CDNI extensions for HTTPS delegation
draft-ietf-cdni-interfaces-https-delegation-08
| Document | Type | Active Internet-Draft (cdni WG) | |
|---|---|---|---|
| Authors | Frédéric Fieau , Stephan Emile , Sanjay Mishra | ||
| Last updated | 2022-03-07 | ||
| Replaces | draft-fieau-cdni-interfaces-https-delegation | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | plain text html xml htmlized pdfized bibtex | ||
| Stream | WG state | WG Document | |
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| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
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| Send notices to | (None) |
draft-ietf-cdni-interfaces-https-delegation-08
CDNI Working Group F. Fieau, Ed.
Internet-Draft E. Stephan
Intended status: Standards Track Orange
Expires: 8 September 2022 S. Mishra
Verizon
7 March 2022
CDNI extensions for HTTPS delegation
draft-ietf-cdni-interfaces-https-delegation-08
Abstract
The delivery of content over HTTPS involving one or more CDNs raises
credential management issues. This document defines new CDNI FCI and
Metadata objects to support HTTPS delegation, especially the ACME-
STAR [RFC9115] method.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 8 September 2022.
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Delegation metadata for CDNI FCI . . . . . . . . . . . . . . 3
4. Delegation metadata for CDNI . . . . . . . . . . . . . . . . 3
4.1. Usage example related to an HostMatch object . . . . . . 3
4.2. AcmeStarDelegationMethod object . . . . . . . . . . . . . 4
5. IANA considerations . . . . . . . . . . . . . . . . . . . . . 5
5.1. CDNI MI AcmeStarDelegationMethod Payload Type . . . . . . 6
5.2. CDNI FCI SupportedDelegationMethods Payload Type . . . . 6
6. Security considerations . . . . . . . . . . . . . . . . . . . 6
7. Privacy considerations . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Content delivery over HTTPS using one or more CDNs along the path
requires credential management. This specifically applies when an
entity delegates delivery of encrypted content to another trusted
entity.
The ACME WG has published ACME STAR [RFC9115] allowing a dCDN to
request a x.509 certificate from uCDN.
This document proposes the CDNI Metadata interface to setup HTTPS
delegation between an upstream CDN (uCDN) and downstream CDN (dCDN)
using the ACME STAR proposal. Furthermore, it includes a proposal of
IANA registry to enable adding of new methods.
Section 2 is about terminology used in this document. Section 3
presents delegation methods specified at the IETF. Section 4
addresses the extension for handling HTTPS delegation in CDNI.
Section 5 describes simple data types. Section 6 addresses IANA
registry for delegation methods. Section 7 covers the security
issues. Section 8 is about comments and questions.
2. Terminology
This document uses terminology from CDNI framework documents such as:
CDNI framework document [RFC7336], CDNI requirements [RFC7337] and
CDNI interface specifications documents: CDNI Metadata interface
[RFC8006] and CDNI Control interface / Triggers [RFC8007].
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3. Delegation metadata for CDNI FCI
The Footprint and Capabilities interface as defined in RFC8008,
allows a dCDN to send a FCI capability type object to a uCDN. This
draft adds an object named FCI.SupportedDelegationMethods.
This object will allow a dCDN to advertise the capabilities regarding
the supported delegation methods and their configuration.
The following is an example of the supported delegated methods
capability object for a CDN supporting STAR delegation method.
{
"capabilities": [
{
"capability-type": "FCI.SupportedDelegationMethods",
"capability-value": {
"delegation-methods": [
"AcmeStarDelegationDelegationMethod",
"... Other delegation methods ..."
]
}
"footprints": [
<Footprint objects>
]
}
]
}
4. Delegation metadata for CDNI
This section defines Delegation metadata using the current Metadata
interface model. This allows bootstrapping delegation methods
between a uCDN and a delegate dCDN.
4.1. Usage example related to an HostMatch object
This section presents the use of CDNI Delegation metadata of an
HostMatch object, as defined in [RFC8006] as specified in the
following sections.
The existence of the delegation methods in metadata in a CDNI Object
shall enable the use of one of this methods, chosen by the delegating
entity. In the case of an HostMatch object, the delegation method
will be activated for the set of Host defined in the HostMatch. See
Section 4.2 for more details about delegation methods metadata
specification.
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The HostMatch object can reference a host metadata that points at the
delegation information. Delegation metadata are added to a Metadata
object.
Below shows both HostMatch its Metadata related to a host, for
example, here is a HostMatch object referencing "video.example.com":
HostMatch:
{
"host": "video.example.com",
"host-metadata": {
"type": "MI.HostMetadata",
"href": "https://metadata.ucdn.example/host1234"
}
}
Following the example above, the metadata can be modeled
for ACMEStarDelegationMethod as:
"generic-metadata-value": {
"acme-delegations": [
"https://acme.ucdn.example/acme/delegation/ogfr8EcolOT",
"https://acme.ucdn.example/acme/delegation/wSi5Lbb61E4"
]
}
This extension allows to explicitly indicate support for a given
method. Therefore, the presence (or lack thereof) of an
AcmeStarDelegationMethod, and/or further delegation methods, implies
support (or lack thereof) for the given method.
Those metadata can apply to other MI objects such as PathMatch object
metadata.
4.2. AcmeStarDelegationMethod object
This section defines the AcmeStarDelegationMethod object which
describes metadata related to the use of ACME/STAR API presented in
[RFC9115]
As expressed in [RFC9115], when an origin has set a delegation to a
specific domain (i.e. dCDN), the dCDN should present to the end-user
client, a short-term certificate bound to the master certificate.
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dCDN uCDN Content Provider CA
| ACME/STAR proxy ACME/STAR client ACME/STAR srv
| | | |
| 1. GET Metadata incl. Delegation Method object with CSR template|
+-------------------->| | |
| 200 OK + Metadata incl. CSR template [CDNI] |
|<--------------------+ | |
| 2. Request delegation: video.dcdn.example + dCDN public key |
+-------------------->| | |
| | 3. Request STAR Cert + dCDN public key |
| +-------------------->| 4. Request STAR cert|
| | | + Pubkey |
| | |-------------------->|
| | | 5. STAR certificate |
| | 6. STAR certificate |<--------------------|
| 7. STAR certificate |<--------------------+ |
+<--------------------| | |
| | | |
| 8. Retrieve STAR certificate (credential-location-uri) |
+---------------------------------------------------------------->|
| | | 9. renew +--|
| | | cert | |
| 10. Star certificate | +->|
|<----------------------------------------------------------------+
| ... | | |
Figure 1: Example call-flow of STAR delegation in CDNI showing 2 levels
of delegation
Property: acme-delegations
Description: an array of delegation objects associated with the
dCDN account on the uCDN ACME server (see Section 2.3.1 of
[RFC9115] for the details).
Type: Objects
Mandatory-to-Specify: Yes
5. IANA considerations
This document requests the registration of the following entries
under the "CDNI Payload Types" registry hosted by IANA regarding
"CDNI delegation":
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+-------------------------------+---------------+
| Payload Type | Specification |
+-------------------------------+---------------+
| MI.AcmeStarDelegationMethod | RFCthis |
+-------------------------------+---------------+
| FCI.SupportedDelegationMethods| RFCthis |
+-------------------------------+---------------+
[RFC Editor: Please replace RFCthis with the published RFC number for
this document.]
5.1. CDNI MI AcmeStarDelegationMethod Payload Type
Purpose: The purpose of this Payload Type is to distinguish
AcmeStarDelegationMethod MI objects (and any associated capability
advertisement)
Interface: MI
Encoding: see Section 5
5.2. CDNI FCI SupportedDelegationMethods Payload Type
Purpose: The purpose of this Payload Type is to distinguish
SupportedDelegationMethods FCI objects (and any associated capability
advertisement)
Interface: FCI
Encoding: see Section 4
6. Security considerations
Extensions proposed here do not alter nor change Security
Considerations as outlined in the CDNI Metadata and Footprint and
Capabilities RFCs [RFC8006].
However there are still some security questions that should be
addressed such as: Are there concerns about using this incorrectly or
limitations on how this can safely be used?
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7. Privacy considerations
Some privacy questions are still pending: Are there any concerns with
sharing the information that is in the metadata? Is the metadata
safe to redistribute, or is it something that is only valid between
adjacent CDNs?
8. References
8.1. Normative References
[RFC8006] Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma,
"Content Delivery Network Interconnection (CDNI)
Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016,
<https://www.rfc-editor.org/info/rfc8006>.
[RFC8007] Murray, R. and B. Niven-Jenkins, "Content Delivery Network
Interconnection (CDNI) Control Interface / Triggers",
RFC 8007, DOI 10.17487/RFC8007, December 2016,
<https://www.rfc-editor.org/info/rfc8007>.
[RFC8739] Sheffer, Y., Lopez, D., Gonzalez de Dios, O., Pastor
Perales, A., and T. Fossati, "Support for Short-Term,
Automatically Renewed (STAR) Certificates in the Automated
Certificate Management Environment (ACME)", RFC 8739,
DOI 10.17487/RFC8739, March 2020,
<https://www.rfc-editor.org/info/rfc8739>.
[RFC9115] Sheffer, Y., López, D., Pastor Perales, A., and T.
Fossati, "An Automatic Certificate Management Environment
(ACME) Profile for Generating Delegated Certificates",
RFC 9115, DOI 10.17487/RFC9115, September 2021,
<https://www.rfc-editor.org/info/rfc9115>.
8.2. Informative References
[RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, Ed.,
"Framework for Content Distribution Network
Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336,
August 2014, <https://www.rfc-editor.org/info/rfc7336>.
[RFC7337] Leung, K., Ed. and Y. Lee, Ed., "Content Distribution
Network Interconnection (CDNI) Requirements", RFC 7337,
DOI 10.17487/RFC7337, August 2014,
<https://www.rfc-editor.org/info/rfc7337>.
Authors' Addresses
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Frederic Fieau (editor)
Orange
40-48, avenue de la Republique
92320 Chatillon
France
Email: frederic.fieau@orange.com
Emile Stephan
Orange
2, avenue Pierre Marzin
22300 Lannion
France
Email: emile.stephan@orange.com
Sanjay Mishra
Verizon
13100 Columbia Pike
Silver Spring, MD 20904
United States of America
Email: sanjay.mishra@verizon.com
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