Internet DRAFT - draft-hunt-scim-events
draft-hunt-scim-events
SCIM P. Hunt, Ed.
Internet-Draft IndependentId Inc
Obsoletes: draft-hunt-idevent-scim-00 (if 3 March 2022
approved)
Intended status: Standards Track
Expires: 4 September 2022
SCIM Profile for Security Event Tokens
draft-hunt-scim-events-01
Abstract
This specification profiles the Security Event Token specification,
to define a set of events for SCIM Protocol servers that can be used
for asynchronous transaction confirmations, replication, cross-domain
provisioning co-ordination, and 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
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and may be updated, replaced, or obsoleted by other documents at any
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This Internet-Draft will expire on 4 September 2022.
Copyright Notice
Copyright (c) 2022 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 (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
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Table of Contents
1. Introduction and Overview . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Notational Conventions . . . . . . . . . . . . . . . . . 3
1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . . 3
2. Processing Modes for Events . . . . . . . . . . . . . . . . . 4
2.1. Domain Based Replication . . . . . . . . . . . . . . . . 5
2.2. Co-ordinated Provisioning . . . . . . . . . . . . . . . . 5
2.3. Risk Signals . . . . . . . . . . . . . . . . . . . . . . 7
2.4. Async Requests . . . . . . . . . . . . . . . . . . . . . 8
3. SCIM Events . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. Common Event Attributes . . . . . . . . . . . . . . . . . 9
3.2. SCIM Feed Events . . . . . . . . . . . . . . . . . . . . 10
3.2.1. urn:ietf:params:event:SCIM:feed:add . . . . . . . . . 10
3.2.2. urn:ietf:params:event:SCIM:feed:remove . . . . . . . 11
3.3. SCIM Provisioning Events . . . . . . . . . . . . . . . . 11
3.3.1. urn:ietf:params:event:SCIM:prov:create . . . . . . . 12
3.3.2. urn:ietf:params:event:SCIM:prov:patch . . . . . . . . 13
3.3.3. urn:ietf:params:event:SCIM:prov:put . . . . . . . . . 15
3.3.4. urn:ietf:params:event:SCIM:prov:delete . . . . . . . 17
3.3.5. urn:ietf:params:event:SCIM:prov:activate . . . . . . 18
3.3.6. urn:ietf:params:event:SCIM:prov:deactivate . . . . . 18
3.4. SCIM Signals Events . . . . . . . . . . . . . . . . . . . 18
3.4.1. urn:ietf:params:event:SCIM:sig:authMethod . . . . . . 18
3.4.2. urn:ietf:params:event:SCIM:sig:pwdReset . . . . . . . 19
3.5. Miscellaneous Events . . . . . . . . . . . . . . . . . . 19
3.5.1. urn:ietf:params:event:SCIM:misc:asyncResp . . . . . . 20
4. Event Delivery . . . . . . . . . . . . . . . . . . . . . . . 20
4.1. Security Event Token Signing and Encryption . . . . . . . 20
4.2. Point-to-Point Delivery Over HTTP . . . . . . . . . . . . 21
4.3. Using Message Bus Delivery . . . . . . . . . . . . . . . 22
5. Event Handling . . . . . . . . . . . . . . . . . . . . . . . 23
5.1. Conflict Resolution . . . . . . . . . . . . . . . . . . . 23
5.2. Optimizing Events . . . . . . . . . . . . . . . . . . . . 23
6. Security Considerations . . . . . . . . . . . . . . . . . . . 24
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 24
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
9.1. Normative References . . . . . . . . . . . . . . . . . . 25
9.2. Informative References . . . . . . . . . . . . . . . . . 26
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 27
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 27
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 27
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1. Introduction and Overview
This specification profiles Security Event Tokens (SET) [RFC8417] to
define Security Events and mechanisms for delivery with SCIM Protocol
[RFC7644] systems that can be used for asynchronous transaction
confirmations, replication, cross-domain provisioning co-ordination,
and security signals.
1.1. Requirements Language
The key words "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 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 definitions from the following
specifications:
* Security Event Tokens [RFC8417], and
* System for Cross-Domain Identity Management Protocol [RFC7644].
Additionally, the following terms are defined:
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
Section 2.2.
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DBR
Abbreviation for "Domain Based Replication" as defined in
Section 2.1.
Event Feed
This describes the notion that a feed MAY be individualized per
client. A service provider MAY offer to allow Event Receiver's to
"subscribe" to specific event types or events about specific
resources. If no option is offered, it is assumed the client will
receive all events about all resources.
Event Receiver
A system that receives events for the purpose of subsequent action
(e.g. such as replication), co-ordination of workflow, or
signalling.
Event Publisher
A system that issues SETs based on a change that has occurred at a
SCIM Service Provider. For example, events MAY originate from a
SCIM Create, Modify, or Delete per [RFC7644] request. A SCIM
Service Provider MAY be an Event Publisher or an independent
service that aggregates events into Event Receiver feeds.
Message Bus
Any communications protocol or system that enables a message (e.g.
a SET) to be sent to one or more receivers at the same time.
Typically participants connect to a "bus" rather than in point-to-
point transfer such as SET HTTP Push [RFC8935]. The "bus" takes
care of fault-tolerance, routing, and delivery to recipients.
RS
Abbreviation for "Risk Signals" as defined in Section 2.3.
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. Processing Modes for Events
This specification defines 4 processing modes for SCIM Security
Events that have different objectives, data requirements, and
considerations for using Security Event Tokens.
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2.1. Domain Based Replication
The objective of DBR is to synchronize resource changes between SCIM
replicas in a common administrative domain. In this mode,
information about changes for resources are shared between replicas
for immediate processing. The intention is that every replica node
contains the same information content in a timely fashion.
┌────────────────┐
┌────────┐ │SCIM │ ┌────────────────────────┐
│Client A│ │Service Provider│ │Service Provider Replica│
└───┬────┘ └───────┬────────┘ └───────────┬────────────┘
│ "SCIM Operation" ┌┴┐ │
│ ────────────────────>│ │ │
│ │ │ │
│ "SCIM Response" │ │ ┌┴┐
│ <────────────────────│ │ │ │
│ └┬┘ │ │
│ │ "Event SCIM:prov:<op>│ │
│ │ id:xyz" │ │
│ │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─>│ │
│ │ │ │
│ │ │ │
│ │ │ │────┐
"Update local node"│ │ │
│ │<───┘
└┬┘
Figure 1: Domain Based Replication Sequence
In this mode, replication is a server-to-server process and it is
assumed that access rights between servers is identical. Access to
these messages MUST be limited to communication between replicating
nodes with appropriate authorization. From a Privacy Perspective, it
is assumed that all replicas of the server are in the same
administrative domain and that the sharing of information is
primarily for performance and availability reasons and the sharing
information between replicas does not by itself enable access to new
parties (e.g. where a user may not have consented).
2.2. Co-ordinated Provisioning
In "Co-ordinated Provisioning" (CP), SCIM resource change events are
shared between domains with the restriction that the actual attribute
value data is omitted. In any Event Publisher and Receiver
relationship, the set of SCIM resources that are co-ordinated is
managed within the context of a "Feed" and MAY be a subset of the
total set of resources on either side. To support this, "feed"
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events are defined that indicate the addition and removal of SCIM
resources from a feed. For example, 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 2: 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.
2.3. Risk Signals
The sharing of risk signals (RS) is intended for the purpose of co-
ordinating 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.
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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.
2.4. Async Requests
A SCIM provisioning client MAY wish to request "asynchronous"
processing using the "Prefer Header for HTTP", Section 4.1 [RFC7240].
In this mode, a normal SCIM protocol POST, PUT, PATCH, or DELETE
request is made, and the HTTP Header Prefer is included with the
value respond-async. When a SCIM Client signals respond-async, the
SCIM server response changes to HTTP Status 202 Accepted as defined
in [RFC7231]. The Location header returned is the final resource
location and no payload is present. Following acceptance of an
asynchronous request, a notification of completion can be issued
using the Async Event Notification per Section 3.5.1. The location
returned SHALL correspond to the sub claim in the future Async Event
SET message.
{
┌──────────────┐ ┌────────────────┐
┌────────┐ │Client A │ │SCIM │
│Client A│ │Event Receiver│ │Service Provider│
└───┬────┘ └──────┬───────┘ └───────┬────────┘
│ "SCIM Modify ┌┴┐
│ w/Respond Async" │ │
│ ──────────────────────────────────────────────────>│ │
│ │ │ │
│ "Accepted Status 202" │ │
│ "Location: /Users/xyz" │ │
│ <──────────────────────────────────────────────────│ │
│ │ │ └┬┘
│ │ │ "Event SCIM:misc:asyncResp │
│ │ │ sub: /Users/xyz │
│ │ │ id:xyz, method: PUT" │
│ │ │ <─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─│
│ └┬┘ │
│ "ID: xyz created" │ │
│ <─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ │
Figure 3: Asychronous Request Sequence
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3. SCIM Events
A SCIM event is a message, in the form of a Security Event Token
[RFC8417], that conveys information about changes that have occurred
at a SCIM Service Provider that may be of interest to a receiving
system. Examples of events include:
* Resource lifecycle events including creation, activation,
deactivation, and removal of a resource.
* Risk signal events (e.g. password reset, authentication factor
change) which may be used by a receiver to take a security
response such as resetting or revoking current user sessions and
tokens.
* A Password update event is used to securely distribute a hashed
value in an administrative domain.
* A Async Event is used to acknowledge completion status of an
Asynchronous SCIM Request.
3.1. Common Event Attributes
The following attributes are available for all events defined. The
values are contained within the event payload per Section 2
[RFC8417].
id
A SCIM id attribute identifying the SCIM Service Provider's
resource that was modified. This value is required.
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.
txn
For the purposes of SCIM, this SET claim should be used to
identify unique transactions originating at a SCIM Service
Provider. The purpose is to detect duplicate transactions that
may have been received. If not provided, the SET jti claim MAY be
used. The difference is that txn identifies uniqueness within a
SCIM Service Provider whereas JTI only identifies a unique JWT
token.
data
Defined in SCIM Bulk Operations, Section 3.7 [RFC7644], contains
the information necessary to propagate the transaction to the
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receiving node. 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
An array of attributes that were added, revised, or removed. For
example:
"attributes": ["username","emails"]
Depending on the Processing Mode or Event definition, usually only
one of data or attributes is provided.
The sub claim SHALL hold the SCIM Service Provider's Resource URI
value of the affected object. Note: that the SCIM Bulk path
attribute is SHALL NOT be used as this duplicates the sub claim.
This specifications defines a new schema URI prefix
urn:ietf:params:event:SCIM which is used as the prefix for the
following defined SCIM Events.
3.2. SCIM Feed Events
This section defines events related to notices about which resources
are being added or removed from an event feed. These events are 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:event:SCIM:feed
3.2.1. urn:ietf:params:event:SCIM: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.
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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2b2f880af6674ac284bae9381673d462",
"txn": "b7b953f11cc6489bbfb87834747cc4c1",
"events":{
"urn:ietf:params:event:SCIM:feed:add": {
"id":"2b2f880af6674ac284bae9381673d462"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 4: Example SCIM Feed Add Event
3.2.2. urn:ietf:params:event:SCIM: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.
{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2b2f880af6674ac284bae9381673d462",
"events":{
"urn:ietf:params:event:SCIM:feed:remove": {
"id": "2b2f880af6674ac284bae9381673d462"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 5: Example SCIM Feed Remove Event
3.3. SCIM Provisioning Events
This section defines provisioning events 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:event:SCIM:prov
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3.3.1. urn:ietf:params:event:SCIM:prov:create
Indicates a new SCIM resource has been created by the SCIM Service
Provider and has been added to the Event Feed. Note that when a
create event is sent, a corresponding
urn:ietf:params:event:SCIM:feed:add event SHOULD NOT be issued in the
same feed. In DBR mode mode, all claims of the new resource are
included. In CP mode, the attributes returned discloses what
attributes were created at the publisher. In DBR mode, the set of
values reflecting the final state of the resource at the service
provider are provided using the "data" attribute. Note that because
this is a replication request, the id attribute that was assigned by
the SCIM Service Provider is shared so that all replicas in the
domain use the same resource identifier.
{
"jti": "4d3559ec67504aaba65d40b0363faad8",
"iat": 1458496404,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754",
"https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7"
],
"sub": "/Users/44f6142df96bd6ab61e7521d9",
"events":{
"urn:ietf:params:event:SCIM:prov:create":{
"id":"44f6142df96bd6ab61e7521d9",
"externalId":"jdoe",
"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 6: Example SCIM Create (Domain Replication Mode)
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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": "/Users/44f6142df96bd6ab61e7521d9",
"events": {
"urn:ietf:params:event:SCIM:prov:create": {
"id": "44f6142df96bd6ab61e7521d9",
"externalId": "jdoe",
"attributes": [
"id",
"name",
"userName",
"password",
"emails"
]
}
}
}
Figure 7: Example SCIM Create Event (CP Mode)
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.
3.3.2. urn:ietf:params:event:SCIM:prov:patch
The specified resource has been updated using SCIM PATCH. When in
DBR mode, the data attribute contains the PATCH Request body. In CP
mode, only the modified attribute name is included.
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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Groups/acbf3ae7-8463-...-9b4da3f908ce",
"events":{
"urn:ietf:params:event:SCIM:prov:patch": {
"id": "acbf3ae7-8463-...-9b4da3f908ce",
"externalId":"crmUsers",
"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 8: Example SCIM Patch Event (DBR Mode)
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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Groups/acbf3ae7-8463-...-9b4da3f908ce",
"events":{
"urn:ietf:params:event:SCIM:prov:patch": {
"id": "acbf3ae7-8463-...-9b4da3f908ce",
"externalId":"crmUsers",
"attributes": ["members"],
"version": "a330bc54f0671c9"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 9: Example SCIM Patch Event (CP Mode)
3.3.3. urn:ietf:params:event:SCIM:prov:put
The specified resource has been updated (e.g. one or more attributes
has changed). In DBR mode, the SCIM PUT request body is included in
the data attribute; or, In CP mode the modified attributes are listed
using attributes.
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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2819c223-7f76-453a-919d-413861904646",
"events":{
"urn:ietf:params:event:SCIM:prov:patch": {
"id": "2819c223-7f76-453a-919d-413861904646",
"version": "a330bc54f0671c9",
"data": {
"schemas":["urn:ietf:params:scim:schemas:core:2.0:User"],
"id":"2819c223-7f76-453a-919d-413861904646",
"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 10: Example SCIM Put Event (DBR Mode)
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{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2819c223-7f76-453a-919d-413861904646",
"events":{
"urn:ietf:params:event:SCIM:prov:patch": {
"id": "2819c223-7f76-453a-919d-413861904646",
"version": "a330bc54f0671c9",
"attributes": ["userName","externalId","name","roles","emails"]
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 11: Example SCIM Put Event (CP Mode)
3.3.4. urn:ietf:params:event:SCIM:prov:delete
The specified resource has been deleted from the SCIM publisher. The
resource is also removed from the feed. When a DELETE is sent, a
corresponding feedRemove is not issued. A delete event has minimal
disclosure profile only.
{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2b2f880af6674ac284bae9381673d462",
"events":{
"urn:ietf:params:event:SCIM:prov:delete": {
"id": "2b2f880af6674ac284bae9381673d462",
"externalId": "jDoe"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 12: Example SCIM Delete Event
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3.3.5. urn:ietf:params:event:SCIM:prov:activate
The specified resource (e.g. User) has been activated. This event
indicates a high-level change in state as agreed between the Event
Publisher and Event Receiver. For example, an activated resource is
one that can now have an active session (may log in) from a security
perspective.
{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/2b2f880af6674ac284bae9381673d462",
"events":{
"urn:ietf:params:event:SCIM:prov:activate": {
"id": "2b2f880af6674ac284bae9381673d462"
}
},
"iat": 1458505044,
"iss":"https://scim.example.com",
"aud":[
"https://scim.example.com/Feeds/98d52461fa5bbc879593b7754"
]
}
Figure 13: Example SCIM Activate Event
3.3.6. urn:ietf:params:event:SCIM:prov:deactivate
The specified resource (e.g. User) has been deactivated and
disabled. The exact meaning must 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.
3.4. SCIM Signals Events
This section defines security signal events that have occured within
a SCIM Service Provider.The URI prefix for these events is:
urn:ietf:params:event:SCIM:signal
3.4.1. urn:ietf:params:event:SCIM: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.
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{
"jti": "3d0c3cf797584bd193bd0fb1bd4e7d30",
"sub": "/Users/44f6142df96bd6ab61e7521d9",
"events":{
"urn:ietf:params:event:SCIM:sig:authMethod": {
"id": "44f6142df96bd6ab61e7521d9"
}
},
"iat": 1458496025,
"iss": "https://scim.example.com"
}
Figure 14: Example SCIM Authentication Factor Change Event
3.4.2. urn:ietf:params:event:SCIM: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": "/Users/44f6142df96bd6ab61e7521d9",
"events": {
"urn:ietf:params:event:SCIM:sig:pwdReset": {
"id": "44f6142df96bd6ab61e7521d9"
}
},
"iat": 1458496025,
"iss": "https://scim.example.com",
"aud":[
"https://jhub.example.com/Feeds/98d52461fa5bbc879593b7754",
"https://jhub.example.com/Feeds/5d7604516b1d08641d7676ee7"
]
}
Figure 15: Example SCIM Password Change Event
3.5. Miscellaneous Events
This section defines events related miscellaneous events such as
Asynchronous Request complettion that have occured within a SCIM
Service Provider. The URI prefix for these events is:
urn:ietf:params:event:SCIM:misc
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3.5.1. urn:ietf:params:event:SCIM:misc:asyncResp
This event signals the completion of a SCIM request. The 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.
{
"jti": "6164f3bbf6ff41a88dc94f18cb0620e8",
"sub": "/Users/b7c14771-226c-4d05-8860-134711653041",
"txn": "7880fc68a2f0428ebbb5a906e5aeae53",
"events":{
"urn:ietf:params:event:SCIM:misc:asyncResp": {
"id":"b7c14771-226c-4d05-8860-134711653041",
"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
4. Event Delivery
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 [RFC7540], and Message Buses (e.g. [RFC3259], Apache
Kafka [Kafka]). This draft discusses 2 general delivery methods:
Message Bus and Point-to-Point.
4.1. 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 unsecurity, 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
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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
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 securable (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 mesage itself.
4.2. 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.
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* 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.
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 can be used 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.
4.3. Using Message Bus Delivery
Security Event Tokens MAY be delivered using a message bus. While
this draft will not talk about any particular message bus, it will
discuss the pros and cons for message buses in general and any
anticipated issues and requirements.
Message buses have the following advantages:
* Connection management and credentials may be greatly simplified as
participants only need to authenticate to the "bus" to issue and
receive events.
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* Message buses can have "broadcast" features that are able to
deliver the same event to many recipients such as in a global
deployment of replicated SCIM servers. Issuers save resources by
only having to publish once to a bus rather than to each receiver
directly.
* Depending on the implementation, a Message Bus can be used as a
buffer and in some cases for data recovery. For example, some
buses may have infinite retention of events.
* Message-buses can support bi-directional and other more complex
flow relationships (e.g. sharding).
Message buses may have following disadvantages:
* A message bus may have some delivery delays (seconds to minutes)
when compared to point-to-point systems.
* Message buses may require significant infrastructure commitments
in order to meet delivery reliability. However it may also be
true that a point-to-point system may also impose significant
resource requirements requiring a SCIM service provider to assume
the same work.
* Multi-issuer scenarios may require more conflict resolution
processing. E.g. such as prioritizing specific nodes as "masters"
for specific SCIM attributes.
5. Event Handling
5.1. Conflict Resolution
In scenarios where there may be multiple issuers of SCIM Events, it
becomes possible that conflicts can arise when the same version of a
resource is modified by multiple parties.
Editors note: TO BE COMPLETED
5.2. Optimizing Events
In cases where resources change frequently, SCIM Service Providers
MAY choose to release events on an interval basis in order to reduce
traffic. For example, a large Group with millions of members may
have hundreds of changes per minute. For optimization, a SCIM
Service Provider MAY choose to issue a cumulative event once per
minute instead of for each change event.
Editors note: TO BE COMPLETED
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6. Security Considerations
[[TO BE COMPLETED]]
7. Privacy Considerations
[[TO BE COMPLETED]]
8. IANA Considerations
This section registers the schema extensions found in Section 3 in
the "Event" registry as per Section 4.2 [RFC8417].
Schema URI: SeeSection 3.
Schema Name: See corresponding names underSection 3.
Intented ResourceType: N/A. Events are not intended to be persisted
in SCIM.
Purpose: See each description inSection 3.
Single-valued Attributes: None.
Multi-valued Attributes: All schemas in this specification share the
same attributes. SeeSection 3.1.
Summary of schema URI registrations:
+==========================================+==============+=========+
|Schema URI |Name |Reference|
+==========================================+==============+=========+
|urn:ietf:params:event:SCIM:feed:add |Resource added|Section |
| |to Feed Event |3.2.1 |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:feed:remove |Remove resouce|Section |
| |From Feed |3.2.2 |
| |Event | |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:prov:create |New Resource |Section |
| |Event |3.3.1 |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:prov:patch |Resource Patch|Section |
| |Event |3.3.2 |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:prov:put |Resource Put |Section |
| |Event |3.3.3 |
+------------------------------------------+--------------+---------+
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|urn:ietf:params:event:SCIM:prov:delete |Resource |Section |
| |Deleted Event |3.3.4 |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:prov:activate |Resource |Section |
| |Activated |3.3.5 |
| |Event | |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:prov:deactivate|Resource |Section |
| |Deactivated |3.3.6 |
| |Event | |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:sig:authMethod |New |Section |
| |authentication|3.4.1 |
| |method added | |
+------------------------------------------+--------------+---------+
|urn:ietf:params:event:SCIM:sig:pwdReset |Password Reset|Section |
| |Event |3.4.2 |
+------------------------------------------+--------------+---------+
Table 1
9. References
9.1. 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>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>.
[RFC7240] Snell, J., "Prefer Header for HTTP", RFC 7240,
DOI 10.17487/RFC7240, June 2014,
<https://www.rfc-editor.org/info/rfc7240>.
[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>.
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[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>.
[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>.
[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>.
[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>.
[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.
9.2. Informative References
[Kafka] Apache Software Foundation, "Apache Kafka", 2017.
[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>.
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[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>.
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015,
<https://www.rfc-editor.org/info/rfc7540>.
[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>.
Appendix A. 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 the SCIM
working group and the id-event list for their support of this
specification.
Appendix B. Change Log
Draft 00 - PH - First Draft
Author's Address
Phil Hunt (editor)
Independent Identity Inc
Email: phil.hunt@independentid.com
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