Message contains NUL characters ...
johnml at michaweb.net
Mon May 2 07:34:44 EDT 2005
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:
> | 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.
> | text = %d1-9 / ; Characters excluding CR and LF
> | %d11 /
> | %d12 /
> | %d14-127 /
> | obs-text
> | body = *(*998text CRLF) *998text
> No NUL allowed.
> So as before, it's illegal to send them.
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
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
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