[__b__]

"I should be able to see what data an app is sending..."

And you can. There are many ways. Something as simple as 2 socat instances and netsed works great as a quick and dirty but very robust solution. See also sslsplit which will generate certificates on the fly.

Anyone who is telling you that you can place complete trust in the use of x509 certificates on the open internet is either naive or dishonest.

I think you have the right attitude.

[tokenizerrr]

You should read up on how certificate pinning works. Obviously you can still decompile and recompile the app with different certificates baked in but it's a bit more difficult than what you're implying.

[__b__]

Any device that prevents a user from installing their own CA root cert is not one I would use. I'm not sure if they have started to do this or not.

In terms of protecting users, there's no valid reason the owner of the hardware should not be able to control the list of endpoints that she has already authenticated and is willing to trust.

It would be like if SSH did not allow the user any control over known_hosts or to decide that she will accept or not accept a connection.

[tokenizerrr]

The entire point of certificate pinning is to ignore the certificates the user installs... Nothing to do with the operating system at all. If the software doesn't want to connect because the wrong certificate is presented to it that's where it ends. You can install as many local roots as you want, it won't change a thing.

[__b__]

"... it won't change a thing."

So if the user does not want to trust a certificate installed by someone else on the device, she can "revoke" it?

And by the same token if she wants to explicitly trust a certificate, regardless of who installed it, she can do so?

Does the user have control of the process of "trust" or not? The entire point of the device, OS and apps is to benefit the user, not some third party trying to hide data being sent from the device... from the user.

Do you believe a user should be able to "MITM" her own traffic or not?

[tokenizerrr]

> Do you believe a user should be able to "MITM" her own traffic or not?

I do, but that is utterly irrelevant to this discussion. We are discussing what certificate pinning is and how it works.

You can currently perform certificate pinning on every single operating system you can imagine. You can do this in a way that completely ignores the trust store of that operating system, and anything the user does to this is ignored by the application.

This has been possible for years on Android. This has been possible for years on Windows. This has been possible for years on Linux.

All the developer has to do is include the certificate of their own CA with the application, restrict the SSL's trust store to this one certificate, and then also check the fingerprint of the resulting certificate offered by the server. Then if the application notices this fingerprint is incorrect, it bails.

This is reality. This is how it works. Nothing I believe or want will change this. No amount of certificates I install in my operating system's trust store will change this either.

What android is doing is making MITMing yourself harder. But it's always been 100% possible for developers to make MITMing impossible without first reverse engineering the app and replacing the baked in certificate.

That's just the way it works.

[__b__]

"What android is doing is making MITMing yourself harder."

That's not good for users.

I do not rely on Android, Windows or Linux. Not really much an app user either.

But if I were a user of these systems I would avoid apps where the user is not allowed to see what is being sent. Irrespective of any justifications put forth. By a company that relies on collecting personal information and selling advertising to make money.