X.400 Image Body Parts
Defines how JPEG and GIF images are carried through X.400 mail and mapped to their MIME types.
Alvestrand, H., "X.400 Image Body Parts", RFC 2158, DOI 10.17487/RFC2158, January 1998, <https://www.rfc-editor.org/info/rfc2158>.
@misc{rfc2158,
series = {Request for Comments},
number = 2158,
howpublished = {RFC 2158},
publisher = {RFC Editor},
doi = {10.17487/RFC2158},
url = {https://www.rfc-editor.org/info/rfc2158},
author = {H. Alvestrand},
title = {{X.400 Image Body Parts}},
pagetotal = 4,
year = 1998,
month = jan,
} RFC text
Contents
Network Working Group H. Alvestrand
Request for Comments: 2158 UNINETT
Category: Standards Track January 1998
X.400 Image Body Parts
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 (1998). All Rights Reserved.
1. Introduction
This document contains the body parts defined in RFC 1495 for
carrying image formats that were originally defined in MIME through
an X.400 system.
It also documents the OIDs assigned to these data formats as FTAM
body parts, which allow the MIME types to be converted to FTAM body
parts; this will probably be more useful than the new body parts
defined here.
2. Newly defined X.400 body parts
2.1. The JPEG body part
The following Extended Body Part is defined for JPEG data streams.
It has no parameters.
jpeg-body-part EXTENDED-BODY-PART-TYPE
DATA OCTET STRING
::= mime-jpeg-body
mime-jpeg-body OBJECT IDENTIFIER ::=
{ mixer-bp-data 3 }
The content is as defined in [MIME].
2.2. The GIF body part
The following Extended Body Part is defined for GIF data streams. It
has no parameters.
gif-body-part EXTENDED-BODY-PART-TYPE
DATA OCTET STRING
::= mime-gif-body
mime-gif-body OBJECT IDENTIFIER ::=
{ mixer-bp-data 4 }
The content is as defined in [MIME].
3. Defined equivalences with MIME types
3.1. image/jpeg - jpeg-body-part
X.400 Body Part: Extended Body Part, OID jpeg-body-part
MIME Content-Type: image/jpeg
Conversion: None
3.2. image/jpeg - FTAM EMA JPEG
X.400 Body Part: FTAM EMA JPEG
MIME Content-Type: image/jpeg
Conversion: None
The OID assigned to JPEG by EMA in [MAWG] is
{ ema objects(2) messaging (2) attachments(1) jpeg-image(6) }
while EMA's OID is
{ joint-iso-ccitt(2) country(16) us(840) organization(1)
ema(113694) }
making the total OID, numeric only
{ 2 16 840 1 113694 2 2 1 6 }
3.3. image/gif - gif-body-part
X.400 Body Part: Extended Body Part, OID gif-body-part
MIME Content-Type: image/gif
Conversion: None
3.4. image/gif - FTAM EMA GIF
X.400 Body Part: FTAM EMA GIF
MIME Content-Type: image/jpeg
Conversion: None
The OID assigned to JPEG by EMA in [MAWG] is
{ ema objects(2) messaging (2) attachments(1) gif-image(4) }
4. Security Considerations
Security issues are not considered in this memo.
5. References
[MIME]
Freed, N., and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message Bodies",
RFC 2045, November 1996.
[MAWG]
Electronic Messaging Association Message Attachment Working Group
(MAWG): File Transfer Body Part Feasibility Project Guide -
version 1.5.1 - March 1996.
6. Author's Address
Harald Tveit Alvestrand
UNINETT
Postboks 6883 Elgeseter
N-7002 TRONDHEIM
Phone: +47 73 59 70 94
EMail: Harald.T.Alvestrand@uninett.no
7. Full Copyright Statement
Copyright (C) The Internet Society (1998). All Rights Reserved.
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.
AI ELI5
On this page
§1Purpose
This document carries the body parts defined in RFC 1495 for image formats that were originally defined in MIME through an X.400 system.
It also documents the object identifiers (OIDs) assigned to these formats as FTAM body parts, so the MIME types can be converted to FTAM body parts. The RFC says this will probably be more useful than the new body parts it defines.
Two mail systems speak different languages. This note gives picture files a name tag in the older one.
§2The JPEG and GIF Body Parts
Two new Extended Body Parts are defined, jpeg-body-part and gif-body-part. Both have no parameters, and their data is an OCTET STRING whose content is as defined in MIME.
Each is identified by an object identifier under mixer-bp-data: JPEG is { mixer-bp-data 3 } and GIF is { mixer-bp-data 4 }.
Each picture type gets its own numbered label, and the picture bytes go inside untouched.
§3Equivalences with MIME Types
Four equivalences are listed, all with conversion type "None". The image/jpeg type maps to the JPEG Extended Body Part and to the FTAM EMA JPEG body part. The image/gif type maps to the GIF Extended Body Part and to the FTAM EMA GIF body part.
The EMA JPEG OID is built from the EMA organization identifier and works out to the numeric form { 2 16 840 1 113694 2 2 1 6 }. The EMA GIF OID ends in gif-image(4) under the same EMA prefix.
A table says which old-system label matches which new-system label. Because the picture bytes are the same, nothing has to be changed on the way across.
| MIME type | X.400 body part | Conversion |
|---|---|---|
| image/jpeg | Extended Body Part, jpeg-body-part | None |
| image/jpeg | FTAM EMA JPEG | None |
| image/gif | Extended Body Part, gif-body-part | None |
| image/gif | FTAM EMA GIF | None |
§4Security
The RFC says only that security issues are not considered in this memo. It adds no security mechanism of its own.
The note does not say anything about keeping pictures secret or safe.