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Hi there,

we are currently implementing a NIO-bases IMAP-Server. We use a
line-delimiter for break down the "buffers" and push them down to the
processors. This works fine so far but we are a bit concerned about
how to limit the max buffer size in a case of a very-very long line.
We saw there is a rfc which refer to something about 8000 octets per
command-line.

RFC 2683 section 3.2.1 (imap4 implementation
recommendations):

"For its part, a server should allow for a command line of at least
 8000 octets. This provides plenty of leeway for accepting reasonable
 length commands from clients. The server should send a BAD response
 to a command that does not end within the server's maximum accepted
 command length."

But I think this only is true for commands lines without the literal
usage. So at the moment we limit a line to be max of 64kb to guard
against a DOS but I'm not sure its really the way to go. Anyone has
some expirience with such needs ?

Thx,
Norman

With the exception of the APPEND command, most literals that are likely to
appear in an IMAP command are relatively small.  UW and Panda IMAP have a
limit of 10,000 octets which is far more than what anything is ever likely
to use.

APPEND (and APPEND-class exceptions such as CATENATE) is the exception.
Those literals can be as large as an email message (so potentially
hundreds of megabytes).

Many servers handle APPEND as a special case command.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.