Poor man's encrypted data

[Pierre Sahores]

Richard Gaskin a écrit :
> 
> Dave Cragg wrote:
> 
> > At 9:46 am -0800 5/4/03, Richard Gaskin wrote:
> >> Dave Cragg wrote:
> >>
> >>> At 8:21 am -0800 5/4/03, Richard Gaskin wrote:
> >>>> For sending data across the net in a semi-secure format, can you think of
> >>>> any downsides to simply storing the data in custom props in a
> >>>> password-protected stack?
> >>>
> >>> One possible downside is that, although the contents of the custom
> >>> props will be encrypted, if someone is able to get the entire stack
> >>> data, then with a copy of Rev/Metacard (the starter kit will do) you
> >>> can still "get" the custom props. (Password-protecting only denies
> >>> access to the scripts.)
> >>
> >> It was my successful test that prompted my post: with the MC 2.4.3 engine it
> >> seems custom props are also encrypted.
> >
> > The custom props are encrypted when you view the file data, but if
> > you open the stack with Rev or Metacard, you can still "get" a custom
> > property without setting the passkey.
> 
> It should be easy for Scott to lock that custom prop access along with
> script editing.
> 
> In the meantime, I just wrote these two simple handlers to tuck sizable data
> into a script by just making sure it only occupies one line:
> 
> on SuckUp
>   answer file "Select a file:"
>   if it is empty then exit to top
>   put url ("binfile:"&it) into s
>   put compress(s) into s
>   -- Convert to ASCII:
>   put base64encode(s) into s
>   -- Remove returns:
>   replace cr with "<RETURN_PLACEHOLDER>" in s
>   set the script of fld 1 to s
> end SuckUp
> 
> on SpitOut
>   ask file "Name new file:"
>   if it is empty then exit to top
>   put the script of fld 1 into s
>   replace "<RETURN_PLACEHOLDER>" with cr in s
>   put base64decode(s) into s
>   put decompress(s) into s
>   set the filetype to "MSIEWAFF"
>   put s into url ("binfile:"&it)
> end SpitOut
> 
> The filetype is only a convenience for my testing -- I used an MSIE page
> archive as it has a nice mix of ASCII and binary data, and I have several
> lying around that are a few hundred k.
> 
> Interestingly, MC's limit of 64k per line only seems to affect fields, but
> not the script property itself.  I just ran this on a 142k file and it
> worked great.  The base64 adds some overhead to the file size, but at least
> withu any control chars its very save for transport.  Conceivably, one could
> use this to store up to 10 files per script with the scriptlimits at play.
> 
> So with that out of the way, we're back to the original question:  for what
> uses would a hard-to-break but not military-grade encryption be acceptable?
> 
> --
>  Richard Gaskin
>  Fourth World Media Corporation
>  Developer of WebMerge 2.2: Publish any database on any site
>  ___________________________________________________________
>  Ambassador at FourthWorld.com       http://www.FourthWorld.com
>  Tel: 323-225-3717                       AIM: FourthWorldInc
> 
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Thanks Richard for this share. Stored for future uses.
--
Kind Regards, Pierre Sahores

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