NETCONF Working Group                                          K. Watsen
Internet-Draft                                          Juniper Networks
Intended status: Standards Track                        November 3, 2016
Expires: May 7, 2017


                      TLS Client and Server Models
                draft-ietf-netconf-tls-client-server-01

Abstract

   This document defines two YANG modules, one defines groupings for a
   generic TLS client and the other defines groupings for a generic TLS
   server.  It is intended that these groupings will be used by
   applications using the TLS protocol.

Editorial Note (To be removed by RFC Editor)

   This draft contains many placeholder values that need to be replaced
   with finalized values at the time of publication.  This note
   summarizes all of the substitutions that are needed.  No other RFC
   Editor instructions are specified elsewhere in this document.

   This document contains references to other drafts in progress, both
   in the Normative References section, as well as in body text
   throughout.  Please update the following references to reflect their
   final RFC assignments:

   o  draft-ietf-netconf-keystore

   Artwork in this document contains shorthand references to drafts in
   progress.  Please apply the following replacements:

   o  "XXXX" --> the assigned RFC value for this draft

   o  "YYYY" --> the assigned RFC value for draft-ietf-netconf-keystore

   Artwork in this document contains placeholder values for the date of
   publication of this draft.  Please apply the following replacement:

   o  "2016-11-02" --> the publication date of this draft

   The following two Appendix sections are to be removed prior to
   publication:

   o  Appendix A.  Change Log

   o  Appendix B.  Open Issues



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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 May 7, 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The TLS Client Model  . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .   4
     2.3.  YANG Model  . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  The TLS Server Model  . . . . . . . . . . . . . . . . . . . .   7
     3.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   7
     3.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .   8
     3.3.  YANG Model  . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
     5.1.  The IETF XML Registry . . . . . . . . . . . . . . . . . .  11



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     5.2.  The YANG Module Names Registry  . . . . . . . . . . . . .  12
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .  14
     A.1.  server-model-09 to 00 . . . . . . . . . . . . . . . . . .  14
   Appendix B.  Open Issues  . . . . . . . . . . . . . . . . . . . .  14
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   This document defines two YANG [RFC6020] modules, one defines
   groupings for a generic TLS client and the other defines groupings
   for a generic TLS server (TLS is defined in [RFC5246]).  It is
   intended that these groupings will be used by applications using the
   TLS protocol.  For instance, these groupings could be used to help
   define the data model for an HTTPS [RFC2818] server or a NETCONF over
   TLS [RFC7589] based server.

   The two YANG modules in this document each define two groupings.  One
   grouping defines everything other than what's needed for the TCP
   [RFC793] protocol layer.  The other grouping uses the first grouping
   while adding TCP layer specifics (e.g., addresses to connect to,
   ports to listen on, etc.).  This separation is done in order to
   enable applications the opportunity to define their own strategy for
   how the underlying TCP connection is established.  For instance,
   applications supporting NETCONF Call Home
   [draft-ietf-netconf-call-home] could use the first grouping for the
   TLS parts it provides, while adding data nodes for the reversed TCP
   layer.

1.1.  Terminology

   The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1.2.  Tree Diagrams

   A simplified graphical representation of the data models is used in
   this document.  The meaning of the symbols in these diagrams is as
   follows:

   o  Brackets "[" and "]" enclose list keys.

   o  Braces "{" and "}" enclose feature names, and indicate that the
      named feature must be present for the subtree to be present.



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   o  Abbreviations before data node names: "rw" means configuration
      (read-write) and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node, "!"
      means a presence container, and "*" denotes a list and leaf-list.

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

2.  The TLS Client Model

   EDITOR NOTE: Please ignore this section, it is incomplete.

   The TLS client model presented in this section contains two YANG
   groupings, one for a client that initiates the underlying TCP
   connection and another for a client that has had the TCP connection
   opened for it already (e.g., call home).

   Both of these groupings reference data nodes defined by the Keystore
   model [draft-ietf-netconf-keystore].  For instance, a reference to
   the keystore model is made to indicate which trusted CA certificate a
   client should use to authenticate the server's certificate.

2.1.  Tree Diagram

   The following tree diagram presents the data model for the two
   groupings defined in the ietf-tls-client module.

   module: ietf-tls-client
     groupings:
     initiating-tls-client-grouping
         +---- some-TBD-tcp-client-stuff?   string
         +---- some-TBD-tls-client-stuff?   string

     non-initiating-tls-client-grouping
         +---- some-TBD-tls-client-stuff?   string


2.2.  Example Usage

   This section shows how it would appear if the initiating-tls-client-
   grouping were populated with some data.  This example is consistent
   with the examples presented in Section 2.2 of
   [draft-ietf-netconf-keystore].




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   FIXME

2.3.  YANG Model

   This YANG module has a normative references to [RFC6991] and
   [draft-ietf-netconf-keystore].


   <CODE BEGINS> file "ietf-tls-client@2016-11-02.yang"

   // Editor's Note:
   // This module is incomplete at this time.  Below is
   // just a skeleton so there's something in the draft.
   // Please ignore this module for now!

   module ietf-tls-client {
     yang-version 1.1;

     namespace "urn:ietf:params:xml:ns:yang:ietf-tls-client";
     prefix "tlsc";
   /*
     import ietf-inet-types {
       prefix inet;
       reference
         "RFC 6991: Common YANG Data Types";
     }

     import ietf-keystore {
       prefix ks;
       reference
         "RFC YYYY: Keystore Model";
     }
   */
     organization
      "IETF NETCONF (Network Configuration) Working Group";

     contact
      "WG Web:   <http://tools.ietf.org/wg/netconf/>
       WG List:  <mailto:netconf@ietf.org>

       WG Chair: Mehmet Ersue
                 <mailto:mehmet.ersue@nsn.com>

       WG Chair: Mahesh Jethanandani
                 <mailto:mjethanandani@gmail.com>

       Editor:   Kent Watsen
                 <mailto:kwatsen@juniper.net>";



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     description
      "This module defines a reusable grouping for a TLS client that
       can be used as a basis for specific TLS client instances.

       Copyright (c) 2014 IETF Trust and the persons identified as
       authors of the code. All rights reserved.

       Redistribution and use in source and binary forms, with or
       without modification, is permitted pursuant to, and subject
       to the license terms contained in, the Simplified BSD
       License set forth in Section 4.c of the IETF Trust's
       Legal Provisions Relating to IETF Documents
       (http://trustee.ietf.org/license-info).

       This version of this YANG module is part of RFC XXXX; see
       the RFC itself for full legal notices.";

     revision "2016-11-02" {
       description
        "Initial version";
       reference
        "RFC XXXX: TLS Client and Server Models";
     }

     grouping initiating-tls-client-grouping {
       description
         "A reusable grouping for a TLS client that initiates the
          underlying TCP transport connection.";
       leaf some-TBD-tcp-client-stuff {
         type string;
         description "";
       }
       uses non-initiating-tls-client-grouping;
     }

    grouping non-initiating-tls-client-grouping {
       description
         "A reusable grouping for a TLS client that does not initiate
          the underlying TCP transport connection.";
       leaf some-TBD-tls-client-stuff {
         type string;
         description "";
       }
     }

   }





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   <CODE ENDS>

3.  The TLS Server Model

   The TLS server model presented in this section contains two YANG
   groupings, one for a server that opens a socket to accept TCP
   connections and another for a server that has had the TCP connection
   opened for it already (e.g., inetd).

   Both of these groupings reference data nodes defined by the Keystore
   model [draft-ietf-netconf-keystore].  For instance, a reference to
   the keystore model is made to indicate the certificate a server
   should present.

3.1.  Tree Diagram

   The following tree diagram presents the data model for the two
   groupings defined in the ietf-tls-server module.

 module: ietf-tls-server
   groupings:
   listening-tls-server-grouping
       +---- address?        inet:ip-address
       +---- port?           inet:port-number
       +---- certificates
       |  +---- certificate* [name]
       |     +---- name?   -> /ks:keystore/private-keys/private-key/cert
 ificate-chains/certificate-chain/name
       +---- client-auth
          +---- trusted-ca-certs?       -> /ks:keystore/trusted-certific
 ates/name
          +---- trusted-client-certs?   -> /ks:keystore/trusted-certific
 ates/name

   non-listening-tls-server-grouping
       +---- certificates
       |  +---- certificate* [name]
       |     +---- name?   -> /ks:keystore/private-keys/private-key/cert
 ificate-chains/certificate-chain/name
       +---- client-auth
          +---- trusted-ca-certs?       -> /ks:keystore/trusted-certific
 ates/name
          +---- trusted-client-certs?   -> /ks:keystore/trusted-certific
 ates/name







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3.2.  Example Usage

   This section shows how it would appear if the listening-tls-server-
   grouping were populated with some data.  This example is consistent
   with the examples presented in Section 2.2 of
   [draft-ietf-netconf-keystore].

   <listening-tls-server
     xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-server">
     <port>6513</port>
     <certificates>
       <certificate>
         <name>ex-key-sect571r1-cert</name>
       </certificate>
     </certificates>
     <client-auth>
       <trusted-ca-certs>
         deployment-specific-ca-certs
       </trusted-ca-certs>
       <trusted-client-certs>
         explicitly-trusted-client-certs
       </trusted-client-certs>
     </client-auth>
   </listening-tls-server>

3.3.  YANG Model

   This YANG module has a normative references to [RFC6991], and
   [draft-ietf-netconf-keystore].


   <CODE BEGINS> file "ietf-tls-server@2016-11-02.yang"

   module ietf-tls-server {
     yang-version 1.1;

     namespace "urn:ietf:params:xml:ns:yang:ietf-tls-server";
     prefix "tlss";

     import ietf-inet-types {
       prefix inet;
       reference
         "RFC 6991: Common YANG Data Types";
     }

     import ietf-keystore {
       prefix ks;
       reference



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         "RFC YYYY: Keystore Model";
     }

     organization
      "IETF NETCONF (Network Configuration) Working Group";

     contact
      "WG Web:   <http://tools.ietf.org/wg/netconf/>
       WG List:  <mailto:netconf@ietf.org>

       WG Chair: Mehmet Ersue
                 <mailto:mehmet.ersue@nsn.com>

       WG Chair: Mahesh Jethanandani
                 <mailto:mjethanandani@gmail.com>

       Editor:   Kent Watsen
                 <mailto:kwatsen@juniper.net>";


     description
      "This module defines a reusable grouping for a TLS server that
       can be used as a basis for specific TLS server instances.

       Copyright (c) 2014 IETF Trust and the persons identified as
       authors of the code. All rights reserved.

       Redistribution and use in source and binary forms, with or
       without modification, is permitted pursuant to, and subject
       to the license terms contained in, the Simplified BSD
       License set forth in Section 4.c of the IETF Trust's
       Legal Provisions Relating to IETF Documents
       (http://trustee.ietf.org/license-info).

       This version of this YANG module is part of RFC XXXX; see
       the RFC itself for full legal notices.";

     revision "2016-11-02" {
       description
        "Initial version";
       reference
        "RFC XXXX: TLS Client and Server Models";
     }


     // grouping
     grouping non-listening-tls-server-grouping {
       description



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         "A reusable grouping for a TLS server that can be used as a
          basis for specific TLS server instances.";
       container certificates {
         description
           "The list of certificates the TLS server will present when
            establishing a TLS connection in its Certificate message,
            as defined in Section 7.4.2 in RRC 5246.";
         reference
           "RFC 5246:
              The Transport Layer Security (TLS) Protocol Version 1.2";
         list certificate {
           key name;
           min-elements 1;
           description
             "An unordered list of certificates the TLS server can pick
              from when sending its Server Certificate message.";
           reference
             "RFC 5246: The TLS Protocol, Section 7.4.2";
           leaf name {
             type leafref {
               path "/ks:keystore/ks:private-keys/ks:private-key/"
                    + "ks:certificate-chains/ks:certificate-chain/"
                    + "ks:name";
             }
             description
               "The name of the certificate in the keystore.";
           }
         }
       }

       container client-auth {
         description
           "A reference to a list of trusted certificate authority (CA)
            certificates and a reference to a list of trusted client
            certificates.";
         leaf trusted-ca-certs {
           type leafref {
             path "/ks:keystore/ks:trusted-certificates/ks:name";
           }
           description
             "A reference to a list of certificate authority (CA)
              certificates used by the TLS server to authenticate
              TLS client certificates.";
         }

         leaf trusted-client-certs {
           type leafref {
             path "/ks:keystore/ks:trusted-certificates/ks:name";



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           }
           description
             "A reference to a list of client certificates used by
              the TLS server to authenticate TLS client certificates.
              A clients certificate is authenticated if it is an
              exact match to a configured trusted client certificate.";
         }
       }
     }


     grouping listening-tls-server-grouping {
       description
         "A reusable grouping for a TLS server that can be used as a
          basis for specific TLS server instances.";
       leaf address {
         type inet:ip-address;
         description
          "The IP address of the interface to listen on.  The TLS
           server will listen on all interfaces if no value is
           specified. Please note that some addresses have special
           meanings (e.g., '0.0.0.0' and '::').";
       }
       leaf port {
         type inet:port-number;
         description
          "The local port number on this interface the TLS server
           listens on.  When this grouping is used, it is RECOMMENDED
           that refine statement is used to either set a default port
           value or to set mandatory true.";
       }
       uses non-listening-tls-server-grouping;
     }
   }



   <CODE ENDS>

4.  Security Considerations

5.  IANA Considerations

5.1.  The IETF XML Registry

   This document registers two URIs in the IETF XML registry [RFC2119].
   Following the format in [RFC3688], the following registrations are
   requested:



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      URI: urn:ietf:params:xml:ns:yang:ietf-tls-client
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

      URI: urn:ietf:params:xml:ns:yang:ietf-tls-server
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

5.2.  The YANG Module Names Registry

   This document registers two YANG modules in the YANG Module Names
   registry [RFC6020].  Following the format in [RFC6020], the the
   following registrations are requested:

      name:         ietf-tls-client
      namespace:    urn:ietf:params:xml:ns:yang:ietf-tls-client
      prefix:       tlsc
      reference:    RFC XXXX

      name:         ietf-tls-server
      namespace:    urn:ietf:params:xml:ns:yang:ietf-tls-server
      prefix:       tlss
      reference:    RFC XXXX

6.  Acknowledgements

   The authors would like to thank for following for lively discussions
   on list and in the halls (ordered by last name): Andy Bierman, Martin
   Bjorklund, Benoit Claise, Mehmet Ersue, David Lamparter, Alan Luchuk,
   Ladislav Lhotka, Radek Krejci, Tom Petch, Juergen Schoenwaelder, Phil
   Shafer, Sean Turner, and Bert Wijnen.

7.  References

7.1.  Normative References

   [draft-ietf-netconf-keystore]
              Watsen, K., "Keystore Model", draft-ieft-netconf-
              keystore-00 (work in progress), 2016,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-
              keystore>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.





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   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <http://www.rfc-editor.org/info/rfc6991>.

   [RFC7589]  Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
              NETCONF Protocol over Transport Layer Security (TLS) with
              Mutual X.509 Authentication", RFC 7589,
              DOI 10.17487/RFC7589, June 2015,
              <http://www.rfc-editor.org/info/rfc7589>.

7.2.  Informative References

   [draft-ietf-netconf-call-home]
              Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
              draft-ieft-netconf-call-home-17 (work in progress), 2015,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-
              call-home-17>.

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818,
              DOI 10.17487/RFC2818, May 2000,
              <http://www.rfc-editor.org/info/rfc2818>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <http://www.rfc-editor.org/info/rfc3688>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <http://www.rfc-editor.org/info/rfc5246>.

   [RFC793]   Postel, J., "TRANSMISSION CONTROL PROTOCOL", STD 7,
              September 1981, <https://www.ietf.org/rfc/rfc793.txt>.













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Appendix A.  Change Log

A.1.  server-model-09 to 00

   o  This draft was split out from draft-ietf-netconf-server-model-09.

   o  Noted that '0.0.0.0' and '::' might have special meanings.

Appendix B.  Open Issues

   Please see: https://github.com/netconf-wg/tls-client-server/issues.

Author's Address

   Kent Watsen
   Juniper Networks

   EMail: kwatsen@juniper.net

































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