PKCS #8 Private-Key Information Content Types

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Table of Contents

1. Introduction

The syntax for private-key information was originally described in [RFC5208] and later obsoleted by [RFC5958]. This document defines PKCS #8 content types for use with PrivateKeyInfo and EncryptedPrivateKeyInfo.¶

2. Conventions and Definitions

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. Private-Key Information Content Types

This section defines a content type for private-key information and encrypted private-key information.¶

The PrivateKeyInfo content type is identified by the following object identifier:¶

id-ct-privateKeyInfo OBJECT IDENTIFIER ::= { iso(1)
 member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
 smime(16) ct(1) TBD1 }

The EncryptedPrivateKeyInfo content type is identified by the following object identifier:¶

id-ct-encrPrivateKeyInfo OBJECT IDENTIFIER ::= { iso(1)
 member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
 smime(16) ct(1) TBD2 }

4. Security Considerations

The security considerations in [RFC5958] apply here.¶

5. IANA Considerations

For the private key info content types defined in section Section 3, IANA is requested to assign an object identifier (OID) for each of the content types. The OIDs for the content types should be alloacted in the "SMI Security for S/MIME CMS Content Type" registry (1.2.840.113549.1.9.16.1), and the description should be set to id-ct-privateKeyInfo (TDB1) and id-ct-encrPrivateKeyInfo (TBD2).¶

For the ASN.1 Module in Section 6, IANA is requested to assign an object identifier (OID) for the module identifier. The OID for the module should be allocated in the "SMI Security for S/MIME Module Identifier" registry (1.2.840.113549.1.9.16.0), and the Description for the new OID should be set to "id-mod-pkcs8ContentType".¶

6. ASN.1 Module

PrivateKeyInfoContentTypes
 { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
   pkcs-9(9) smime(16) modules(0) id-mod-pkcs8ContentType(TBD0) }

DEFINITIONS IMPLICIT TAGS ::=
BEGIN

-- EXPORTS ALL

IMPORTS

CONTENT-TYPE
 FROM CryptographicMessageSyntax-2009 -- in [RFC5911]
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
     pkcs-9(9) smime(16) modules(0) id-mod-cms-2004-02(41) }

PrivateKeyInfo, EncryptedPrivateKeyInfo
 FROM AsymmetricKeyPackageModuleV1 -- in [RFC5958]
    { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
      pkcs-9(9) smime(16) modules(0)
      id-mod-asymmetricKeyPkgV1(50) }  ;


PrivateKeyInfoContentTypes CONTENT-TYPE ::= {
 ct-privateKeyInfo | ct-encrPrivateKeyInfo,
 ... -- Expect additional content types --  }

ct-privateKeyInfo CONTENT-TYPE ::= { PrivateKeyInfo
 IDENTIFIED BY id-ct-privateKeyInfo }

id-ct-privateKeyInfo OBJECT IDENTIFIER ::= { iso(1)
 member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
 smime(16) ct(1) TBD1 }

ct-encrPrivateKeyInfo CONTENT-TYPE ::= { EncryptedPrivateKeyInfo
 IDENTIFIED BY id-ct-encrPrivateKeyInfo }

id-ct-encrPrivateKeyInfo OBJECT IDENTIFIER ::= { iso(1)
 member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
 smime(16) ct(1) TBD2 }

END

7. Normative References

[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>.

[RFC5208]

Kaliski, B., "Public-Key Cryptography Standards (PKCS) #8: Private-Key Information Syntax Specification Version 1.2", RFC 5208, DOI 10.17487/RFC5208, May 2008, <https://www.rfc-editor.org/rfc/rfc5208>.

[RFC5911]

Hoffman, P. and J. Schaad, "New ASN.1 Modules for Cryptographic Message Syntax (CMS) and S/MIME", RFC 5911, DOI 10.17487/RFC5911, June 2010, <https://www.rfc-editor.org/rfc/rfc5911>.

[RFC5958]

Turner, S., "Asymmetric Key Packages", RFC 5958, DOI 10.17487/RFC5958, August 2010, <https://www.rfc-editor.org/rfc/rfc5958>.

[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>.

Acknowledgments

TODO acknowledge.¶

Authors' Addresses