ACME Working Group                                          R. Shoemaker
Internet-Draft                                                      ISRG
Intended status: Standards Track                       February 14, 2019
Expires: August 18, 2019


                ACME IP Identifier Validation Extension
                         draft-ietf-acme-ip-05

Abstract

   This document specifies identifiers and challenges required to enable
   the Automated Certificate Management Environment (ACME) to issue
   certificates for IP addresses.

Status of This Memo

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  IP Identifier . . . . . . . . . . . . . . . . . . . . . . . .   2
   4.  Identifier Validation Challenges  . . . . . . . . . . . . . .   3
   5.  HTTP Challenge  . . . . . . . . . . . . . . . . . . . . . . .   3
   6.  TLS with Application Level Protocol Negotiation (TLS ALPN)
       Challenge . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   7.  DNS Challenge . . . . . . . . . . . . . . . . . . . . . . . .   3
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
     8.1.  Identifier Types  . . . . . . . . . . . . . . . . . . . .   3
     8.2.  Challenge Types . . . . . . . . . . . . . . . . . . . . .   3
   9.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   4
   10. Normative References  . . . . . . . . . . . . . . . . . . . .   4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   5

.  Introduction

   The Automatic Certificate Management Environment (ACME)
   [I-D.ietf-acme-acme] only defines challenges for validating control
   of DNS host name identifiers which limits its use to being used for
   issuing certificates for DNS identifiers.  In order to allow
   validation of IPv4 and IPv6 identifiers for inclusion in X.509
   certificates this document specifies how challenges defined in the
   original ACME specification and the TLS-ALPN extension specification
   [I-D.ietf-acme-tls-alpn] can be used to validate IP identifiers.

.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in BCP 14,
   [RFC2119].

.  IP Identifier

   [I-D.ietf-acme-acme] only defines the identifier type "dns" which is
   used to refer to fully qualified domain names.  If a ACME server
   wishes to request proof that a user controls a IPv4 or IPv6 address
   it MUST create an authorization with the identifier type "ip".  The
   value field of the identifier MUST contain the textual form of the
   address as defined in [RFC1123] Section 2.1 for IPv4 and in [RFC5952]
   Section 4 for IPv6.

   An identifier for the IPv6 address 2001:db8::1 would be formatted
   like so:




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   {"type": "ip", "value": "2001:db8::1"}

.  Identifier Validation Challenges

   IP identifiers MAY be used with the existing "http-01" and "tls-alpn-
   01" challenges from [I-D.ietf-acme-acme] Section 8.3 and
   [I-D.ietf-acme-tls-alpn] Section 3 respectively.  To use IP
   identifiers with these challenges their initial DNS resolution step
   MUST be skipped and the IP address used for validation MUST be the
   value of the identifier.

.  HTTP Challenge

   For the "http-01" challenge the Host header MUST be set to the IP
   address being used for validation per [RFC7230].  The textual form of
   this address MUST be those defined in [RFC1123] Section 2.1 for IPv4
   and in [RFC5952] Section 4 for IPv6.

.  TLS with Application Level Protocol Negotiation (TLS ALPN) Challenge

   For the "tls-alpn-01" challenge the subjectAltName extension in the
   validation certificate MUST contain a single iPAddress which matches
   the address being validated.  As [RFC6066] does not permit IP
   addresses to be used in the SNI extension HostName the server MUST
   instead use the IN-ADDR.ARPA [RFC1034] or IP6.ARPA [RFC3596] reverse
   mapping of the IP address as the HostName value instead of the
   literal IP address.  For example if the IP address being validated is
   2001:db8::1 the SNI HostName should contain "1.0.0.0.0.0.0.0.0.0.0.0.
   0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.".

.  DNS Challenge

   The existing "dns-01" challenge MUST NOT be used to validate IP
   identifiers.

.  IANA Considerations

8.1.  Identifier Types

   Adds a new type to the Identifier list defined in Section 9.7.7 of
   [I-D.ietf-acme-acme] with the label "ip" and reference I-D.ietf-acme-
   ip.

8.2.  Challenge Types

   Adds the value "ip" to the Identifier Type column in the Validation
   Methods list defined in Section 9.7.8 of [I-D.ietf-acme-acme] for the
   "http-01" and "tls-alpn-01" challenges.



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.  Acknowledgments

   The author would like to thank those who contributed to this document
   and offered editorial and technical input, especially Jacob Hoffman-
   Andrews and Daniel McCarney.

.  Normative References

   [FIPS180-4]
              Department of Commerce, National., "NIST FIPS 180-4,
              Secure Hash Standard", March 2012,
              <http://csrc.nist.gov/publications/fips/fips180-4/
              fips-180-4.pdf>.

   [I-D.ietf-acme-acme]
              Barnes, R., Hoffman-Andrews, J., McCarney, D., and J.
              Kasten, "Automatic Certificate Management Environment
              (ACME)", draft-ietf-acme-acme-18 (work in progress),
              December 2018.

   [I-D.ietf-acme-tls-alpn]
              Shoemaker, R., "ACME TLS ALPN Challenge Extension", draft-
              ietf-acme-tls-alpn-05 (work in progress), August 2018.

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
              <https://www.rfc-editor.org/info/rfc1034>.

   [RFC1123]  Braden, R., Ed., "Requirements for Internet Hosts -
              Application and Support", STD 3, RFC 1123,
              DOI 10.17487/RFC1123, October 1989,
              <https://www.rfc-editor.org/info/rfc1123>.

   [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/info/rfc2119>.

   [RFC3596]  Thomson, S., Huitema, C., Ksinant, V., and M. Souissi,
              "DNS Extensions to Support IP Version 6", STD 88,
              RFC 3596, DOI 10.17487/RFC3596, October 2003,
              <https://www.rfc-editor.org/info/rfc3596>.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, DOI 10.17487/RFC4291, February
              2006, <https://www.rfc-editor.org/info/rfc4291>.





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   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/info/rfc4648>.

   [RFC5952]  Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
              Address Text Representation", RFC 5952,
              DOI 10.17487/RFC5952, August 2010,
              <https://www.rfc-editor.org/info/rfc5952>.

   [RFC6066]  Eastlake 3rd, D., "Transport Layer Security (TLS)
              Extensions: Extension Definitions", RFC 6066,
              DOI 10.17487/RFC6066, January 2011,
              <https://www.rfc-editor.org/info/rfc6066>.

   [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Message Syntax and Routing",
              RFC 7230, DOI 10.17487/RFC7230, June 2014,
              <https://www.rfc-editor.org/info/rfc7230>.

Author's Address

   Roland Bracewell Shoemaker
   Internet Security Research Group

   Email: roland@letsencrypt.org


























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