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Re: Read binary file

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Stefan Weiss wrote:

> Thomas 'PointedEars' Lahn wrote:
>> Herbert Kleebauer wrote:
>>> Suppose the Server B provides this information:
>>> "download the picture http://ikomi.de/test/1.jpg and
>>> increase brightness by 10% and decrease contrast by 5%".
> [...]
> 
>> The Canvas API appears to be what you are looking for:
>> 
>> <https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Pixel_manipulation_with_canvas>
>> 
>> (CORS obviously cannot help you there as you do not control the server of
>> the original work.)
> 
> As I mentioned earlier, this does not work cross-origin without CORS.

Indeed.  The Canvas tutorial should be updated with that information.

> Adding image data from server A to the canvas will taint it, preventing
> data extraction and manipulation.

Yes, but:

The Same Origin Policy (SOP) does not depend on the server; it depends on 
protocol and domain names, and port numbers.

Therefore:

> >>> I know how (it is actually trivial if you think it through),
> > (JFTR: Canvas is not what I meant with this.  I had not thought of that 
> > possibility at the time.)
> 
> So, now that the copyright situation has been explained, what's the
> trivial solution?

Transparent HTTP proxying with mod_rewrite, mod_proxy, mod_proxy_http & 
friends.  If the Web browser does not know that a resource has a different 
origin, the SOP does not apply.  WFM with Apache/2.4.18 (Debian) in Chromium 
“46.0.2490.71 Built on 8.2, running on Debian stretch/sid (64-bit)” (which 
would without proxying and CORS block access precisely as you described).

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | SVN: <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | ES Matrix: <http://PointedEars.de/es-matrix>
Please do not cc me. / Bitte keine Kopien per E-Mail.

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Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-16 23:20 +0100
  Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 01:04 +0100
    Re: Read binary file Stefan Weiss <krewecherl@gmail.com> - 2016-03-17 02:34 +0100
      Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 07:56 +0100
    Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-17 08:31 +0100
      Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 19:10 +0100
        Re: Read binary file Stefan Weiss <krewecherl@gmail.com> - 2016-03-17 19:59 +0100
          Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 21:43 +0100
            Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-17 22:36 +0100
              Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 23:15 +0100
              Re: Read binary file Stefan Weiss <krewecherl@gmail.com> - 2016-03-18 00:43 +0100
                Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-18 17:22 +0100
                Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-18 21:14 +0100
                Re: Read binary file Matthias Wiehl <mw@kwarg.de> - 2016-03-19 00:02 +0100
                Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-19 08:48 +0100
                There is no javascript (was: Read binary file) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-19 13:02 +0100
                Re: There is no javascript (was: Read binary file) Mark - <nonemail@spamspamapam.net> - 2016-03-19 14:33 +0000
                Re: There is no javascript (was: Read binary file) Andrew Poulos <ap_prog@hotmail.com> - 2016-03-20 14:30 +1100
                Re: There is no javascript (was: Read binary file) Mark - <nonemail@spamspamapam.net> - 2016-03-20 13:07 +0000
                Re: There is no javascript (was: Read binary file) John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-20 10:39 +0000
                Re: There is no javascript (was: Read binary file) John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-20 11:19 +0000
                Re: There is no javascript (was: Read binary file) Philip Herlihy <thiswillbounceback@you.com> - 2016-03-21 17:06 +0000
                Re: Read binary file Scott Sauyet <scott.sauyet@gmail.com> - 2016-03-22 17:18 -0700
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-23 10:12 +0100
                Re: Read binary file John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-23 16:27 +0000
                Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-24 10:41 +0100
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 11:14 +0100
                Re: Read binary file John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-24 11:41 +0000
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 13:36 +0100
                Re: Read binary file John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-25 10:07 +0000
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-25 11:28 +0100
                Re: Read binary file "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-03-24 11:31 +0100
                Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-24 12:34 +0100
                Re: Read binary file "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-03-24 17:15 +0100
                Re: Read binary file Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-03-24 11:33 +0000
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 11:05 +0100
                Re: Read binary file Scott Sauyet <scott.sauyet@gmail.com> - 2016-03-23 20:16 -0700
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 10:36 +0100
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 11:18 +0100
                Re: Read binary file Scott Sauyet <scott.sauyet@gmail.com> - 2016-03-27 10:22 -0700
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-28 00:18 +0200
                Re: Read binary file Scott Sauyet <scott.sauyet@gmail.com> - 2016-03-28 05:35 -0700
                Re: Read binary file "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-29 00:53 +0200
  Re: Read binary file Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-17 02:23 +0100
  Re: Read binary file Herbert Kleebauer <klee@unibwm.de> - 2016-03-17 08:42 +0100
  Re: Read binary file Dr J R Stockton <reply1600@merlyn.demon.co.uk.invalid> - 2016-03-20 22:03 +0000

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