Internet-Draft draft-hunt-scim-mv-filtering October 2021
Hunt Expires 26 April 2022 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-hunt-scim-mv-filtering-00
Published:
Intended Status:
Standards Track
Expires:
Author:
P. Hunt, Ed.
IndependentId

SCIM Protocol: Multi-Value Filtering Extension

Abstract

The System for Cross-Domain Identity Management (SCIM) specifications define a profile of HTTP protocol and a schema that enable managing identities in cross-domain scenarios. This specification extends SCIM protocol resource retrieval and query functions to enable paging and filtering of multi-valued attributes in a SCIM service provider resource.

Status of This Memo

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

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This Internet-Draft will expire on 4 April 2022.

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Table of Contents

1. Introduction and Overview

SCIM Protocol [RFC7644] is an application-level, HTTP protocol for provisioning and managing identity data on the web and in cross-domain environments such as enterprise to cloud, or inter-cloud scenarios. The protocol supports creation, modification, retrieval, and discovery of core identity resources such as Users and Groups, as well as custom resources and resource extensions.

The definition of resources, attributes, and overall schema are defined in the SCIM Core Schema document (see [RFC7643]).

This specification extends SCIM resource retrieval and query functions to enable filtering and paging of mulit-valued attributes. For example, attributes that may contain large numbers of values such as a SCIM Group.

1.1. Intended Audience

This document is intended as a guide to extend SCIM protocol usage for both SCIM HTTP service providers and HTTP clients who may provision information to service providers or retrieve information from them.

1.2. 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.

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.

1.3. Definitions

This specification uses the definitions from the SCIM Schema Specification [RFC7643] and the SCIM Protocol Specification [RFC7644].

2. Multi-Value Paging Extension

Detecting the availability of multi-valued attribute filtering and paging extension is covered in Section 3.

When supported, returned values for multi-valued attributes can be filtered or paged using filters and/or paging parameters appended to attributes specified in the SCIM attributes parameter. Attributes listed in the attributes parameter MAY be appended with value qualifiers using square brackets("[ ]") that contains a valFilter (see Figure 1 [RFC7644]), paging parameters (see Section 3.9 [RFC7644]), or a combination of both separated by the & character.

In order to qualify specific attributes without changing the default list of attributes returned for a query, an asterix * MAY be used in the attributes parameter to indicate the default set of attributes is to be returned in addition to any specific attributes listed. For example: attributes=*,members[type eq "user"] specifies all default attributes are to be returned and only values of members which have type set to user.

When an attribute has a multi-value filter or paging qualifier, the service provider SHALL include additional meta sub-attributes (see Section 3.1 of [RFC7643]). The name of the multi-valued attribute plus the String cnt is used to indicate the count of attribute values available expressed as an Integer (see Section 2.3.4 of [RFC7643]). When a valFilter expression is used, the number SHALL indicate the total number of matches that may be returned based on the filter. When no filter expression is specified, the number SHALL indicate the total number of values. For an example, see emails.cnt inFigure 2. This count indicates that there is only one value with type equal to work .

When startIndex is used as an attribute paging qualifier and the value is greater than the number of values, the server SHALL omit the attribute from the result to indicate no values exist at that index.

In the following example, a user is returned, but only work emails are to be returned.

GET /Users/2819c223-7f76-453a-919d-413861904646? \
    attributes=*,emails[type eq \"work\"]
Host: example.com
Accept: application/scim+json
Authorization: Bearer h480djs93hd8
Figure 1: Using a filter to return only work email values

The service provider responds with:

HTTP/1.1 200 OK
Content-Type: application/scim+json
Location:
  https://example.com/v2/Users/2819c223-7f76-453a-919d-413861904646
ETag: W/"f250dd84f0671c3"

{
  "schemas":["urn:ietf:params:scim:schemas:core:2.0:User"],
  "id":"2819c223-7f76-453a-919d-413861904646",
  "externalId":"bjensen",
  "meta":{
    "resourceType":"User",
    "created":"2011-08-01T18:29:49.793Z",
    "lastModified":"2011-08-01T18:29:49.793Z",
    "location":
"https://example.com/v2/Users/2819c223-7f76-453a-919d-413861904646",
    "version":"W\/\"f250dd84f0671c3\"",
    "emails.cnt":1
  },
  "name":{
    "formatted":"Ms. Barbara J Jensen III",
    "familyName":"Jensen",
    "givenName":"Barbara"
  },
  "userName":"bjensen",
  "phoneNumbers":[
    {
      "value":"555-555-8377",
      "type":"work"
    }
  ],
  "emails":[
    {
      "value":"bjensen@example.com",
      "type":"work"
    }
  ]
}
Figure 2: Response with filtered emails attribute

In the following example, all Groups are searched and only Groups whose name starts with "Group" are selected. Additionally, the members attribute values are filtered return only member values with type equal to groups (as in sub-groups) returning only the first 5 values using the attributes paging qualifying parameters.

GET /v2/Groups?filter=displayName sw 'Group'& \
    attributes=*,members[type eq \"Group\"&count=5&startIndex=1]
Host: example.com
Accept: application/scim+json
Authorization: Bearer h480djs93hd8
Figure 3: Querying multiple groups with attribute qualifiers

The server responds with 2 matched resources. The first resource only has one Group member value, while the second resource has 7 member values and has been limited to the first 5 members per the count paging parameter .

HTTP/1.1 200 OK
Content-Type: application/scim+json

{
  "schemas": ["urn:ietf:params:scim:api:messages:2.0:ListResponse"],
  "totalResults": 2,
  "Resources": [
    {
      "id": "c3a26dd3-27a0-4dec-a2ac-ce211e105f97",
      "schemas": ["urn:ietf:params:scim:schemas:core:2.0:Group"],
      "displayName": "Group A",
      "meta": {
        "resourceType": "Group",
        "created": "2011-08-01T18:29:49.793Z",
        "lastModified": "2011-08-01T18:29:51.135Z",
        "location":
"https://example.com/v2/Groups/c3a26dd3-27a0-4dec-a2ac-ce211e105f97",
        "version": "W\/\"mvwNGaxB5SDq074p\"",
        "members.cnt":1
      },
      "members": [
        {
          "value": "6c5bb468-14b2-4183-baf2-06d523e03bd3",
          "$ref":
"https://example.com/v2/Groups/6c5bb468-14b2-4183-baf2-06d523e03bd3",
          "type": "Group"
        }
      ]
    },
    {
      "id": "6c5bb468-14b2-4183-baf2-06d523e03bd3",
      "schemas": ["urn:ietf:params:scim:schemas:core:2.0:Group"],
      "displayName": "Group B",
      "meta": {
        "resourceType": "Group",
        "created": "2011-08-01T18:29:50.873Z",
        "lastModified": "2011-08-01T18:29:50.873Z",
        "location":
"https://example.com/v2/Groups/6c5bb468-14b2-4183-baf2-06d523e03bd3",
        "version": "W\/\"wGB85s2QJMjiNnuI\"",
        "members.cnt":7
      },
      "members": [
        {
          "value": "c3a26dd3-27a0-4dec-a2ac-ce211e105f97",
          "$ref":
"https://example.com/v2/Groups/c3a26dd3-27a0-4dec-a2ac-ce211e105f97",
          "type": "Group"
        }
        {
          "value": "596ec090-2f66-4d3e-ad4c-68d9ac05ad53",
          "$ref":
"https://example.com/v2/Groups/596ec090-2f66-4d3e-ad4c-68d9ac05ad53",
          "type": "Group"
        }
        {
          "value": "aaf4c421-ceba-4ce0-a119-3d62418f5f9f",
          "$ref":
"https://example.com/v2/Groups/aaf4c421-ceba-4ce0-a119-3d62418f5f9f",
          "type": "Group"
        }
        {
          "value": "58b64358-82e7-4a77-a8eb-9c6d644f9752",
          "$ref":
"https://example.com/v2/Groups/58b64358-82e7-4a77-a8eb-9c6d644f9752",
          "type": "Group"
        }
        {
          "value": "3e32ee8c-246c-42ab-a750-2c2e84d57f1f",
          "$ref":
"https://example.com/v2/Groups/3e32ee8c-246c-42ab-a750-2c2e84d57f1f",
          "type": "Group"
        }
      ]
    }
  ]
}
Figure 4: Returning multiple results with paged attribute values

In Figure 3 the client may observe that the number of matches available for the second Group (whose id is 6c5bb468-14b2-4183-baf2-06d523e03bd3) is 7. In Figure 4, the client may return the second page, by repeating the query with startIndex set to 6.

In the following example, paging of member values of a specific group is requested.

GET /v2/Groups/6c5bb468-14b2-4183-baf2-06d523e03bd3? \
    attributes=*,members[type eq \"Group\"&count=5&startIndex=6]
Host: example.com
Accept: application/scim+json
Authorization: Bearer h480djs93hd8
Figure 5: Query returning the second page of values for an attribute 
HTTP/1.1 200 OK
Content-Type: application/scim+json
Location:
 https://example.com/v2/Groups/e9e30dba-f08f-4109-8486-d5c6a331660a
ETag: W/"lha5bbazU3fNvfe5"

{
  "id": "6c5bb468-14b2-4183-baf2-06d523e03bd3",

  "schemas": ["urn:ietf:params:scim:schemas:core:2.0:Group"],
  "displayName": "Group B",
  "meta": {
    "resourceType": "Group",
    "created": "2011-08-01T18:29:50.873Z",
    "lastModified": "2011-08-01T18:29:50.873Z",
    "location":
"https://example.com/v2/Groups/6c5bb468-14b2-4183-baf2-06d523e03bd3",
    "version": "W\/\"wGB85s2QJMjiNnuI\"",
    "members.cnt":7
  },

  "members": [
    {
      "value": "596ec090-2f66-4d3e-ad4c-68d9ac05ad53",
      "$ref":
"https://example.com/v2/Groups/596ec090-2f66-4d3e-ad4c-68d9ac05ad53",
      "type": "Group"
    }
    {
      "value": "2e6afed5-282d-4563-83dc-9ef7183b0003",
      "$ref":
"https://example.com/v2/Groups/2e6afed5-282d-4563-83dc-9ef7183b0003",
      "type": "Group"
    }
  ]
}
Figure 6: Returning the second page of values for an attribute

3. Service Provider Configuration Feature Discovery

Multi-value paging support may be determined by querying the /ServiceProviderConfig endpoint and looking up the Boolean attribute mvpaging indicating support for multi-valued paging and filtering.

4. Security Considerations

To be completed

5. Privacy Considerations

To be completed.

6. IANA Considerations

No IANA considerations.

7. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3986]
Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, , <https://www.rfc-editor.org/info/rfc3986>.
[RFC7643]
Hunt, P., Ed., Grizzle, K., Wahlstroem, E., and C. Mortimore, "System for Cross-domain Identity Management: Core Schema", RFC 7643, DOI 10.17487/RFC7643, , <https://www.rfc-editor.org/info/rfc7643>.
[RFC7644]
Hunt, P., Ed., Grizzle, K., Ansari, M., Wahlstroem, E., and C. Mortimore, "System for Cross-domain Identity Management: Protocol", RFC 7644, DOI 10.17487/RFC7644, , <https://www.rfc-editor.org/info/rfc7644>.

Appendix A. Acknowledgments

This draft is an updated submission based on the original ID draft-hunt-scim-mv-paging-00 contributed by Phil Hunt and Gregg Wilson.

Appendix B. Change Log

[[This section to be removed prior to publication as an RFC]]

Draft 00 - PH - Initial draft

Author's Address

Phil Hunt (editor)
Independent Identity Inc.