Support anti-DPI feature for Korea Telecom

[piquark6046]

In 2019, South Korean government announced that they use SNI snooping to censor HTTPS websites ^1.

Currently, AdGuard can neutralize DPI systems of SK Telecom and LG U+. But, DPI system of Korea Telecom, one of major telecommunication companies of South Korea, cannot be neutralized with AdGuard.

In public, Unicorn HTTPS, an anti-DPI program made by Unicornsoft Co Ltd [^3], is widely used for neutralizing the system if a visitor in South Korea doesn't want to use a VPN to neutralize.

[^3]: Also, they are developer of Unicorn Pro adblocker.

[sfionov]

@piquark6046 Can you try to play with advanced Protect from DPI parameters such as "split HTTP fragment size" and "split ClientHello fragment size"? 1 byte is default - packet is split to 1 byte and a tail. But another values can be used also (2, 40, etc.)

[piquark6046]

In fact, I already tested at June 14 (KST) with AdGuard for Android 4.0 stable. I cannot access https://www.womenonweb.org via my school network using KT with the following configuration:

• HTTP space juggling + ClientHello fragment 1 + HTTP request fragment 1
• HTTP space juggling + ClientHello fragment 16 + HTTP request fragment 16
• ClientHello fragment 16 + HTTP request fragment 16
• ClientHello fragment 1 + HTTP request fragment 1

The number 16 is blurred in my memory.

[ameshkov]

@sfionov I'll order a residential proxy with KST so that we could test it on our side.

UPD: done, I've passed the proxy to @sfionov. Can confirm the issue with womenonweb with that proxy.

[piquark6046]

Also, referring the following websites blocked in South Korea can be helpful:

• PetuBucket ( https://www.petbucket.com/ )
• Many pron websites (examples)
  • https://hitomi.la/
  • https://www.pornhub.com/
  • https://xvideos.com/
  • https://www.fakku.net/

https://ko.wikipedia.org/wiki/%EB%8C%80%ED%95%9C%EB%AF%BC%EA%B5%AD%EC%97%90%EC%84%9C_%EC%B0%A8%EB%8B%A8%EB%90%9C_%EC%9B%B9%EC%82%AC%EC%9D%B4%ED%8A%B8_%EB%AA%A9%EB%A1%9D https://namu.wiki/w/%ED%8B%80:%EC%84%B1%EC%9D%B8%20%EC%82%AC%EC%9D%B4%ED%8A%B8

[piquark6046]

Please reconsider priority of this issue. This issue can be a fork of choosing between Unicorn Pro adblocker or AdGuard.

[sfionov]

@piquark6046 We found a solution and it will be implemented in CoreLibs version currently in development

[piquark6046]

The issue is being watched by someone who wants to switch from Unicorn Pro adblocker to AdGuard if the issue is resolved:

• https://gall.dcinside.com/mgallery/board/view/?id=galaxy&no=998970
• https://gall.dcinside.com/mgallery/board/view/?id=galaxy&no=999759

[hsp1020]

I am korean KT user. I look forward to solving this problem. Due to this issue I have deleted AdGuard and am using Unicorn Pro. When this problem is solved, I'll switch back to AdGuard

[piquark6046]

@hsp1020 Do you want to experience like Unicorn Pro adblocker with AdGuard? If so, can you describe it?

[hsp1020]

@hsp1020 Do you want to experience like Unicorn Pro adblocker with AdGuard? If so, can you describe it?

What exactly should I do?

[piquark6046]

@hsp1020 The question is what the advantage and disadvantage between them when they are compared.

[hsp1020]

@hsp1020 The question is what the advantage and disadvantage between them when they are compared.

@piquark6046 Yes, i can compare the two apps to explain their relative advantage and disadvantage.

The advantages of Unicorn Pro over AdGuard are 1.Support anti-DPI feature for Korea Telecom (this issue), 2.Web browser Assistant support for iOS/Android, 3.Optimized for Korean websites and apps, and faster. Especially in Korea, more than 50% of users use Korea Telecom. However, because of this issue, many korean users are using Unicorn pro instead of Adguard.

Advantages of AdGuard over Unicorn Pro are 1.DNS filter selectable, 2.There are various types of built-in filters. 3.Block more ads on websites outside of Korea 4.Tracking protection (stealth mode) is more powerful. the default functionality is more power

[piquark6046]

3.Optimized for Korean websites and apps, and faster. Especially in Korea, more than 50% of users use Korea Telecom. However, because of this issue, many korean users are using Unicorn pro instead of Adguard.

Have you ever tested with only List-KR filter excluding other filters? And, do you hear about https://github.com/List-KR/filter-customizer that is in development?

[hsp1020]

@piquark6046

Yes, I have tested only with List-KR filters except for other filters. However, Unicorn pro can use the list-KR filter just like AdGuard. The speed difference on the Korean site is estimated to be the difference between the base filters embedded in the two apps. And the biggest reason why Koreans use Unicorn Pro instead of AdGuard is whether it is Support anti-DPI feature for Korea Telecom.

[piquark6046]

However, Unicorn Pro can also use the list-kt filter.

No. Unicorn Pro adblocker cannot use List-KR filter right now even if the filter can be registered in app. Unicorn Pro does not support scriptlet, redirection resources, etc that resolve many advertisements and almost anti-adblock script. Even if the app supports them, I don't have a plan to support Unicorn Pro adblocker as one of supported adblockers in List-KR filter.

[hsp1020]

@piquark6046

I was wrong about that part. I thought it was working because I could add it to the Unicorn pro filter list. However, for Koreans, the most important part when choosing AdGuard and Unicorn Pro is not whether the list-KR filter is supported, but whether Korea Telecom supports anti-DPI functions. If this issue is not resolved, many Koreans will use Unicorn Pro. This is because even if list-KR does not support Unicorn pro, most advertisements on Korean sites are blocked only by Unicorn pro base filters.

[piquark6046]

This is because even if list-KR does not support Unicorn pro, most advertisements on Korean sites are blocked only by Unicorn pro base filters.

There is common advertisement servers that are used in Korean language websites and other language websites. For example, Google Ads is used in almost websites regardless of language of a website.

[hsp1020]

@piquark6046

Unicorn Pro also has a dedicated Korean filter that is set by default. This allows you to block advertisements in Korean at a level similar to list-KR. Therefore, whether to apply for list-KR is not an important part for Koreans. Therefore, AdGuard developers need to support anti-DPI features for Korea Telecom as soon as possible.

[piquark6046]

Unicorn Pro also has a dedicated Korean filter that is set by default. As a result, advertisements in Korean can be blocked at a similar level to list-KR. Therefore, whether to support for list-KR is not an important part for Koreans.

List-KR filter can block advertisements on copyright-abusing torrent and streaming websites as this is mentioned in https://gall.dcinside.com/mgallery/board/view/?id=galaxy&no=998970. Also, List-KR filter can block Naver PowerLink advertisements on m.humoruniv.com using scriptlets without changing the related rules regularly.

List-KR filter uses scriptlet to mitigate DNS filtering exception.

[hsp1020]

@piquark6046 list-KR filters may perform better than Unicorn pro Korea filters. However, there are many sites that are not accessible in Korea unless Adguard supports Anti-DPI function for Korean Telecom. (Most of the torrents and streaming websites you mentioned are also not accessible.) This reduces the advantages of list-KR.

[piquark6046]

For a visitor who is interested in the issue, currently updated CoreLibs has not been applied CoreLib-based AdGuard program [^1].

[^1]: AdGuard for Windows, AdGuard for Android and AdGuard for Mac

To see what CoreLibs version of AdGuard you use, please refer https://adguard.com/ko/versions/windows/release.html. To see GitHub issues about CoreLibs version update for the programs, please visit the following URLs and search 1.13:

• AdGuard for Android: https://github.com/AdguardTeam/AdguardForAndroid/issues?q=is%3Aissue+is%3Aopen+label%3Aautomatic
• AdGuard for Windows: https://github.com/AdguardTeam/AdguardForWindows/issues?q=is%3Aissue+is%3Aopen+label%3Aautomatic
• AdGuard for Mac: https://github.com/AdguardTeam/AdguardForMac/issues?q=is%3Aissue+is%3Aopen+label%3Aautomatic

[sfionov]

Adguard for Android 4.3 nightly 19 is out with CoreLibs 1.13

[haksal732]

@sfionov @piquark6046

I'm currently using KT's network, and AdGuard also updated it to Android 4.3 nightly 19, but the site is still not unblocked.

[piquark6046]

@hsp1020 @NoName926 Did you test with KT mobile network?

[zelesdev]

KT network dpi bypass is not applied even on Android 4.3 nightly 20 It is not a kt mobile network

[piquark6046]

Maybe we can receive what is wrong in the coming week.

[hsp1020]

I'm using kt (kt mobile) for both my home internet and my phone, but I updated it to the latest version of nightly, but this problem is not being solved.

[piquark6046]

Unfortunately, The checking will be delayed until Nov 13 at least.

[piquark6046]

Currently the delaying between split chunks feature that can help to bypass the DPI system is not included in any AdGuard nightly. If it is included, you can configure the option in the section located in:

• AdGuard for Android: Protection tab -> Tracking protection (privacy protection level: custom) -> Protect against DPI.
• AdGuard for Windows: AdGuard settings -> General tab -> Advanced Settings
• AdGuard for Mac: AdGuard settings icon -> Advanced -> Advanced settings

[sfionov]

@piquark6046 @hsp1020 @NoName926 Does it work better on 4.3 nightly 32?