Message contains NUL characters ...

[John Fawcett]

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
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