Re: Re(2) : AS{035}2, MIME {038} X.400

[carl@xxxxxxxxx (Carl Hage)]

Keith Moore (moore@xxxxxxxxxx) wrote:
: Perhaps we need a special MIME<>X.400 mapping for multipart/signed,
: which preserves the multipart/signed structure.

Nothing special over what is already defined is really required. It's sort
of obvious that any software eating MIME wrappers, digesting the contents,
and emitting some converted protocol, has to do that by interpreting the
MIME headers and map those to the equivalent in the destination protocol.

When a multipart/signed is encountered, the author of the "digester"
software should be aware that when converting the signature format,
the content cannot be altered. A gateway might convert a signature
into PKCS7 embedded signed data, but in order to do this, the implementor
would always know not to alter the content.

There might be some faulty digesters that improperly assume
multipart/signed is the same as multipart/mixed, e.g. improperly drop the
qualifier on the multipart. The problem here is that such a gateway does
not follow the MIME spec. Fixing this problem in the gateway software
should be relatively easy since all that is needed is to disable
conversion of multipart/signed, and pass it intact as ASCII 7 bit data.
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Carl Hage                                              C. Hage Associates
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