Quoting Timo Sirainen <t...@iki.fi>:
On 21.5.2013, at 9.40, Michael M Slusarz <slus...@curecanti.org> wrote:
Using 2.2.2, I see this:
C: 6 APPEND "INBOX" (\seen) "16-May-2013 22:05:14 -0600" CATENATE
(URL "/INBOX;UIDVALIDITY=1255685337/;UID=48812/;SECTION=HEADER"
TEXT ~{40}
S: 6 NO [UNKNOWN-CTE] Binary input allowed only when the first part
is binary.
Why is there this limitation? It seems to me that CATENATE is
confusing the content-type encoding of the data/part itself with
the encoding of the IMAP literal.
A literal 8 is nothing more than a series of OCTET's that *may*
contain nulls, but not necessarily. i.e., in the above example the
40 octets of data are US-ASCII text, which is perfectly acceptable
to send as a literal8. (Client rationale: If BINARY exists on the
server, we don't bother to scan IMAP literal's for null data -- we
just send them as literal8's. It's an optimization that I would
hate to get rid of.)
Well, the problem is that if it does contain NULs, the MIME part
needs to be converted to something that doesn't. And to do that it
needs to modify the previous header, which with current code was
already read..
Is altering the header something that BINARY/CATENATE is allowed to
do? Especially regarding the header. I know there is language about
the server changing the CTE, but this is potentially troubling since
cryptographic signatures may rely on the header text. Changing things
will break the message.
I can see the server altering the body text to match the header. But
I think the reverse is bothersome.
Or are you saying that the error is fine if the text contains NULs,
but simply should be allowed as long as it doesn't?
This. As mentioned before, it seems the code is simply assuming that
the text part contains NULs without ever checking it. My reading of
the literal8 is that there is no requirement that NULs MUST exist in
the string.
In our code, the append data is often from code that the IMAP library
doesn't have access to. So at APPEND time, it is unaware whether the
data contains NUL or not - it just has a blob of data and a length.
If BINARY exists, it is much easier for us to simply send as literal8
and stream the data - no extra overhead is needed on our side. Since
each individual byte need to be handled by the server as it comes in,
it seems much more efficient to do NUL checking there.
michael
