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MIME sniffing

Keith Moore <moore@network-heretics.com> Wed, 02 December 2020 11:42 UTC

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Subject: MIME sniffing
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From: Keith Moore <moore@network-heretics.com>
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Date: Wed, 02 Dec 2020 06:42:49 -0500
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On 12/2/20 12:00 AM, Phillip Hallam-Baker wrote:

> The biggest mistake in the Web protocols was accepting the dictum of 
> being permissive in what is accepted. Horrors like MIME sniffing might 
> had been avoided if enough browsers had insisted on literal 
> interpretation of content type.

The fundamental problem there is that the server doesn't have a reliable 
way of knowing the content-type.   The server can't reliably tell it 
using filename suffix.   And since the client is blamed when it displays 
content incorrectly, the pressure is inevitably on the client to fix 
things.    I don't think this could have been avoided by different 
language in the HTTP specification.

Keith

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