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Independent Submission T. Harding, Ed. Request for Comments: 5402 Axway Category: Informational February 2010 ISSN: 2070-1721

                 Compressed Data within an Internet
             Electronic Data Interchange (EDI) Message

Abstract

 This document explains the rules and procedures for utilizing
 compression (RFC 3274) within an Internet EDI (Electronic Data
 Interchange) 'AS' message, as defined in RFCs 3335, 4130, and 4823.

Status of This Memo

 This document is not an Internet Standards Track specification; it is
 published for informational purposes.

 This is a contribution to the RFC Series, independently of any other
 RFC stream.  The RFC Editor has chosen to publish this document at
 its discretion and makes no statement about its value for
 implementation or deployment.  Documents approved for publication by
 the RFC Editor are not a candidate for any level of Internet
 Standard; see Section 2 of RFC 5741.

 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc5402.

IESG Note

 The content of this RFC was at one time considered by the IETF, and
 therefore it may resemble a current IETF work in progress or a
 published IETF work.  This RFC is not a candidate for any level of
 Internet Standard.  Readers of this RFC should exercise caution in
 evaluating its value for implementation and deployment.

Copyright Notice

 Copyright (c) 2010 IETF Trust and the persons identified as the
 document authors.  All rights reserved.

 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http:trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents

Harding Informational [Page 1] RFC 5402 Compressed Data in an Internet EDI Message February 2010

 carefully, as they describe your rights and restrictions with respect
 to this document.

1. Introduction

 Historically, electronic messages produced by systems following the
 guidelines as outlined in the IETF EDIINT Working Group
 specifications AS1 [AS1], AS2 [AS2], and AS3 [AS3] did not have a way
 to provide a standardized transport neutral mechanism for compressing
 large payloads.  However, with the development of RFC 3274,
 "Compressed Data Content Type for Cryptographic Message Syntax
 (CMS)", we now have a transport-neutral mechanism for compressing
 large payloads.

 A typical EDIINT 'AS' message is a multi-layered MIME message,
 consisting of one or more of the following: payload layer, signature
 layer, and/or encryption layer.  When an 'AS' message is received, a
 Message Integrity Check (MIC) value must be computed based upon
 defined rules within the EDIINT 'AS' RFCs and must be returned to the
 sender of the message via a Message Disposition Notification (MDN).

 The addition of a new compression layer will require this document to
 outline new procedures for building/layering 'AS' messages and
 computing a MIC value that is returned in the MDN receipt.

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].

2. Compressed Data MIME Layer

 The compressed-data CMS (Cryptographic Message Syntax) MIME entity as
 described in [COMPRESSED-DATA] may encapsulate a MIME entity that
 consists of either an unsigned or signed business document.

 Implementers are to follow the appropriate specifications identified
 in the "MIME Media Types" registry [MIME-TYPES] maintained by IANA
 for the type of object being packaged.  For example, to package an
 XML object, the MIME media type of "application/xml" is used in the
 Content-Type MIME header field and the specifications for enveloping
 the object are contained in [XMLTYPES].

 MIME entity example:

 Content-type: application/xml; charset="utf-8"

 <?xml version="1.0" encoding="UTF-8"?>
 <!-- sample xml document -->

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 The MIME entity will be compressed using [ZLIB] and placed inside a
 CMS compressed-data object as outlined in [COMPRESSED-DATA].  The
 compressed-data object will be MIME encapsulated according to details
 outlined in [S/MIME3.1], RFC 3851, Section 3.5.

 Example:

 Content-Type: application/pkcs7-mime; smime-type=compressed-data;
 name=smime.p7z
 Content-Transfer-Encoding: base64
 Content-Disposition: attachment; filename=smime.p7z

 MIAGCyqGSIb3DQEJEAEJoIAwgAIBADANBgsqhkiG9w0BCRADCDCABgkqhkiG9w0BBwGg
 Hnic7ZRdb9owFIbvK/k/5PqVYPFXGK12YYyboVFASSp1vQtZGiLRACZE49/XHoUW7S/0
 fU5ivWnasml72XFb3gb5druui7ytN803M570nii7C5r8tfwR281hy/p/KSM3+jzH5s3+
 P3VT3QbLusnt8WPIuN5vN/vaA2+DulnXTXkXvNTr8j8ouZmkCmGI/UW+ZS/C8zP0bz2d
 UEk2M8mlaxjRMByAhZTj0RGYg4TvogiRASROsZgjpVcJCb1KV6QzQeDJ1XkoQ5Jm+C5P
 v+ORAcshOGeCcdFJyfgFxdtCdEcmOrbinc/+BBMzRThEYpwl+jEBpciSGWQkI0TSlREm
 SGLuESm/iKUFt1y4XHBO2a5oq0IKJKWLS9kUZTA7vC5LSxYmgVL46SIWxIfWBQd6Adrn
 vGxVibLqRCtIpp4g2qpdtqK1LiOeolpVK5wVQ5P7+QjZAlrh0cePYTx/gNZuB9Vhndtg
 W9ogK+3rnmg3YWygnTuF5GDS+Q/jIVLnCcYZFc6Kk/+c80wKwZjwdZIqDYWRH68MuBQS
 3CAaYOBNJMliTl0X7eV5DnoKIFSKYdj3cRpD/cK/JWTHJRe76MUXnfBW8m7Hd5zhQ4ri
 +kV1/3AGSlJ32bFPd2BsQD8uSzIx6lObkjdz95c0AAAAAAAAAAAAAAAA

 Note: Content-Transfer-Encoding of base64 would only be required if
 the compressed-data MIME bodypart is transferred via a 7-bit protocol
 like SMTP and is visible in the outer layer of the MIME message.  If
 the compressed-data MIME bodypart is placed inside of an encrypted
 MIME bodypart, content-transfer-encoding would not be required on the
 compressed-data MIME bodypart, but would be required on the encrypted
 MIME bodypart.

3. Structure of an EDI MIME Compressed Message

 When compressing a document that will be signed, the application MAY
 compress the innermost MIME body before signing (see Sections 3.2 and
 3.5), or it MAY compress the outer multipart/signed MIME body (see
 Sections 3.3 and 3.6), but it MUST NOT do both within the same
 document.  The receiving application MUST support both methods of
 compression when unpackaging an inbound document.

 Note: The following sections (3.1 - 3.6) show the individual layers
 of a properly formatted EDI MIME message with a compressed data
 layer.  Please refer to the appropriate RFCs for the proper
 construction of the resulting MIME message.  "application/xxxxxxx" is
 used to indicate an application media subtype.

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3.1. No Encryption, No Signature

RFC5322/2045
1. [COMPRESSED-DATA](application/pkcs7-mime)
  1. [MIME-TYPES](application/xxxxxxx)(compressed)

 This section shows the layers of an unsigned, unencrypted compressed
 message.  The first line indicates that the MIME message conforms to
 [RFC5322] and [RFC2045] with a Content-Type of
 application/pkcs7-mime.  Within the pkcs7-mime entity is a compressed
 MIME entity containing the electronic business document.

3.2. No Encryption, Signature

RFC5322/2045
1. [RFC1847] (multipart/signed)
  1. [COMPRESSED-DATA](application/pkcs7-mime)
    1. [MIME-TYPES](application/xxxxxxx)(compressed)
  2. RFC3851 (application/pkcs7-signature)

 This section shows the layers of a signed, unencrypted compressed
 message where the payload is compressed before being signed.

3.3. No Encryption, Signature

RFC5322/2045
1. [COMPRESSED-DATA](application/pkcs7-mime)
  1. [RFC1847] (multipart/signed)(compressed)
    1. [MIME-TYPES](application/xxxxxxx)(compressed)
    2. RFC3851 (application/pkcs7-signature)(compressed)

 This section shows the layers of a signed, unencrypted compressed
 message where a signed payload is compressed.

3.4. Encryption, No Signature

RFC5322/2045
1. RFC3851 (application/pkcs7-mime)
  1. [COMPRESSED-DATA](application/pkcs7-mime) (encrypted)
    1. [MIME-TYPES](application/xxxxxxx)(compressed)(encrypted)

 This section shows the layers of an unsigned, encrypted compressed
 message where the payload is compressed before it is encrypted.

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3.5. Encryption, Signature

RFC5322/2045
1. RFC3851 (application/pkcs7-mime)
  1. [RFC1847] (multipart/signed) (encrypted)
    1. [COMPRESSED-DATA](application/pkcs7-mime) (encrypted)
      1. [MIME-TYPES](application/xxxxxxx) (compressed)(encrypted)
    2. RFC3851 (application/pkcs7-signature) (encrypted)

 This section shows the layers of a signed, encrypted compressed
 message where the payload is compressed before being signed and
 encrypted.

3.6. Encryption, Signature

RFC5322/2045
1. RFC3851 (application/pkcs7-mime)
  1. [COMPRESSED-DATA](application/pkcs7-mime) (encrypted)
    1. [RFC1847] (multipart/signed) (compressed)(encrypted)
      1. [MIME-TYPES](application/xxxxxxx) (compressed)(encrypted)
      2. RFC3851 (application/pkcs7-signature)(compressed)(encrypted)

 This section shows the layers of a signed, encrypted compressed
 message where the payload is signed before being compressed and
 encrypted.

4. MIC Calculations for Compressed Messages Requesting Signed Receipts

4.1. MIC Calculation for Signed Message

 For any signed message, the MIC to be returned is calculated over the
 same data that was signed in the original message as per [AS1].  The
 signed content will be a MIME bodypart that contains either
 compressed or uncompressed data.

4.2. MIC Calculation for Encrypted, Unsigned Message

 For encrypted, unsigned messages, the MIC to be returned is
 calculated over the uncompressed data content including all MIME
 header fields and any applied Content-Transfer-Encoding.

4.3. MIC Calculation for Unencrypted, Unsigned Message

 For unsigned, unencrypted messages, the MIC is calculated over the
 uncompressed data content including all MIME header fields and any
 applied Content-Transfer-Encoding.

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5. Error Disposition Modifier

 For a received message where a receipt has been requested and
 decompression fails, the following disposition modifier will be
 returned in the signed MDN.

 "Error: decompression-failed" - the receiver could not decompress
                                 the message

6. EDIINT Version Header Field

 Any application that supports the compression methods outlined within
 this document MUST use a version identifier value of "1.1" or greater
 within the AS2 or AS3 Version header field as describe in [AS2] and
 [AS3].

7. Compression Formats

 Implementations MUST support ZLIB [ZLIB], which utilizes DEFLATE
 [DEFLATE].

8. Security Considerations

 This document is not concerned with security, except for any security
 concerns mentioned in the referenced RFCs.

9. Normative References

 [AS1]         Harding, T., Drummond, R., and C. Shih, "MIME-based
               Secure Peer-to-Peer Business Data Interchange over the
               Internet", RFC 3335, September 2002.

 [AS2]         Moberg, D. and R. Drummond, "MIME-Based Secure Peer-to-
               Peer Business Data Interchange Using HTTP,
               Applicability Statement 2 (AS2)", RFC 4130, July 2005.

 [AS3]         Harding, T. and R. Scott, "FTP Transport for Secure
               Peer-to-Peer Business Data Interchange over the
               Internet", RFC 4823, April 2007.

 [ZLIB]        Deutsch, P. and J-L. Gailly, "ZLIB Compressed Data
               Format Specification version 3.3", RFC 1950, May 1996.

 [DEFLATE]     Deutsch, P., "DEFLATE Compressed Data Format
               Specification version 1.3", RFC 1951, May 1996.

 [MIME-TYPES]  IANA, "MIME Media Types" registry, available from
               http://www.iana.org.

Harding Informational [Page 6] RFC 5402 Compressed Data in an Internet EDI Message February 2010

 [RFC1847]     Galvin, J., Murphy, S., Crocker, S., and N. Freed,
               "Security Multiparts for MIME: Multipart/Signed and
               Multipart/Encrypted", RFC 1847, October 1995.

 [RFC2045]     Freed, N. and N. Borenstein, "Multipurpose Internet
               Mail Extensions (MIME) Part One: Format of Internet
               Message Bodies", RFC 2045, November 1996.

 [RFC2119]     Bradner, S., "Key words for use in RFCs to Indicate
               Requirement Levels", BCP 14, RFC 2119, March 1997.

 [RFC5322]     Resnick, P., Ed., "Internet Message Format", RFC 5322,
               October 2008.

 [S/MIME3.1]   Ramsdell, B. and S. Turner, "Secure/Multipurpose
               Internet Mail Extensions (S/MIME) Version 3.2 Message
               Specification", RFC 5751, January 2010.

 [XMLTYPES]    Murata, M., St. Laurent, S., and D. Kohn, "XML Media
               Types", RFC 3023, January 2001.

 [COMPRESSED-DATA]
               Gutmann, P., "Compressed Data Content Type for
               Cryptographic Message Syntax (CMS)", RFC 3274, June
               2002.

10. Acknowledgments

 A number of the members of the EDIINT Working Group have also worked
 very hard and contributed to this document. The following people have
 made direct contributions to this document:

 David Fischer, Dale Moberg, Robert Asis, and everyone involved in the
 AS1, AS2 Interop testing during 2002.

Author's Address

 Terry Harding
 Axway
 Scottsdale, Arizona
 USA

 EMail: tharding@us.axway.com

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