The difficulty of making sure your website is broken

https://letsencrypt.org/2026/04/10/test-sites.html

by mcpherrinm • 3 months ago

71 38 3 months ago

paulirish• 3 months ago

https://badssl.com/ also offers several test subdomains in the same vein.

NicolaiS• 3 months ago

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.

bheadmaster• 3 months ago

Incomplete chain seems to load on Android Chrome...

bullen3• 3 months ago

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?

xandrius• 3 months ago

Did you self-ban?

bullen3• 3 months ago

XD Nope, more like self destruct! ;)

horsawlarway• 3 months ago

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.

bullen3• 3 months ago

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...

NooneAtAll33• 3 months ago

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?

ipython• 3 months ago

Interesting. Chrome (146, macOS) shows no error messages on the revoked cert pages, but Firefox does (also macOS).

mcpherrinm• 3 months ago

Yeah, Chrome only partly supports revocation (Not sure exactly the criteria, but our test sites don't match it).

moralestapia• 3 months ago

Same with Brave, so it is a Chromium thing.

omoikane• 3 months ago

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

lifis• 3 months ago

Vanadium, Chrome and Firefox (all for Android) all accept all the revoked certificates... But revoked.badssl.com is considered revoked

RunningDroid• 3 months ago

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

sureglymop• 3 months ago

I don't think those certs are revoked yet.

nottorp4• 3 months ago

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.

Groxx• 3 months ago

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.

nottorp4• 3 months ago

I think he figured it out eventually, used some software tool. But I heard the complaining first.

gnopgnip• 3 months ago

You can simulate bad wifi with the throttling option on the network tab of your browser's developer tools

dieulot• 3 months ago

That’s an unreliable way of simulating an unreliable network, as overviewed in https://calendar.perfplanet.com/2016/testing-with-realistic-...

patmorgan23• 3 months ago

Slow networks != Bad networks. Bad networks could be slow, or drop random packets, or corrupt packets, or have jitter, etc

SOLAR_FIELDS• 3 months ago

You can always also simulate bad WiFi by walking away from your access point until you have bad wifi

nottorp4• 3 months ago

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...

a_t48• 3 months ago

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.

callistocodes• 3 months ago

Putting a StarLink dish so it has a tree branch in the way is a good way to get packet loss.

makr17• 3 months ago

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.

NooneAtAll33• 3 months ago

maybe look into jammers?

bigfatkitten2• 3 months ago

Not an option if you want to act lawfully.

sublinear• 3 months ago

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.

astrange• 3 months ago

Not necessarily, it could also be on-band or off-bad interference, or bugs in the AP, or too many clients on the network.

nottorp4• 3 months ago

Oh I'll write that down! Looks like it can at least do something bad to the signal.

contraposit• 3 months ago

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...

tdg5• 3 months ago

I miss https://highscalabilty.com ;( The “Stuff The Internet Says On Scalability” posts were always worth a read.

BuildTheRobots• 3 months ago

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.

JackSlateur• 3 months ago

Notice how your browser happily accepts the expired certificates :)

The difficulty of making sure your website is broken

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