Cryptographic Message Syntax (CMS) Algorithms
RFC 3370

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Network Working Group                                         R. Housley
Request for Comments: 3370                              RSA Laboratories
Obsoletes: 2630, 3211                                        August 2002
Category: Standards Track

             Cryptographic Message Syntax (CMS) Algorithms

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document describes the conventions for using several
   cryptographic algorithms with the Cryptographic Message Syntax (CMS).
   The CMS is used to digitally sign, digest, authenticate, or encrypt
   arbitrary message contents.

Table of Contents

   1     Introduction ...............................................  2
   1.1   Changes Since RFC 2630 .....................................  2
   1.2   Terminology ................................................  2
   2     Message Digest Algorithms ..................................  3
   2.1   SHA-1 ......................................................  3
   2.2   MD5 ........................................................  3
   3     Signature Algorithms .......................................  4
   3.1   DSA ........................................................  4
   3.2   RSA ........................................................  5
   4     Key Management Algorithms ..................................  6
   4.1   Key Agreement Algorithms ...................................  6
   4.1.1 X9.42 Ephemeral-Static Diffie-Hellman ......................  7
   4.1.2 X9.42 Static-Static Diffie-Hellman .........................  8
   4.2   Key Transport Algorithms ...................................  9
   4.2.1 RSA (PKCS #1 v1.5) ......................................... 10
   4.3   Symmetric Key-Encryption Key Algorithms .................... 10
   4.3.1 Triple-DES Key Wrap ........................................ 11
   4.3.2 RC2 Key Wrap ............................................... 12
   4.4   Key Derivation Algorithms .................................. 12

Housley                     Standards Track                     [Page 1]
RFC 3370                     CMS Algorithms                  August 2002

   4.4.1 PBKDF2 ..................................................... 13
   5     Content Encryption Algorithms .............................. 13
   5.1   Triple-DES CBC ............................................. 14
   5.2   RC2 CBC .................................................... 14
   6     Message Authentication Code (MAC) Algorithms ............... 15
   6.1   HMAC with SHA-1 ............................................ 15
   7     ASN.1 Module ............................................... 16
   8     References ................................................. 18
   9     Security Considerations .................................... 20
   10    Acknowledgments ............................................ 22
   11    Author's Address ........................................... 23
   12    Full Copyright Statement ................................... 24

1  Introduction

   The Cryptographic Message Syntax (CMS) [CMS] is used to digitally
   sign, digest, authenticate, or encrypt arbitrary message contents.
   This companion specification describes the use of common
   cryptographic algorithms with the CMS.  Implementations of the CMS
   may support these algorithms; implementations of the CMS may also
   support other algorithms as well.  However, if an implementation
   chooses to support one of the algorithms discussed in this document,
   then the implementation MUST do so as described in this document.

   The CMS values are generated using ASN.1 [X.208-88], using BER-
   encoding [X.209-88].  Algorithm identifiers (which include ASN.1
   object identifiers) identify cryptographic algorithms, and some
   algorithms require additional parameters.  When needed, parameters
   are specified with an ASN.1 structure.  The algorithm identifier for
   each algorithm is specified, and when needed, the parameter structure
   is specified.  The fields in the CMS employed by each algorithm are
   identified.

1.1  Changes Since RFC 2630

   This document obsoletes section 12 of RFC 2630 [OLDCMS].  RFC 3369
   [CMS] obsoletes the rest of RFC 2630.  Separation of the protocol and
   algorithm specifications allows each one to be updated without
   impacting the other.  However, the conventions for using additional
   algorithms with the CMS are likely to be specified in separate
   documents.

1.2  Terminology

   In this document, the key words MUST, MUST NOT, REQUIRED, SHOULD,