2 May 2005 13:34
Re: Message contains NUL characters ...
John Fawcett <johnml <at> michaweb.net>
2005-05-02 11:34:44 GMT
2005-05-02 11:34:44 GMT
David R Bosso wrote: > --On Thursday, April 28, 2005 4:13 PM -0400 Joseph Brennan > <brennan <at> columbia.edu> wrote: > >> >> >> --On Thursday, April 28, 2005 16:22 -0300 "Marc G. Fournier" >> <scrappy <at> hub.org> wrote: >> >> >>> Someone mentioned that this was, in fact, not forbid'd in the RFCs ... >>> could you point to the relevant RFC where it is? Considering how >>> 'strict' postfix seems to be, having an RFC to back that up might show >>> some changes over in that camp, at least ... >> >> >> >> RFC 2822, section 4.1, makes null an obsolete character. >> >> But same, section 2.3, does not explicitly forbid them in bodies. It >> does say the body must be US-ASCII characters, and following that >> appears to get to section 4.1 defining what characters are. > > > It's not allowed unless you're talking about the obsolete section as > mentioned in my previous email. > > See the following that defines the syntax: > > 3.1 > | In some of the definitions, there will be nonterminals whose names > | start with "obs-". These "obs-" elements refer to tokens defined in > | the obsolete syntax in section 4. In all cases, these productions > | are to be ignored for the purposes of generating legal Internet > | messages and MUST NOT be used as part of such a message. However, > | when interpreting messages, these tokens MUST be honored as part of > | the legal syntax. In this sense, section 3 defines a grammar for > | generation of messages, with "obs-" elements that are to be ignored, > | while section 4 adds grammar for interpretation of messages. > > 3.2.1 > | text = %d1-9 / ; Characters excluding CR and LF > | %d11 / > | %d12 / > | %d14-127 / > | obs-text > > 3.5 > | body = *(*998text CRLF) *998text > > No NUL allowed. > > So as before, it's illegal to send them. > > -David > The question in my mind is whether it is legal to reject them. Reading the above it seems that nulls should be accepted as legal syntax. If I am correct in this interpretation, an MTA which passes them on to Cyrus (ie did not generate them but did accept them) is behaving correctly? John --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html