RFC 3854 (rfc3854) - Page 2 of 15


Securing X



Alternative Format: Original Text Document



RFC 3854               Securing X.400 with S/MIME              July 2004


   This document defines how to create an X.400 content type that has
   been cryptographically enhanced according to [CMS].  In order to
   create S/MIME messages carrying X.400 content, an S/MIME agent has to
   follow specifications in this document, as well as the specifications
   listed in [CMS].  This memo also defines new parameter values for the
   application/pkcs7-mime MIME type that can be used to transport those
   body parts.

   Throughout this document, there are requirements and recommendations
   made for how receiving agents handle incoming messages.  There are
   separate requirements and recommendations for how sending agents
   create outgoing messages.  In general, the best strategy is to "be
   liberal in what you receive and conservative in what you send".  Most
   of the requirements are placed on the handling of incoming messages
   while the recommendations are mostly on the creation of outgoing
   messages.

   This document does not address transport of CMS-X.400 content.  It is
   assumed that CMS-X.400 content would be transported by Internet mail
   systems, X.400, or other suitable transport.

   This document describes applying security services to the content of
   entire X.400 messages, which may or may not be IPMS messages.  These
   objects can be carried by several means, including SMTP-based mail
   and X.400 mail.  Note that cooperating S/MIME agents must support
   common forms of message content in order to achieve interoperability.

   If the CMS objects are sent as parts of an RFC 822 message, a
   standard MIXER gateway [MIXER] will most likely choose to encapsulate
   the message.  This is not likely to be a format that is usable by an
   X.400 recipient.  MIXER is specifically focused on translation
   between X.420 Interpersonal Messages and non-secure RFC 822/MIME
   messages.  The discussion of security-related body parts in sections
   7.3 and 7.4 of [BODYMAP] is relevant to CMS messages.

   Definition of gateway services to support relay of CMS object between
   X.400 and SMTP environments is beyond the scope of this document.

1.2.  Terminology

   The key words "MUST", "SHALL", "REQUIRED", "SHOULD", "RECOMMENDED",
   and "MAY" in this document are to be interpreted as described in BCP
   14, RFC 2119 [MUSTSHOULD].








Hoffman, et al.             Standards Track