Certificate Management over CMS (CMC): Transport Protocols
draft-mandel-lamps-rfc5273bis-02
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Joe Mandel , Sean Turner | ||
| Last updated | 2024-03-04 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
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| Stream | Stream state | (No stream defined) | |
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draft-mandel-lamps-rfc5273bis-02
LAMPS Working Group J. Mandel, Ed
Internet-Draft AKAYLA, Inc.
Obsoletes: 5273, 6402 (if approved) S. Turner, Ed
Intended status: Standards Track sn3rd
Expires: 5 September 2024 4 March 2024
Certificate Management over CMS (CMC): Transport Protocols
draft-mandel-lamps-rfc5273bis-02
Abstract
This document defines a number of transport mechanisms that are used
to move CMC (Certificate Management over CMS (Cryptographic Message
Syntax)) messages. The transport mechanisms described in this
document are HTTP, file, mail, and TCP.
This document obsoletes RFCs 5273 and 6402.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-mandel-lamps-rfc5273bis/.
Discussion of this document takes place on the WG LAMPS mailing list
(mailto:spasm@ietf.org), which is archived at
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https://www.ietf.org/mailman/listinfo/spasm/.
Source for this draft and an issue tracker can be found at
https://github.com/seanturner/cmcbis.
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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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
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This Internet-Draft will expire on 5 September 2024.
Copyright Notice
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This document is subject to BCP 78 and the IETF Trust's Legal
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Terminology . . . . . . . . . . . . . . . . . . 3
3. Changes Since 5273 and 6402 . . . . . . . . . . . . . . . . . 3
4. File-Based Protocol . . . . . . . . . . . . . . . . . . . . . 3
5. Mail-Based Protocol . . . . . . . . . . . . . . . . . . . . . 4
6. HTTP/HTTPS-Based Protocol . . . . . . . . . . . . . . . . . . 5
6.1. PKI Request . . . . . . . . . . . . . . . . . . . . . . . 5
6.2. PKI Response . . . . . . . . . . . . . . . . . . . . . . 6
7. TCP-Based Protocol . . . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
9. Security Considerations . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 8
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
This document defines a number of transport methods that are used to
move CMC messages (defined in [CMC-STRUCT]). The transport
mechanisms described in this document are HTTP, file, mail, and TCP.
This document obsoletes [CMC-TRANSv1] and [CMC-Updates]. This
document also incorporates [erratum3593].
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2. Requirements Terminology
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. Changes Since 5273 and 6402
| Note: For now, this section will be list of the changes
| introduced by each version. After WGLC, this section will be
| finalized.
TODO for -03:
* Consider AuthEnvelopedData
-02 version changes:
* Replaced TLS 1.0 with TLS 1.2
-01 version changes:
* Changed RFC 5272 references to draft-mandel-lamps-rfc5272bis
* Merged [erratum3593]
-00 version changes:
* Moved 2119-text to its own section
* Added "Changes Since 5273 and 6402" section
* Updated references
* Merged [CMC-Updates] text
* Updated and moved Acknowledgments
4. File-Based Protocol
Enrollment messages and responses may be transferred between clients
and servers using file-system-based mechanisms, such as when
enrollment is performed for an off-line client. When files are used
to transport binary, Full PKI Request or Full PKI Response messages,
there MUST be only one instance of a request or response message in a
single file. The following file type extensions SHOULD be used:
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+=====================+================+
| Message Type | File Extension |
+=====================+================+
| Simple PKI Request | .p10 |
+---------------------+----------------+
| Full PKI Request | .crq |
+---------------------+----------------+
| Simple PKI Response | .p7c |
+---------------------+----------------+
| Full PKI Response | .crp |
+---------------------+----------------+
Table 1: File PKI Request/Response
Identification
5. Mail-Based Protocol
MIME wrapping is defined for those environments that are MIME native.
The basic mime wrapping in this section is taken from [SMIMEV4].
When using a mail-based protocol, MIME wrapping between the layers of
CMS wrapping is optional. Note that this is different from the
standard S/MIME (Secure MIME) message.
Simple enrollment requests are encoded using the "application/pkcs10"
content type. A file name MUST be included either in a content-type
or a content-disposition statement. The extension for the file MUST
be ".p10".
Simple enrollment response messages MUST be encoded as content type
"application/pkcs7-mime". An smime-type parameter MUST be on the
content-type statement with a value of "certs-only". A file name
with the ".p7c" extension MUST be specified as part of the content-
type or content-disposition statement.
Full enrollment request messages MUST be encoded as content type
"application/pkcs7-mime". The smime-type parameter MUST be included
with a value of "CMC-request". A file name with the ".p7m" extension
MUST be specified as part of the content-type or content-disposition
statement.
Full enrollment response messages MUST be encoded as content type
"application/pkcs7-mime". The smime-type parameter MUST be included
with a value of "CMC-response". A file name with the ".p7m"
extension MUST be specified as part of the content-type or content-
disposition statement.
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+====================+==============+================+==============+
| Item | MIME Type | File Extension | SMIME Type |
+====================+==============+================+==============+
| Simple PKI | application/ | .p10 | N/A |
| Request | pkcs10 | | |
+--------------------+--------------+----------------+--------------+
| Full PKI | application/ | .p7m | CMC-request |
| Request | pkcs7-mime | | |
+--------------------+--------------+----------------+--------------+
| Simple PKI | application/ | .p7c | certs-only |
| Response | pkcs7-mime | | |
+--------------------+--------------+----------------+--------------+
| Full PKI | application/ | .p7m | CMC-response |
| Response | pkcs7-mime | | |
+--------------------+--------------+----------------+--------------+
Table 2: MIME PKI Request/Response Identification
6. HTTP/HTTPS-Based Protocol
This section describes the conventions for use of HTTP [HTTP] as a
transport layer. In most circumstances, the use of HTTP over TLS
[HTTP] provides any necessary content protection from eavesdroppers.
In order for CMC clients and servers using HTTP to interoperate, the
following rules apply.
Clients MUST use the POST method to submit their requests.
Servers MUST use the 200 response code for successful responses.
Clients MAY attempt to send HTTP requests using TLS 1.2 [TLS] or
later, although servers are not required to support TLS.
Servers MUST NOT assume client support for any type of HTTP
authentication such as cookies, Basic authentication, or Digest
authentication.
Clients and servers are expected to follow the other rules and
restrictions in [HTTP]. Note that some of those rules are for
HTTP methods other than POST; clearly, only the rules that apply
to POST are relevant for this specification.
6.1. PKI Request
A PKI Request using the POST method is constructed as follows:
The Content-Type header MUST have the appropriate value from Table 2.
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The body of the message is the binary value of the encoding of the
PKI Request.
6.2. PKI Response
An HTTP-based PKI Response is composed of the appropriate HTTP
headers, followed by the binary value of the BER (Basic Encoding
Rules) encoding of either a Simple or Full PKI Response.
The Content-Type header MUST have the appropriate value from Table 2.
7. TCP-Based Protocol
When CMC messages are sent over a TCP-based connection, no wrapping
is required of the message. Messages are sent in their binary
encoded form.
The client closes a connection after receiving a response, or it
issues another request to the server using the same connection.
Reusing one connection for multiple successive requests, instead of
opening multiple connections that are only used for a single request,
is RECOMMENDED for performance and resource conservation reasons. A
server MAY close a connection after it has been idle for some period
of time; this timeout would typically be several minutes long.
CMC requires a registered port number to send and receive CMC
messages over TCP. The title of this IP Protocol number is "pkix-
cmc". The value of this TCP port is 5318.
Prior to [CMC-Updates], CMC did not have a registered port number and
used an externally configured port from the Private Port range.
Client implementations MAY want to continue to allow for this to
occur. Servers SHOULD change to use the new port. It is expected
that HTTP will continue to be the primary transport method used by
CMC installations.
8. IANA Considerations
IANA has assigned a TCP port number in the Registered Port Number
range for the use of CMC.
Service name: pkix-cmc
Port Number: 5318
Transport protocol: TCP
Description: PKIX Certificate Management using CMS (CMC)
Reference: RFC 6402
Assignee: iesg@ietf.org
Contact: chair@ietf.org
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9. Security Considerations
Mechanisms for thwarting replay attacks may be required in particular
implementations of this protocol depending on the operational
environment. In cases where the Certification Authority (CA)
maintains significant state information, replay attacks may be
detectable without the inclusion of the optional nonce mechanisms.
Implementers of this protocol need to carefully consider
environmental conditions before choosing whether or not to implement
the senderNonce and recipientNonce attributes described in
Section 6.6 of [CMC-STRUCT]. Developers of state-constrained PKI
clients are strongly encouraged to incorporate the use of these
attributes.
Initiation of a secure communications channel between an end-entity
and a CA or Registration Authority (RA) -- and, similarly, between an
RA and another RA or CA -- necessarily requires an out-of-band trust
initiation mechanism. For example, a secure channel may be
constructed between the end-entity and the CA via IPsec [IPsec] or
TLS [TLS]. Many such schemes exist, and the choice of any particular
scheme for trust initiation is outside the scope of this document.
Implementers of this protocol are strongly encouraged to consider
generally accepted principles of secure key management when
integrating this capability within an overall security architecture.
In some instances, no prior out-of-band trust will have been
initiated prior to use of this protocol. This can occur when the
protocol itself is being used to download onto the system the set of
trust anchors to be used for these protocols. In these instances,
the Enveloped Data content type (Section 3.2.1.3.3 of [CMC-STRUCT])
must be used to provide the same shrouding that TLS would have
provided.
10. References
10.1. Normative References
[CMC-STRUCT]
Mandel, J. and S. Turner, "Certificate Management over CMS
(CMC)", Work in Progress, Internet-Draft, draft-mandel-
lamps-rfc5272bis-01, 8 January 2024,
<https://datatracker.ietf.org/doc/html/draft-mandel-lamps-
rfc5272bis-01>.
[erratum3593]
"RFC 5273 erratum 3593", April 2013,
<https://www.rfc-editor.org/errata/eid3593>.
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[HTTP] 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>.
[IPsec] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/rfc/rfc4301>.
[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>.
[SMIMEV4] Schaad, J., Ramsdell, B., and S. Turner, "Secure/
Multipurpose Internet Mail Extensions (S/MIME) Version 4.0
Message Specification", RFC 8551, DOI 10.17487/RFC8551,
April 2019, <https://www.rfc-editor.org/rfc/rfc8551>.
10.2. Informative References
[CMC-TRANSv1]
Mandel, J. and S. Turner, "Certificate Management over CMS
(CMC): Transport Protocols", Work in Progress, Internet-
Draft, draft-mandel-lamps-rfc5273bis-01, 8 January 2024,
<https://datatracker.ietf.org/doc/html/draft-mandel-lamps-
rfc5273bis-01>.
[CMC-Updates]
Schaad, J., "Certificate Management over CMS (CMC)
Updates", RFC 6402, DOI 10.17487/RFC6402, November 2011,
<https://www.rfc-editor.org/rfc/rfc6402>.
[TLS] 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>.
Acknowledgements
Obviously, the authors of this version of the document would like to
thank Jim Schaad and Michael Myers for their work on the previous
version of this document.
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The acknowledgment from the previous version of this document
follows:
The authors and the PKIX Working Group are grateful for the
participation of Xiaoyi Liu and Jeff Weinstein in helping to author
the original versions of this document.
The authors would like to thank Brian LaMacchia for his work in
developing and writing up many of the concepts presented in this
document. The authors would also like to thank Alex Deacon and Barb
Fox for their contributions.
Contributors
Jim Schaad
August Cellars
Michael Myers
TraceRoute Security, Inc.
Authors' Addresses
Joseph Mandel
AKAYLA, Inc.
Email: joe@akayla.com
Sean Turner (editor)
sn3rd
Email: sean@sn3rd.com
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