[Bug 2745] wd-19: base64 and linefeeds

http://www.w3.org/Bugs/Public/show_bug.cgi?id=2745

           Summary: wd-19: base64 and linefeeds
           Product: XML Schema
           Version: 1.1 only
          Platform: PC
               URL: http://lists.w3.org/Archives/Public/www-xml-schema-
                    comments/2004OctDec/0023.html
        OS/Version: Windows XP
            Status: NEW
          Keywords: needsDrafting
          Severity: normal
          Priority: P2
         Component: Datatypes: XSD Part 2
        AssignedTo: cmsmcq@w3.org
        ReportedBy: holstege@mathling.com
         QAContact: www-xml-schema-comments@w3.org


RFC 3548 is better reference than RFC 2045 (MIME) for defining Base64 in XML 
Schema Part 2. Future versions, at least, should use the newer document as a 
reference. The good news is that XML Schema's departure from RFC 2045 regarding 
linefeeds and whitespace (disallowing them in the canonical representation) is 
in agreement with RFC 3548:

2.1. Line feeds in encoded data

MIME is often used as a reference for base 64 encoding. However, MIME does not 
define "base 64" per se, but rather a "base 64 Content-Transfer-Encoding" for 
use within MIME. As such, MIME enforces a limit on line length of base 64 
encoded data to 76 characters. MIME inherits the encoding from PEM stating it is 
"virtually identical", however PEM uses a line length of 64 characters. The MIME 
and PEM limits are both due to limits within SMTP.

Implementations MUST NOT not add line feeds to base encoded data unless the 
specification referring to this document explicitly directs base encoders to add 
line feeds after a specific number of characters. 

Proposal concerning
Part 2
base64Binary

Transition history
raised on 24 Nov 2004 by Xan Gregg (http://lists.w3.org/Archives/Public/www-xml-
schema-comments/2004OctDec/0023.html)
agreed on 22 Apr 2005 (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/
2005Apr/0056.html)

MSM proposed that we agree with the comment; no dissent.

Acknowledgment cycle
announced by group on 22 Apr 2004 (http://lists.w3.org/Archives/Member/w3c-xml-
schema-ig/2005Apr/0056.html)
agreement by reviewer on 22 Apr 2004 (http://lists.w3.org/Archives/Member/w3c-
xml-schema-ig/2005Apr/0056.html)

Action history
Part 2 Editors
accepted on 22 Apr 2005 (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/
2005Apr/0056.html)

DT editors to check that RFC 3548 is (still) the latest, and update references 
in Datatypes to point to latest RFC, thus resolving wd-19. (Result will take the 
form of an Editorial Proposal.)

Received on Friday, 20 January 2006 21:23:00 UTC