Security Event Token (SET)
draft-hunt-idevent-token-02

Abstract

This specification defines the Security Event token which may be distributed via a protocol such as HTTP. A Security Event Token (SET) is based on the JSON Web Token and may be optionally signed and/or encrypted. A SET describes a statement of fact that may be shared by an event publisher with registered subscribers.

Status of This Memo

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

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on February 12, 2017.

Copyright Notice

Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

• 1. Introduction and Overview
• 1.1. Notational Conventions
• 1.2. Definitions
• 2. Events
• 2.1. Core Event Attributes
• 2.2. Security Event Token Construction
• 3. Security Considerations
• 4. Privacy Considerations
• 5. IANA Considerations
• 6. References
• 6.1. Normative References
• 6.2. Informative References
• Appendix A. Contributors
• Appendix B. Acknowledgments
• Appendix C. Change Log
• Authors' Addresses

1. Introduction and Overview

This specification defines an extensible security event token (SET) format which may be exchanged using protocols such as HTTP. The specification builds on the JSON Web Token format [RFC7519] in order to provide a self-contained token that can be optionally signed using JSON Web Signature [RFC7515] and/or encrypted using JSON Web Encryption [RFC7516].

For the purpose of this specification an event is a statement of fact by a publisher (also known as the event issuer) that the state of a security subject (e.g. a web resource, token, IP address) it controls or is aware of, has changed in some way (explicitly or implicitly). A security subject may be permanent (e.g. a User account) or temporary (e.g. a login session) in nature. A state change may include direct changes of entity state, implicit changes to state or other higher-level security statements such as:

• The creation, modification, removal of a resource.
• The reseting or suspension of an account.
• The revoking of a security token prior to its expiry.
• The logout of a user session. Or,
• A cumulative conclusion such as to indicate that a user has taken over an email identifier that may have been used in the past by another user.

Based on some agreed upon criteria for an event feed, the publisher distributes events to the appropriate subscribers. While an event may be delivered via synchronous means (e.g. HTTP POST), the distribution of the event often happens asynchronously to the change of state which generated the security event. As an example, an OAuth2 Authorization server [RFC6749], having received a token revocation request [RFC7009], may issue a token revocation event to downstream web resource providers. Having been informed of a token revocation, the OAuth2 web resource service provider may add the token identifier to its local revocation list assuming the token has not already expired.

A subscriber having received an event, validates and interprets the event and takes its own independent action, if any. For example, having been informed of a personal identifier now being associated with a different security subject (i.e. is being used by someone-else), the subscriber may choose to ensure that the new user is not granted access to resources associated with the previous user. Or it may not have any relationship with the subject and no action is taken.

While subscribers will often take actions upon receiving one or more events, events MUST NOT be assumed to be commands or requests. To do so requires complex bi-directional signals and error recovery mechanisms which fall outside the scope of this specification. The intent of this specification is to define a way of exchanging statements of fact that subscribers may interpret for their own purposes. Since events are typically historical statements by a publisher and are not commands, idempotency or lack there of, does not apply.

Unless otherwise specified, this specification uses example events intended as non-normative examples showing how an event may be used. It is expected that other specifications will use this specification to define normative events.

This specification is scoped to security and identity related events. While event tokens may be used for other purposes, the specification only considers security and privacy concerns relevant to identity and personal information.

1.1. Notational Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. These keywords are capitalized when used to unambiguously specify requirements of the protocol or application features and behavior that affect the inter-operability and security of implementations. When these words are not capitalized, they are meant in their natural-language sense.

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

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

1.2. Definitions

The following definitions are used with Identity Events:

Feed Publisher

The Feed Publisher provides events to be distributed to registered subscribers. In JWT terminology, the Feed Publisher is also known as the issuer iss).

Event

An event is a security event token that is a statement that is to be distributed to one or more registered subscribers. An event is constructed as a JWT token and MAY be signed or encrypted using JWS/JWE for authentication and confidentiality reasons.

Feed

A feed a logical grouping of events or a context under which events may be issued. An interested client registers with the Feed Publisher to subscribe to events associated with a feed. How a feed is defined or the method for subscription is out-of-scope of this specification.

Subscriber

A Subscriber registers to receive event notifications from a Feed Publisher using a protocol such as HTTP. The method of registration and delivery is out-of-scope of this specification.

Security Subject

The security subject about which the event is about. A security subject may be a principle (e.g. Section 4.1.2 [RFC7519]), a web resource, or other thing such as an IP address about which an Event is about.

2. Events

A SET conveys a statement (in the form of a JWT token [RFC7519]) about a Security Subject that may be of interest to a subscriber or set of subscribers receiving events from a Feed Publisher.

The schema and structure of an event follows the JWT [RFC7519] specification. An event token has the following characteristics: iss and aud, an SET contains the attribute events with at least one URI value used to indicate the type of event that has occurred and what information (attributes) may be present in the event token. and what type of event (e.g. resource modified) is contained in the event token.

• a common set of attributes common to every event at the top level including an events attribute describing the type of event, and
• one or more JSON sub-objects that attributes associated with an event URI value. The attributes to be included with any particular event are to be defined by the event as specified by the event URI value in the events attribute.

In addition to the JWT attributes

An event MAY contain an attribute for each value of events whose value is a JSON object (also known as an event extension object) that contains additional attributes relevant to the specified event URI. For example, many events will include an iss that identifies the context of the Security Subject being reported (as distinct from the issuer of the SET), and a sub or jti or some other attribute that uniquely identifies the Security Subject.

{ 
  "jti": "3d0c3cf797584bd193bd0fb1bd4e7d30",
  "events":[
    "urn:ietf:params:scim:event:passwordReset",
    "https://example.com/scim/event/password"
  ],
  "iat": 1458496025,
  "iss": "https://scim.example.com",  
  "aud":[
    "https://jhub.example.com/Feeds/98d52461fa5bbc879593b7754",
    "https://jhub.example.com/Feeds/5d7604516b1d08641d7676ee7"
  ],  
  "urn:ietf:params:scim:event:passwordReset":{
    "id":"44f6142df96bd6ab61e7521d9",
    "sub": 
      "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9"
  },
  "https://example.com/scim/event/password":{
     "resetAttempts":5
  }
}

{
  "iss": "https://server.example.com",
  "aud": "s6BhdRkqt3",
  "jti": "3d0c3cf797584bd193bd0fb1bd4e7d30",
  "iat": 1458668180,
  "exp": 1458668580,
  "events": [
    "https://specs.openid.net/logout"
  ],
  "https://specs.openid.net/logout": {
    "iss": "https://token.example.com",
    "sub": "248289761001",
    "jti": "08a5019c-17e1-4977-8f42-65a12843ea02"
  }
}

{ 
  "jti": "fb4e75b5411e4e19b6c0fe87950f7749",
  "events":[
    "https://openid.net/heart/consent.html"
  ],
  "iat": 1458496025,
  "iss": "https://my.examplemed.com",  
  "aud":[
    "https://examplemedlab/Feeds/98d52461fa5bbc879593b7754"
  ],  
  "https://openid.net/heart/consent":{
    "iss": "https://token.example.com",
    "sub": "248289761001",
    "consentUri":[
      "https://terms.examplemed.com/labdisclosure.html#Agree"
    ]
  }
}

{  
  "jti": "4d3559ec67504aaba65d40b0363faad8",
  "iat": 1458496404,
  "iss": "https://scim.example.com",  
  "aud":[
   "https://scim.example.com/Feeds/98d52461fa5bbc879593b7754",
   "https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7"
  ],  
  
  "events":[
    "urn:ietf:params:scim:event:create"
  ],
  "urn:ietf:params:scim:event:create":{
    "ref": "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9",
    "attributes":["id","name","userName","password","emails"],
    "values":{
      "emails":[
       {"type":"work","value":"jdoe@example.com"}
      ],
      "password":"not4u2no",
      "userName":"jdoe",
      "id":"44f6142df96bd6ab61e7521d9",
      "name":{
        "givenName":"John",
        "familyName":"Doe"
      }
    }  
  }
}

{"alg":"none"}

eyJhbGciOiJub25lIn0
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eyJhbGciOiJub25lIn0
.
eyAgCiAgImp0aSI6ICI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsCiAg
ImlhdCI6IDE0NTg0OTY0MDQsCiAgImlzcyI6ICJodHRwczovL3NjaW0uZXhhbXBsZS5j
b20iLCAgCiAgImF1ZCI6WwogICAiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0ZlZWRz
Lzk4ZDUyNDYxZmE1YmJjODc5NTkzYjc3NTQiLAogICAiaHR0cHM6Ly9zY2ltLmV4YW1w
bGUuY29tL0ZlZWRzLzVkNzYwNDUxNmIxZDA4NjQxZDc2NzZlZTciCiAgXSwgIAogIAog
ICJldmVudHMiOlsKICAgICJ1cm46aWV0ZjpwYXJhbXM6c2NpbTpldmVudDpjcmVhdGUi
CiAgXSwKICAidXJuOmlldGY6cGFyYW1zOnNjaW06ZXZlbnQ6Y3JlYXRlIjp7CiAgICAi
cmVmIjogImh0dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9Vc2Vycy80NGY2MTQyZGY5NmJk
NmFiNjFlNzUyMWQ5IiwKICAgICJhdHRyaWJ1dGVzIjpbImlkIiwibmFtZSIsInVzZXJO
YW1lIiwicGFzc3dvcmQiLCJlbWFpbHMiXSwKICAgICJ2YWx1ZXMiOnsKICAgICAgImVt
YWlscyI6WwogICAgICAgeyJ0eXBlIjoid29yayIsInZhbHVlIjoiamRvZUBleGFtcGxl
LmNvbSJ9CiAgICAgIF0sCiAgICAgICJwYXNzd29yZCI6Im5vdDR1Mm5vIiwKICAgICAg
InVzZXJOYW1lIjoiamRvZSIsCiAgICAgICJpZCI6IjQ0ZjYxNDJkZjk2YmQ2YWI2MWU3
NTIxZDkiLAogICAgICAibmFtZSI6ewogICAgICAgICJnaXZlbk5hbWUiOiJKb2huIiwK
ICAgICAgICAiZmFtaWx5TmFtZSI6IkRvZSIKICAgICAgfQogICAgfSAgCiAgfQp9
.