Internet DRAFT - draft-hardt-gnap-advanced
draft-hardt-gnap-advanced
Network Working Group D. Hardt, Ed.
Internet-Draft SignIn.Org
Intended status: Standards Track 15 August 2020
Expires: 16 February 2021
The Grant Negotiation and Authorization Protocol - Advanced Features
draft-hardt-gnap-advanced-01
Abstract
TBD
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Grant Management APIs . . . . . . . . . . . . . . . . . . . . 4
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2.1. List Grants . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Update Grant . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Delete Grant . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Grant Options . . . . . . . . . . . . . . . . . . . . . . 5
3. Authorization Management APIs . . . . . . . . . . . . . . . . 5
3.1. Update Access . . . . . . . . . . . . . . . . . . . . . . 6
3.2. Delete Access . . . . . . . . . . . . . . . . . . . . . . 6
3.3. Access Options . . . . . . . . . . . . . . . . . . . . . 6
4. Reciprocal Grant . . . . . . . . . . . . . . . . . . . . . . 7
5. GS Initiated Grant . . . . . . . . . . . . . . . . . . . . . 8
6. User Exists . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Multiple Interactions . . . . . . . . . . . . . . . . . . . . 10
8. Error Responses . . . . . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
11. Security Considerations . . . . . . . . . . . . . . . . . . . 12
12. Normative References . . . . . . . . . . . . . . . . . . . . 12
Appendix A. Document History . . . . . . . . . . . . . . . . . . 12
A.1. draft-hardt-gnap-advanced-00 . . . . . . . . . . . . . . 12
A.2. draft-hardt-gnap-advanced-01 . . . . . . . . . . . . . . 13
Appendix B. GS API Table . . . . . . . . . . . . . . . . . . . . 13
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
This document includes additional features for the Grant Negotiation
and Authorization Protocol (GNAP) [GNAP], and presumes familiarity
and knowledge of GNAP.
*Terminology*
This document uses the following terms defined in [GNAP]:
* authN
* authZ
* Access
* Access URI
* Claim
* Grant Client (GC)
* Registered Client
* Grant
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* Grant Server (GS)
* Grant URI
* Grant Request
* Grant Response
* GS URI
* Interaction
* NumericDate
* Resource Owner (RO)
* Resource Server (RS)
* User
*Notational Conventions*
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
specification are to be interpreted as described in [RFC2119].
Certain security-related terms are to be understood in the sense
defined in [RFC4949]. These terms include, but are not limited to,
"attack", "authentication", "authorization", "certificate",
"confidentiality", "credential", "encryption", "identity", "sign",
"signature", "trust", "validate", and "verify".
Unless otherwise noted, all the protocol parameter names and values
are case sensitive.
Some protocol parameters are parts of a JSON document, and are
referred to in JavaScript notation. For example, foo.bar refers to
the "bar" boolean attribute in the "foo" object in the following
example JSON document:
{
"foo" : {
"bar": true
}
}
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2. Grant Management APIs
In addition to creating and reading a Grant as specified in GNAP The
GC MAY list, update, delete, and discover a Grant.
2.1. List Grants
The GC MAY list the Grants provided to the GC by doing an a GET on
the GS URI. The GS MUST respond with a list of Grant URIs [ format
TBD] or one of the following errors:
* TBD
from Error Responses Section 8.
2.2. Update Grant
The GC updates a Grant by doing an HTTP PUT of a JSON document to the
corresponding Grant URI.
The JSON document MUST include the following from the [GNAP] Grant
Request JSON:
* iat
* uri set to the Grant URI
and MAY include the following from the [GNAP] Grant Request JSON:
* user
* interaction
* authorization or authorizations
* claims
The GS MUST respond with one of the standard GNAP responses (Grant
Response, Interaction Response, Wait Response) or one of the
following errors:
* TBD
from Error Responses Section 8.
Following is a non-normative example where the GC wants to update the
Grant Request with additional claims:
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{
"iat" : 15790460234,
"uri" : "https://as.example/endpoint/grant/example3",
"claims": {
"oidc": {
"userinfo" : {
"email" : { "essential" : true },
"name" : { "essential" : true },
"picture" : null
}
}
}
}
2.3. Delete Grant
The GC deletes a Grant by doing an HTTP DELETE of the corresponding
Grant URI.
The GS MUST respond with OK 200, or one of the following errors:
* TBD
from Error Responses Section 8.
2.4. Grant Options
The GC can get the supported operations for a Grant by doing an HTTP
OPTIONS of the corresponding Grant URI.
The GS MUST respond with the supported methods
[Format TBD]
or one of the following errors:
* TBD
from Error Responses Section 8.
3. Authorization Management APIs
In addition to reading an Authorization as specified in [GNAP], The
GC MAY update, delete, and discover an Authorization.
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3.1. Update Access
The GC updates an Authorization by doing an HTTP PUT to the
corresponding Access URI of the following JSON. All of the following
MUST be included.
* *iat* - the time of the request as a NumericDate.
* *uri* - the Access URI.
* *access* - the new access requested per the [GNAP] Grant Request
JSON "access" object.
The GS MUST respond with a GNAP Access JSON document, or one of the
following errors:
* TBD
from Error Responses Section 8.
3.2. Delete Access
The GC deletes an Access by doing an HTTP DELETE to the corresponding
Access URI.
The GS MUST respond with OK 200, or one of the following errors:
* TBD
from Error Responses Section 8.
A GS MAY indicate support for this feature by including the "DELETE"
method in the Access URI OPTIONS response.
3.3. Access Options
The GC can get the supported operations for an Access by doing an
HTTP OPTIONS of the corresponding Access URI.
The GS MUST respond with the supported methods
[Format TBD]
or one of the following errors:
* TBD
from Error Responses Section 8.
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4. Reciprocal Grant
Party A and Party B both want to obtain a Grant from the other party.
Each party will be both Grant Client and Grant Server. This would
require two complete GNAP flows with an awkward redirect between
them, and the User may have to authenticate multiple times as context
is lost. Reciprocal Grant simplifies the User experience.
In the following sequence, steps 1 - 7 & 9 are a standard GNAP
sequence.
Party A Party B
+--------+ +--------+
| | | |
| Client |--(1)-- Create Grant A ->| GS |
| | | |
| Client |<--- Interaction ---(2)--| GS |
| | Response | |
| | | |
| Client |--(3)--- Read Grant A -->| GS | +---+
| | | | | U |
| Client |--(4)--- Interaction --- | - - - | ----->| s |
| | Transfer | | | e |
| | | GS |<-(5)->| r |
| | | | authN | |
| | | GS |<-(6)->| |
| | | | authZ | |
| Client |<------- Grant A ---(7)--| GS | +---+
| | Response | |
| | | |
| GS |<- Create Grant B --(8)--| Client |
+---+ | | user.reciprocal | |
| U | | | | |
| s |<------ | - - - | --- Interaction --(9)---| GS |
| e | | | Transfer | |
| r |<-(10)->| GS | | |
| | AuthZ | | | |
+---+ | GS |--(11)-- Grant B ------->| Client |
| | Response | |
+--------+ +--------+
Client = Grant Client
1. *Create Grant A* Party A makes a Create Grant request to the
Party B GS URI.
2. *Interaction Response* Party B returns an interaction response
containing the Grant A URI.
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3. *Read Grant A* Party A does an HTTP GET of the Grant A URI.
4. *Interaction Transfer* Party A transfers User interaction to the
Party B.
5. *User Authentication* Party B authenticates the User.
6. *User Authorization* If required, Party B interacts with the
User to determine which identity claims and/or authorizations in
the Grant A Request are to be granted.
7. *Create GrantB* Party B creates its Grant B Request with
user.reciprocal set to the Grant A URI that will be in the step
(2) Grant A Response, and sends it with an HTTP POST to the
Party A GS URI. This enables Party A to correlate the Grant B
Request and its Grant and the User.
8. *Grant S Response* Party B responds to Party A's Create Grant A
Request with a Grant A Response.
9. *Interaction Transfer* Party B redirects the User to the
Completion URI at Party A.
10. *User Authorization* If required, Party A interacts with the
User to determine which identity claims and/or authorizations in
Party B's Grant B Request are to be granted.
11. *Grant B Response* Party A responds with the Grant B Response.
* *reciprocal* - a new attribute of the [GNAP] Request JSON user
object. MUST be set to a Grant URI.
5. GS Initiated Grant
The User is at the GS, and wants to interact with a Registered
Client. The GC has previously configured an initiation_uri at the
GS, and the Grant it requires.
In this sequence, the GS creates a Grant and redirects the User to
the GC's initiation_uri passing a Grant URI:
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+--------+ +-------+ +------+
| GC | | GS | | User |
| | | |<--(1)-->| |
| | | | | |
| |<----- GS Initiation Redirect --- | - - - | --(2)---| |
| (3) | | | | |
| verify |--(4)--- Read Grant ------------->| | +------+
| | | |
| |<--------- Grant Response --(5)---| |
| | | |
+--------+ +-------+
1. *User Interaction* The GS interacts with the User to determine
the GC and what identity claims and / or authorizations to
provide. The GS creates a Grant and corresponding Grant URI.
2. *GS Initiated Redirect* The GS redirects the User to the GC's
initiation_uri, adding a query parameter with the name
"grant_uri" and the value being the URL encoded Grant URI.
3. *Client Verification* The GC verifies the Grant URI starts with a
GS URI from a GS the GC trusts.
4. *Read Grant* The GC does an HTTP GET of the Grant URI.
5. *Grant Response* The GS responds with a Grant Response.
* *initiation_uri* - a URI at the GC that contains no query or
fragment. How the GS learns the GC initiation_uri and require
Grant is out of scope of this document.
6. User Exists
The GC may want to provide a different experience to the User
depending on if a User already exists at the GS. By including one or
more identifiers in the Grant Request user.identifiers object, and
setting user.exists to true, the GS MAY include a user.exists
attribute in a GNAP Interaction Response. The value is true if the
GS has a user with one or more of the GC provided identifers, and
false if not.
* *exists* - a new attribute of the "user" object. If present in a
GNAP Grant Request, it MUST be set to true.
A GS indicates support for this feature by returning the
features.user_exists attribute in the GS Options response set to
true.
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7. Multiple Interactions
There are situations where the GC can not, or prefers not, to ask for
all identity claims and/or authorizations it requires.
In this example sequence, the GC requests an identity claim to
determine who the User is. Once the GC learns who the User is, the
GC updates the Grant for additional identity claims which the GS
prompts the User for and returns to the GC. Once those additional
claims are received, the GC updates the Grant with the remaining
identity claims required.
+--------+ +-------+
| Client | | GS |
| |--(1)--- Create Grant ----------->| |
| | multi = true | |
| | | |
| |<--- Interaction Response ---(2)--| |
| | multi = true | |
| | | |
| |--(3)--- Read Grant ------------->| | +------+
| | | | | User |
| |--(4)--- Interaction Transfer --- | - - - | ------->| |
| | | | | |
| | | |<--(5)-->| |
| | | | authN | |
| |<--------- Grant Response ---(6)--| | | |
| (7) | | | | |
| eval |--(8)--- Update Grant ----------->| | | |
| | multi = true | |<--(9)-->| |
| | | | authZ | |
| |<--------- Grant Response --(10)--| | | |
| | multi = true | |
| (11) | | | | |
| eval |--(12)-- Update Grant ----------->| | | |
| | multi = false | |<--(13)->| |
| | | | authZ | |
| | | | | |
| |<--- Interaction Transfer --(14)- | - - - | --------| |
| | | | | |
| |<--------- Grant Response --(15)--| | +------+
| | multi = false | |
| | | |
+--------+ +-------+
Client = Grant Client
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1. *Create Grant* The GC creates a Grant Request (CreateGrant)
including an identity claim and interaction.global.multi set to
true, and sends it with an HTTP POST to the GS GS URI.
2. *Interaction Response* The GS sends an Interaction Response
containing the Grant URI and an interaction object, and
interaction.global.multi set to true.
3. *Read Grant* The GC does an HTTP GET of the Grant URI.
4. *Interaction Transfer* The GC transfers User interaction to the
GS.
5. *User Authentication* The GS authenticates the User.
6. *Grant Response* The GS responds with a Grant Response including
the identity claim from User authentication and
interaction.global.multi set to true.
7. *Grant Evaluation* The GC queries its User database and does not
find a User record matching the identity claim.
8. *Update Grant* The GC creates an Update Grant Request
Section 2.2 including the initial identity claims required and
interaction.global.multi set to true, and sends it with an HTTP
PUT to the Grant URI.
9. *User AuthN* The GS interacts with the User to determine which
identity claims in the Update Grant Request are to be granted.
10. *Grant Response* The GS responds with a Grant Response including
the identity claims released by the User and
interaction.global.multi set to true.
11. *Grant Evaluation* The GC evaluates the identity claims in the
Grant Response and determines the remaining User identity claim
required.
12. *Update Grant* The GC creates an Update Grant Request
Section 2.2 including the remaining required identity claims and
interaction.global.multi set to false, and sends it with an HTTP
PUT to the Grant URI.
13. *User AuthZ* The GS interacts with the User to determine which
identity claims in the Update Grant Request are to be granted.
14. *Interaction Transfer* The GS transfers User interaction to the
GC.
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15. *Grant Response* The GS responds with a Grant Response including
the identity claims released by the User and
interaction.global.multi set to false.
* *multi* - a new boolean attribute of the GNAP interaction.global
object.
A GS indicates support for this feature by returning the
features.interaction_multi attribute in the GS Options response set
to true.
8. Error Responses
* TBD
9. Acknowledgments
TBD
10. IANA Considerations
TBD
11. Security Considerations
TBD
12. 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>.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
<https://www.rfc-editor.org/info/rfc4949>.
[GNAP] Hardt, D., "The Grant Negotiation and Authorization
Protocol", June 2020,
<https://tools.ietf.org/html/draft-hardt-xauth-protocol>.
Appendix A. Document History
A.1. draft-hardt-gnap-advanced-00
* Initial version
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A.2. draft-hardt-gnap-advanced-01
* renamed verb to method
* renamed Authorization to Access
* renamed Client to Grant Client (GC)
Appendix B. GS API Table
Below is a consolidated table of GS APIs from [GNAP] and this
document:
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+==============+=============+========+=============================+
| request | http method | uri | response |
+==============+=============+========+=============================+
| Create Grant | POST | GS URI | interaction, |
| | | | wait, or Grant |
+--------------+-------------+--------+-----------------------------+
| List Grants | GET | GS URI | Grant list |
+--------------+-------------+--------+-----------------------------+
| Verify Grant | PATCH | Grant | Grant |
| | | URI | |
+--------------+-------------+--------+-----------------------------+
| Read Grant | GET | Grant | wait, or grant |
| | | URI | |
+--------------+-------------+--------+-----------------------------+
| Update Grant | PUT | Grant | Interaction, |
| | | URI | wait, or Grant |
+--------------+-------------+--------+-----------------------------+
| Delete Grant | DELETE | Grant | success |
| | | URI | |
+--------------+-------------+--------+-----------------------------+
| Read Access | GET | Access | Access |
| | | URI | |
+--------------+-------------+--------+-----------------------------+
| Update | PUT | Access | Access |
| Access | | URI | |
+--------------+-------------+--------+-----------------------------+
| Delete | DELETE | Access | success |
| Access | | URI | |
+--------------+-------------+--------+-----------------------------+
| GS Options | OPTIONS | GS URI | metadata |
+--------------+-------------+--------+-----------------------------+
| Grant | OPTIONS | Grant | metadata |
| Options | | URI | |
+--------------+-------------+--------+-----------------------------+
| Access | OPTIONS | Access | metadata |
| Options | | URI | |
+--------------+-------------+--------+-----------------------------+
Table 1
Author's Address
Dick Hardt (editor)
SignIn.Org
United States
Email: dick.hardt@gmail.com
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