   3
     1.2.  Definitions . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Soft Delete . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Soft Delete Schema Extension  . . . . . . . . . . . . . .   4
     2.2.  ServiceProviderConfig Extension . . . . . . . . . . . . .   5
     2.3.  SCIM Create . . . . . . . . . . . . . . . . . . . . . . .   5
     2.4.  SCIM Retrieve . . . . . . . . . . . . . . . . . . . . . .   5
     2.5.  SCIM Modify . . . . . . . . . . . . . . . . . . . . . . .   5
     2.6.  SCIM Delete . . . . . . . . . . . . . . . . . . . . . . .   5
     2.7.  SCIM Bulk . . . . . . . . . . . . . . . . . . . . . . . .   6
     2.8.  SCIM Undelete . . . . . . . . . . . . . . . . . . . . . .   6
     2.9.  SCIM Hard Delete  . . . . . . . . . . . . . . . . . . . .   6
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Appendix A.  Contributors . . . . . . . . . . . . . . . . . . . .   7
   Appendix B.  Acknowledgments  . . . . . . . . . . . . . . . . . .   7
   Appendix C.  Change Log . . . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction and Overview

   The System for Cross-Domain Identity Management (SCIM) specification
   is an HTTP based protocol that makes managing identities in multi-
   domain scenarios easier to support through a standardized HTTP
   service.





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   For some services, even after a resource has been "deleted" from the
   identity system, there are many artifacts that remain in the
   application/services layer that were created/touched by the deleted
   user.  Such objects need to remain connected to the deleted object
   and provide basic information.  For example if a user created a
   document, post, event, even after the user is removed, other users of
   the system may still interact with these objects and need to see who
   created the object even if the user is no longer part of the system.
   Another use case is to protect against accidental loss of references
   in case of a mistaken "delete" of a resource.  Once a resource is
   removed from the identity system, all that resource's references to
   any data type is lost given the id of the resource will not be
   recycled.  Recreating the same resource is not going to revive its id
   and essentially creates a new instance with a new id.

   While SCIM delete operation as defined in Section 3.6 of
   [I-D.ietf-scim-api] allows a service provider to keep a resource
   after deletion, it does not provide any additional guidance or
   specification on how the "deleted" resource will be managed beyond
   the initial delete in cases the service provider does not want to
   permanently remove a resource.

   This specification defines a set of extensions to SCIM API
   [I-D.ietf-scim-api] to allow additional operations on resources that
   have been soft deleted:

   o  Query for resources that have been soft deleted

   o  Hard delete a soft deleted resource

   o  Undelete a soft deleted resource

   o  Extension to the ServiceProviderConfig [I-D.ietf-scim-core-schema]
      to allow discovery of softDelete extensions

1.1.  Notational Conventions

   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].  These
   keywords are capitalized when used to unambiguously specify
   requirements of the protocol or application features and behavior
   that affect the interoperability and security of implementations.
   When these words are not capitalized, they are meant in their
   natural-language sense.






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   For purposes of readability examples are not URL encoded.
   Implementers MUST percent encode URLs as described in Section 2.1 of
   [RFC3986].

   Throughout this documents all figures MAY contain spaces and extra
   line-wrapping for readability and space limitations.  Similarly, some
   URI's contained within examples, have been shortened for space and
   readability reasons.

1.2.  Definitions

   Soft Deleted Resources  A SCIM resource that has been deleted using
      standard SCIM DELETE operation

2.  Soft Delete

   A SCIM endpoint supporting Soft Delete extensions MUST implement SCIM
   DELETE operation in such a way that the resource being deleted is not
   permanently deleted and stored in an alternate "soft deleted" state.
   Other standard SCIM operations will continue to function as if soft
   deleted resources do not exist in the system.  READ, MODIFY, PATCH,
   BULK requests with the soft deleted resource id MUST result in a HTTP
   NOT FOUND (404).  A create request for a user resource with a
   userName that has been soft deleted, MUST NOT fail with an HTTP
   status 409 due to the userName conflict with the soft deleted record.

2.1.  Soft Delete Schema Extension

   Any SCIM resource type that supports soft delete extensions MUST
   extend the schema of the resource type by adding the extension
   defined in this section.

   The following Singular Attributes are defined:

   isSoftDeleted
      A Boolean attribute set to "true" for any resource that is soft
      deleted.  No value or "false" means the resource is not soft
      deleted.  This attribute has mutability of "readOnly"

   softDeleted
      A DateTime attribute set to the time the resource was softDeleted.
      This attribute has mutability of "readOnly".  This attribute
      should be deleted once a resource is not in soft delete state.








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2.2.  ServiceProviderConfig Extension

   SCIM endpoints that support Soft Delete extensions MUST advertise
   this support in the ServiceProviderConfig endpoint as defined:

   softDelete
      A complex type that specifies Soft Delete configuration options.
      REQUIRED.

      supported Boolean value specifying whether the operation is
      supported.  REQUIRED.

2.3.  SCIM Create

   SCIM Create SHOULD NOT ignore namespace conflicts arising from soft
   deleted objects.  For example if there exists a user resource with
   userName value of "user1" that have been soft deleted, a create
   request for userName with the same value should not fail because of
   userName conflict.

2.4.  SCIM Retrieve

   SCIM retrieve operations MUST NOT match soft deleted objects unless
   the request includes a filter with the value of "isSoftDeleted=true".
   This is the only case where a soft deleted resource can be returned
   as a result of a retrieve operation.

2.5.  SCIM Modify

   SCIM modify operation on resources that have been soft deleted MUST
   result in a HTTP NOT FOUND 404.

2.6.  SCIM Delete

   SCIM Delete operations on normal resources MUST NOT remove the
   resource, but put it in the soft deleted state by modifying the
   resource and setting isSoftDeleted attribute on the resource to
   "true" and setting the softDeleted timestamp value to the time of the
   delete operation.

   Delete operations on soft deleted resource MUST result in an HTTP NOT
   FOUND 404 error.

   [ToDo]Define reference semantics as resources are soft deleted







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2.7.  SCIM Bulk

   SCIM Bulk operations should follow the semantics defined in this
   section for regular SCIM operations.error.

2.8.  SCIM Undelete

   To allow soft deleted resources to be restored to regular state, a
   SCIM modify operations can be performed with a query parameter of
   "isSoftDeleted=true" on the resource.  The SCIM Endpoint MUST change
   the state of the resource to reflect the change from soft deleted
   state back to normal by removing the softDeleted attribute from the
   resource and setting the isSoftDeleted attribute value to "false".

   Furthermore if the process of undeleting the resource results in a
   namespace conflict, the operation MUST fail and return an HTTP Status
   409, with "scimType" error code of "uniqueness".

   The SCIM client can optionally provide new attribute values as part
   of the modify request to resolve the conflicts.  For example to
   undelete a user resource where the userName has been recycled, a
   modify with a new userName value can be sent to the SCIM endpoint to
   undelete the user resource by setting the value of userName to the
   new value to avoid the conflict case.

2.9.  SCIM Hard Delete

   A soft deleted resource can be permanently deleted by sending a SCIM
   Delete request with a query parameter of "isSoftDeleted=true".  This
   SCIM endpoint SHOULD permanently remove the resource.

3.  Security Considerations

   Soft deleted users MUST NOT be allowed to authenticate to the service
   provider or access any resources.  Furthermore soft deleted resources
   SHOULD NOT be used in authorization decision and act as if those
   resources do not exist.

   [TO BE COMPLETED]

4.  IANA Considerations

   [TO BE COMPLETED]








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5.  References

5.1.  Normative 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.

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

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66, RFC
              3986, January 2005.

5.2.  Informative References

   [I-D.ietf-scim-use-cases]
              Hunt, P., Khasnabish, B., Nadalin, A., Li, K., and Z.
              Zeltsan, "SCIM Use Cases", draft-ietf-scim-use-cases-04
              (work in progress), March 2015.

Appendix A.  Contributors

Appendix B.  Acknowledgments

   The editor would like to thank the participants in the the SCIM
   working group for their support of this specification.

Appendix C.  Change Log

   Draft 00 - MA - First Draft

Authors' Addresses

   Morteza Ansari (editor)
   Cisco Corporation

   Email: morteza.ansari@cisco.com




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   Phil Hunt
   Oracle Corporation

   Email: phil.hunt@yahoo.com















































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