The application/pkcs10 Media Type
The media type label for sending a PKCS #10 certificate request, carried over from an old S/MIME RFC.
Turner, S., "The application/pkcs10 Media Type", RFC 5967, DOI 10.17487/RFC5967, August 2010, <https://www.rfc-editor.org/info/rfc5967>.
@misc{rfc5967,
series = {Request for Comments},
number = 5967,
howpublished = {RFC 5967},
publisher = {RFC Editor},
doi = {10.17487/RFC5967},
url = {https://www.rfc-editor.org/info/rfc5967},
author = {S. Turner},
title = {{The application/pkcs10 Media Type}},
pagetotal = 6,
year = 2010,
month = aug,
} RFC text
Contents
Internet Engineering Task Force (IETF) S. Turner
Request for Comments: 5967 IECA
Updates: 2986 August 2010
Category: Informational
ISSN: 2070-1721
The application/pkcs10 Media Type
Abstract
This document specifies a media type used to carry PKCS #10
certification requests as defined in RFC 2986. It carries over the
original specification from RFC 2311, which recently has been moved
to Historic status, and properly links it to RFC 2986.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5967.
Copyright Notice
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than English.
1. Introduction
[RFC2311] first defined the application/pkcs10 media type. When
[RFC2633] was published, the application/pkcs10 section was dropped,
but for some reason the text was not incorporated into the PKCS #10
document [RFC2986]. [RFC2311] was moved to Historic status by
[RFC5751]. To ensure the IANA media type registration points to a
non-Historic document, this document updates [RFC2986] with the
definition of the application/pkcs10 media type and an IANA
registration based on [RFC4288].
The text for Section 2 is adapted from Section 3.7 of [RFC2311].
1.1. Requirements Terminology
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 [RFC2119].
2. Creating a Certification Request
A typical application that allows a user to generate cryptographic
information has to submit that information to a Certification
Authority (CA), who transforms it into a certificate. PKCS #10
[RFC2986] describes a syntax for certification requests.
The details of certification requests and the process of obtaining a
certificate are beyond the scope of this memo. Instead, only the
format of data used in application/pkcs10 is defined.
2.1. Format of the application/pkcs10 Body
PKCS #10 defines the ASN.1 type CertificationRequest for use in
submitting a certification request. For transfer to a CA, this
abstract syntax needs to be encoded and identified in a unique
manner. When the media type application/pkcs10 is used, the body
MUST be a CertificationRequest.
A robust application SHOULD output Distinguished Encoding Rules
(DER), but allow Basic Encoding Rules (BER) or DER on input.
Data produced by BER or DER is 8-bit, but some transports are limited
to 7-bit data. In such cases, a suitable 7-bit transfer encoding
MUST be applied; in MIME-compatible transports, the base64 encoding
[RFC4648] SHOULD be used with application/pkcs10, although any 7-bit
transfer encoding may work.
2.2. Sending and Receiving an application/pkcs10 Body Part
For sending a certificate-signing request, the application/pkcs10
message format MUST be used to convey a PKCS #10 certificate-signing
request. Note that for sending certificates and Certificate
Revocation Lists (CRLs) without any signed content, the
application/pkcs7-mime message format MUST be used to convey a
degenerate PKCS #7 signedData "certs-only" message [RFC5751].
To send an application/pkcs10 body, the application generates the
cryptographic information for the user. The details of the
cryptographic information are beyond the scope of this memo.
Step 1. The cryptographic information is placed within a PKCS #10
CertificationRequest.
Step 2. The CertificationRequest is encoded according to BER or DER
(preferred, DER).
Step 3. As a typical step, the encoded CertificationRequest is also
base64 encoded so that it is 7-bit data suitable for transfer
in ESMTP. This then becomes the body of an
application/pkcs10 body part.
The result might look like this:
Content-Type: application/pkcs10; name=smime.p10
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p10
rfvbnj756tbBghyHhHUujhJhjH77n8HHGT9HG4VQpfyF467GhIGfHfYT6
7n8HHGghyHhHUujhJh4VQpfyF467GhIGfHfYGTrfvbnjT6jH7756tbB9H
f8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4
0GhIGfHfQbnj756YT64V
A typical application only needs to send a certification request. It
is a Certification Authority that has to receive and process the
request. The steps for recovering the CertificationRequest from the
message are straightforward but are not presented here. The
procedures for processing the certification request are beyond the
scope of this document.
3. IANA Considerations
IANA has updated the registration for the application/pkcs10 media
subtype in the Application Media Types registry using the filled-in
template from BCP 13 [RFC4288] given below.
3.1. Registration of Media Subtype application/pkcs10
The media subtype for a PKCS #10 certification request is
application/pkcs10.
Type name: application
Subtype name: pkcs10
Required parameters: None
Optional parameters: None
Encoding considerations: binary; see Section 2.
Security considerations:
Clients use a certification request to request that a
Certification Authority certify a public key. The
certification request is digitally signed. Also, see
Section 6.
Interoperability considerations: See Section 2.
Published specification: This specification.
Applications which use this media type:
Applications that support PKCS #10 certification requests
[RFC2986].
Additional information:
Magic number(s): None
File extension(s): .p10
Macintosh File Type Code(s):
Person & email address to contact for further information:
Sean Turner <turners@ieca.com>
Restrictions on usage: none
Author: Sean Turner <turners@ieca.com>
Intended usage: COMMON
Change controller: The IESG
4. Security Considerations
The security considerations of [RFC2986] and [RFC5751] apply; no new
security considerations are introduced by this document.
5. Acknowledgements
I wish to thank the authors of RFC 2311, Steve Dusse, Paul Hoffman,
Blake Ramsdell, Laurence Lundblade, and Lisa Repka.
I would also like to thank Bjoern Hoehrmann for his review of the
media subtype application.
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2986] Nystrom, M. and B. Kaliski, "PKCS #10: Certification
Request Syntax Specification Version 1.7", RFC 2986,
November 2000.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006.
[RFC5751] Ramsdell, B. and S. Turner, "Secure/Multipurpose Internet
Mail Extensions (S/MIME) Version 3.2 Message
Specification", RFC 5751, January 2010.
[X.690] ITU-T Recommendation X.690 (2002) | ISO/IEC 8825-1:2002.
Information Technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules
(DER).
6.2. Informative References
[RFC2311] Dusse, S., Hoffman, P., Ramsdell, B., Lundblade, L., and
L. Repka, "S/MIME Version 2 Message Specification", RFC
2311, March 1998.
[RFC2633] Ramsdell, B., Ed., "S/MIME Version 3 Message
Specification", RFC 2633, June 1999.
Author's Address
Sean Turner
IECA, Inc.
3057 Nutley Street, Suite 106
Fairfax, VA 22031
USA
EMail: turners@ieca.com
ISO Plain Language
On this page
§1Why the Media Type Needed a New Home
RFC 2311 first defined the application/pkcs10 media type. When RFC 2633 was published, the application/pkcs10 section was dropped, and for some reason the text was not incorporated into the PKCS #10 document, RFC 2986. RFC 2311 was moved to Historic status by RFC 5751.
To ensure the IANA media type registration points to a non-Historic document, this document updates RFC 2986 with the definition of the application/pkcs10 media type and an IANA registration based on RFC 4288. The text for the section on the body format is adapted from Section 3.7 of RFC 2311.
The label for certificate requests was first written down in one S/MIME specification. The next S/MIME specification dropped the section, the PKCS #10 specification never picked it up, and the original document was later retired. This memo puts it back in a document that is still current.
§2.1The Format of the Body
A typical application that lets a user generate cryptographic information has to submit that information to a Certification Authority (CA), which transforms it into a certificate. PKCS #10 (RFC 2986) describes a syntax for certification requests.
The details of certification requests and the process of obtaining a certificate are beyond the scope of this memo. Only the format of the data used in application/pkcs10 is defined. PKCS #10 defines the ASN.1 type CertificationRequest for use in submitting a certification request. For transfer to a CA, this abstract syntax needs to be encoded and identified in a unique manner. When the media type application/pkcs10 is used, the body MUST be a CertificationRequest.
A robust application SHOULD output Distinguished Encoding Rules (DER), but allow Basic Encoding Rules (BER) or DER on input. Data produced by BER or DER is 8-bit, but some transports are limited to 7-bit data. In such cases a suitable 7-bit transfer encoding MUST be applied. In MIME-compatible transports, the base64 encoding (RFC 4648) SHOULD be used with application/pkcs10, although any 7-bit transfer encoding may work.
The body of the message is one object, the CertificationRequest, and nothing else. The object is written in a standard binary encoding. That encoding uses eight-bit bytes, so on a transport that can only carry seven-bit text, the bytes have to be wrapped in a text-safe encoding first, normally base64.
§2.2Sending and Receiving the Body
For sending a certificate-signing request, the application/pkcs10 message format MUST be used to convey a PKCS #10 certificate-signing request. For sending certificates and Certificate Revocation Lists (CRLs) without any signed content, the application/pkcs7-mime message format MUST be used to convey a degenerate PKCS #7 signedData certs-only message (RFC 5751).
To send an application/pkcs10 body, the application generates the cryptographic information for the user. The details of the cryptographic information are beyond the scope of this memo. The process has three steps. First, the cryptographic information is placed within a PKCS #10 CertificationRequest. Second, the CertificationRequest is encoded according to BER or DER, with DER preferred. Third, as a typical step, the encoded CertificationRequest is also base64 encoded so that it is 7-bit data suitable for transfer in ESMTP. That then becomes the body of an application/pkcs10 body part.
A typical application only needs to send a certification request. It is a Certification Authority that has to receive and process the request. The steps for recovering the CertificationRequest from the message are straightforward but are not presented here, and the procedures for processing the certification request are beyond the scope of this document.
Three steps, in order: build the request object, encode it, then wrap it in base64 so it can travel as text. A file of this kind carries a request only. To send an issued certificate or a revocation list, a different format, application/pkcs7-mime, has to be used.
Content-Type: application/pkcs10; name=smime.p10
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p10
rfvbnj756tbBghyHhHUujhJhjH77n8HHGT9HG4VQpfyF467GhIGfHfYT6
7n8HHGghyHhHUujhJh4VQpfyF467GhIGfHfYGTrfvbnjT6jH7756tbB9H
f8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4
0GhIGfHfQbnj756YT64V§3.1The IANA Registration
IANA has updated the registration for the application/pkcs10 media subtype in the Application Media Types registry using the filled-in template from BCP 13 (RFC 4288).
The media subtype for a PKCS #10 certification request is application/pkcs10. The type name is application and the subtype name is pkcs10. Required parameters: none. Optional parameters: none. Encoding considerations: binary, see the section on the body format.
On security, the registration says that clients use a certification request to request that a Certification Authority certify a public key, and that the certification request is digitally signed. On interoperability, it points to the section on the body format. The published specification is this specification. The applications that use this media type are applications that support PKCS #10 certification requests (RFC 2986).
Additional information: magic numbers, none. File extensions: .p10. Macintosh File Type Codes: none given. The person and email address to contact for further information is the author. Restrictions on usage: none. The author is the same person. Intended usage: COMMON. Change controller: the IESG.
The registration record is short because the format itself is narrow. There are no parameters to set, the file name extension is .p10, and there is no magic number to look for. The intended usage is COMMON, which in the media type registry means the format is expected to be used by many applications.
| Field | Value |
|---|---|
| Type name | application |
| Subtype name | pkcs10 |
| Required parameters | None |
| Optional parameters | None |
| Encoding considerations | Binary |
| Magic number | None |
| File extension | .p10 |
| Restrictions on usage | None |
| Intended usage | COMMON |
| Change controller | The IESG |
§4Security Considerations
The security considerations of RFC 2986 and RFC 5751 apply. No new security considerations are introduced by this document.
Nothing new. The security rules for certificate requests and for S/MIME messages are the ones already written down, and they carry over unchanged.