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RE: [Asrg] How to defeat spam that uses encryption?

2003-04-20 11:32:42
HBP> Base64 exists for one reason alone - because stupid MTAs had a
HBP> habit of molesting the messages they were transmitting.

DC> Base64 was added to permit sending random 8-bit data
DC> within a 7-bit stream.

DC> There was no intent to try to trick intermediaries.

I think Dave's real problem was with the term "molest" -- if a 7-bit 
protocol is given 8-bit data, it can't do *anything* wrong or 
malicious 
-- having been fed illegal data, its behavior is completely 
unspecified.  You're lucky it doesn't release poison gas into your 
server room.  :-)  -- Nathaniel

Oh there are worse problems than 7-bit transport which was in
decline long before MIME came arround.

Lots of MTAs perform arbitrary transformations on text before
it is sent. In many cases an MTA will wrap lines so as not to
cause overflow on the user terminal of the MTA. Changing CR to
CRLF is common, as is the exact opposite. Lots of IBM mainframes
have MTAs that append the sequence =20 to the end of each line
for reasons only known to themselves. 

The word 'molest' was chosen quite deliberately. And all these 
problems exist whether you have 8-bit or 7-bit transport.

                Phill
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