Re: [websec] Issue 17: Registry for magic numbers

["Martin J. Dürst" <[e-mail]>]

Hello Adam,

On 2011/10/25 11:21, Adam Barth wrote:
> http://trac.tools.ietf.org/wg/websec/trac/ticket/17 refers to an IANA
> registry with magic numbers for various media types.  I wanted to
> compare them to what's in the draft, but I couldn't find it.  I found
> the media type registry, e.g., for images:
>
> http://www.iana.org/assignments/media-types/image/index.html
>
> but I don't see any magic numbers.  Would someone be willing to point
> me in the right direction?

They are in the templates. To get the template for a registration, start 
at the overview page 
(http://www.iana.org/assignments/media-types/index.html).

Then go to the page that lists all the registration for a give top 
level, e.g. http://www.iana.org/assignments/media-types/image/index.html 
for images.

Then look at each registration template (click on the link in the left 
column, or in the right column if the left one doesn't have a link and 
the right one is to an RFC). You may then find a magic number in the 
registration template. As an example, for image/jp2, the template is at 
http://www.iana.org/assignments/media-types/image/jp2.

But it looks like earlier templates didn't have a field for a magic 
number, and this and the reasons Anne gave make this information helpful 
for cross-checking, but not much more.

Regards,   Martin.