Wow, this guy has the completely opposite attitude of me. He seems to think it's a bad thing, an attack!, for users to see just what the hell data you're pulling off someone's phone. And, bizarrely, uses an example of an app that essentially stole data from its users.
I should be able to see what data an app is sending, and certificate pinning (and ATS according to another comment) kills that. That's not a good thing.
It's not an uncommon attitude, and it's also one I detest --- many articles about "security" have some authoritarian/paternalistic aspects to them. Then again, encouraging ignorant users is the easiest way to monetise, analyse, and otherwise manipulate them... and if this ignorance is a convenient byproduct of arranging things so "it's for your security" ostensibly, all the better.
Certificate pinning does prevent an important class of MitM attacks, though.
I think some applications use certificate pinning when validating a certificate provided by a default certificate authority, but, if you manually install a root certificate onto your device, the app will accept the override. That's one possible middle ground.
While the privacy concerns are more than valid, reverse engineering is common practice in trying to copy your product.
Reverse engineering isn't inherently good or bad, it's just a tool. That tool can be used for both good and bad.
I always recommend certificate pinning in order to prevent MITM attacks. I also recommend it if you're backend API gives out a lot of information about your product's "secret ingredient".
Reverse Engineering to copy is even considered a legal tool in the EU.
The argument of the European Court of Justice was that car manufacturers also buy cars from competitors, take them apart, and use the gained knowledge on their own products. The same happens in every industry — but in Software Engineering, it should now be forbidden? That's not possible.
If you want to protect yourself from that, publish your secret sauce and patent it.
disabling system-wide is pretty much impossible. If OSes added such a toggle, people would start using their own SSL stack and overall security would suffer (because people won't be keeping their SSL stacks up to date)
That's what you'd like to think, but the numerous terms & conditions that you've agreed to for your apps means that you're wrong, some data isn't yours.
No, it really doesnt. Terms of service are only legally binding within the law and the EU has already ruled that reverse Engineering software on your own device is just fine.
OK, then how do we separate the data that is his versus data that belongs to somene else? Maybe we would have to look at what is being sent from the app?
Who knows? The two things are unrelated. My comment wasn't anti-reverse engineering, just stating a fact: just because something is in your phone doesn't mean it's yours.
"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.
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.
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.
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.
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?
> 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.
"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.
Yeah, no shit. But that's not my, or your, point. Do you even have a concrete point you're getting at, or is it just "I don't like Google"?
Android is making it MITMing apps harder if the application itself did not attempt to make it hard. It has ALWAYS been possible for applications to pin their certificates and to make MITMnig them a pain in the butt. On every OS. On Windows. On Linux. On Mac. On iOS. And yes, on Android too. It has always been that way. I already went over this. Here, go read this: http://security.stackexchange.com/questions/29988/what-is-ce...
But, there is a solution! One that they (Google) also clearly indicated in the blog post when they announced this whole thing. And that solution is: Install a custom rom which does not have these security features. Bam. Done! That's all it takes. If you care about your privacy you're already running a custom rom. And if you care about MTIMing apps, then installing a custom ROM is not that much of a hurdle either.
A million times as many people are being spied on without their knowledge than want to check their own data though. Not like these things were invented because of users, they were added to stop MITM by governments etc.
If you don't want to use OSes, devices and software that's designed to protect the average user from being hacked, then pick a system which gives you root.
I should be able to see what data an app is sending, and certificate pinning (and ATS according to another comment) kills that. That's not a good thing.