[jdev] base64 line endings

[Norman Rasmussen]

It seems that JEP-0084 is inadvertently conflicting with itself by
saying that data must be encoded the RFC 3548 way, and not explicitly
allowing line feeds.

So something to add to JEP-0084 v0.8 would be to explicitly allow line feeds.

JEP-0084: User Avatar refers to RFC 3548 (The Base16, Base32, and
Base64 Data Encodings), and in Section 2.1 it says:

   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.

In  XML Schemas (http://www.w3.org/TR/xmlschema-2/#base64Binary) it says:

   For compatibility with older mail gateways, [RFC 2045] suggests
that base64 data should have lines limited to at most 76 characters in
length. This line-length limitation is not mandated in the lexical
forms of base64Binary data and must not be enforced by XML Schema
processors.

JEP-0153: vCard-Based Avatars refers to RFC 2045 (Multipurpose
Internet Mail Extensions), and in Section 6.8 it says:

   The encoded output stream must be represented in lines of no more
   than 76 characters each.  All line breaks or other characters not
   found in Table 1 must be ignored by decoding software.  In base64
   data, characters other than those in Table 1, line breaks, and other
   white space probably indicate a transmission error, about which a
   warning message or even a message rejection might be appropriate
   under some circumstances.

--
- Norman Rasmussen
 - Email: norman at rasmussen.co.za
 - Home page: http://norman.rasmussen.co.za/