Base64 support

Various discussions related to Adblock Plus development
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Atak_Snajpera
Posts: 7
Joined: Sun Nov 29, 2015 6:59 pm

Base64 support

Post by Atak_Snajpera »

Can adblock plus automatically decode links encoded in base64 format?

Example
http://iwtjxgfu.wp.pl/Uk0vQm94LzIwMTYtM ... 93cC5qcGc=

I can't create blocking rules in this case. BTW. Decoded link looks like this.
http://iwtjxgfu.wp.pl/RM/Box/2016-05/ja ... 200_wp.jpg
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mapx
Posts: 21940
Joined: Thu Jan 06, 2011 2:01 pm

Re: Base64 support

Post by mapx »

You could block the whole subdomain (probably is dedicated to ads)
iwtjxgfu.wp.pl

or another approach (block all subdomains and whitelist only those without ads)
see here:
forum/viewtopic.php?p=150078#p150078
lewisje
Posts: 2743
Joined: Mon Jun 14, 2010 12:07 pm

Re: Base64 support

Post by lewisje »

Atak_Snajpera wrote:Can adblock plus automatically decode links encoded in base64 format?
That would require a major change to how ABP works: Currently, it intercepts HTTP requests to decide whether to block or allow, but data URIs have no request associated with them, so the best ABP can do now is hide it, if the image or a containing element is selectable with a CSS selector.

I believe there were performance-related reasons for not just outright removing HTML elements that are hidden, but maybe that could be re-considered in light of the increasing use of data URIs.
There's a buzzin' in my brain I really can't explain; I think about it before they make me go to bed.
Atak_Snajpera
Posts: 7
Joined: Sun Nov 29, 2015 6:59 pm

Re: Base64 support

Post by Atak_Snajpera »

mapx wrote:You could block the whole subdomain (probably is dedicated to ads)
iwtjxgfu.wp.pl

or another approach (block all subdomains and whitelist only those without ads)
see here:
viewtopic.php?p=150078#p150078
As you can see that subdomain contains random letters. Those letters change from time to time.

I'm disappointed that Adblock Plus can't decode Base64 on fly. It looks like wp.pl has found a good way to avoid filters. Maybe guys behind uBlock will have solution for those links.
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mapx
Posts: 21940
Joined: Thu Jan 06, 2011 2:01 pm

Re: Base64 support

Post by mapx »

Read the second part of my post (and the linked post)
lewisje
Posts: 2743
Joined: Mon Jun 14, 2010 12:07 pm

Re: Base64 support

Post by lewisje »

Atak_Snajpera wrote:I'm disappointed that Adblock Plus can't decode Base64 on fly. It looks like wp.pl has found a good way to avoid filters. Maybe guys behind uBlock will have solution for those links.
The same issues would exist with uBlock Origin: Decoding Base64 isn't the problem, it's performantly removing HTML content which is what you'd need to do in order to "block" content that is embedded in the page rather than loaded from a URL referenced by that page.

With that said, Raymond Hill has figured out how to performantly block all inline scripts, and also how to block particular functions (but I think that's Firefox-only), but unless you provide a persuasive case for this new functionality, he'll tell you your brand-new GitHub Issue is invalid and summarily close it; also, I'm active there too, so if you propose it there, I'll call the idea stupid there, just like I have a couple times before in the uBlock issues, unless gorhill takes the effort to directly say so himself instead of being brief about dismissing your ~revolutionary idea~ that he explicitly tells people not to use Issues to suggest.
There's a buzzin' in my brain I really can't explain; I think about it before they make me go to bed.
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