It's a thin HTTP/2 and HTTP/3 tunneling protocol for TCP, UDP, and ICMP traffic.
It should be easy to write an independent implementation based on this specification provided you already have an HTTP/2 or HTTP/3 library. Pretty neat!
More or less, built on top of it with added udp/icmp.
When writing server and client a lot of time is consumed by additional features, not on implementing the spec itself. For instance, in order to be truly stealthy we have to make sure that it looks *exactly* like Chromium on the outside, and then maintain this similarity as Chromium changes TLS implementation from version to version. Or here’s another example: on the server-side we need to have an anti-probing protection to make it harder to detect what the server does.
Very cool! Thanks for supporting open source (unlike a half-hearted attempt, like ExpressVPN's Lightway). Quick question: the website animated gif has no arrows from the website to the VPN server. Am I missing something?
Update: just followed the quickstart and worked great; speed is virtually line speed - impressive!
One clarification that may not be obvious: open-sourcing this isn’t primarily about signaling or auditability. If that were the goal, a standalone protocol spec or a minimal reference repo would have been enough.
Instead, we’re deliberately shipping full client and server implementations because the end goal is for this to become an independent, vendor-neutral project, not something tied to AdGuard.
We want it to be usable by any VPN or proxy stack and, over time, to serve as a common baseline for stealthy transports — similar to the role xray/vless play today.
Happy to answer questions or clarify design choices.
We do, and from what we know a bigger problem in China is detecting traffic patterns. SNI filtering is not that big of a deal, in order to block your domain it needs to first learn which one you’re using. What for the traffic patterns, people in China prefer to selectively route traffic to the tunnel. For instance, the client apps allow you to route *.cn domains (or any other domains) directly. It makes it harder to detect that you’re using a VPN.
>GFW has been able to filter SNI to block https traffic for a few years now.
SNI isn't really the threat here, because any commercial VPN is going to be blocked by IP, no need for SNI. The bigger threat is tell-tale patterns of VPN use because of TLS-in-TLS, TLS-in-SSH, or even TLS-in-any-high-entropy-stream (eg. shadowsocks).
Performance reasons aside, TrustTunnel is developed by the team whose main language is C++ (and the client library is actually written in C++) so Rust was a more natural choice for them.
Likewise interested in the authoritative answer, but: if I needed to write a decent chunk of code that had to run as close to wire/CPU limits as possible and run across popular mobile and desktop platforms I would 100% reach for Rust.
Go has a lot of strengths, but embedding performance-critical code as a shared library in a mobile app isn't among them.
I can't thank Adguard enough for providing so much to the community, they are a BIG part of my privacy-funded lifestyle.
Out of the topic — but if you by any chance work on the mobile apps.
Do you know why the iOS version is still sub-par compared to Android?
You all add more features for rooted Android but what about Jailbroken iOS devices?
I have bought 20+ Adguard licenses and have never regretted buying them. Only if the iOS version could be much better.
We are very cautious with Apple as we suffered from them before [1]. So we're trying to stick to the APIs they provide. I hope the new URL filtering API [2] will improve the situation with the system-wide filtering, but our request for API access is still being reviewed by Apple.
Regarding jailbroken iOS devices, unlike Android the numbers are really marginal so it won't be feasible to support them.
I like and use your products, so, first of all, thank you!
that the protocol was not open was one of my main issues for not using the vpn service,?it is great to see. i look forward for the upcoming audits.
one thing i would like to see more is info about the company. the team, the offices, etc. there have been rumors and contradictory infos over the years, and the blog always have a “stock photo”, shady vibe. putting your address in google maps brings you to a shady alley… improving the image of the company (in my opinion) as it is now would do lots to create and improve trust.
(we are moving to a bit bigger office in the neighboring building, no nice photos on google yet)
We do not have a dedicated team page on the website, but we’re not hiding our faces, the team can be found on Github. Members of the team often visit AFDS [1] [2], you can see some faces there (including mine).
What makes this worth using over something like vless? Work blocked my gatcha game so I've had to set up a xray/vless/xhttp/tls proxy and it works flawlessly. Gets through the corp firewall unscathed at full bandwidth and no appreciable increase in latency.
It won't help you get around the endpoint compliance software, I use this for my byod phone (Streisand is a nice ios client). VLESS is the proxy protocol, kinda like SOCKS I guess. It uses xhttp over TLS as the transport.
Does anyone know if this protocol uses QUIC's RFC 9221 extension in order to eliminate overhead when tunnelling UDP over QUIC? According to their blog post, TrustTunnel does somehow avoid that overhead, but the actual protocol specification doesn't mention anything of that sort.
Excellent, thanks for the quick response! Are there any plans to add support for full-cone NAT as well, in order to improve compatibility with some games?
It’s great for you to open source the protocol and implementation, it written in rust which I will definitely consider to learn it add add to my vpn client in the future
Standard wireguard is blocked by DPI in Russia, China, Iran, etc.
The soluton in the post for VPNs as in "censorship bypass", not as in "virtual lan over the internet for businesses". Like AmneziaWG or VLESS protocols.
One interesting thing I’ve noticed is that AdGuard means different things in different parts of the world. In some places, people know us primarily as an ad blocker, in others we’re best known for our DNS service and in some regions AdGuard is associated almost exclusively with our VPN. The reality is that AdGuard makes several different products, not just one.
It would be also nice if they could hold their implicit promise of having the AdGuard extension working on Safari iOS, it's broken for me even when I reinstal it. Anyone else have the same problem?
This is not a common issue tbh. What sometimes may happen is that after an iOS update the content blockers in Safari becomes corrupted and the only thing that fixes it is not just a reinstall, but uninstall + reboot + reinstall after that. If even this doesn’t help please contact me at “am at adguard.com”, I will try to help.
Link to the protocol specification: https://github.com/TrustTunnel/TrustTunnel/blob/master/PROTO...
It's a thin HTTP/2 and HTTP/3 tunneling protocol for TCP, UDP, and ICMP traffic.
It should be easy to write an independent implementation based on this specification provided you already have an HTTP/2 or HTTP/3 library. Pretty neat!
Looks very similar to the HBONE protocol the istio folks created for ambient mesh: https://istio.io/latest/docs/ambient/architecture/hbone/
just did some spec reading, it's quite clear and nit.
I can understand that put UDP payload into a single HTTP stream, at least when QUIC transport is in use, there is no UDP in TCP case.
The Source Address/Port in the UDP payload message serve as key to handle to the tunnel client if I understand correctly?
Basically a CONNECT proxy? That's definitely not a difficult thing to write.
More or less, built on top of it with added udp/icmp.
When writing server and client a lot of time is consumed by additional features, not on implementing the spec itself. For instance, in order to be truly stealthy we have to make sure that it looks *exactly* like Chromium on the outside, and then maintain this similarity as Chromium changes TLS implementation from version to version. Or here’s another example: on the server-side we need to have an anti-probing protection to make it harder to detect what the server does.
7 replies →
Very cool! Thanks for supporting open source (unlike a half-hearted attempt, like ExpressVPN's Lightway). Quick question: the website animated gif has no arrows from the website to the VPN server. Am I missing something?
Update: just followed the quickstart and worked great; speed is virtually line speed - impressive!
Hi, I’m one of the people working on this.
One clarification that may not be obvious: open-sourcing this isn’t primarily about signaling or auditability. If that were the goal, a standalone protocol spec or a minimal reference repo would have been enough.
Instead, we’re deliberately shipping full client and server implementations because the end goal is for this to become an independent, vendor-neutral project, not something tied to AdGuard.
We want it to be usable by any VPN or proxy stack and, over time, to serve as a common baseline for stealthy transports — similar to the role xray/vless play today.
Happy to answer questions or clarify design choices.
Does your team have Chinese memebers?
GFW has been able to filter SNI to block https traffic for a few years now.
We do, and from what we know a bigger problem in China is detecting traffic patterns. SNI filtering is not that big of a deal, in order to block your domain it needs to first learn which one you’re using. What for the traffic patterns, people in China prefer to selectively route traffic to the tunnel. For instance, the client apps allow you to route *.cn domains (or any other domains) directly. It makes it harder to detect that you’re using a VPN.
5 replies →
>GFW has been able to filter SNI to block https traffic for a few years now.
SNI isn't really the threat here, because any commercial VPN is going to be blocked by IP, no need for SNI. The bigger threat is tell-tale patterns of VPN use because of TLS-in-TLS, TLS-in-SSH, or even TLS-in-any-high-entropy-stream (eg. shadowsocks).
3 replies →
Thanks for all impressive work on AdGuard.
Any particular reason to adopt Rust for this project instead of Go as many of your other products?
Because I think since you have quite extensive Go codebase I would imagine you had to rewrite possibly a significant amount of code.
Performance reasons aside, TrustTunnel is developed by the team whose main language is C++ (and the client library is actually written in C++) so Rust was a more natural choice for them.
Likewise interested in the authoritative answer, but: if I needed to write a decent chunk of code that had to run as close to wire/CPU limits as possible and run across popular mobile and desktop platforms I would 100% reach for Rust.
Go has a lot of strengths, but embedding performance-critical code as a shared library in a mobile app isn't among them.
Embedding Go code into other binaries sucks ass. Debugging is worse, it installs some signal handlers.
I can't thank Adguard enough for providing so much to the community, they are a BIG part of my privacy-funded lifestyle.
Out of the topic — but if you by any chance work on the mobile apps.
Do you know why the iOS version is still sub-par compared to Android? You all add more features for rooted Android but what about Jailbroken iOS devices?
I have bought 20+ Adguard licenses and have never regretted buying them. Only if the iOS version could be much better.
Hi, thank you very much for supporting AG!
We are very cautious with Apple as we suffered from them before [1]. So we're trying to stick to the APIs they provide. I hope the new URL filtering API [2] will improve the situation with the system-wide filtering, but our request for API access is still being reviewed by Apple.
Regarding jailbroken iOS devices, unlike Android the numbers are really marginal so it won't be feasible to support them.
[1]: https://adguard.com/en/blog/adguard-pro-discontinued.html
[2]: https://adguard.com/en/blog/apple-url-filter-system-wide-fil...
2 replies →
So happy that you guys are doing this!
I like and use your products, so, first of all, thank you!
that the protocol was not open was one of my main issues for not using the vpn service,?it is great to see. i look forward for the upcoming audits.
one thing i would like to see more is info about the company. the team, the offices, etc. there have been rumors and contradictory infos over the years, and the blog always have a “stock photo”, shady vibe. putting your address in google maps brings you to a shady alley… improving the image of the company (in my opinion) as it is now would do lots to create and improve trust.
There are no shady alleys in Cyprus:)
We have only one office in Limassol, the company is mostly remote: https://maps.app.goo.gl/pounSEQqBvYftZGZ6?g_st=ic
(we are moving to a bit bigger office in the neighboring building, no nice photos on google yet)
We do not have a dedicated team page on the website, but we’re not hiding our faces, the team can be found on Github. Members of the team often visit AFDS [1] [2], you can see some faces there (including mine).
[1]: https://adfilteringdevsummit.com/
[2]: https://youtube.com/playlist?list=PL61EKVIQWizG0tIYqNDoenVaO...
> https://adfilteringdevsummit.com/
Google sponsoring this summit is peak irony.
1 reply →
right, thanks! nice to see. note that your legal address in the website points to another address, which is the one I mean. Maybe needs an update:
https://adguard.com/en/contacts.html
1 reply →
What makes this worth using over something like vless? Work blocked my gatcha game so I've had to set up a xray/vless/xhttp/tls proxy and it works flawlessly. Gets through the corp firewall unscathed at full bandwidth and no appreciable increase in latency.
Could you please drop names/links to the magic sauce if there's anything more than the names mentioned?
I need to open ssh myself and for now I decided on tunnelling over http/3 terminated somewhere in aws/gcp/cf, but maybe your method is better.
Just use Amnezia VPN - it can masquerade as https.
1 reply →
https://github.com/XTLS/Xray-core
It won't help you get around the endpoint compliance software, I use this for my byod phone (Streisand is a nice ios client). VLESS is the proxy protocol, kinda like SOCKS I guess. It uses xhttp over TLS as the transport.
1 reply →
Does anyone know if this protocol uses QUIC's RFC 9221 extension in order to eliminate overhead when tunnelling UDP over QUIC? According to their blog post, TrustTunnel does somehow avoid that overhead, but the actual protocol specification doesn't mention anything of that sort.
No, but it's a very good point, we'll add it to the backlog
Excellent, thanks for the quick response! Are there any plans to add support for full-cone NAT as well, in order to improve compatibility with some games?
How does this compare to Obscura
Obscura is WireGuard-over-QUIC, not a new protocol.
https://obscura.net/#faq-technical
It’s great for you to open source the protocol and implementation, it written in rust which I will definitely consider to learn it add add to my vpn client in the future
Super cool stuff! Excited to see what p2p between clients might look like, and how it compares on speed with Wireguard.
So what are the reasons to use this over Wireguard?
Standard wireguard is blocked by DPI in Russia, China, Iran, etc.
The soluton in the post for VPNs as in "censorship bypass", not as in "virtual lan over the internet for businesses". Like AmneziaWG or VLESS protocols.
Does it support the mwss protocol?
I'm surprised that the browser extension to block ads has a proprietary vpn-like protocol. WTF?
One interesting thing I’ve noticed is that AdGuard means different things in different parts of the world. In some places, people know us primarily as an ad blocker, in others we’re best known for our DNS service and in some regions AdGuard is associated almost exclusively with our VPN. The reality is that AdGuard makes several different products, not just one.
I'm an American. I knew about the VPN service, but mostly associate your brand with the DNS services and lists you provide (thank you!).
And AdGuard Home is a wonderful alternative to Pi-hole :)
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One of my first experiences with adguard was using it to block ads on an unrooted phone. It pipes your connection through a local vpn to do it.
[dead]
It would be also nice if they could hold their implicit promise of having the AdGuard extension working on Safari iOS, it's broken for me even when I reinstal it. Anyone else have the same problem?
This is not a common issue tbh. What sometimes may happen is that after an iOS update the content blockers in Safari becomes corrupted and the only thing that fixes it is not just a reinstall, but uninstall + reboot + reinstall after that. If even this doesn’t help please contact me at “am at adguard.com”, I will try to help.
Thanks for the suggestion! I'll definitely try the uninstall-reboot-reinstall flow. I was about to switch browsers on all the elderly devices.