CDNI Working Group                                         F. Fieau, Ed.
Internet-Draft                                                E. Stephan
Intended status: Standards Track                                  Orange
Expires: March 21, 2019                                        S. Mishra
                                                                 Verizon
                                                      September 17, 2018


                  CDNI extensions for HTTPS delegation
            draft-fieau-cdni-interfaces-https-delegation-05

Abstract

   The delivery of content over HTTPS involving multiple CDNs raises
   credential management issues.  This document proposes extensions in
   CDNI Control and Metadata interfaces to setup HTTPS delegation from
   an Upstream CDN (uCDN) to a Downstream CDN (dCDN).

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 21, 2019.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Known delegation methods  . . . . . . . . . . . . . . . . . .   3
   4.  Extending the CDNI metadata model . . . . . . . . . . . . . .   3
     4.1.  Extension to PathMetadata object  . . . . . . . . . . . .   3
     4.2.  Delegation methods  . . . . . . . . . . . . . . . . . . .   5
       4.2.1.  AcmeStarDelegationMethod object . . . . . . . . . . .   5
       4.2.2.  SubcertsDelegationMethod object . . . . . . . . . . .   6
   5.  Metadata Simple Data Type Descriptions  . . . . . . . . . . .   7
     5.1.  Periodicity . . . . . . . . . . . . . . . . . . . . . . .   8
   6.  IANA considerations . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  CDNI MI AcmeStarDelegationMethod Payload Type . . . . . .   8
     6.2.  CDNI MI SubCertsDelegationMethod Payload Type . . . . . .   8
   7.  Security considerations . . . . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

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.

   Several delegation methods are currently proposed within different
   IETF working groups.  They specify different methods for provisioning
   HTTPS delivery credentials.

   This document extends the CDNI Metadata interface to setup HTTPS
   delegation between an upstream CDN (uCDN) and downstream CDN (dCDN).
   Furthermore, it includes a proposal of IANA registry to enable the
   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 is about an IANA
   registry for delegation methods.  Section 7 raises the security
   issues.





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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].

3.  Known delegation methods

   There are currently two Internet drafts within the TLS and ACME
   working groups adopted to handle delegation of HTTPS delivery between
   entities.

   This I-D proposes standardizing HTTPS delegation between the entities
   using CDNI interfaces.

   This document considers the following two I-D that supports HTTPS
   delegation:

   - Sub-certificates [I-D.ietf-tls-subcerts]

   - Short-term certificates in ACME using STAR API [I-D.ietf-acme-star]

4.  Extending the CDNI metadata model

   This section defines a CDNI extension to the current Metadata
   interface model that allows bootstrapping delegation methods between
   a uCDN and a delegate dCDN.

4.1.  Extension to PathMetadata object

   This extension reuses PathMetadata object, as defined in [RFC8006],
   by adding new "Delegation methods" objects as specified in the
   following sections.

   This allows to explicitly indicate support for the given method.
   Therefore, the presence (or lack thereof) of an
   AcmeStarDelegationMethod, SubcertsDelegationMethod, and/or further
   delegation methods, imply support (or lack thereof) for the given
   method.

   Example:

   The PathMatch object can reference a path-metadata that points at the
   delegation information.  Delegation metadata are added to
   PathMetaData object.





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  PathMatch:
  {
   "path-pattern": {
        "pattern": "/movies/*",
        "case-sensitive": true
   },
   "path-metadata": {
     "type": "MI.PathMetadata",
        "href": "https://metadata.ucdn.example/video.example.com/movies"
   }
  }

  Below shows the PathMetaData Object related to /movie/*
  (located at https://metadata.ucdn.example/video.example.com/movies)

  PathMetadata:
  {
      "metadata": [
       {
        "generic-metadata-type": "MI.TimeWindowACL",
        "generic-metadata-value": {
        "times": [{
         "windows": [
         {
          "start": "1213948800",
          "end": "1478047392"
         }]}],
        "action": "allow",
       }},
       {
          "generic-metadata-type": "MI.AcmeStarDelegationMethod",
          "generic-metadata-value": {
          "starproxy": "10.2.2.2",
          "acmeserver" : "10.2.3.3",
          "credentialslocationuri": "www.ucdn.com/credentials",
          "periodicity": 36000
       }}]
  }


   The existence of the "MI.AcmeStarDelegationMethod" object in a
   PathMetaData Object shall enable the use of one of the
   AcmeStarDelegation Methods, chosen by the delegate.  The delegation
   method will be activated for the set of Path defined in the
   PathMatch.  See next section for more details about delegation
   methods metadata specification.





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4.2.  Delegation methods

   This section defines the delegation methods objects metadata.  Those
   metadata allows bootstrapping a secured delegatioin by providing the
   dCDN with the needed parameters to set it up.

4.2.1.  AcmeStarDelegationMethod object

   This section defines the AcmeStarDelegationMethod object which
   describes metadata related to the use of Acme Star API presented in
   [I-D.ietf-acme-star]

   As expressed in [I-D.ietf-acme-star], 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.

   Property: starproxy

      Description: Used to advertise the STAR Proxy to the dCDN.
      Endpoint type defined in RFC8006, section 4.3.3

      Type: Endpoint

      Mandatory-to-Specify: Yes

   Property: acmeserver

      Description: used to advertise the ACME server to the dCDN.
      Endpoint type is defined in RFC8006, section 4.3.3

      Type: Endpoint

      Mandatory-to-Specify: Yes

   Property: credentialslocationuri

      Description: expresses the location of the credentials to be
      fetched by the dCDN.  Link type is as defined in RFC8006, section 
      4.3.1

      Type: Link

      Mandatory-to-Specify: Yes

   Property: periodicity





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      Description: expresses the credentials renewal periodicity.  See
      next section on simple meta data type.

      Type: Periodicity

      Mandatory-to-Specify: Yes

   As an example, AcmeStarDelegationMethod object could express the
   Acme-Star delegation as the following:


   AcmeStarDelegationMethod: {
       "generic-metadata-type": "MI.AcmeStarDelegationMethod",
       "generic-metadata-value": {
           "starproxy": "10.2.2.2",
           "acmeserver": "10.2.3.3",
           "credentialslocationuri": "www.ucdn.com/credentials",
           "periodicity": 36000
       }
   }


4.2.2.  SubcertsDelegationMethod object

   This section defines the SubcertsDelegationMethod object which
   describes metadata related to the use of Subcerts as presented in
   [I-D.ietf-tls-subcerts]

   As expressed in [I-D.ietf-tls-subcerts], when an origin has set a
   delegation to a specific domain (i.e. dCDN), the dCDN should present
   the Origin or uCDN certificate or "delegated_credential" during the
   TLS handshake [RFC8446] to the end-user client application, instead
   of its own certificate.

   Property: credentialsdelegatingentity

      Description: Endpoint ID (IP) of the delegating Entity (uCDN).
      Endpoint type defined in RFC8006, section 4.3.3

      Type: Endpoint

      Mandatory-to-Specify: Yes

   Property: credentialrecipiententity

      Description: Endpoint ID (IP) of the delegated entity (dCDN).
      Endpoint type is defined in RFC8006, section 4.3.3




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      Type: Endpoint

      Mandatory-to-Specify: Yes

   Property: credentialslocationuri

      Description: expresses the location of the credentials to be
      fetched by the dCDN.  Link type is as defined in RFC8006, section 
      4.3.1

      Type: Link

      Mandatory-to-Specify: Yes

   Property: periodicity

      Description: expresses the credentials renewal periodicity.  See
      next section on simple meta data type.

      Type: Periodicity

      Mandatory-to-Specify: Yes

   As an example, when a uCDN has delegated HTTPS delivery to dCDN, a
   SubcertsDelegationMethod object can express the SubCerts delegation
   as the following:


   SubcertsDelegationMethod: {
       "generic-metadata-type": "MI.SubcertsDelegationMethod",
       "generic-metadata-value": {
           "credentialsdelegatingentity": "10.2.2.2",
           "credentialsrecepiententity": "10.2.3.3",
           "credentialslocationuri": "www.ucdn.com/credentials",
           "periodicity": 36000
       }
   }


5.  Metadata Simple Data Type Descriptions

   This section describes the simple data types that are used for
   properties for objects in this document.








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5.1.  Periodicity

   A time value expressed in seconds to indicate a periodicity.

   Type: Integer

6.  IANA considerations

   This document requests the registration of the following entries
   under the "CDNI Payload Types" registry hosted by IANA regarding
   "CDNI delegation":


   +----------------------------+---------------+
   | Payload Type               | Specification |
   +----------------------------+---------------+
   | MI.AcmeStarDelegationMethod| RFCthis       |
   | MI.SubCertDelegationMethod | RFCthis       |
   +----------------------------+---------------+

   [RFC Editor: Please replace RFCthis with the published RFC number for
      this document.]



6.1.  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/FCI

   Encoding: see Section 4.2.1

6.2.  CDNI MI SubCertsDelegationMethod Payload Type

   Purpose: The purpose of this Payload Type is to distinguish
   SubcertsDelegationMethod MI objects (and any associated capability
   advertisement)

   Interface: MI/FCI

   Encoding: see Section 4.2.2







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7.  Security considerations

   Extensions proposed here do not change Security Considerations as
   outlined in the CDNI Metadata and Footprint and Capabilities RFCs
   [RFC8006].

8.  References

8.1.  Normative References

   [RFC7937]  Le Faucheur, F., Ed., Bertrand, G., Ed., Oprescu, I., Ed.,
              and R. Peterkofsky, "Content Distribution Network
              Interconnection (CDNI) Logging Interface", RFC 7937,
              DOI 10.17487/RFC7937, August 2016,
              <https://www.rfc-editor.org/info/rfc7937>.

   [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>.

   [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>.

8.2.  Informative References

   [I-D.ietf-acme-star]
              Sheffer, Y., Lopez, D., Dios, O., Pastor, A., and T.
              Fossati, "Support for Short-Term, Automatically-Renewed
              (STAR) Certificates in Automated Certificate Management
              Environment (ACME)", draft-ietf-acme-star-03 (work in
              progress), March 2018.

   [I-D.ietf-tls-subcerts]
              Barnes, R., Iyengar, S., Sullivan, N., and E. Rescorla,
              "Delegated Credentials for TLS", draft-ietf-tls-
              subcerts-02 (work in progress), August 2018.

   [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>.



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   [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

   Frederic Fieau (editor)
   Orange
   40-48, avenue de la Republique
   Chatillon  92320
   France

   Email: frederic.fieau@orange.com


   Emile Stephan
   Orange
   2, avenue Pierre Marzin
   Lannion  22300
   France

   Email: emile.stephan@orange.com


   Sanjay Mishra
   Verizon
   13100 Columbia Pike
   Silver Spring  MD 20904
   USA

   Email: sanjay.mishra@verizon.com



















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