Hector Santos wrote:
Hector Santos wrote:
The document editor and others believe this is a MLM BUG. It could
be, but we don't know if its really an normal attempt to add HEADER
text that was empty:
Create List Message for Distribution:
Body = EMPTY;
Body += AppendText(GetHeaderNoticeForList()) + CRLF;
Body += AppendText(GetMessageBody()) + CRLF;
Body += AppendText(GetFooterNoticeForList()) + CRLF;
We just don't know. Of course, for programmers, one can easily see
that there is a "mite" there where extra CRLF will be added. We
recognized it with the ending CRLF but "forgot" that list header text
was also possible. The key point is for "40" years, it wasn't a
problem until a new kid in the block came and now demands MLMs adjust
to work with it
As a follow up, the above is very conceivable when you also consider
the addition of List-* [headers] which is normally done with templates:
Head = EMPTY;
Head = GetMessageHeaders();
Head += GetListHeaders();
Body = EMPTY;
Body += GetHeaderNoticeForList()+CRLF;
Body += GetMessageBody() + CRLF;
Body += GetFooterNoticeForList() + CRLF;
Mail = Head + CRLF + Body;
Of course, regardless of DKIM, to be aesthetically "clean" in
displays, it should perform trailing CRLF checks to avoid extra lines:
Head = EMPTY;
Head = GetMessageHeaders();
Head += TrimCRLF(GetListHeaders()); // no extra CRLF
Body = EMPTY;
TextHeader = TrimCRLF(GetHeaderNoticeForList()); // no extra CRLF
if (TextHeader != EMPTY) Body += TextHeader +CRLF;
Body += GetMessageBody();
TextFooter = TrimCRLF(GetFooterNoticeForList()); // no extra CRLF
if (TextFooter) Body += CRLF+ TextFooter + CRLF;
Mail = Head + CRLF + Body;
So its easy to see that a MLM not being 100% in its "clean" header and
footer text additions to the header and body is possible without being
label as a "BUG" or bad until something that deals with the purity of
integrity and C14N comes into play.
The MLM I-D *SHOULD* at least acknowledge that an extra line is
conceivable.
Base on possible code analysis , here is what I recommend:
current text in section 3.3:
Minor body changes: Some lists prepend or append a few lines to each
message to remind subscribers of an administrative URL for
subscription issues, or of list policy, etc.
proposed changed (starter text):
Minor body changes: Some lists prepend or append a few lines to each
message to remind subscribers of an administrative URL for
subscription issues, or of list policy, etc. These few lines can
have extra blank lines or empty text with only CRLF characters
which under normal circumstances would be trimmed or pruned.
The goal is to give the MLM audience reading this document insights
into their long running current code which may need some modern CRLF
trimming considerations, if any, even if the MLM is non-DKIM aware or
a list is setup by the admin not to DKIM resign mail submissions. No
need to mention C14N kludges or new C14N (i.e. STRIP) proposals.
--
Hector Santos, CTO
http://www.santronics.com
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