idnits 2.17.1 draft-ietf-smime-compression-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** The document seems to lack a 1id_guidelines paragraph about 6 months document validity -- however, there's a paragraph with a matching beginning. Boilerplate error? == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 1 longer page, the longest (page 1) being 187 lines Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** The document seems to lack separate sections for Informative/Normative References. All references will be assumed normative when checking for downward references. ** There are 2 instances of too long lines in the document, the longest one being 2 characters in excess of 72. ** The document seems to lack a both a reference to RFC 2119 and the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords -- however, there's a paragraph with a matching beginning. Boilerplate error? RFC 2119 keyword, line 48: '...entations of CMS SHOULD include this e...' RFC 2119 keyword, line 82: '...Implementations SHOULD use the SMIMECa...' Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == The "Author's Address" (or "Authors' Addresses") section title is misspelled. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (February 2001) is 8468 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Missing reference section? 'RFC 2630' on line 47 looks like a reference -- Missing reference section? 'ASN1' on line 50 looks like a reference -- Missing reference section? 'RFC2119' on line 55 looks like a reference -- Missing reference section? 'RFC 1950' on line 92 looks like a reference -- Missing reference section? 'RFC 1951' on line 92 looks like a reference Summary: 6 errors (**), 0 flaws (~~), 4 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Internet Draft Editor: Peter Gutmann 2 draft-ietf-smime-compression-01.txt University of Auckland 3 August 29, 2000 4 Expires February 2001 6 Compressed Data Content Type for S/MIME 8 Status of this memo 10 This document is an Internet-Draft and is in full conformance with all 11 provisions of Section 10 of RFC2026. 13 Internet-Drafts are working documents of the Internet Engineering Task 14 Force (IETF), its areas, and its working groups. Note that other 15 groups may also distribute working documents as Internet-Drafts. 17 Internet-Drafts are draft documents valid for a maximum of six months 18 and may be updated, replaced, or obsoleted by other documents at any 19 time. It is inappropriate to use Internet- Drafts as reference 20 material or to cite them other than as "work in progress." 22 The list of current Internet-Drafts can be accessed at 23 http://www.ietf.org/ietf/1id-abstracts.txt 25 The list of Internet-Draft Shadow Directories can be accessed at 26 http://www.ietf.org/shadow.html. 28 Abstract 30 The Cryptographic Message Syntax data format doesn't currently contain 31 any provisions for compressing data before processing it. Compressing 32 data before transmission provides a number of advantages including the 33 elimination of data redundancy which could help an attacker, speeding 34 up processing by reducing the amount of data to be processed by later 35 steps such as signing or encryption, and reducing overall message size. 36 Although there have been proposals for adding compression at other 37 levels (for example at the MIME or SSL level) these don't address the 38 problem of compression of CMS content unless the compression is 39 supplied by an external means (for example by intermixing MIME and 40 CMS). This document defines a format for using compressed data as a 41 CMS content type. 43 1. Introduction 45 This document describes a compressed data content encryption type for 46 S/MIME. This is implemented as a new ContentInfo type and is an 47 extension to the types currently defined in CMS [RFC 2630]. Future 48 implementations of CMS SHOULD include this extension. 50 The format of the messages are described in ASN.1:1994 [ASN1]. 52 The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", 53 "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be 54 interpreted as described in [RFC2119]. 56 1.1 Compressed Data Content Type 58 The compressed-data content type consists of content of any type 59 compressed using a specified algorithm. The following object 60 identifier identifies the compressed-data content type: 62 id-ct-compressedData OBJECT IDENTIFIER ::= { iso(1) member-body(2) 63 us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) ct(1) 9 } 65 The compressed-data content type shall have ASN.1 type CompressedData: 67 CompressedData ::= SEQUENCE { 68 version CMSVersion, 69 compressionAlgorithm CompressionAlgorithmIdentifier, 70 encapContentInfo EncapsulatedContentInfo 71 } 73 The fields of type CompressedData have the following meanings: 75 version is the syntax version number. It shall be 0. 77 compressionAlgorithm is a compression algorithm identifier, as 78 defined in section 2. 80 encapContentInfo is the content which is compressed. 82 Implementations SHOULD use the SMIMECapabilities attribute to indicate 83 their ability to process compressed content types. A compression 84 SMIMECapability consists of the AlgorithmIdentifier for the supported 85 compression algorithm, in the case of the algorithm specified in this 86 document this is id-alg-zlibCompression with parameters NULL. 87 Alternatively, the use of compression may be handled by prior 88 arrangement (for example as part of an interoperability profile). 90 2. Compression Types 92 CMS implementations should include ZLIB [RFC 1950] [RFC 1951], which is 93 free of any intellectual property restrictions and has a freely- 94 available, portable and efficient reference implementation. The 95 following object identifier identifies ZLIB: 97 id-alg-zlibCompress OBJECT IDENTIFIER ::= { iso(1) member-body(2) 98 us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) alg(3) 8 } 100 The parameters for this algorithm are NULL. 102 3. Security Considerations 104 This RFC is not concerned with security, except for the fact that 105 compressing data before encryption can enhance the security provided by 106 other processing steps by reducing the quantity of known plaintext 107 available to an attacker. 109 Author Address 111 Peter Gutmann 112 University of Auckland 113 Private Bag 92019 114 Auckland, New Zealand 115 pgut001@cs.auckland.ac.nz 117 References 119 ASN1 Recommendation X.680: Specification of Abstract Syntax Notation 120 One (ASN.1), 1994. 122 RFC2119 Key Words for Use in RFC's to Indicate Requirement Levels, 123 S.Bradner, March 1997. 125 RFC1950 ZLIB Compressed Data Format Specification version 3.3, 126 P.Deutsch and J-L Gailly, May 1996. 128 RFC1951 DEFLATE Compressed Data Format Specification version 1.3, 129 P.Deutsch, May 1996. 131 RFC 2630 Cryptographic Message Syntax, R.Housley, June 1999. 133 Appendix A: ASN.1 Module 135 CompressedDataContent 136 { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) 137 smime(16) modules(0) compress(11) } 139 DEFINITIONS IMPLICIT TAGS ::= 140 BEGIN 142 IMPORTS 143 CMSVersion, EncapsulatedContentInfo FROM CryptographicMessageSyntax 144 { iso(1) member-body(2) us(840) rsadsi(113549) 145 pkcs(1) pkcs-9(9) smime(16) modules(0) cms(1) }, 146 AlgorithmIdentifier FROM AuthenticationFramework 147 { joint-iso-itu-t ds(5) module(1) authenticationFramework(7) 3 }; 149 CompressedData ::= SEQUENCE { 150 version CMSVersion, -- Always set to 0 151 compressionAlgorithm CompressionAlgorithmIdentifier, 152 encapContentInfo EncapsulatedContentInfo 153 } 155 CompressionAlgorithmIdentifer ::= AlgorithmIdentifier 157 END 159 Full Copyright Statement 161 Copyright (C) The Internet Society 1999. All Rights Reserved. 163 This document and translations of it may be copied and furnished to 164 others, and derivative works that comment on or otherwise explain it or 165 assist in its implementation may be prepared, copied, published and 166 distributed, in whole or in part, without restriction of any kind, 167 provided that the above copyright notice and this paragraph are 168 included on all such copies and derivative works. However, this 169 document itself may not be modified in any way, such as by removing the 170 copyright notice or references to the Internet Society or other 171 Internet organizations, except as needed for the purpose of developing 172 Internet standards in which case the procedures for copyrights defined 173 in the Internet Standards process must be followed, or as required to 174 translate it into languages other than English. 176 The limited permissions granted above are perpetual and will not be 177 revoked by the Internet Society or its successors or assigns. 179 This document and the information contained herein is provided on an 180 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 181 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT 182 NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL 183 NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR 184 FITNESS FOR A PARTICULAR PURPOSE.