ietf-scim-events-03.txt

Internet DRAFT - draft-ietf-scim-events

draft-ietf-scim-events

Last Version:	draft-ietf-scim-events-03.txt	Tracker Entry
Date:	`23-Oct-2023`
Disposition:	current
Previous Versions:	draft-ietf-scim-events-02.txt (diff) - 11-Jul-2023
	draft-ietf-scim-events-01.txt (diff) - 21-Jan-2023
	draft-ietf-scim-events-00.txt (diff) - 12-Jul-2022

SCIM P. Hunt, Ed.
Internet-Draft IndependentId
Intended status: Standards Track N. Cam-Winget
Expires: 25 April 2024 Cisco Systems
M. Kiser
Sailpoint
J. Schreiber
Workday
23 October 2023

SCIM Profile for Security Event Tokens
draft-ietf-scim-events-03

Abstract

This specification defines a set of SCIM Security Events using the
Security Event Token Specification RFC8417 to enable the asynchronous
exchange of messages between SCIM Service Providers and receivers.
SCIM Security Events are typically used for: asynchronous request
completion, resource replication, provisioning co-ordination, and
shared security signals.

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 https://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 25 April 2024.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.

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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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.

Table of Contents

1. Introduction and Overview . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.2. Notational Conventions . . . . . . . . . . . . . . . . . 4
1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2. SCIM Events . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1. Identifying the Subject of an Event . . . . . . . . . . . 6
2.2. Common Event Attributes . . . . . . . . . . . . . . . . . 8
2.3. SCIM Feed Events . . . . . . . . . . . . . . . . . . . . 8
2.3.1. urn:ietf:params:SCIM:event:feed:add . . . . . . . . . 9
2.3.2. urn:ietf:params:SCIM:event:feed:remove . . . . . . . 9
2.4. SCIM Provisioning Events . . . . . . . . . . . . . . . . 10
2.4.1.
urn:ietf:params:SCIM:event:prov:create:{notice|full} 10
2.4.2.
urn:ietf:params:SCIM:event:prov:patch:{notice|full} . 12
2.4.3. urn:ietf:params:SCIM:event:prov:put:{notice|full} . . 14
2.4.4. urn:ietf:params:SCIM:event:prov:delete . . . . . . . 16
2.4.5. urn:ietf:params:SCIM:event:prov:activate . . . . . . 17
2.4.6. urn:ietf:params:SCIM:event:prov:deactivate . . . . . 17
2.5. SCIM Signals Events . . . . . . . . . . . . . . . . . . . 17
2.5.1. urn:ietf:params:SCIM:event:sig:authMethod . . . . . . 18
2.5.2. urn:ietf:params:SCIM:event:sig:pwdReset . . . . . . . 18
2.6. Miscellaneous Events . . . . . . . . . . . . . . . . . . 19
2.6.1. Asynchronous Events . . . . . . . . . . . . . . . . . 19
3. Event Delivery Feeds . . . . . . . . . . . . . . . . . . . . 25
3.1. Security Event Token Signing and Encryption . . . . . . . 27
3.2. Point-to-Point Delivery Over HTTP . . . . . . . . . . . . 28
4. Events Discovery Schema for Service Provider Configuration . 29
5. Security Considerations . . . . . . . . . . . . . . . . . . . 30
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 31
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31
7.1. SCIM Async Txn Header Registration . . . . . . . . . . . 31
7.2. Registration of the SCIM Event URIs Sub-Registry . . . . 32
7.3. Initial Events Registry . . . . . . . . . . . . . . . . . 33
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.1. Normative References . . . . . . . . . . . . . . . . . . 34
8.2. Informative References . . . . . . . . . . . . . . . . . 35
Appendix A. Use Cases . . . . . . . . . . . . . . . . . . . . . 36
A.1. Domain Based Replication . . . . . . . . . . . . . . . . 37
A.2. Co-ordinated Provisioning . . . . . . . . . . . . . . . . 37

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A.3. Risk Signals . . . . . . . . . . . . . . . . . . . . . . 40
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 40
Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 40
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40

1. Introduction and Overview

This specification defines Security Events for SCIM Service Providers
and receivers as specified by the Security Event Tokens (SET)
[RFC8417] specification. Scim Security Events in this specification
include: asynchronous request completion, resource replication,
provisioning co-ordination, and security signals.

This specification also profiles the use of the HTTP Header "Prefer:
Async-response" [RFC7240] to allow a SCIM Protocol Client [RFC7644]
to request an asynchronous response (see Section 2.6.1.1).

In a typical HTTP client-server relationship, a SCIM Protocol Client
issues commands to a SCIM Service Provider using HTTP methods such as
POST, PATCH, and DELETE [RFC7644] that cause a state change to a SCIM
Resource. When multiple independent SCIM Clients update SCIM
resources, individual clients become out of date as state changes
occur. Some clients may need to be informed of these changes for co-
ordination or reconciliation purposes. This could be done using SCIM
periodic SCIM GET requests over time, but this rapidly problematic as
the number of changes and the number of resources increases.

Security Event Tokens [RFC8417] and SCIM Events offers the ability to
exchange messages that act as triggers for receivers to monitor over
time in an asynchronous approach. This enables greater scale and
timeliness, where only changed information is exchanged between
parties.

A SET token conveys a signal about a state changes that has occurred
in a publishing SCIM Service Provider. That token may be of interest
to one or more receivers and can be delivered asynchronously to the
originating SCIM client making the change. Unlike SCIM Protocol
requests which convey protocol commands, Security Events describe
statements of fact about changes that have already occurred at the
SCIM Provider. This approach allows the event receiver to determine
the best local follow-up action to take within the context of the
receiver. For example, the receiver can reconcile intentional schema
and population differences between the domain as the receiver.

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1.1. Requirements Language

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.

1.2. Notational Conventions

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

Throughout this document 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 definitions from the following
specifications:

* Json Web Tokens (JWT) [RFC7519],

* Security Event Tokens (SET) [RFC8417], and

* System for Cross-Domain Identity Management Protocol [RFC7644].

In Json Web Tokens and Security Event Tokens the term "claim" is used
to refer to JSON attribute values in a Json Web Token [RFC7519]
structure. The term "claim" in tokens is used to indicate that an
attribute value may not be verified and its accuracy can be
questioned. In the context of SCIM, claims are referred to as
attributes. For the purposes of this specification claims and
attributes are inter-changeable. For consistency, JWT and SET IANA
registered attributes will continue to be called claims, while event
attributes (i.e. those in an event payload) will be referred to as
attributes.

Additionally, the following terms are defined:

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Attributes and Claims
The JWT specification [RFC7519] upon which SET is based uses the
term "claims" to refer to attributes in a JSON token. SCIM in
contrast uses the term "attributes" to refer to JSON attributes.
For the purposes of this draft, the terms "attributes" and
"claims" are equivalent.

CP
Abbreviation for "Co-ordinated Provisioning" as defined in
Appendix A.2. In these relationships an Event Publisher and
Receiver typically exchange resource change events without
exchanging data. For a receiver to know the value of the data,
the Event Receiver usually has calls back to the SCIM Event
Publisher domain to receive a new copy of data (e.g. Uses a SCIM
GET request).

DBR
Abbreviation for "Domain Based Replication" as defined in
Appendix A.1. In this mode because there is an administrative
relationship spanning multiple operational domains, data shared in
Events typically uses the full mode variation of change events
including the data payload attribute. This eliminates the need
for a call back to retrieve additional data.

Event Feed / Event Stream
This describes the quality that a feed (aka stream) MAY be managed
per receiving client. A SET transfer (see [RFC8935] [RFC8936])
service provider MAY offer to allow Event Receiver's to
"subscribe" to specific event types or events about specific
resources (see Feed Management events Section 2.3).

Event Receiver
An entity receives events typically via [RFC8935], [RFC8936], or
HTTP GET (see Section 2.6.1.1). In the case of SET Push Transfer
[RFC8935], the Event Receiver is an HTTP Service Endpoint that
receives requests. In the case of SET Poll-Based Transfer
[RFC8936], the receiver is an HTTP client that initiates HTTP
request to an Event Publisher endpoint.

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Event Publisher
A system that issues SET tokens based on a resource state changes
that have occurred at a SCIM Service Provider. For example,
events MAY be the result of a SCIM Create, Modify, or Delete as
defined in [RFC7644]. A SCIM Service Provider MAY be an Event
Publisher or an independent service that aggregates events into
Event Receiver feeds. As described above, when using [RFC8935],
the Event Publisher is an HTTP Client that initiates HTTP POST
requests to a defined Event Receiver endpoint. When using
[RFC8936], the Event Publisher provides an HTTP endpoint which a
receiver MAY use to "poll" for Security Events.

RS
Abbreviation for "Risk Signals" as defined in Appendix A.3.

SCIM Client
An HTTP client that initiates SCIM Protocol [RFC7644] requests and
receives responses.

SCIM Service Provider
An HTTP server that implements SCIM Protocol [RFC7644] and SCIM
Schema [RFC7643].

SET
Abbreviation for "Security Event Token" as defined in [RFC8417]

2. SCIM Events

A SCIM event is a signal, in the form of a Security Event Token
[RFC8417] that describe some event that has occurred. A SET event
consists of a set of standard JWT "top-level" claims, an "events"
claim that contains one or more event URI subclaims (JSON attributes)
each with a JSON object containing relevant event information.

2.1. Identifying the Subject of an Event

SCIM Events SHALL use the "sub_id" claim defined by Subject
Identifiers for Security Event Tokens [SUBID] specification to
identify the subject of events. The sub_id claim MUST be contained
within the main JWT claims body and SHALL NOT be located within an
Event payload within the events claim. A SET with multiple event
URI's indicates that the events arise from the same transaction or
resource state change for a single resource or subject. Finally, as
recommended in [RFC8417] the JWT "sub" claim SHALL NOT be used.

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{
"iss": "issuer.example.com",
"iat": 1508184845,
"aud": "aud.example.com",
"sub_id": {
"format": "scim",
"uri": "/Users/2b2f880af6674ac284bae9381673d462",
"externalId": "alice@example.com"
},
"events": {
...
}
}

Figure 1: SCIM Subject Id Example

The top-level claim "sub_id" SHALL contain the subclaim "format"
whose value is set to scim to indicate the other attributes present
are SCIM attributes. The following sub_id attributes are defined:

uri
The SCIM relative path for the resource which usually consists of
the resource type endpoint plus the resource id. For example
/Users/2b2f880af6674ac284bae9381673d462. This attribute MUST be
provided in a SCIM Event sub_id claim. Note the relative path is
the path component after the SCIM Service Provider Base URI as
defined in Section 1.3 [RFC7644]. In cases where the Event
Receiver is unable to match a URI, the Event Receiver MAY issue a
call-back to a previously agreed SCIM Service Provider Base URI
plus the relative uri value and perform a SCIM GET request per
Section 3.4.1 [RFC7644].

externalId
If known, the externalId value of the SCIM Resource that MAY be
used by a receiver to identify the corresponding resource in the
Event Receiver's domain.

id
The SCIM Id attribute MAY be used for backwards compatibility
reasons in addition to the uri claim.

emails,username, ...
A SCIM attribute that is unique to both the Event Publisher and
Receiver. Typically, attributes like email or usernames are used
in situations where normal SCIM identifiers (id and externalId)
are insufficient to identify a common resource between an Event
Publisher and Event Receiver.

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2.2. Common Event Attributes

The following attributes are available for all events defined. Some
attributes are defined as SET/JWT claims, while others are "Event
Payload" claims as defined in Section 1.2 [RFC8417].

txn
For the purposes of SCIM, this SET defined claim identifies a
unique transaction originating at a SCIM Service Provider and/or
its underlying data repository or database. The claim is used to
detect duplicate transactions that may have been received (e.g. in
the case of a re-transmitted or recovered event). If not
provided, the SET jti claim MAY be used. Where txn identifies a
unique transaction within a SCIM Service Provider, multiple SETs
MAY be issued each with distinct JTI's stemming from a common
originating transaction with identical txn values.

data
This event payload attribute contains information described in
SCIM Bulk Operations data attribute, Section 3.7 [RFC7644]. The
JSON object contains the equivalent SCIM command processed by the
SCIM Service provider. For example, after processing a SCIM
Create operation, the data contained includes the final
representation of the created entity by the SCIM Service Provider
including the assigned id value.

attributes
This payload attribute contains an array of attributes that were
added, revised, or removed. For example:
"attributes": ["username","emails"]

Only one of data or attributes claims SHALL be provided depending on
the event definition.

This specification defines a new URI prefix
urn:ietf:params:SCIM:event which is used as the prefix for the
following defined SCIM Events (see Section 7.2).

2.3. SCIM Feed Events

This section defines events related to changes in the content of an
event feed. For example, SCIM resources that are being added or
removed from an event feed. For example, the events may be used in
Co-operative Provisioning scenarios where only a sub-set of entities
are shared across an Event Feed. The URI prefix for these events is:
urn:ietf:params:SCIM:event:feed

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2.3.1. urn:ietf:params:SCIM:event:feed:add

The specified resource was added to the Event Feed. A feed:add does
not indicate a resource is new or has been recently created. For
example, an existing user has had a new role (e.g. CRM_User) added
to their profile which has caused their resource to join a feed.

{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"txn": "b7b953f11cc6489bbfb87834747cc4c1",
"sub_id": {
"format": "scim",
"uri": "/Users/2b2f880af6674ac284bae9381673d462",
"externalId": "jdoe"
},
"events":{
"urn:ietf:params:SCIM:event:feed:add": {}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 2: Example SCIM Feed Add Event

2.3.2. urn:ietf:params:SCIM:event:feed:remove

The specified resource has been removed from the feed. Removal does
not indicate that the resource was deleted or otherwise deactivated.
This event has minimal disclosure.

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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2b2f880af6674ac284bae9381673d462"
"externalId": "jdoe",
},
"events":{
"urn:ietf:params:SCIM:event:feed:remove": {}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 3: Example SCIM Feed Remove Event

2.4. SCIM Provisioning Events

This section defines resource changes that have occurred within a
SCIM Service Provider. These events are used in both Domain Based
Replication (DBR) and Co-operative Provisioning (CP) mode. The URI
prefix for these events is: urn:ietf:params:SCIM:event:prov

2.4.1. urn:ietf:params:SCIM:event:prov:create:{notice|full}

Indicates a new SCIM resource has been created by the SCIM Service
Provider and has been added to the Event Feed. When the data payload
attribute is included, the event uri SHALL end with full otherwise,
the event URI ends with notice. In full mode, the set of values
reflecting the final state of the resource at the service provider
are provided using the data attribute. In notice mode, attributes is
returned disclosing the list of attributes included in the create
request. Note that because the event MAY be used for replication,
the final id attribute that was assigned by the SCIM Service Provider
is shared so that all replicas in the domain MAY use the same
resource identifier.

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{
"jti": "4d3559ec67504aaba65d40b0363faad8",

"iat": 1458496404,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754",
"https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7"
],
"sub_id": {
"format": "scim",
"uri": "/Users/44f6142df96bd6ab61e7521d9",
"externalId":"jdoe"
}
"events":{
"urn:ietf:params:SCIM:event:prov:create:full":{
"data":{
"schemas":[ "urn:ietf:params:scim:schemas:core:2.0:User"],
"emails":[
{"type":"work","value":"jdoe@example.com"}
],
"userName":"jdoe",
"name":{
"givenName":"John",
"familyName":"Doe"
}
}
}
}
}

Figure 4: Example SCIM Create (Full)

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{
"jti": "4d3559ec67504aaba65d40b0363faad8",
"iat": 1458496404,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754",
"https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7"
],
"sub_id": {
"format": "scim",
"uri": "/Users/44f6142df96bd6ab61e7521d9",
"externalId": "jdoe"
},
"events": {
"urn:ietf:params:SCIM:event:prov:create:notice": {
"attributes": [
"id",
"name",
"userName",
"password",
"emails"
]
}
}
}

Figure 5: Example SCIM Create Event (Notice)

The event above notifies the Event Receiver which attributes have
changed but does not convey the actual information. The Event
Receiver MAY retrieve that information by performing a SCIM GET to
the sub value specified.

2.4.2. urn:ietf:params:SCIM:event:prov:patch:{notice|full}

The specified resource has been updated using SCIM PATCH. In full
mode, the data payload attribute is included. When the event URI
ends with notice, the list of attributes changed is provided.

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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Groups/176f397ec4c44b94b2cfcb759780b8c2",
"externalId": "crmUsers"
},
"events":{
"urn:ietf:params:SCIM:event:prov:patch:full": {
"version": "a330bc54f0671c9",
"data": {
"schemas":
["urn:ietf:params:scim:api:messages:2.0:PatchOp"],
"Operations":[{
"op":"add",
"path":"members",
"value":[{
"display": "Babs Jensen",
"$ref": "/Users/2819c223...413861904646",
"value": "2819c223-7f76-453a-919d-413861904646"
}]
}]
}
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 6: Example SCIM Patch Event (Full)

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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Groups/176f397ec4c44b94b2cfcb759780b8c2",
"externalId": "crmUsers"
},
"events":{
"urn:ietf:params:SCIM:event:prov:patc:notice": {
"attributes": ["members"],
"version": "a330bc54f0671c9"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 7: Example SCIM Patch Event (Notice)

2.4.3. urn:ietf:params:SCIM:event:prov:put:{notice|full}

The specified resource has been updated (e.g. one or more attributes
has changed). In full mode, the SCIM PUT request body is included in
the data attribute. In notice mode the modified attributes are
listed using attributes.

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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2819c223-7f76-453a-919d-413861904646"
},
"events":{
"urn:ietf:params:SCIM:event:prov:put:full": {
"version": "a330bc54f0671c9",
"data": {
"schemas":["urn:ietf:params:scim:schemas:core:2.0:User"],
"userName":"jdoe",
"externalId":"jdoe",
"name":{
"formatted":"Mr. Jon Jack Doe III",
"familyName":"Doe",
"givenName":"Jon",
"middleName":"Jack"
},
"roles":[],
"emails":[
{"value":"jdoe@example.com"},
{"value":"anon@jdoe.org"}
]
}
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 8: Example SCIM Put Event (Full)

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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2819c223-7f76-453a-919d-413861904646"
},
"events":{
"urn:ietf:params:SCIM:event:prov:put:notice": {
"version": "a330bc54f0671c9",
"attributes": ["userName","externalId","name","roles","emails"]
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 9: Example SCIM Put Event (Notice)

2.4.4. urn:ietf:params:SCIM:event:prov:delete

The specified resource has been deleted from the SCIM Service
Provider. The resource is also removed from the feed. When a DELETE
is sent, a corresponding feedRemove is not issued. A delete event
has no payload attributes. Note that because the delete event has no
attributes, the qualifiers full and notice SHALL NOT be used.

{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2b2f880af6674ac284bae9381673d462",
"externalId": "jDoe"
},
"events":{
"urn:ietf:params:SCIM:event:prov:delete": {}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 10: Example SCIM Delete Event

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2.4.5. urn:ietf:params:SCIM:event:prov:activate

The specified resource (e.g. User) has been "activated". This does
not necessarily reflect any particular state change at the SCIM
Service Provider but may simply indicate the account defined by the
SCIM resource is ready for use as agreed upon by the Event Publisher
and Event Receiver. For example, an activated resource represents an
account that may be logged in.

{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2b2f880af6674ac284bae9381673d462"
},
"events":{
"urn:ietf:params:SCIM:event:prov:activate": {}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 11: Example SCIM Activate Event

2.4.6. urn:ietf:params:SCIM:event:prov:deactivate

The specified resource (e.g. User) has been deactivated and
disabled. The exact meaning SHOULD be agreed to by the Event
Publisher and its corresponding Event Receiver. Typically, this
means the sub may no longer have an active security session. As with
the activate event, this event has minimal disclosure requirements.

2.5. SCIM Signals Events

This section defines security signal events that have occurred within
a SCIM Service Provider. The URI prefix for these events is:
urn:ietf:params:SCIM:event:signal

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2.5.1. urn:ietf:params:SCIM:event:sig:authMethod

A new authentication method has been added to the User profile. As
attackers often use new authentication methods to lock-out Users from
their account, this signal can be used by the receiver that the
chance of account them may be temporarily elevated. The receiver MAY
also wish to take action such as resetting current authorizations or
sessions.

Figure 12: Example SCIM Authentication Factor Change Event

2.5.2. urn:ietf:params:SCIM:event:sig:pwdReset

The specified resource (e.g. User) has changed its password or the
password has been reset. When the password has changed, the
attributes attribute is supplied with the value "password".

{
"jti": "3d0c3cf797584bd193bd0fb1bd4e7d30",
"sub_id": {
"format": "scim",
"uri": "/Users/44f6142df96bd6ab61e7521d9"
},
"events": {
"urn:ietf:params:SCIM:event:sig:pwdReset": {}
},
"iat": 1458496025,
"iss": "https://scim.example.com",
"aud":[
"https://jhub.example.com/Feeds/98d52461fa5bbc879593b7754",
"https://jhub.example.com/Feeds/5d7604516b1d08641d7676ee7"
]
}

Figure 13: Example SCIM Password Change Event

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2.6. Miscellaneous Events

This section defines events related miscellaneous events such as
Asynchronous Request completion that has occurred within a SCIM
Service Provider. The URI prefix for these events is:
urn:ietf:params:SCIM:event:misc

2.6.1. Asynchronous Events

2.6.1.1. Making an Asynchronous SCIM Request

A SCIM client making SCIM HTTP requests defined in [RFC7644] MAY
request "asynchronous" processing using the "Prefer" HTTP Header as
defined in Section 4.1 [RFC7240]. The client may do this for a
number of reasons such as: avoiding holding HTTP connections open
during long requests, because the result of the request is not
needed, or for co-ordination reasons where the result is delivered to
another entity for further action.

To initiate an async SCIM request, a normal SCIM protocol POST, PUT,
PATCH, or DELETE request is performed with the HTTP Header Prefer
with a value of respond-async as defined in [RFC9110]. The HTTP
Accept header SHALL be ignored.

In response, and as indicated in the SCIM Service Provider
Configuration (see Section 4, The SCIM Service Provider responds with
either a normal SCIM response, or respond asynchronously by returning
HTTP Status 202 Accepted. The asynchronous response SHOULD contain
no response body. To enable correlation of the future event, the
HTTP response header "Set-txn" is returned with a value corresponding
to a future Security Event Token to be received whose "txn" claim
SHALL match. Per Section 3 [RFC7240], the response will also include
the header Preference-Applied. The Location header returned SHALL be
one of the following:

* A location URI where the completion token MAY be retrieved using
HTTP GET, or

* The normal SCIM location header response specified by [RFC7644].

In the following non-normative example, a "Prefer" header is set to
"respond-async":

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PUT /Users/2819c223-7f76-453a-919d-413861904646
Host: scim.example.com
Prefer: respond-async
Content-Type: application/scim+json
Authorization: Bearer h480djs93hd8
{
"schemas":["urn:ietf:params:scim:schemas:core:2.0:User"],
"id":"2819c223-7f76-453a-919d-413861904646",
"userName":"bjensen",
"externalId":"bjensen",
"name":{
"formatted":"Ms. Barbara J Jensen III"
},
"roles":[],
"emails":[
{
"value":"bjensen@example.com"
}
]
}

Figure 14: Example Asynchronous SCIM Protocol Request

The SCIM Service Provider responds with HTTP 202 Accepted and
includes the Set-txn header:

HTTP/1.1 202 Accepted
Set-txn: 734f0614e3274f288f93ac74119dcf78
Preference-Applied: respond-async
Location:
"/Users/2819c223-7f76-453a-919d-413861904646"

Figure 15

2.6.1.2. Asynchronous Bulk Endpoint Requests

SCIM Protocol Section 3.7 [RFC7644] provides the ability to submit
multiple SCIM operations in a single request. When an asynchronous
response is requested, a single Async Request Completion Event SHALL
be generated for each requested operation. For example, if a single
SCIM Bulk request had 10 operations, then 10 Async Event completions
events would be generated.

The "txn" claim MUST be set to the value originally returned to the
requesting SCIM client (see Section 2.6.1.1) appended with a dash "-"
followed by the request operation number. For example, if the "txn"
claim value was "2d80e537a3f64622b0347b641ebc8f44", then the first
Async Response Event Token representing the first operation SHALL

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have a "txn" claim value of "2d80e537a3f64622b0347b641ebc8f44-1", the
second operation SHALL have a value of
"2d80e537a3f64622b0347b641ebc8f44-2", and so on.

If a SCIM service provider elects to optimize the sequence of
operations (per Section 3.7 [RFC7644]), the Async Request Completion
events generated MAY also be generated out of sequence from the order
of operations in the original request. In this case, the "txn"
claims generated SHALL use operation numbers that correspond to the
original request order.

2.6.1.3. urn:ietf:params:SCIM:event:misc:asyncResp

The Async Response event signals the completion of a SCIM request.
The event payload contains the attributes defined in SCIM Bulk
Section 3.7 [RFC7644] and is the same a single SCIM Bulk Response
Operation as per Section 3.7.3. In the event, the "txn" claim must
be set to the value originally returned to the requesting SCIM client
(see Section 2.6.1.1).

{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2819c223-7f76-453a-919d-413861904646"
},
"txn": "734f0614e3274f288f93ac74119dcf78",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "PUT",
"version": "W\/\"huJj29dMNgu3WXPD\"",
"status": "200"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 16: Example SCIM Async Response Event

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An error may occur in the SCIM server's asynchronous processing of
the SCIM request. In that case, the event's operation MUST include a
"response" attribute to indicate a non-200-series HTTP status as
defined in Section 3.7 [RFC7644]. The response attribute MUST
contain the sub-attributes defined in Section 3.12 [RFC7644]. Note
that the "status" attribute of the event operation should match the
"status" attribute of the response.

{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub_id": {
"format": "scim",
"uri": "/Users/2819c223-7f76-453a-919d-413861904646"
},
"txn": "734f0614e3274f288f93ac74119dcf78",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "PUT",
"version": "W\/\"huJj29dMNgu3WXPD\"",
"status": "400",
"response": {
"schemas": ["urn:ietf:params:scim:api:messages:2.0:Error"],
"scimType":"invalidSyntax",
"detail": "Request is unparsable",
"status":"400"
}
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 17: Example SCIM Async Error Response Event

The following 4 figures show Async Completion events for the example
in Section 3.7.3 of [RFC7644].

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{
"jti": "dbae9d7506b34329aa7f2f0d3827848b",
"sub_id": {
"format": "scim",
"uri": "/Users/92b725cd-9465-4e7d-8c16-01f8e146b87a"
},
"txn": "2d80e537a3f64622b0347b641ebc8f44-1",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "POST",
"bulkId": "qwerty",
"version": "W\/\"oY4m4wn58tkVjJxK\"",
"status": "201"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 18: Example SCIM Async Response Event Operation 1/4

{
"jti": "ca977d05ba5c43929e3a69023d5392a9",
"sub_id": {
"format": "scim",
"uri": "/Users/b7c14771-226c-4d05-8860-134711653041"
},
"txn": "2d80e537a3f64622b0347b641ebc8f44-2",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "PUT",
"version": "W\/\"huJj29dMNgu3WXPD\"",
"status": "200"
}
},
"iat": 1458505045,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 19: Example SCIM Async Response Event Operation 2/4

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{
"jti": "4bb87d70a4ab463bbdcd1f99111cbbf1",
"sub_id": {
"format": "scim",
"uri": "/Users/5d8d29d3-342c-4b5f-8683-a3cb6763ffcc"
},
"txn": "2d80e537a3f64622b0347b641ebc8f44-3",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "PATCH",
"version": "W\/\"huJj29dMNgu3WXPD\"",
"status": "200"
}
},
"iat": 1458505046,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 20: Example SCIM Async Response Event Operation 3/4

{
"jti": "6a7843a7f5244d0eb62ca38b641d9139",
"sub_id": {
"format": "scim",
"uri": "/Users/e9025315-6bea-44e1-899c-1e07454e468b"
},
"txn": "2d80e537a3f64622b0347b641ebc8f44-4",
"events":{
"urn:ietf:params:SCIM:event:misc:asyncResp": {
"method": "DELETE",
"status": "204"
}
},
"iat": 1458505047,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}

Figure 21: Example SCIM Async Response Event Operation 4/4

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3. Event Delivery Feeds

In addition to retrieving a single security event as described in
Section 2.6.1.1, Event Feeds (or Streams) provide the ability
exchange a series of events between pre-arranged endpoints using the
following Security Event Token exchange methods:

[RFC8935]
Push-Based Security Event Token (SET) Delivery delivers tokens to
an Event Receiver with an accessible HTTP Endpoint.

[RFC8936]
Poll-Based Security Event Token (SET) Delivery enables an event
receiver to initiate calls to SET Event publisher endpoint to
receive 1 or more events. This is particularly advantageous when
an Event Receiver is behind a firewall or other network
restriction that would prevent Push Delivery. An Event Receiver
may also use HTTP "Long-polling" to achieve real time event
delivery.

In the figure below, a possible distribution architecture is shown.
This specification is only normatively concerned with the actual
Security Event Transfer mechanism. SCIM Service providers MAY choose
to implement SET transfer directly, or they may use a method of
allowing a single Event Publisher to assemble streams of events for
transfer to a receiver. Likewise, on the receiving side, the only
normative requirement is to be able to receive events and implement
storage of Events to local recovery needs.

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┌───────────────┐ ┌───────────────┐ ┌───────────────┐
│ │ │ │ │ │
│ SCIM Server 1 │ │ SCIM Server 2 │ ...│ SCIM Server n │
│ │ │ │ │ │
└───────┬───────┘ └───────┬───────┘ └───────┬───────┘
│ │ │
┌───────▼──────────────────▼────────────────────▼───────┐
│ Local Event Delivery System │
└───────────────────────────┬───────────────────▲───────┘
│ │
┌────────▼────────┐ ┌──────┴───────┐
│ │ │ Recovery │
│ Event Publisher ◄───► Buffer │
│ │ └──────────────┘
└────────┬────────┘
┌── │
│ ┌────────▼────────┐
│ │ SET Trans Txmtr │
│ │ (RFC 8935/8936) │
Minimum │ └────────┬────────┘
Interop │ │
Requirement│ │
│ ┌────────▼────────┐ ┌──────────────┐
│ │ SET Trans Rcvr │ │ Event │
│ │ (RFC 8935/8936) ├───► Storage │
│ └────────┬────────┘ └──────────────┘
└── │
┌────────▼────────┐
│ Receiver Domain │
│ Event Processor │
└────────┬────────┘
│
▼

Figure 22

As Security Event Tokens are based on JWT tokens, it is possible to
exchange events by a number of transfer mechanisms such as: XMPP
[RFC6120], HTTP [RFC9113], and Message Buses (e.g. [RFC3259], Apache
Kafka [Kafka]). For example, on the publishing side, a cluster or
network of SCIM servers may publish events to a common SET publisher
service for distribution to 1 or more receivers. The Event Publisher
MAY be incorporated directly into each SCIM Server, or a Local Event
Delivery System might be used to collect events for an Event
Publisher service for forwarding. How this is done is up to the
implementer. This specification is only concerned with the
interoperability of SET transfer between domains using [RFC8935] and
[RFC8936].

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The SET Transfer specifications provide a short-term method of
recovery to ensure SET Events are successfully transferred. Once a
receiving domain has successfully stored events to its own recovery
needs, the receiving domain acknowledges the transfer of SET Events
to the publisher using the method defined in [RFC8935] and [RFC8936].
SET does not specify local server event recovery mechanisms, this is
up to the service implementation within each domain. This is done to
enable cross-domain independence between domains. As an example, a
hosted SCIM service provider with a series of SCIM servers replicates
through a proprietary system. An enterprise customer who is the
common client across both providers wants to establish a single
administrative domain and wants to share SCIM change events between
providers. Each domain has its own SCIM implementation and its own
local replication strategy. The publishing domain issues events that
the receiving domain picks up. Once the receiving domain has
processed the event, the receiving domains own internal replication
and recovery takes over. Because there is no need for the publishing
domain to retain the event, it has the option to purge the event once
the receiving domain has acknowledged it. This may be particularly
critical if a publishing domain has dozens or even thousands of event
receiving domains each with their own sub-set of data. Retaining all
events for all receivers would become impractical.

3.1. Security Event Token Signing and Encryption

This specification uses Security Event Tokens as the message format
for SCIM Events. As SETs are based on JWT tokens [RFC7519], they can
be transmitted insecurely, signed, or encrypted. For more
information see the JWT Cookbook specification [RFC7520] for
examples. The decision on whether to use JWS and JWE depends on
operational considerations. For each SCIM Feed relationship, it is
up to deployers to decide on signing, encryption and algorithm
requirements. Deployers SHOULD be aware that too much emphasis on
turning on every possible encryption feature may cause operational
performance to suffer. Deployers MUST weigh the security trade-offs
of up-to-date SCIM services, vs. the potential information loss of an
event.

Unsecured
Per Section 6 [RFC7519], tokens MAY be generated with
{"alg":"none"}. This mode speeds up processing and is best used
in DBR scenarios. Unencrypted tokens MUST be transferred over
authenticated TLS layer encryption and SHOULD only be used in a
restricted network environment.

Signed
JWS ([RFC7515]) signed SETs are useful when it is important to be
able to verify the issuer of a SET as valid. In addition, some

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systems MAY wish to validate the authenticity of the event in a
review process which may occur at a later date. While the content
can be validated as originating from the correct issuer and is
unmodified, the message contents remain unsecure. Signed SETs
MUST be transferred over encrypted transport.

Encrypted
JWE ([RFC7516]) are encrypted SETs and are useful when the
transport mechanism is not fully secured (e.g. messages carried by
a third party). The use of JWEs ensures only the designated
receiver can read the event and provides mutual authentication
within the SET message itself.

3.2. Point-to-Point Delivery Over HTTP

Security Event Tokens MAY be delivered using push-based HTTP delivery
[RFC8935], or pull-based HTTP Polling [RFC8936]. Both of these
protocols define a method of transfer and acknowledgement to prevent
loss-of-information and to provide re-transmission and recover. The
method of transfer is best decided by considering the following
advantages and disadvantages in a production scenario:

Push-based delivery has the following advantages:

* Message transfer is instant (when compared to using a common Event
Publisher acting as a relay), and in high event frequency
scenarios, HTTP connections can be kept open.

* Scales well when an SCIM Event Publisher has thousands of event
receivers and TCP resources may be limited.

* Does not require events to be routed to a single publisher node.
SCIM Events may be issued by SCIM Service Provider nodes where the
transaction occurred.

* SCIM Events only need to be retained until they have been
delivered to designated receivers.

Push-delivery has the following disadvantages:

* A SCIM Event Publisher system needs authorization credentials
enabling it to access the HTTP SCIM Event delivery endpoint.

* When synchronizing business data that is behind protected
firewalls, a virtual network or other firewall policy may be
required to allow external network based SCIM providers to deliver
SCIM Events to internally hosted systems.

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Delivery by HTTP Polling has the following advantages:

* It is possible for a SCIM Event Receiver to use the same SCIM
credentials it uses when access the normal SCIM Service Provider
service defined by [RFC7644].

* Systems behind protected network boundaries can reach externally
hosted systems without requiring special firewall or network
configuration.

* Instantaneous transfer MAY be supported using HTTP Long-polling as
described Section 2.1 of [RFC8936].

Polling-based delivery has the following disadvantages:

* Long-polling requires the use of persistent connections for which
TCP resources may be limited. HTTP Long-polling is best used in
scenarios when there are relatively few Event Receivers.

* The SCIM Event Publisher MUST retain events for the Event Receiver
until delivered.

4. Events Discovery Schema for Service Provider Configuration

Section 5 of [RFC7643] defines SCIM Service Provider configuration
schema. This section defines additional attributes that enable a
SCIM client to discover the additional capabilities defined by this
specification.

securityEvents
A SCIM Complex attribute that specifies the available capabilities
related to asynchronous Security Events based on [RFC8417]. This
attribute is OPTIONAL and when absent indicates the SCIM server
does not support or is not currently configured for Security
Events. The following sub-attributes are defined:

asyncRequest
A string value specifying one of the following:

* NONE indicates async SCIM requests defined in
Section 2.6.1.1 are not supported;

* LONG indicates the SCIM Service Provider MAY complete
asynchronously at its discretion (e.g. based on a max wait
time);

* REQUEST indicates the request SHALL complete asynchronously
when requested by the SCIM Client.

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eventUris
A multivalued string listing the SET Event URIs (defined in
[RFC8417]) the server is capable of generating and deliverable
via a SET Stream (see [RFC8935] and [RFC8936]). This
information is informational only. Stream registration and
configuration is out of scope of this specification.

5. Security Considerations

This specification depends on the Security Considerations for
[RFC8417].

The use of Json Web Encryption (JWE) [RFC7516] can impose performance
limitations when used in high event frequency scenarios. JWE is
primarily useful only when the transfer of SETs involves an unsecured
transfer method (e.g. URL) that would not otherwise be protected by
the transfer protocol (e.g. SET Transfer over TLS [RFC8446]).

For SCIM Provisioning events, the long-term series of changes may be
critical to both sides. As such Event Publishers SHOULD consider
storing events for receivers for longer periods of time in the case
of an extended SET Transfer service failure. Similarly, Event
Receivers MUST ensure events are persisted directly or indirectly
sufficient to meet local recovery needs before acknowledging received
SET Events.

When SET Events are stored for future delivery or retained local
recovery MUST be limited only to the parties needed to support
recovery or SET forwarding.

JWS [RFC7515] signed SET Events SHOULD be used to verify authenticity
of the origin of a SET Event. Validating event signatures is both
useful on the initial transfer of SET Events, and may also be useful
for auditing purposes.

In operation, some SCIM resources such as SCIM Groups may have a high
rate of change. Implementors and operators SHOULD consider use of
throttling techniques to balance immediacy and frequency. For
example, a large group whose members change dozens of times per
second may not need discrete SET Patch Events per change. Instead,
issuing a single consolidated change per second or even minute may be
beneficial to keeping Event Receivers up-to-date. Likewise, a Co-
ordinated Provisioning Event Receiver (Section 2.2), does not
necessarily need to retrieve the full Group on every change request.
It MAY choose to do lookups on a less frequent scale for
reconciliation.

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When using Asynchronous SCIM Requests (see Section 2.6.1.1), and
location returned in a SCIM Accepted response is a URI for retrieving
the event result, the URI SHOULD be protected requiring an HTTP
Authorization header. Or in the alternative, the SET's retrieved
SHOULD be encrypted in order to authenticate the receiver. The
retrieval endpoint SHOULD be protected

6. Privacy Considerations

This specification enables the sharing of information between
domains. The specification assumes that implementers and deployers
are operating under one of the following scenarios:

* A common administrative domain where there is one administrative
owner of the data. In these cases the objective is to protect
privacy and security of the owner and user data by keeping
information systems co-ordinated and up-to-date. For example, the
domains decide to use Domain Based Replication mode in order to
keep employee information synchronized.

* In a co-operative or co-ordinated relationship, parties have
decided to share a limited amount of data and or signals for the
benefits of their users. Depending on end-user consent,
information is shared on an as authorized and/or as needed basis.
For example, the domains agree to use Co-ordinated Provision mode
that exchanges things like account status, or specific minimal
attribute information needed that must be fetched on request after
receiving notice of a change. This enables authorization to be
verified each time data is transferred.

In general the sharing of SCIM Event information falls within a pre-
existing SCIM Client and Service Provider relationship. In the case
of SCIM Risk Signals Events, the existing relationship may need to be
reviewed. By their nature, however, SCIM Signals carry no personal
information and aid parties in ensuring the protection of privacy
information and account security.

Privacy considerations of [RFC8417] MUST also be observed.

7. IANA Considerations

7.1. SCIM Async Txn Header Registration

This specification registers the HTTP Set-txn field name in the "HTTP
Field Name Registry" defined in Section 16.3.1 [RFC9110].

Field name:
Set-txn

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Status:
Permanent

Specification Document:
this specification, Section 2.2 and Section 2.6.1.1.

Comments:
See also Section 2.2 [RFC8417] Security Event Tokens.

7.2. Registration of the SCIM Event URIs Sub-Registry

IANA will add the following new registry "SCIM Events Registry"
within the "SCIM URN Sub-namespace" registry defined in Section 10.1
[RFC7643] called the "SCIM Event URI Registry"

Namespace ID:
The sub-namespace ID of "event" is assigned within the "scim"
namespace.

Syntactic Structure:
The Namespace Specific String (NSS) of all URNs that use the
"event" Namespace ID SHALL have the following structure:

"urn:ietf:params:scim:event:{class}:{name}:{other}

The keywords have the following meaning:

class
The class of events which is one of: "feed", "prov", "sig", or
"misc".

name
A US-ASCII string that conforms to URN syntax requirements (see
[RFC8141]) and defines a descriptive event name (e.g.
"create").

other
An optional US-ASCII string that conforms to URN syntax
requirements (see [RFC8141]) and serves as an additional sub-
category or qualifier. For example "full" and "notice".

Identifier Uniqueness Considerations:
The designated contact shall be responsible for reviewing and
enforcing uniqueness.

Identifier Persistence Considerations:
Once a name has been allocated it MUST NOT be re-allocated for a
different purpose. The rules provided for assignments of values

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within a sub-namespace MUST be constructed so that the meaning of
values cannot change. This registration mechanism is not
appropriate for naming values whose meaning may change over time.

Registration format:
An event registration MUST include the following fields:

* Event Uri

* Descriptive Name

* Reference to event definition

Initial values to be added to the SCIM Events Registry
Section 7.3.

7.3. Initial Events Registry

Summary of Event URI registrations:

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Table 1

8. References

8.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<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, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.

[RFC7240] Snell, J., "Prefer Header for HTTP", RFC 7240,
DOI 10.17487/RFC7240, June 2014,
<https://www.rfc-editor.org/info/rfc7240>.

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[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <https://www.rfc-editor.org/info/rfc7515>.

[RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)",
RFC 7516, DOI 10.17487/RFC7516, May 2015,
<https://www.rfc-editor.org/info/rfc7516>.

[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<https://www.rfc-editor.org/info/rfc7519>.

[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, September
2015, <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,
September 2015, <https://www.rfc-editor.org/info/rfc7644>.

[RFC8141] Saint-Andre, P. and J. Klensin, "Uniform Resource Names
(URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017,
<https://www.rfc-editor.org/info/rfc8141>.

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.

[RFC8417] Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari,
"Security Event Token (SET)", RFC 8417,
DOI 10.17487/RFC8417, July 2018,
<https://www.rfc-editor.org/info/rfc8417>.

[RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", STD 97, RFC 9110,
DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/info/rfc9110>.

[SUBID] Ed, A. B., Scurtescu, M., and P. Jain, "Subject
Identifiers for Security Event Tokens (Draft 18)", 24 June
2023.

8.2. Informative References

[Kafka] Apache Software Foundation, "Apache Kafka", 2017.

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[RFC3259] Ott, J., Perkins, C., and D. Kutscher, "A Message Bus for
Local Coordination", RFC 3259, DOI 10.17487/RFC3259, April
2002, <https://www.rfc-editor.org/info/rfc3259>.

[RFC6120] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 6120, DOI 10.17487/RFC6120,
March 2011, <https://www.rfc-editor.org/info/rfc6120>.

[RFC7520] Miller, M., "Examples of Protecting Content Using JSON
Object Signing and Encryption (JOSE)", RFC 7520,
DOI 10.17487/RFC7520, May 2015,
<https://www.rfc-editor.org/info/rfc7520>.

[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.

[RFC8935] Backman, A., Ed., Jones, M., Ed., Scurtescu, M., Ansari,
M., and A. Nadalin, "Push-Based Security Event Token (SET)
Delivery Using HTTP", RFC 8935, DOI 10.17487/RFC8935,
November 2020, <https://www.rfc-editor.org/info/rfc8935>.

[RFC8936] Backman, A., Ed., Jones, M., Ed., Scurtescu, M., Ansari,
M., and A. Nadalin, "Poll-Based Security Event Token (SET)
Delivery Using HTTP", RFC 8936, DOI 10.17487/RFC8936,
November 2020, <https://www.rfc-editor.org/info/rfc8936>.

[RFC9113] Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113,
DOI 10.17487/RFC9113, June 2022,
<https://www.rfc-editor.org/info/rfc9113>.

[SSWG] Tulshibagwale, A., Cappalli, T., Scurtescu, M., Backman,
A., and J. Bradley, "OpenID Shared Signals and Events
Framework Specification 1.0 - draft 01", 8 June 2021.

Cappalli, T. and A. Tulshibagwale, "OpenID Continuous
Access Evaluation Profile 1.0 - draft 02", 8 June 2021.

Appendix A. Use Cases

SCIM Events may be used in a number of ways. The following non-
normative sections describe some of the expected uses.

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A.1. Domain Based Replication

The objective of "Domain Based Replication" events (DBR) is to
synchronize resource changes between SCIM service providers in a
common administrative domain. In this mode, complete information
about changes for resources are shared between replicas for immediate
processing.

┌────────────────┐
┌────────┐ │SCIM │ ┌────────────────────────┐
│Client A│ │Service Provider│ │Service Provider Replica│
└───┬────┘ └───────┬────────┘ └───────────┬────────────┘
│ "SCIM Operation" ┌┴┐ │
│ ────────────────────>│ │ │
│ │ │ │
│ "SCIM Response" │ │ ┌┴┐
│ <────────────────────│ │ │ │
│ └┬┘ │ │
│ │ "Event SCIM:prov:<op>│ │
│ │ id:xyz" │ │
│ │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─>│ │
│ │ │ │
│ │ │ │
│ │ │ │────┐
"Update local node"│ │ │
│ │<───┘
└┬┘

Figure 23: Domain Based Replication Sequence

From a security perspective, it is assumed that servers sharing DBR
events are secured by a common access policy and all servers are
required to be up-to-date. From a Privacy Perspective, because all
servers are in the same administrative domain, the primary objective
is to keep individual service provider nodes or cluster synchronized.

A.2. Co-ordinated Provisioning

In "Co-ordinated Provisioning" (CP), SCIM resource change events
perform the function of change notification without the need to
provide raw data. In any Event Publisher and Receiver relationship,
the set of SCIM resources (e.g. Users) that are linked or co-
ordinated is managed within the context of an event feed and which
MAY be a subset of the total set of resources on either side. For
example, an event feed could be limited to users who have consented
to the sharing of information between domains. To support
capability, "feed" specific events are defined to indicate the
addition and removal of SCIM resources from a feed. For example,

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when a user consents to the sharing of information between domains,
events about the User MAY be added to the feed between the Event
Publisher and Receiver.

┌────────────────┐ ┌──────────────┐ ┌─────────────┐
┌───────────┐ │SCIM │ │Client A │ │Co-op Action │
│SCIM Client│ │Service Provider│ │Co-op Receiver│ │Endpoint │
└─────┬─────┘ └───────┬────────┘ └──────┬───────┘ └───────┬─────┘
│ "SCIM Ope" ┌┴┐ │ │
│──────────────>│ │ │ │
│ │ │ │ │
│ "SCIM Resp" │ │ ┌┴┐ │
│<──────────────│ │ │ │ │
│ │ │ │ │ │
│ │ │ │ │ │
│ ╔═══════╤╪═╪════════════════╪═╪═════════════════╪════╗
│ ║ LOOP ││ │ │ │ │ ║
│ ╟───────┘└┬┘ Event: │ │ │ ║
│ ║ │ SCIM:prov:<op>│ │ │ ║
│ ║ │ id:xyz │ │ │ ║
│ ║ │ ─ ─ ─ ─ ─ ─ ─ >│ │ │ ║
│ ║ │ │ │ │ ║
│ ║ │ ╔════════════╧═╧══════════════╗ │ ║
│ ║ │ ║Receiver may accumulate ║ │ ║
│ ║ │ ║events for periodic action. ║ │ ║
│ ║ │ ╚════════════╤═╤══════════════╝ │ ║
│ ║ │ SCIM GET <id> │ │ │ ║
│ ║ │ <───────────────│ │ │ ║
│ ║ │ │ │ │ ║
│ ║ │ Filtered │ │ │ ║
│ ║ │ Resource Resp │ │ │ ║
│ ║ │ ───────────────>│ │ │ ║
│ ║ │ │ │ │ ║
│ ║ │ │ │ "Co-ord Action" │ ║
│ ║ │ │ │ ───────────────>│ ║
│ ╚═════════╪═════════════════╪═╪═════════════════╪════╝

Figure 24: Co-Ordinated Provisioning Sequence

In CP mode, the receiver of an event must call back to the
originating SCIM Service Provider (e.g. using a SCIM GET request) to
reconcile the newly changed resource in order to obtain the changes.

Co-ordinated provisioning has the following benefits:

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* Differences in schema (e.g. attributes) between domains. For
example, a receiving domain may only be interested or only be
allowed access to a few attributes (e.g. role based access data)
to enable access to an application.

* Different Event Receivers MAY have differing needs access to
information and thus be assigned varying access rights. Minimal
information events combined with call-backs for data allows data
filtering to be applied.

* Receivers can take independent action. For example deciding which
attributes or resource lifecycle changes to accept. For example,
in the case of a conflict, a receiver can prioritize one domain
source over another.

* A receiver MAY throttle or buffer changes rather than act
immediately on a notification. For example, for a frequently
changing resource, the receiver MAY choose to make scheduled SCIM
GET for resources that have been marked "dirty" by events received
in the last scheduled cycle.

A disadvantage of the CP approach is that it may be considered costly
in the sense that each event received might trigger a call back to
the event issuer. This cost should be weighed against the cost
producing filtered information in each event for each receiver.
Further a receiver is not required to make a call-back on every
provisioning event.

It is assumed that an underlying relationship between domains exists
that permits the exchange of personal information and credentials.
For example the decision to perform SCIM provisioning operations at
the SCIM Service Provider issuing change events, was previously
authorized and appropriate confidentiality and privacy agreements
have been met in cross-domain scenarios. Examples of this might be
services for hire by an employer or a specific consent from an end-
user as part of a online authorization where individual consent was
obtained.

When sharing information between parties, CP Events minimize the
information shared in each message requiring the Security Event
Receiver to call back to the event publisher to retrieve more
information if required. In this way, the Event Publisher is able to
have regular access to information through normal SCIM protocol
access restrictions.

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A.3. Risk Signals

The sharing of risk signals (RS) is used for the purpose of co-
ordinating account change events between a SCIM Service Provider and
another related security service. For example, when a password or
other authentication factor has changed, a receiving security system
can choose to terminate current User sessions to force a re-
authentication against the modified User resource.

These signals MAY also include those described in the OpenID Shared
Signals Working Group Specifications [SSWG].

These events are intended for receivers where there is a prior
relationship on behalf of the users described in the SCIM Service
Provider. The intent of sharing information about security events is
for the purpose of securing a user account and ensuring privacy.

Appendix B. Acknowledgments

Thanks to Morteza Ansari who contributed significantly to draft-hunt-
idevent-scim-00, upon which this draft is based.

The editor would like to thank the participants in the SCIM working
group and the id-event list for their support of this specification.

Appendix C. Change Log

Draft 00 - PH - First WG Draft

Draft 01 - PH - Moved non-normative sections to Appendix, Security
and Privacy Considerations

Draft 02 - PH - Clarifications on Async Events, IANA Considerations

Draft 03 - PH - Fixed Header Field registration to
RFC9110."Preference-Applied" header in async response. Support for
Async Bulk requests. Added IANA SCIM Event Registry

Authors' Addresses

Phil Hunt (editor)
Independent Identity Inc
Email: phil.hunt@independentid.com

Nancy Cam-Winget
Cisco Systems
Email: ncamwing@cisco.com

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Mike Kiser
Sailpoint Technologies
Email: mike.kiser@sailpoint.com

Jen Schreiber
Workday Incorporated
Email: jennifer.winer@workday.com

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