Internet X.509 Public Key Infrastructure -- HTTP Transfer for the Certificate Management Protocol (CMP)
draft-ietf-lamps-rfc6712bis-10

LAMPS Working Group                                         H. Brockhaus
Internet-Draft                                             D. von Oheimb
Obsoletes: 6712 9480 (if approved)                               Siemens
Intended status: Standards Track                            M. Ounsworth
Expires: 13 July 2025                                            J. Gray
                                                                 Entrust
                                                          9 January 2025

   Internet X.509 Public Key Infrastructure -- HTTP Transfer for the
                 Certificate Management Protocol (CMP)
                     draft-ietf-lamps-rfc6712bis-10

Abstract

   This document describes how to layer the Certificate Management
   Protocol (CMP) over HTTP.

   It includes the updates to RFC 6712 specified in RFC 9480 Section 3.
   These updates introduce CMP URIs using a Well-known prefix.  It
   obsoletes RFC 6712 and together with I-D.ietf-lamps-rfc4210bis and it
   also obsoletes RFC 9480.

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 https://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 13 July 2025.

Copyright Notice

   Copyright (c) 2025 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 (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.

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   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 Revised BSD License text as
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Changes Made by RFC 9480  . . . . . . . . . . . . . . . .   4
     1.2.  Changes Made by This Document . . . . . . . . . . . . . .   4
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   4
   3.  HTTP-Based Protocol . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  General Form  . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Media Type  . . . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  Communication Workflow  . . . . . . . . . . . . . . . . .   5
     3.4.  HTTP Request-URI  . . . . . . . . . . . . . . . . . . . .   6
     3.5.  Pushing of Announcements  . . . . . . . . . . . . . . . .   6
   4.  Implementation Considerations . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Appendix A.  History of Changes . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   [RFC Editor: please delete:

   During IESG telechat the CMP Updates document was approved on
   condition that LAMPS provides a RFC6712bis document.  Version -00 of
   this document shall be identical to RFC 6712 and version -01
   incorporates the changes specified in CMP Updates Section 3.

   A history of changes is available in Appendix A of this document.

   The authors of this document wish to thank Tomi Kause and Martin
   Peylo, the original authors of RFC 6712, for their work and invite
   them, next to further volunteers, to join the -bis activity as co-
   authors.

   ]

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   The Certificate Management Protocol (CMP) [I-D.ietf-lamps-rfc4210bis]
   requires a well-defined transfer mechanism to enable End Entities
   (EEs), Registration Authorities (RAs), and Certification Authorities
   (CAs) to pass PKIMessage structures between them.

   The first version of the CMP specification [RFC2510] included a brief
   description of a simple transfer protocol layer on top of TCP.  Its
   features were simple transfer-level error handling and a mechanism to
   poll for outstanding PKI messages.  Additionally, it was mentioned
   that PKI messages could also be conveyed using file-, E-mail-, and
   HTTP-based transfer, but those were not specified in detail.

   Since the second version of the CMP specification [RFC4210]
   incorporated its own polling mechanism and thus the need for a
   transfer protocol providing this functionality vanished.  The
   remaining features CMP requires from its transfer protocols are
   connection and error handling.

   CMP can benefit from utilizing reliable transport as CMP requires
   connection and error handling from the transfer protocol.  All these
   features are covered by HTTP.  Additionally, delayed delivery of CMP
   response messages may be handled at transfer level, regardless of the
   message contents.  Since [RFC9480] extends the polling mechanism
   specified in the second version of CMP [RFC4210] to cover all types
   of PKI management transactions, delays detected at application level
   may also be handled within CMP, using pollReq and pollRep messages.

   The usage of HTTP (e.g., HTTP/1.1 as specified in [RFC9110] and
   [RFC9112]) for transferring CMP messages exclusively uses the POST
   method for requests, effectively tunneling CMP over HTTP.  While this
   is generally considered bad practice (see BCP 56 [RFC9205] for best
   current practice on building protocols with HTTP) and should not be
   emulated, there are good reasons to do so for transferring CMP.  HTTP
   is used as it is generally easy-to-implement and it is able to
   traverse network borders utilizing ubiquitous proxies.  Most
   importantly, HTTP is already commonly used in existing CMP
   implementations.  Other HTTP request methods, such as GET, are not
   used because PKI management operations can only be triggered using
   CMP's PKI messages, which need to be transferred using a POST
   request.

   With its status codes, HTTP provides needed error reporting
   capabilities.  General problems on the server side, as well as those
   directly caused by the respective request, can be reported to the
   client.

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   As CMP implements a transaction identification (transactionID),
   identifying transactions spanning over more than just a single
   request/response pair, the statelessness of HTTP is not blocking its
   usage as the transfer protocol for CMP messages.

1.1.  Changes Made by RFC 9480

   CMP Updates [RFC9480] updated Section 3.6 of [RFC6712], supporting
   the PKI management operations specified in the Lightweight CMP
   Profile [RFC9483], in the following areas:

   *  Introduce the HTTP URI path prefix '/.well-known/cmp'.

   *  Add options for extending the URI structure with further segments
      and define a new protocol registry group to that aim.

1.2.  Changes Made by This Document

   This document obsoletes [RFC6712].  It includes the changes specified
   in Section 3 of [RFC9480] as described in Section 1.1 of this
   document.  Additionally, it adds the following changes:

   *  Removed the requirement to support HTTP/1.0 [RFC1945] in
      accordance with Section 4.1 of [RFC9205].

   *  Implementations MUST forward CMP messages when an HTTP error
      status code occurs, see Section 3.1.

   *  Removed Section 3.8 of [RFC6712] as it contains information
      redundant with current HTTP specification.

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  HTTP-Based Protocol

   For direct interaction between two entities, where a reliable
   transport protocol like TCP [RFC9293] is available, HTTP [RFC9110]
   SHOULD be utilized for conveying CMP messages.  This specification
   requires using the POST method (Section 3.1) and the "Content-Type"
   header field (Section 3.2), which are available since HTTP/1.0
   [RFC1945].

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   Note: In some situations, CMP requires multiple request/response
   pairs to perform a PKI management operation.  Their affiliation with
   a PKI management operation is indicated by a transaction identifier
   in the CMP message header (see transactionID described in
   Section 5.1.1 of [I-D.ietf-lamps-rfc4210bis]).  For details on how to
   transfer multiple requests see Section 4.11 of [RFC9205].

3.1.  General Form

   A DER-encoded [ITU.X690.1994] PKIMessage (Section 5.1 of
   [I-D.ietf-lamps-rfc4210bis]) MUST be sent as the content of an HTTP
   POST request.  If this HTTP request is successful, the server returns
   the CMP response in the content of the HTTP response.  The HTTP
   response status code in this case MUST be 200 (OK) status code; other
   Successful 2xx status codes MUST NOT be used for this purpose.  HTTP
   responses to pushed CMP announcement messages described in
   Section 3.5 utilize the status codes 201 and 202 to identify whether
   the received information was processed.

   While Redirection 3xx status codes MAY be supported by
   implementations, clients should only be enabled to automatically
   follow them after careful consideration of possible security
   implications.  As described in Section 5, 301 (Moved Permanently)
   status code could be misused for permanent denial of service.

   All applicable Client Error 4xx or Server Error 5xx status codes MAY
   be used to inform the client about errors.  Whenever a client
   receives an HTTP response with a status code in the 2xx, 4xx, or 5xx
   ranges, it MUST support handling response message content containing
   a CMP response PKIMessage.

3.2.  Media Type

   The Internet Media Type "application/pkixcmp" MUST be set in the HTTP
   "Content-Type" header field when conveying a PKIMessage.

3.3.  Communication Workflow

   In CMP, most communication is initiated by the EEs where every CMP
   request triggers a CMP response message from the CA or RA.

   The CMP announcement messages described in Section 3.5 are an
   exception.  Their creation may be triggered by certain events or done
   on a regular basis by a CA.  The recipient of the announcement only
   replies with an HTTP status code acknowledging the receipt or
   indicating an error, but not with a CMP response.

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   If the receipt of an HTTP request is not confirmed by receiving an
   HTTP response, it MUST be assumed that the transferred CMP message
   was not successfully delivered to its destination.

3.4.  HTTP Request-URI

   Each CMP server on a PKI management entity supporting HTTP or HTTPS
   transfer MUST support the use of the path prefix '/.well-known/' as
   defined in [RFC8615] and the registered name 'cmp' to ease
   interworking in a multi-vendor environment.

   CMP clients have to be configured with sufficient information to form
   the CMP server URI.  This is at least the authority portion of the
   URI, e.g., 'www.example.com:80', or the full operation path segment
   of the PKI management entity.  Additionally, path segments MAY be
   added after the registered application name as part of the full
   operation path to provide further distinction.  The path segment 'p'
   followed by an arbitraryLabel <name> could, for example, support the
   differentiation of specific CAs or certificate profiles.  Further
   path segments, e.g., as specified in the Lightweight CMP Profile
   [RFC9483], could indicate PKI management operations using an
   operationLabel <operation>.  The following list examples of valid
   full CMP URIs:

      http://www.example.com/.well-known/cmp

      http://www.example.com/.well-known/cmp/<operation>

      http://www.example.com/.well-known/cmp/p/<name>

      http://www.example.com/.well-known/cmp/p/<name>/<operation>

   Note that https can also be used instead of http, see item 5 in the
   Security Considerations (Section 5).

3.5.  Pushing of Announcements

   A CMP server may create event-triggered announcements or generate
   them on a regular basis.  It MAY utilize HTTP transfer to convey them
   to a suitable recipient.  In this use case, the CMP server acts as an
   HTTP client, and the recipient needs to utilize an HTTP server.  As
   no request messages are specified for those announcements, they can
   only be pushed to the recipient.

   If an EE wants to poll for a potential CA Key Update Announcement or
   the current CRL, a PKI Information Request using a General Message as
   described in Appendix D.5 of [I-D.ietf-lamps-rfc4210bis] can be used.

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   When pushing announcement messages, PKIMessage structures MUST be
   sent as the content of an HTTP POST request.

   Suitable recipients for CMP announcements might, for example, be
   repositories storing the announced information, such as directory
   services.  Those services listen for incoming messages, utilizing the
   same HTTP Request-URI scheme as defined in Section 3.4.

   The following types of PKIMessage are announcements that may be
   pushed by a CA.  The prefixed numbers reflect ASN.1 tags of the
   PKIBody structure (Section 5.1.2 of [I-D.ietf-lamps-rfc4210bis]).

      [15] CA Key Update Announcement
      [16] Certificate Announcement
      [17] Revocation Announcement
      [18] CRL Announcement

   CMP announcement messages do not require any CMP response.  However,
   the recipient MUST acknowledge receipt with an HTTP response having
   an appropriate status code and an empty content.  When not receiving
   such a response, it MUST be assumed that the delivery was not
   successful.  If applicable, the sending side MAY try sending the
   announcement again after waiting for an appropriate time span.

   If the announced issue was successfully stored in a database or was
   already present, the answer MUST be an HTTP response with a 201
   (Created) status code and an empty content.

   In case the announced information was only accepted for further
   processing, the status code of the returned HTTP response MAY also be
   202 (Accepted).  After an appropriate delay, the sender may then try
   to send the announcement again and may repeat this until it receives
   a confirmation that it has been successfully processed.  The
   appropriate duration of the delay and the option to increase it
   between consecutive attempts should be carefully considered.

   A receiver MUST answer with a suitable 4xx or 5xx error code when a
   problem occurs.

4.  Implementation Considerations

   Implementers should be aware that other implementations might exist
   that use a different approach for transferring CMP over HTTP.
   Further, implementations based on earlier I-Ds that led to [RFC6712]
   might use an unregistered "application/pkixcmp-poll" Media Type.
   Conforming implementations MAY handle this type like "application/
   pkixcmp".

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5.  Security Considerations

   All security considerations in HTTP [RFC9110] apply.  The following
   items need to be considered by implementers and users:

   1.  There is the risk for denial-of-service attacks through resource
       consumption by opening many connections to an HTTP server.
       Therefore, idle connections should be terminated after an
       appropriate timeout; this may also depend on the available free
       resources.

   2.  Without being encapsulated in effective security protocols, such
       as Transport Layer Security (TLS) [RFC5246] or [RFC8446], or
       without using HTTP digest [RFC9530] there is no integrity
       protection at the HTTP level.  Therefore, information from the
       HTTP should not be used to change state of the transaction,
       regardless of whether any mechanism was used to ensure the
       authenticity or integrity of HTTP messages (e.g., TLS or HTTP
       digests).

   3.  Client users should be aware that storing the target location of
       an HTTP response with the 301 (Moved Permanently) status code
       could be exploited by a meddler-in-the-middle attacker trying to
       block them permanently from contacting the correct server.

   4.  If no measures to authenticate and protect the HTTP responses to
       pushed announcement messages are in place, their information
       regarding the announcement's processing state may not be trusted.
       In that case, the overall design of the PKI system must not
       depend on the announcements being reliably received and processed
       by their destination.

   5.  CMP provides inbuilt integrity protection and authentication.
       The information communicated unencrypted in CMP messages does not
       contain sensitive information endangering the security of the PKI
       when intercepted.  However, it might be possible for an
       eavesdropper to utilize the available information to gather
       confidential personal, technical, or business critical
       information.  The protection of the confidentiality of CMP
       messages together with an initial authentication of the RA/CA
       before the first CMP message is transmitted ensures the privacy
       of the EE requesting certificates.  Therefore, users of the HTTP
       transfer for CMP messages should consider using HTTP over TLS
       according to [RFC9110] or using virtual private networks created,
       for example, by utilizing Internet Protocol Security according to
       [RFC7296].

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6.  IANA Considerations

   The reference to [RFC2510] at https://www.iana.org/assignments/media-
   types/media-types.xhtml should be replaced with a reference to this
   document.

   The reference to [RFC4210] at https://www.iana.org/assignments/core-
   parameters/core-parameters.xhtml should be replaced with a reference
   to this document.

   The reference to [RFC9480] at https://www.iana.org/assignments/well-
   known-uris/well-known-uris.xhtml and
   https://www.iana.org/assignments/cmp/cmp.xhtmlshould should be
   replaced with a reference to this document.

   No further action by the IANA is necessary for this document or any
   anticipated updates.

7.  Acknowledgments

   The authors wish to thank Tomi Kause and Martin Peylo, the original
   authors of [RFC6712], for their work.

   We also thank all reviewers for their valuable feedback.

8.  References

8.1.  Normative References

   [RFC1945]  Berners-Lee, T., Fielding, R., and H. Frystyk, "Hypertext
              Transfer Protocol -- HTTP/1.0", RFC 1945,
              DOI 10.17487/RFC1945, May 1996,
              <https://www.rfc-editor.org/rfc/rfc1945>.

   [RFC8615]  Nottingham, M., "Well-Known Uniform Resource Identifiers
              (URIs)", RFC 8615, DOI 10.17487/RFC8615, May 2019,
              <https://www.rfc-editor.org/rfc/rfc8615>.

   [RFC9110]  Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
              Ed., "HTTP Semantics", STD 97, RFC 9110,
              DOI 10.17487/RFC9110, June 2022,
              <https://www.rfc-editor.org/rfc/rfc9110>.

   [RFC9112]  Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
              Ed., "HTTP/1.1", STD 99, RFC 9112, DOI 10.17487/RFC9112,
              June 2022, <https://www.rfc-editor.org/rfc/rfc9112>.

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   [I-D.ietf-lamps-rfc4210bis]
              Brockhaus, H., von Oheimb, D., Ounsworth, M., and J. Gray,
              "Internet X.509 Public Key Infrastructure -- Certificate
              Management Protocol (CMP)", Work in Progress, Internet-
              Draft, draft-ietf-lamps-rfc4210bis-15, 18 November 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lamps-
              rfc4210bis-15>.

   [ITU.X690.1994]
              International Telecommunications Union, "Information
              Technology - ASN.1 encoding rules: Specification of Basic
              Encoding Rules (BER), Canonical Encoding Rules (CER) and
              Distinguished Encoding Rules (DER)", ITU-T Recommendation
              X.690, 1994.

   [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/rfc/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

8.2.  Informative References

   [RFC9480]  Brockhaus, H., von Oheimb, D., and J. Gray, "Certificate
              Management Protocol (CMP) Updates", RFC 9480,
              DOI 10.17487/RFC9480, November 2023,
              <https://www.rfc-editor.org/rfc/rfc9480>.

   [RFC9483]  Brockhaus, H., von Oheimb, D., and S. Fries, "Lightweight
              Certificate Management Protocol (CMP) Profile", RFC 9483,
              DOI 10.17487/RFC9483, November 2023,
              <https://www.rfc-editor.org/rfc/rfc9483>.

   [RFC2510]  Adams, C. and S. Farrell, "Internet X.509 Public Key
              Infrastructure Certificate Management Protocols",
              RFC 2510, DOI 10.17487/RFC2510, March 1999,
              <https://www.rfc-editor.org/rfc/rfc2510>.

   [RFC4210]  Adams, C., Farrell, S., Kause, T., and T. Mononen,
              "Internet X.509 Public Key Infrastructure Certificate
              Management Protocol (CMP)", RFC 4210,
              DOI 10.17487/RFC4210, September 2005,
              <https://www.rfc-editor.org/rfc/rfc4210>.

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

   [RFC6712]  Kause, T. and M. Peylo, "Internet X.509 Public Key
              Infrastructure -- HTTP Transfer for the Certificate
              Management Protocol (CMP)", RFC 6712,
              DOI 10.17487/RFC6712, September 2012,
              <https://www.rfc-editor.org/rfc/rfc6712>.

   [RFC7296]  Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
              Kivinen, "Internet Key Exchange Protocol Version 2
              (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
              2014, <https://www.rfc-editor.org/rfc/rfc7296>.

   [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/rfc/rfc8446>.

   [RFC9530]  Polli, R. and L. Pardue, "Digest Fields", RFC 9530,
              DOI 10.17487/RFC9530, February 2024,
              <https://www.rfc-editor.org/rfc/rfc9530>.

   [RFC9205]  Nottingham, M., "Building Protocols with HTTP", BCP 56,
              RFC 9205, DOI 10.17487/RFC9205, June 2022,
              <https://www.rfc-editor.org/rfc/rfc9205>.

   [RFC9293]  Eddy, W., Ed., "Transmission Control Protocol (TCP)",
              STD 7, RFC 9293, DOI 10.17487/RFC9293, August 2022,
              <https://www.rfc-editor.org/rfc/rfc9293>.

Appendix A.  History of Changes

   Note: This appendix will be deleted in the final version of the
   document.

   From version 09 -> 10:

   *  Addressed IESG review comments from Mahesh Jethanandani and
      responded to comments from Orie Steele and Zaheduzzaman Sarker via
      email

   From version 08 -> 09:

   *  Incorporated relevant text from former Sections 3.1 and 3.2 in the
      introduction of Section 3 as proposed by HTTPDIR review

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   *  Added reference to HTTP Security Considerations to Section 5 and
      updated the first item as proposed by HTTPDIR review

   From version 07 -> 08:

   *  Addressed HTTPDIR, SECDIR, OPSDIR and ARTART review comments

   *  Aligned the terminology with https://httpwg.org/admin/editors/
      style-guide

   *  Implemented editorial changes proposed by OPSDIR reviewer

   *  Removed requirement to support HTTP/1.0

   *  Added normative language in Sections 3.3 and 3.7 for clarity

   *  Added the requirement to provide any HTTP response message content
      to the application

   *  Removed the paragraph on the "Content-Length" header field and
      Section 3.8 to reduce redundancy with current versions HTTP/1.1

   From version 06 -> 07:

   *  Updated the the page header to 'HTTP Transfer for CMP'

   *  Removed one instruction to RFC Editors

   *  Deprecated PKIMessages as plural of PKIMessage to prevent
      confusion with ASN.1 type PKIMessages

   *  Fixed some nits in Section 1

   *  Aligned Section 3.6 and Section 5 with RFC 9483 and draft-ietf-
      anima-brski-ae

   From version 05 -> 06:

   *  Updates IANA considerations addressing IANA early review (see
      thread "[IANA #1368693] Early review: draft-ietf-lamps-
      rfc4210bis-12 (IETF 120)").

   From version 04 -> 05:

   *  Added IANA considerations addressing IANA early review.

   From version 03 -> 04:

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   *  Aligned with released RFC 9480 - RFC 9483.

   From version 02 -> 03:

   *  Fixing one formatting nit.

   From version 01 -> 02:

   *  Updated Section 3.4 including the requirement to add the content-
      length filed into the HTTP header.

   *  Added a reference to TLS 1.3.

   *  Addressed idnits feedback, specifically changing the following RFC
      references: RFC2616 -> RFC9112; RFC2818 -> RFC9110, and RFC5246 ->
      RFC8446

   From version 00 -> 01:

   *  Performed all updates specified in CMP Updates Section 3.

   Version 00:

   This version consists of the text of RFC6712 with the following
   changes:

   *  Introduced the authors of this document and thanked the authors of
      RFC6712 for their work.

   *  Added a paragraph to the introduction explaining the background of
      this document.

   *  Added the change history to this appendix.

Authors' Addresses

   Hendrik Brockhaus
   Siemens
   Werner-von-Siemens-Strasse 1
   80333 Munich
   Germany
   Email: hendrik.brockhaus@siemens.com
   URI:   https://www.siemens.com

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   David von Oheimb
   Siemens
   Werner-von-Siemens-Strasse 1
   80333 Munich
   Germany
   Email: david.von.oheimb@siemens.com
   URI:   https://www.siemens.com

   Mike Ounsworth
   Entrust
   1187 Park Place
   Minneapolis, MN 55379
   United States of America
   Email: mike.ounsworth@entrust.com
   URI:   https://www.entrust.com

   John Gray
   Entrust
   1187 Park Place
   Minneapolis, MN 55379
   United States of America
   Email: john.gray@entrust.com
   URI:   https://www.entrust.com

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