RFC 2314

PKCS #10: Certification Request Syntax Version 1.5

📅 published March 1998, from ietf

RFC 2314: PKCS #10: Certification Request Syntax, Version 1.5 🎀

okay bestie, let's start with the title block because it's the ID card of this doc 🪪

RFC: 2314
Title: PKCS #10: Certification Request Syntax, Version 1.5
Author: B. Kaliski, RSA Laboratories East
Category: Informational
Date: March 1998
Series: Network Working Group
Obsoletes / Updates: the header doesn't list either one, so nothing to report here 🙈

Status of This Memo 📜

so this memo is giving "for your information" 💜 It's here to inform the Internet community. It does not specify an Internet standard of any kind, so it's not a rule book. Distribution of this memo is unlimited, so share it with everyone 🦋

Copyright Notice 🌈

Overview ✨

This document describes a syntax for certification requests. That's the whole main quest 🧚

1. Scope 💖

okay so a certification request is basically a little package with three things in it: a distinguished name, a public key, and optionally a set of attributes. The entity asking for the certificate signs the whole package together 🔏 It then gets sent to a certification authority (CA), who turns it into an X.509 public-key certificate, or into a PKCS #6 extended certificate. 👑

How the CA sends the newly signed certificate back is outside the scope of this document. A PKCS #7 message is one possibility, but it's not the only option 💅

The attributes have two jobs. First, they carry extra info about the entity, like a postal address where the signed certificate can be sent if email isn't an option. They can also hold a "challenge password," which the entity can use later to ask for certificate revocation 🔐 Second, they provide attributes for a PKCS #6 extended certificate. A non-exhaustive list of attributes lives in PKCS #9, so go check there for more 📚

CAs might also want non-electronic forms of request, and they may send non-electronic replies too 📮 Those forms are outside the scope of this document, but the CA should have descriptions of them available 🫶

The preliminary intended application of this document is to support PKCS #7 cryptographic messages. Other applications are expected to be developed later, so this is just the beginning, bestie ✨

2. References 📚

PKCS #1: RSA Laboratories. PKCS #1: RSA Encryption Standard. Version 1.5, November 1993.
PKCS #6: RSA Laboratories. PKCS #6: Extended-Certificate Syntax. Version 1.5, November 1993.
PKCS #7: RSA Laboratories. PKCS #7: Cryptographic Message Syntax. Version 1.5, November 1993.
PKCS #9: RSA Laboratories. PKCS #9: Selected Attribute Types. Version 1.1, November 1993.
RFC 1424: Kaliski, B., "Privacy Enhancement for Internet Electronic Mail: Part IV: Key Certification and Related Services," RFC 1424, February 1993.
X.208: CCITT. Recommendation X.208: Specification of Abstract Syntax Notation One (ASN.1). 1988.
X.209: CCITT. Recommendation X.209: Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1). 1988.
X.500: CCITT. Recommendation X.500: The Directory--Overview of Concepts, Models and Services. 1988.
X.501: CCITT. Recommendation X.501: The Directory--Models. 1988.
X.509: CCITT. Recommendation X.509: The Directory--Authentication Framework. 1988.

3. Definitions 🍓

For the purposes of this document, the following definitions apply. Let's get the vocab down 🧠

AlgorithmIdentifier: A type that identifies an algorithm (by object identifier) and any associated parameters. This type is defined in X.509.
Attribute: A type that contains an attribute type (specified by object identifier) and one or more attribute values. This type is defined in X.501.
ASN.1: Abstract Syntax Notation One, as defined in X.208.
BER: Basic Encoding Rules, as defined in X.209.
Certificate: A type that binds an entity's distinguished name to a public key with a digital signature. This type is defined in X.509. This type also contains the distinguished name of the certificate issuer (the signer), an issuer-specific serial number, the issuer's signature algorithm identifier, and a validity period. 🪪
DER: Distinguished Encoding Rules for ASN.1, as defined in X.509, Section 8.7.
Name: A type that uniquely identifies or "distinguishes" objects in an X.500 directory. This type is defined in X.501. In an X.509 certificate, the type identifies the certificate issuer and the entity whose public key is certified. 💜

4. Symbols and abbreviations 🫧

No symbols or abbreviations are defined in this document. Easy, no extra alphabet soup today 😌

5. General overview 🌸

The next section specifies certification request syntax. ✨

This document exports one type, CertificationRequest. That's the main star of the show 👑

6. Certification request syntax 💅

This section gives the syntax for certification requests. Here's the plot 🎬

A certification request consists of three parts: "certification request information," a signature algorithm identifier, and a digital signature on the certification request information. The certification request information is the entity's distinguished name, the entity's public key, and a set of attributes that provide other information about the entity. 🧚

here's how a request gets made, step by step 🩷

A CertificationRequestInfo value containing a distinguished name, a public key, and optionally a set of attributes is constructed by an entity.
The CertificationRequestInfo value is signed with the entity's private key. (See Section 6.2.)
The CertificationRequestInfo value, a signature algorithm identifier, and the entity's signature are collected together into a CertificationRequest value, defined below.

Then the CA handles it. The CA checks the entity's signature. If it's valid, the CA builds an X.509 certificate from the distinguished name and public key, plus an issuer name, serial number, validity period, and signature algorithm of the CA's choice 🎀 If the certification request has a PKCS #9 extended-certificate-attributes attribute, the CA also builds a PKCS #6 extended certificate from the X.509 certificate and that attribute's value 🫶

How the CA returns the new certificate is outside the scope of this document. One possibility is a PKCS #7 cryptographic message with content type signedData, following the degenerate case where there are no signers. The return message may include a certification path from the new certificate to the CA. It may also include other certificates, such as cross-certificates the CA considers helpful, and it may include certificate-revocation lists (CRLs) 📜 Another possibility is that the CA inserts the new certificate into a central database 🗄️

This section is split into two parts. The first part describes the certification-request-information type CertificationRequestInfo, and the second part describes the top-level type CertificationRequest. ✨

Notes. 📝

An entity would typically send a certification request after generating a public-key/private-key pair. It may also do so after a change in the entity's distinguished name. 🔑
The signature on the certification request prevents an entity from requesting a certificate with another party's public key. Such an attack would give the entity the minor ability to pretend to be the originator of any message signed by the other party. This attack is significant only if the entity does not know the message being signed, and the signed part of the message does not identify the signer. The entity would still not be able to decrypt messages intended for the other party, of course. 🙈
How the entity sends the certification request to a certification authority is outside the scope of this document. Both paper and electronic forms are possible. 📮
This document is not compatible with the certification request syntax for Privacy-Enhanced Mail, as described in RFC 1424. The syntax in this document differs in three respects: It allows a set of attributes; it does not include issuer name, serial number, or validity period; and it does not require an "innocuous" message to be signed. The syntax in this document is designed to minimize request size, an important constraint for those certification authorities accepting requests on paper. 📄

6.1 CertificationRequestInfo 🧾

Certification request information shall have ASN.1 type CertificationRequestInfo:

CertificationRequestInfo ::= SEQUENCE {
  version Version,
  subject Name,
  subjectPublicKeyInfo SubjectPublicKeyInfo,
  attributes [0] IMPLICIT Attributes }

Version ::= INTEGER

Attributes ::= SET OF Attribute

The fields of type CertificationRequestInfo have the following meanings. Here's the breakdown 🍭

version is the version number, for compatibility with future revisions of this document. It shall be 0 for this version of the document. 🔢
subject is the distinguished name of the certificate subject, which is the entity whose public key is to be certified. 🫵
subjectPublicKeyInfo contains information about the public key being certified. It identifies the entity's public-key algorithm (and any associated parameters). Examples of public-key algorithms include X.509's rsa and PKCS #1's rsaEncryption. The information also includes a bit-string representation of the entity's public key. For both public-key algorithms just mentioned, the bit string contains the BER encoding of a value of the X.509/PKCS #1 type RSAPublicKey. 🔐
attributes is a set of attributes that provide additional information about the subject of the certificate. Some attribute types that might be useful here are defined in PKCS #9. One example is the challenge-password attribute, which specifies a password by which the entity may request that the certificate be revoked. Another example is the extended-certificate-attributes attribute, which specifies attributes for a PKCS #6 extended certificate. 🌈

6.2 CertificationRequest 📝

okay so a certification request has to be an ASN.1 type called CertificationRequest, no exceptions 💅

   CertificationRequest ::= SEQUENCE {
     certificationRequestInfo CertificationRequestInfo,
     signatureAlgorithm SignatureAlgorithmIdentifier,
     signature Signature }

   SignatureAlgorithmIdentifier ::= AlgorithmIdentifier

   Signature ::= BIT STRING

the fields have these meanings, and they're iconic 💖

certificateRequestInfo is the "certification request information." It is the value being signed.
signatureAlgorithm identifies the signature algorithm (and any associated parameters) under which the certification-request information is signed. Examples include PKCS #1's md2WithRSAEncryption and md5WithRSAEncryption.
signature is the result of signing the certification request information with the certification request subject's private key.

the signing process is two steps, and it's giving very organized 🎀

The value of the certificationRequestInfo field is DER encoded, yielding an octet string.
The result of step 1 is signed with the certification request subject's private key under the specified signature algorithm, yielding a bit string, the signature.

Note. The syntax for CertificationRequest could equivalently be written with the X.509 SIGNED macro 🧚

   CertificationRequest ::= SIGNED CertificateRequestInfo

Security Considerations 🔒

Security issues are discussed throughout this memo. so yeah, read the whole thing, bestie 🙈

Revision history 🕰️

Version 1.0

Version 1.0 is the initial version. ✨

Acknowledgements 🙏

This document is based on a contribution of RSA Laboratories, a division of RSA Data Security, Inc. Any substantial use of the text from this document must acknowledge RSA Data Security, Inc. RSA Data Security, Inc. requests that all material mentioning or referencing this document identify this as "RSA Data Security, Inc. PKCS #10". give them credit, periodt 🫶

Author's Address 📮

Burt Kaliski
RSA Laboratories East
20 Crosby Drive
Bedford, MA  01730

Phone: (617) 687-7000
EMail: burt@rsa.com

the legal stuff, but make it cute 🌈

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 💜

📦 where this page comes from

ietf: rfc2314 1998-03
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