I could understand it if it was a small company doing so at the time when certificates were expensive, but Sennheiser has plenty of money and certificates can be obtained for free nowadays.
The Right Thing (TM) is to not do HTTPS, a modern web browser is supposed to conclude that ::1 and 127.0.0.1 are secure without HTTPS since there is no possibility of a "man in the middle" of your own computer's loopback.
The actual right thing to do is to generate a private key and certificate (for a specific, public name you point to 127.0.0.1) during the software installation and add the latter to the trusted store. Now you don't have this vulnerability because each computer has a different trusted certificate with a different key, so a random attacker cannot just use the key they got to spy on other users.
We're not at that point yet, but running your own trust root is getting quite annoying. For example, Android constantly nags about "network might be monitored" when custom certificates are installed.
This is why I baked my home network certificate into the system trust store when building the ROM.
But for beginners there are some pretty nice LineageOs build guides floating around:
For specific pieces of hardware: https://wiki.lineageos.org/build_guides.html
Generic instructions: https://forum.xda-developers.com/chef-central/android/how-to...
As far as changing the certs, I know offhand to do it with a couple random linux distro's but i'm not 100% sure for android, you might just try searching the repo for the default certs then looking at how they are built into the image and tweaking that.
It won't if you add name constraints to your root certificate (because then it can't be used for blanket monitoring).
It's incredibly shady to have random software install into your trust store.
We saved probably $100 and 2 hours by rolling our own solutions instead of doing things the standard way. It took weeks to clean the mess completely up.
And no, I don't see anything "standard" about not running your own CA, it is perfectly standard as far as I am concerned, and a really good idea as well. Relying on an external CA for internal services just creates risks of both availability and security. If you need an external CA to set up or continue operating internal services, that is an availability risk, and if you trust the whole standard set of root CAs for all of your internal services, that's a massive security risk.
For one, there is no problem hosting your own services elsewhere and having them use your own certificates. But more importantly: Why should your own CA prevent you from obtaining certificates from an external CA for external services? I mean, it just doesn't, that's how I run stuff: Purely internal stuff runs on internal CA, stuff that needs to face the public somehow runs on globally recognized CAs. And it's mostly trivial to switch services from one to the other - or to just run two endpoints, one using the internal CA, one using an external CA.
It seems to me like your problem wasn't your own root CA, your problem was that your services were incompatible with external CAs for some reason, among them probably your private DNS root? But that isn't a reason why you should put your internal services at risk from mismanaged public CAs, that's simply a reason why you should use a global domain and support provisioning of certificates from external CAs.
And also, if you have so many services running that swapping out all of the certificates is a major headache, your primary mistake probably was that that wasn't automated? When keys are compromised, you should be able to reprovision anyway.
Sure it’s annoying clicking through browser warnings but if it’s not public facing I don’t see the danger.
Who should have the ability to install root CA certs?
I like using HTTPS instead of HTTP, so I need some installed. Who should be responsible for managing them?
And before you say the CABF, they're ultimatately not the ones who decide what gets installed on your computer. The answer to that question is much more complicated.
However, the problem is, nobody understands SSL properly. Among the people who don't understand SSL properly is, alas, a number of people writing SSL libraries. Not the actual SSL libraries like OpenSSL, but all the surrounding libraries to make it "easy to use", which includes libraries that try to make HTTP easy to use and abstract the difference between HTTP and HTTPS. Pretty much every "ease of use" library I have ever seen accomplishes its ease of use by dropping features from the underlying SSL support, but it's clear they often don't understand why those features were there and the consequences of dropping them.
I have a particular case where I've got some Perl code that is literally 4 levels deep in "SSL ease of use" code, with pretty much every layer dropping SSL features along the way (even the base level Net::SSLeay is missing a lot of stuff once you go beyond the basics, and it only gets worse as the stack gets higher). Once I had to poke support for a certain feature all the way down through the entire stack because it got dropped really early.
So what you need to do in this case is create your own root store of trust, and then stick your own certs in there from some .pems or something, and then use that to initialize SSL on your connection. But it's complicated to do that at the base level of a lot of SSL libraries, and this is often one of the first features to be "abstracted away" by support libraries, and a lot of HTTP libraries end up trying to "abstract away" SSL so thoroughly that they don't even have parameters to control the SSL elements of the connection, and if they do, they have some ad-hoc selection of random bits that someone once needed, rather than comprehensive support.
The upshot is that I'd consider it likely that they were using one of these libraries, and the only way they could see to get their certificates trusted was to stick them in the default root store, because that's the only thing that would work with such libraries. You can also find web pages and such recommending this approach. It's also possible they just came across one of these web pages or something and put stuff in the root without realizing what it really meant, even though their library allowed them to do everything I said, because it's way easier to slam something into the default trust store than write the code to create your own at run time. (It ought to be easy to write that code. The rather nice Go TLS library makes it almost as easy as I say it is; create cert store, add certificate, set that as your root trust, modulo a bit of error handling it really is just about that many lines of code. But the "ease of use" libraries can really get in the way, when the people adding the "ease of use" abstractions themselves don't understand what that means, or why you might want/need it, or how to make it easy.)
Their goal was to allow the browser to connect to the local daemon, for web-based softphones, so this wouldn't work.