badssl.com is an amazing tool especially for testing "TLS intercepting" boxes. I've seen more than one fortune 500 company that re-sign certain broken certs with their own CA, allowing silent MITM.
Coming up on 20 years ago I was building a system that was going to be deployed at various locations throughout a very large country. All locations had internet access; but the throughput, latency, and quality (e.g. packet drops) were all over the map.
For testing we ended up building a small linux box to proxy for the test environment in the office. We could throttle the throughput to any arbitrary level, introduce latency, and introduce packet drops. It's amazing how poorly a frontend will work when you throttle the network to 128kbps, and introduce a small percentage of dropped packets. But once you get the system to work (for some definition of "work") under those conditions you feel pretty good about deploying it.
The linux kernel traffic control (tc) can do network emulation with qdisc to simulate bad network connections. Add latency, jitter, bandwidth limits, and settable levels of traffic loss to your network interface.
If you're testing hardware or vm's that don't support it or don't have root, you can stick your linux box transparently in the middle by bridging two interfaces, and apply your traffic mangling there. Testing wifi? Use a decent WiFi AP connected to one of these bridges and mangle your traffic once it hits the wire/after it stops being RF.
At a previous job I had a linux box set up with multiple bridges (each set with a different "testing profile" on different vlans) and trunked to a physical switch. Made it very easy for people in the office to attach physical devices through known bad network links by either using pairs of physical switchports or just dumping VMs/SSIDs into the right VLAN so they could test different things (simultaneously) without needing to reconfigure the actual mangling.
Worth noting that tc applies to egress traffic, so if you want a uniformly bad line it needs applying to both sides - but it does mean you can simulate unidirectional link problems too.
Some proxies, iptables extensions, and OS-provided tools exist - there's almost certainly a combo that would work for them. What platform?
Unless it's for a custom physical device, then uh. idk. Probably something, proxying through another computer that is hosting a separate wifi network? But likely a lot harder.
> You can simulate bad wifi with the throttling option on the network tab of your browser's developer tools
Oh? How does that help for native applications?
> You can always also simulate bad WiFi by walking away from your access point until you have bad wifi
That's unfortunately very inconvenient when you work on an embeddeded device prototype that consists of several boards interconnected by hair thin wires :)
Maybe I should make some friends across the street to the point they give me access to their APs...
I'm building a product that helps out Docker usage in poorly networked environments (ie, robotics deployments). I've just been moving the Jetson around the house.
to actually tackle this (on the off chance you're serious, I'm assuming not) - this doesn't work.
The payload that implements your crypto cannot be delivered over http, because any intermediate party can just modify your implementation and trivially compromise it.
If you don't trust TLS, you have to pre-share something. In the case of TLS and modern browser security, the "pre-shared" part is the crypto implementation running in the browser, and the default trusted store of root CAs (which lives in the browser or OS, depending).
If you want to avoid trusting that, you've got to distribute your algorithm through an alternative channel you do trust.
You are right presharing is a requirement, unless you hash the keys used to encrypt the secret into the secret itself, but that can only be prooven later on a channel where the same MITM is not present.
Work in progress, that said presharing solve(d/s) enough for the world to dump DNS and HTTPS in a bin and light it on fire now, because nobody has the power to implement all the MITM needed if everyone "makes their own crypto" on top of allready shared secrets!
https://badssl.com/ also offers several test subdomains in the same vein.
Incomplete chain seems to load on Android Chrome...
badssl.com is an amazing tool especially for testing "TLS intercepting" boxes. I've seen more than one fortune 500 company that re-sign certain broken certs with their own CA, allowing silent MITM.
[dead]
In the same direction, I once wanted to test an embedded device on crap wifi.
So I just ordered the cheapest AP I could find.
Except the damn device worked perfectly. Slow but rock solid.
One of our testers at $CURRENT_JOB also has trouble simulating a crap network, because our network is good.
Coming up on 20 years ago I was building a system that was going to be deployed at various locations throughout a very large country. All locations had internet access; but the throughput, latency, and quality (e.g. packet drops) were all over the map.
For testing we ended up building a small linux box to proxy for the test environment in the office. We could throttle the throughput to any arbitrary level, introduce latency, and introduce packet drops. It's amazing how poorly a frontend will work when you throttle the network to 128kbps, and introduce a small percentage of dropped packets. But once you get the system to work (for some definition of "work") under those conditions you feel pretty good about deploying it.
The linux kernel traffic control (tc) can do network emulation with qdisc to simulate bad network connections. Add latency, jitter, bandwidth limits, and settable levels of traffic loss to your network interface.
If you're testing hardware or vm's that don't support it or don't have root, you can stick your linux box transparently in the middle by bridging two interfaces, and apply your traffic mangling there. Testing wifi? Use a decent WiFi AP connected to one of these bridges and mangle your traffic once it hits the wire/after it stops being RF.
At a previous job I had a linux box set up with multiple bridges (each set with a different "testing profile" on different vlans) and trunked to a physical switch. Made it very easy for people in the office to attach physical devices through known bad network links by either using pairs of physical switchports or just dumping VMs/SSIDs into the right VLAN so they could test different things (simultaneously) without needing to reconfigure the actual mangling.
Worth noting that tc applies to egress traffic, so if you want a uniformly bad line it needs applying to both sides - but it does mean you can simulate unidirectional link problems too.
I remember Facebook while developing it's mobile app in the early days of smartphones did similar tests.
https://highscalability.com/how-facebook-makes-mobile-work-a...
I miss https://highscalabilty.com ;( The “Stuff The Internet Says On Scalability” posts were always worth a read.
Some proxies, iptables extensions, and OS-provided tools exist - there's almost certainly a combo that would work for them. What platform?
Unless it's for a custom physical device, then uh. idk. Probably something, proxying through another computer that is hosting a separate wifi network? But likely a lot harder.
I think he figured it out eventually, used some software tool. But I heard the complaining first.
You can simulate bad wifi with the throttling option on the network tab of your browser's developer tools
That’s an unreliable way of simulating an unreliable network, as overviewed in https://calendar.perfplanet.com/2016/testing-with-realistic-...
Slow networks != Bad networks. Bad networks could be slow, or drop random packets, or corrupt packets, or have jitter, etc
You can always also simulate bad WiFi by walking away from your access point until you have bad wifi
> You can simulate bad wifi with the throttling option on the network tab of your browser's developer tools
Oh? How does that help for native applications?
> You can always also simulate bad WiFi by walking away from your access point until you have bad wifi
That's unfortunately very inconvenient when you work on an embeddeded device prototype that consists of several boards interconnected by hair thin wires :)
Maybe I should make some friends across the street to the point they give me access to their APs...
Why not just loosely wrap the antenna or entire box in foil or move it to the basement/garage/roof?
If you're going for realism, bad wifi is a radio signal problem.
Not necessarily, it could also be on-band or off-bad interference, or bugs in the AP, or too many clients on the network.
Oh I'll write that down! Looks like it can at least do something bad to the signal.
I'm building a product that helps out Docker usage in poorly networked environments (ie, robotics deployments). I've just been moving the Jetson around the house.
Putting a StarLink dish so it has a tree branch in the way is a good way to get packet loss.
maybe look into jammers?
Not an option if you want to act lawfully.
it is lawful if it's your devices only
It’s not your radiofrequency spectrum.
Interesting. Chrome (146, macOS) shows no error messages on the revoked cert pages, but Firefox does (also macOS).
Chrome doesn't want to perform online revocation checks according to this page:
https://chromium.googlesource.com/chromium/src/+/HEAD/docs/s...
found via: https://issues.chromium.org/issues/471199592#comment3
Yeah, Chrome only partly supports revocation (Not sure exactly the criteria, but our test sites don't match it).
Same with Brave, so it is a Chromium thing.
Meanwhile HTTP keeps working just fine and is decentralized.
Just "add your own crypto" on top, which is the ONLY thing a sane person would do.
3... 2... 1... banned?
to actually tackle this (on the off chance you're serious, I'm assuming not) - this doesn't work.
The payload that implements your crypto cannot be delivered over http, because any intermediate party can just modify your implementation and trivially compromise it.
If you don't trust TLS, you have to pre-share something. In the case of TLS and modern browser security, the "pre-shared" part is the crypto implementation running in the browser, and the default trusted store of root CAs (which lives in the browser or OS, depending).
If you want to avoid trusting that, you've got to distribute your algorithm through an alternative channel you do trust.
> default trusted store of root CAs (which lives in the browser or OS, depending).
speaking of that, is there any way to verify that stored certificates are actually valid?
You are right presharing is a requirement, unless you hash the keys used to encrypt the secret into the secret itself, but that can only be prooven later on a channel where the same MITM is not present.
Work in progress, that said presharing solve(d/s) enough for the world to dump DNS and HTTPS in a bin and light it on fire now, because nobody has the power to implement all the MITM needed if everyone "makes their own crypto" on top of allready shared secrets!
Circular arguments, wishful thinking and all...
Did you self-ban?
XD Nope, more like self destruct! ;)
Vanadium, Chrome and Firefox (all for Android) all accept all the revoked certificates... But revoked.badssl.com is considered revoked
> Vanadium, Chrome and Firefox (all for Android) all accept all the revoked certificates... But revoked.badssl.com is considered revoked
Firefox Beta (150.0b7) is accepting all of the revoked certs on my device
I don't think those certs are revoked yet.
Notice how your browser happily accepts the expired certificates :)