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BinaryTime: An Alternate Format for Representing Date and Time in ASN.1 (RFC4049)

IP.com Disclosure Number: IPCOM000124249D
Original Publication Date: 2005-Apr-01
Included in the Prior Art Database: 2005-Apr-13
Document File: 8 page(s) / 12K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Housley: AUTHOR

Abstract

This document specifies a new ASN.1 type for representing time: BinaryTime. This document also specifies an alternate to the signing-time attribute for use with the Cryptographic Message Syntax (CMS) SignedData and AuthenticatedData content types; the binary- signing-time attribute uses BinaryTime. CMS and the signing-time attribute are defined in RFC 3852.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 22% of the total text.

Network Working Group                                        R. Housley
Request for Comments: 4049                               Vigil Security
Category: Experimental                                       April 2005


                              BinaryTime:
      An Alternate Format for Representing Date and Time in ASN.1

Status of This Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This document specifies a new ASN.1 type for representing time:
   BinaryTime.  This document also specifies an alternate to the
   signing-time attribute for use with the Cryptographic Message Syntax
   (CMS) SignedData and AuthenticatedData content types; the binary-
   signing-time attribute uses BinaryTime.  CMS and the signing-time
   attribute are defined in RFC 3852.

1.  Introduction

   This document specifies a new ASN.1 [ASN1] type for representing
   time:  BinaryTime.  This ASN.1 type can be used to represent date and
   time values.

   This document also specifies an alternative to the signing-time
   attribute used with the Cryptographic Message Syntax (CMS) [CMS]
   SignedData and AuthenticatedData content types, allowing the
   BinaryTime type to be used instead of the traditional UTCTime and
   GeneralizedTime types.

1.1.  BinaryTime

   Many operating systems represent date and time as an integer.  This
   document specifies an ASN.1 type for representing date and time in a
   manner that is also an integer.  Although some conversion may be
   necessary due to the selection of a different epoch or a different
   granularity, an integer representation has several advantages over
   the UTCTime and GeneralizedTime types.

Housley                       Experimental                      [Page 1]
RFC 4049                       BinaryTime                     April 2005


   First, a BinaryTime value is smaller than either a UTCTime or a
   GeneralizedTime value.

   Second, in some operating systems, the value can be used with little
   or no conversion.  Conversion, when it is needed, requires only
   straightforward computation.  If the endian ordering is different
   from the ASN.1 representation of an INTEGER, then straightforward
   manipulation is needed to obtain an equivalent integer value.  If the
   epoch is different than the one chosen for BinaryTime, addition or
   subtraction is needed to compensate.  If the granularity is something
   other than seconds, then multiplication or...