Re: Re: selective blocking flashs
Micha <[email protected]>
| Newsgroups | gmane.network.wwwoffle.user |
|---|---|
| Message-ID | <20041217200101.7814fd78@puck> |
Hi Andrew, hi galeon folks, So javascript can circumvent my proxy ? What else can js do then ? Download more code, which also downloads more code which downloads more stuff ? Keeping my machine busy with things i don't have the slightest clue about ? I can't imagine this is true ! At least a browser must be controllable, there should be settings. I remember there were a lot of settings in iexplorer last time i configured and used one (but it's a _long_ while since ;) With galeon, for example, i can set some few limits to what js can do. I didn't discover a way to say don't download flashs from this site yet. But I always believed i can do that and more with a proxy. amb-Uxr6IM1mbv2TY6FTCsQk+9Bc4/[email protected] (Andrew M. Bishop): > The sequence of events is this. > > 1) The server sends HTML including Javascript. > 2) WWWOFFLE is here and hides any flash animations but leaves Javascript unchanged. > 3) The browser runs the Javascript which writes out some extra HTML into the page. > 4) The browser displays the modified HTML which includes the flash animation object tags that the Javascript wrote. > 5) The browser gets the flash animation and displays it. > > Here is an example piece of Javascript that shows how it works (but for images and not flash). > > -------------------- example.html -------------------- > <script LANGUAGE="JAVASCRIPT"> > <!-- > now = new Date(); > tail = now.getTime(); > document.write("<IMG SRC='//images-aud.slashdot.org/pc.gif?l,"); > document.write(tail); > document.write("' WIDTH=1 HEIGHT=1 BORDER=0 ALT=' '>"); > //--> > </SCRIPT> > -------------------- example.html -------------------- > > When this script is run you will end up with some extra HTML that the browser will see in step (4) > but that WWWOFFLE could not see in step (2). The extra image in this case will be loaded by an HTML > tag that looks like shown below but with $$$ replaced by the current time: > > <IMG SRC='//images-aud.slashdot.org/pc.gif?l,$$$' WIDTH=1 HEIGHT=1 BORDER=0 ALT=' '> > > If WWWOFFLE contained a Javascript interpreter that gave exactly the same result as the Javascript > interpreter in the browser then there would be a chance. It would have to detect that the Javascript > changes the HTML in the page and then delete that part of the script. I don't think that this is practical though. > -- > Andrew. > ---------------------------------------------------------------------- > Andrew M. Bishop amb-Uxr6IM1mbv2TY6FTCsQk+9Bc4/[email protected] > http://www.gedanken.demon.co.uk/ ok, it's just this way, granted. The browser interpreting the javascripted html page will send download requests. Why do those requests ignore the proxy then ? Did i configure galeon to work with a proxy and then it's not used in some cases ? Couldn't that be changed at least by the developers (hi there !) ? greets, micha