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NTP Working Group                                              D. Sibold
Internet-Draft                                                       PTB
Intended status: Standards Track                             S. Roettger
Expires: April 26, 2015                                       Google Inc
                                                              K. Teichel
                                                                     PTB
                                                              R. Housley
                                                          Vigil Security
                                                        October 23, 2014


Protecting Network Time Security Messages with the Cryptographic Message
                              Syntax (CMS)
               draft-ietf-ntp-cms-for-nts-message-00.txt

Abstract

   This document describes a convention for using the Cryptographic
   Message Syntax (CMS) to protect the messages in the Network Time
   Security (NTS) protocol.  NTS provides authentication of time servers
   as well as integrity protection of time synchronization messages
   using Network Time Protocol (NTP) or Precision Time Protocol (PTP).

Requirements Language

   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 RFC 2119 [RFC2119].

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 April 26, 2015.






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Copyright Notice

   Copyright (c) 2014 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  CMS Conventions for NTS Message Protection  . . . . . . . . .   3
     2.1.  Fields of the employed CMS Content Types  . . . . . . . .   5
       2.1.1.  ContentInfo . . . . . . . . . . . . . . . . . . . . .   5
       2.1.2.  SignedData  . . . . . . . . . . . . . . . . . . . . .   6
       2.1.3.  EnvelopedData . . . . . . . . . . . . . . . . . . . .   8
   3.  Certificate Conventions . . . . . . . . . . . . . . . . . . .   9
   4.  Implementation Notes: ASN.1 Structures and Use of the CMS . .   9
     4.1.  Preliminaries . . . . . . . . . . . . . . . . . . . . . .   9
     4.2.  Unicast Messages  . . . . . . . . . . . . . . . . . . . .   9
       4.2.1.  Association Messages  . . . . . . . . . . . . . . . .   9
       4.2.2.  Cookie Messages . . . . . . . . . . . . . . . . . . .  10
       4.2.3.  Time Synchronization Messages . . . . . . . . . . . .  11
     4.3.  Broadcast Messages  . . . . . . . . . . . . . . . . . . .  12
       4.3.1.  Broadcast Parameter Messages  . . . . . . . . . . . .  12
       4.3.2.  Broadcast Time Synchronization Message  . . . . . . .  12
       4.3.3.  Broadcast Keycheck  . . . . . . . . . . . . . . . . .  13
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Appendix A.  ASN.1 Module . . . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   This document provides detail on how to construct NTS messages in
   practice.  NTS provides secure time synchronization with time servers
   using Network Time Protocol (NTP) [RFC5905] or Precision Time
   Protocol (PTP) [IEEE1588].  Among other things, this document



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   describes a convention for using the Cryptographic Message Syntax
   (CMS) [RFC5652] to protect messages in the Network Time Security
   (NTS) protocol.  Encryption is used to provide confidentiality of
   secrets, and digital signatures are used to provide authentication
   and integrity of content.

   Sometimes CMS is used in an exclusively ASN.1 [ASN1] environment.  In
   this case, the NTS message may use any syntax that facilitates easy
   implementation.

2.  CMS Conventions for NTS Message Protection

   Regarding the usage of CMS we differentiate between four archetypes
   according to which the NTS message types can be structured:

   NTS-Plain:  This archetype is used for actual time synchronization
      messages (explicitly, the message types: time_request,
      time_response, server_broad, see
      [I-D.ietf-ntp-network-time-security], section 6) as well as for
      the very first messages of a unicast or a broadcast exchange
      (client_assoc or client_bpar, respectively) and the broadcast
      keycheck exchange (client_keycheck and server_keycheck).  This
      archetype does not make use of any CMS structures.

   NTS-Signed-and-Encrypted:  This archetype is used for secure
      transmission of the cookie (only for the server_cook message type,
      see [I-D.ietf-ntp-network-time-security], section 6).  For this,
      the following CMS structure is used:

         First, the NTS message MUST be encrypted using the
         EnvelopedData content type.  EnvelopedData supports nearly any
         form of key management.  In the NTS protocol the client
         provides a certificate in an unprotected message, and the
         public key from this certificate, if it is valid, will be used
         to establish a pairwise symmetric key for the encryption of the
         protected NTS message.

         Second, the EnvelopedData content MUST be digitally signed
         using the SignedData content type.  SignedData supports nearly
         any form of digital signature, and in the NTS protocol the
         server will include its certificate within the SignedData
         content type.

         Third, the SignedData content type MUST be encapsulated in a
         ContentInfo content type.

      Figure 1 illustrates this structure.




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      +---------------------------------------------------------+
      |                                                         |
      | ContentInfo                                             |
      |                                                         |
      | +-----------------------------------------------------+ |
      | |                                                     | |
      | | SignedData                                          | |
      | |                                                     | |
      | | +-------------------------------------------------+ | |
      | | |                                                 | | |
      | | | EnvelopedData                                   | | |
      | | |                                                 | | |
      | | | +---------------------------------------------+ | | |
      | | | |                                             | | | |
      | | | | NTS Message Object                          | | | |
      | | | |                                             | | | |
      | | | |                                             | | | |
      | | | +---------------------------------------------+ | | |
      | | |                                                 | | |
      | | +-------------------------------------------------+ | |
      | |                                                     | |
      | +-----------------------------------------------------+ |
      |                                                         |
      +---------------------------------------------------------+

   NTS-Signed:  This archetype is used for server_assoc and server_bpar
      message types.  It uses the following CMS structure:

         First, the NTS message object MUST be wrapped in a SignedData
         content type.  The messages MUST be digitally signed, and
         certificates included.  SignedData supports nearly any form of
         digital signature, and in the NTS protocol the server will
         include its certificate within the SignedData content type.

         Second, the SignedData content type MUST be encapsulated in a
         ContentInfo content type.

      Figure 2 illustrates this structure.













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      +---------------------------------------------------------+
      |                                                         |
      | ContentInfo                                             |
      |                                                         |
      | +-----------------------------------------------------+ |
      | |                                                     | |
      | | SignedData                                          | |
      | |                                                     | |
      | | +-------------------------------------------------+ | |
      | | |                                                 | | |
      | | | NTS Message Object                              | | |
      | | |                                                 | | |
      | | |                                                 | | |
      | | +-------------------------------------------------+ | |
      | |                                                     | |
      | +-----------------------------------------------------+ |
      |                                                         |
      +---------------------------------------------------------+

   NTS-Certified:  This archetype is used for the client_cook message
      type.  It uses a CMS structure much like the NTS-Signed archetype
      (see Figure 2), with the only difference being that messages
      SHOULD NOT be digitally signed.  This archetype employs the CMS
      structure merely in order to transport certificates.

   Whichever archetype is used, the resulting structure is always
   transported in an extension field of an NTP packet.  In the case of
   messages that also need to carry time synchronization data, this data
   is written into the regular fields of the NTP packet.

2.1.  Fields of the employed CMS Content Types

   Overall, three CMS content types are used for NTS messages:
   ContentInfo, SignedData and EnvelopedData.  The following is a
   description of how the fields of those content types are used in
   detail.

2.1.1.  ContentInfo

   The ContentInfo content type is used in all four archetypes.  The
   fields of the SignedData content type are used as follows:

      contentType -- indicates the type of the associated content.  For
      the archetype NTS-Plain, it MUST identify the NTS message object
      that is included.  For all other archetypes (NTS-Certified, NTS-
      Signed and NTS-Signed-and-Encrypted), it MUST contain the object
      identifier for the SignedData content type:




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           id-signedData OBJECT IDENTIFIER ::= { iso(1) member-body(2)
              us(840) rsadsi(113549) pkcs(1) pkcs7(7) 2 }

      content is the associated content.  For the NTS-Plain archetype,
      it MUST contain the DER encoded NTS message object.  For all other
      archetypes, it MUST contain the DER encoded SignedData content
      type.

2.1.2.  SignedData

   The SignedData content type is used in the NTS-Certified, NTS-Signed
   and NTS-Signed-and-Encrypted archetypes but not in the NTS-Plain
   archetype.  The fields of the SignedData content type are used as
   follows:

      version -- the appropriate value depends on the optional items
      that are included.  In the NTS protocol, the signer certificate
      MUST be included, and other items MAY be included.  The
      instructions in [RFC5652] section 5.1 MUST be followed to set the
      correct value.

      digestAlgorithms -- is a collection of message digest algorithm
      identifiers.  In the NTS protocol, there MUST be exactly one
      algorithm identifier present.  The instructions in Section 5.4 of
      [RFC5652] MUST be followed.

      encapContentInfo -- this structure is always present.  In the NTS
      protocol, it MUST follow these conventions:

         eContentType -- is an object identifier.  In the NTS protocol,
         for the NTS-Certified and NTS-Signed archetypes, it MUST
         identify the type of the NTS message that was encapsulated.
         For the NTS-Signed-and-Encrypted archetype, it MUST contain the
         object identifier for the EnvelopedData content type:

         id-envelopedData OBJECT IDENTIFIER ::= { iso(1) member-body(2)
                us(840) rsadsi(113549) pkcs(1) pkcs7(7) 3 }.

         eContent is the content itself, carried as an octet string.
         For the NTS-Certified and NTS-Signed archetypes, it MUST
         contain the DER encoded encapsulated NTS message object.  The
         instructions in Section 6.3 of [RFC5652] MUST be followed.  For
         the NTS-Signed-and-Encrypted archetype, it MUST contain the DER
         encoded EnvelopedData content type.

      certificates -- is a collection of certificates.  In the NTS
      protocol, it MUST contain the DER encoded certificate [RFC5280] of
      the sender.  It is intended that the collection of certificates be



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      sufficient for the recipient to construct a certification path
      from a recognized "root" or "top-level certification authority" to
      the certificate used by the sender.

      crls -- is a collection of revocation status information.  In the
      NTS protocol, it MAY contain one or more DER encoded CRLs
      [RFC5280].  It is intended that the collection contain information
      sufficient to determine whether the certificates in the
      certificates field are valid.

      signerInfos -- is a collection of per-signer information.  In the
      NTS protocol, for the NTS-Certified archetype, this SHOULD be left
      out.  For both the NTS-Signed and the NTS-Signed-and-Encrypted
      archetypes, there MUST be exactly one SignerInfo structure
      present.  The details of the SignerInfo type are discussed in
      Section 5.3 of [RFC5652].  In the NTS protocol, it MUST follow
      these conventions:

         version -- is the syntax version number.  In the NTS protocol,
         the SignerIdentifier is subjectKeyIdentifier, therefore the
         version MUST be 3.

         sid -- identifies the signer's certificate.  In the NTS
         protocol, the sid field contains the subjectKeyIdentifier from
         the signer's certificate.

         digestAlgorithm -- identifies the message digest algorithm, and
         any associated parameters, used by the signer.  In the NTS
         protocol, the identifier MUST match the single algorithm
         identifier present in the digestAlgorithms.

         signedAttrs -- is a collection of attributes that are signed.
         In the NTS protocol, it MUST be present, and it MUST contain
         the following attributes:

            Content Type -- see Section 11.1 of [RFC5652].

            Message Digest -- see Section 11.2 of [RFC5652].

         In addition, it MAY contain the following attributes:

            Signing Time -- see Section 11.3 of [RFC5652].

            Binary Signing Time -- see Section 3 of [RFC5652].

         signatureAlgorithm -- identifies the signature algorithm, and
         any associated parameters, used by the signer to generate the
         digital signature.



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         signature is the result of digital signature generation, using
         the message digest and the signer's private key.  The
         instructions in Section 5.5 of [RFC5652] MUST be followed.

         unsignedAttrs -- is an optional collection of attributes that
         are not signed.  In the NTS protocol, the it MUST be absent.

2.1.3.  EnvelopedData

   The EnvelopedData content type is used only in the NTS-Signed-and-
   Encrypted archetype.  The fields of the EnvelopedData content type
   are used as follows:

      version -- the appropriate value depends on the type of key
      management that is used.  The instructions in [RFC5652] section
      6.1 MUST be followed to set the correct value.

      originatorInfo -- this structure is present only if required by
      the key management algorithm.  In the NTS protocol, it MUST be
      present when a key agreement algorithm is used, and it MUST absent
      when a key transport algorithm is used.  The instructions in
      Section 6.1 of [RFC5652] MUST be followed.

      recipientInfos -- this structure is always present.  In the NTS
      protocol, it MUST contain exactly one entry that allows the client
      to determine the key used to encrypt the NTS message.  The
      instructions in Section 6.2 of [RFC5652] MUST be followed.

      encryptedContentInfo -- this structure is always present.  In the
      NTS protocol, it MUST follow these conventions:

         contentType -- indicates the type of content.  In the NTS
         protocol, it MUST identify the type of the NTS message that was
         encrypted.

         contentEncryptionAlgorithm -- identifies the content-encryption
         algorithm, and any associated parameters, used to encrypt the
         content.

         encryptedContent -- is the encrypted the content.  In the NTS
         protocol, it MUST contain the encrypted NTS message.  The
         instructions in Section 6.3 of [RFC5652] MUST be followed.

      unprotectedAttrs -- this structure is optional.  In the NTS
      protocol, it MUST be absent.






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3.  Certificate Conventions

   The syntax and processing rules for certificates are specified in
   [RFC5652].  In the NTS protocol, the server certificate MUST contain
   the following extensions:

      Subject Key Identifier -- see Section 4.2.1.2 of [RFC5652].

      Key Usage -- see Section 4.2.1.3 of [RFC5652].

      Extended Key Usage -- see Section 4.2.1.22 of [RFC5652].

   The Extended Key Usage extension MUST include the id-kp-NTSserver
   object identifier.  When a certificate issuer includes this object
   identifier in the extended key usage extension, it provides an
   attestation that the certificate subject is a time server that
   supports the NTS protocol.

   The id-kp-NTSserver object identifier is:

         id-kp-NTSserver OBJECT IDENTIFIER ::= { TBD }

4.  Implementation Notes: ASN.1 Structures and Use of the CMS

   This section gives some hints on the structures of the NTS message
   objects for the different message types when one wishes to implement
   the protocol.

4.1.  Preliminaries

   The following ASN.1 coded data type "NTSNonce" is needed for other
   types used below for NTS messages.  It specifies a 128 bit nonce as
   required in several message types:

   NTSNonce ::= OCTET STRING (SIZE(16))

4.2.  Unicast Messages

4.2.1.  Association Messages

4.2.1.1.  Message Type: "client_assoc"

   This message is structured according to the NTS-Plain archetype.  It
   is realized as an NTP packet with an extension field which holds all
   the data relevant for NTS.  Explicitly, the extension field contains
   an ASN.1 object of type "ClientAssocData", which is structured as
   follows:




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   ClientAssocData ::= SEQUENCE {
       clientId         SubjectKeyIdentifier,
       digestAlgos      DigestAlgorithmIdentifiers,
       keyEncAlgos      KeyEncryptionAlgorithms,
       contentEncAlgos  ContentEncryptionAlgorithms
   }

4.2.1.2.  Message Type: "server_assoc"

   This message is structured according to the NTS-Signed archetype.
   The NTS message object in this case is an ASN.1 object of type
   "ServerAssocData", which is structured as follows:

   ServerAssocData ::= SEQUENCE {
       clientId              SubjectKeyIdentifier,
       choiceDigestAlgo      DigestAlgorithmIdentifier,
       choiceKeyEncAlgo      KeyEncryptionAlgorithmIdentifier,
       choiceContentEncAlgo  ContentEncryptionAlgorithmIdentifier
   }

4.2.2.  Cookie Messages

4.2.2.1.  Message Type: "client_cook"

   This message is structured according to the NTS-Certified archetype.
   The NTS message object is a "ClientCookieData" type ASN.1 object,
   structured as follows:

   ClientCookieData ::= SEQUENCE {
       nonce       NTSNonce,
       signAlgo    SignatureAlgorithmIdentifier,
       digestAlgo  DigestAlgorithmIdentifier,
       encAlgo     ContentEncryptionAlgorithmIdentifier,
       keyEncAlgo  KeyEncryptionAlgorithmIdentifier
   }

   It is identified by the following object identifier (fictional
   values):

   id-clientCookieData OBJECT IDENTIFIER ::=
       {nts(??) cookie(3) clientcookiedata(1)}

4.2.2.2.  Message Type: "server_cook"

   This message is structured according to the "NTS-Signed-and-
   Encrypted" archetype.  The NTS message object is a "ServerCookieData"
   object, specified as:




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   ServerCookieData ::= SEQUENCE {
       nonce     NTSNonce,
       cookie    OCTET STRING (SIZE(16))
   }

   It is identified by the following object identifier (fictional
   values):

   id-serverCookieData OBJECT IDENTIFIER ::=
       {nts(??) cookie(3) servercookiedata(2)}

4.2.3.  Time Synchronization Messages

4.2.3.1.  Message Type: "time_request"

   This message is structured according to the "NTS-Plain" archetype.
   It is realized as an NTP packet which actually contains regular NTP
   time synchronization data, as an unsecured NTP packet from a client
   to a server would.  Furthermore, the packet has an extension field
   which contains an ASN.1 object of type "TimeRequestSecurityData",
   whose structure is as follows:

   TimeRequestSecurityData ::=
   SEQUENCE {
       nonce_t           NTSNonce,
       digestAlgo        DigestAlgorithmIdentifier,
       hashOfClientCert  BIT STRING
   }

4.2.3.2.  Message Type: "time_response"

   This message is also structured according to "NTS-Plain".  It is
   realized as an NTP packet which, like "time_request", contains
   regular NTP time synchronization data, as an unsecured NTP packet
   from a server back to a client would.  The packet also has an
   extension field which contains an ASN.1 object of type
   "TimeResponseSecurityData", with the following structure:

   TimeResponseSecurityData ::=
   SEQUENCE {
       nonce_t  NTSNonce,
   }

   Finally, this NTP packet has a MAC field which contains a Message
   Authentication Code generated over the whole packet (including the
   extension field).





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4.3.  Broadcast Messages

4.3.1.  Broadcast Parameter Messages

4.3.1.1.  Message Type: "client_bpar"

   This first broadcast message is structured according to the NTS-Plain
   archetype.  It is realized as an NTP packet which is empty except for
   an extension field which contains ans ASN.1 object of type
   "BroadcastParameterRequest", which is structured as follows:

   BroadcastParameterRequest ::=
   SEQUENCE {
       clientId  SubjectKeyIdentifier
   }

4.3.1.2.  Message Type: "server_bpar"

   This message is structured according to "NTS-Signed".  It is realized
   as an NTP packet whose extension field carries the necessary CMS
   structure.  The NTS message object in this case is an ASN.1 object of
   type "BroadcastParameterResponse", with the following structure:

   BroadcastParameterRequest ::=
   SEQUENCE {
       oneWayAlgo1         DigestAlgorithmIdentifier,
       oneWayAlgo2         DigestAlgorithmIdentifier,
       lastKey             OCTET STRING (SIZE (16)),
       intervalDuration    BIT STRING,
       disclosureDelay     INTEGER,
       nextIntervalTime    BIT STRING,
       nextIntervalIndex   INTEGER
   }

4.3.2.  Broadcast Time Synchronization Message

4.3.2.1.  Message Type: "server_broad"

   This message is structured according to the "NTS-Plain" archetype.
   Its realization works via an NTP packet which carries regular NTP
   broadcast time data as well as an extension field, which contains an
   ASN.1 object of type "BroadcastTime".  It has the following
   structure:








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   BroadcastTime ::=
   SEQUENCE {
       thisIntervalIndex   INTEGER,
       disclosedKey        OCTET STRING (SIZE (16)),
   }

   In addition, this packet has a MAC field which contains a Message
   Authentication Code generated over the whole packet (including the
   extension field).

4.3.3.  Broadcast Keycheck

4.3.3.1.  Message Type: "client_keycheck"

   This message is structured according to the "NTS-Plain" archetype.
   It is realized as an NTP packet with an extension field, which
   contains an ASN.1 object of type "ClientKeyCheckSecurityData", whose
   structure is as follows:

   ClientKeyCheckSecurityData ::=
   SEQUENCE {
       nonce_k           NTSNonce,
       interval_number   INTEGER,
       digestAlgo        DigestAlgorithmIdentifier,
       hashOfClientCert  BIT STRING
   }

4.3.3.2.  Message Type: "server_keycheck"

   This message is also structured according to "NTS-Plain".  It is also
   realized as an NTP packet with an extension field, which contains an
   ASN.1 object of type "ServerKeyCheckSecurityData", with the following
   structure:

   ServerKeyCheckSecurityData ::=
   SEQUENCE {
       nonce_t           NTSNonce,
       interval_number   INTEGER
   }

   Additionally, this NTP packet has a MAC field which contains a
   Message Authentication Code generated over the whole packet
   (including the extension field).








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5.  IANA Considerations

   IANA needs to assign an object identifier for id-kp-NTSserver key
   purpose and another one for the ASN.1 module in the appendix.

6.  Security Considerations

   To be written.

7.  References

7.1.  Normative References

   [ASN1]     International Telecommunication Union, "Abstract Syntax
              Notation One (ASN.1): Specification of basic notation",
              ITU-T Recommendation X.680, November 2008.

   [IEEE1588]
              IEEE Instrumentation and Measurement Society. TC-9 Sensor
              Technology, "IEEE standard for a precision clock
              synchronization protocol for networked measurement and
              control systems", 2008.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, September 2009.

   [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
              Time Protocol Version 4: Protocol and Algorithms
              Specification", RFC 5905, June 2010.

7.2.  Informative References

   [I-D.ietf-ntp-network-time-security]
              Sibold, D., Roettger, S., and K. Teichel, "Network Time
              Security", draft-ietf-ntp-network-time-security-04 (work
              in progress), July 2014.

Appendix A.  ASN.1 Module

   The ASN.1 module contained in this appendix defines the id-kp-
   NTSserver object identifier.







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      NTSserverKeyPurpose
        { TBD }

      DEFINITIONS IMPLICIT TAGS ::=
      BEGIN

      id-kp-NTSserver OBJECT IDENTIFIER ::= { TBD }

      END

Authors' Addresses

   Dieter Sibold
   Physikalisch-Technische Bundesanstalt
   Bundesallee 100
   Braunschweig  D-38116
   Germany

   Phone: +49-(0)531-592-8420
   Fax:   +49-531-592-698420
   Email: dieter.sibold@ptb.de


   Stephen Roettger
   Google Inc

   Email: stephen.roettger@googlemail.com


   Kristof Teichel
   Physikalisch-Technische Bundesanstalt
   Bundesallee 100
   Braunschweig  D-38116
   Germany

   Phone: +49-(0)531-592-8421
   Email: kristof.teichel@ptb.de


   Russ Housley
   Vigil Security










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