Showing posts with label security. Show all posts
Showing posts with label security. Show all posts

Monday, January 26, 2015

Network May Be Monitored By A Third Party (a.k.a. Android KitKat scary warning message part 3)

I guess people care about this annoying warning message that Android has thrown on us.   No other blog post here has generated anywhere near the number of hits that this issue has generated.  So, to all of your that have found my blog and read what I have to say, I thank you!

Unfortunately, Google doesn't seem to care about this issue.   (Newsflash!  Google doesn't care about making certificates easy to use on Android.   And, by extension, they don't care to make wireless authentication on Android usable either!   I could write volumes on my experiences trying to get things improved.  But, I fear that it would inspire depression in anyone that read it.)   So, we need to do something to try to GET them to care!

There have been several bugs opened about this problem, and most of those bugs have been closed with various reasons that make no sense.  (Which is what I base my claim that they don't care on.)  Some of the other people on the Internet that agree with me that this is a problem have continued to open new bugs to continue to push the problem and make Google listen.   If you care about this problem, PLEASE go to the Google bug tracker, and at least star the issue.   If you have the time, you might consider posting a comment to the bug that outlines why this issue causes you grief, and what changes you would like to see made in order to improve the situation.   (If you are only going to complain, do us all a favor and just star the issue.   If you want to complain, and offer suggestions on how to improve things, please post a comment!)

I'll even make it easy for you.   The URL (with link!) to the current version of the bug is at : https://code.google.com/p/android/issues/detail?id=82036 .


As you make your feelings known, please consider this.   There is actual value in having a warning like this, if you are the kind of person that values privacy and is against network operators using man-in-the-middle tactics to monitor what you are doing.   And, thanks to stupid legislation here in the US, if you are attending a K-12 school that provides Internet access, you SHOULD care about this very much!   US law requires the schools to snoop on students as a condition to continue to receive funding!    I'm lazy, so I am not going to track down the exact law that requires this, but I know it is true because of my day job.   (Not going to say any more than that because my opinion might get me in trouble.)

Because I would prefer that people being snooped on are given any warning that it could be happening, I am actually in favor of the warning message that was added.   However, I have problems with how it was implemented.   I think there are a few tweaks that could be made to the implementation that would take this from being a pointlessly scary warning message to a valuable warning message, and an opportunity to educate at least a few people on some of the security issues that are associated with installing new root CA certificates on any device or OS.   Also, as I have stated before, I don't like people that complain about a problem without offering solutions!

So, here are my suggestions on how to transform the annoying mess that is the "scary certificate warning message" in to something useful and significantly less annoying :


  • Don't show the message (ever) if the certificate is used with 802.1X on a Wi-Fi connection -- Starting with Android 4.3, the "Credential Store" (a.k.a.  Certificate store, or key store) has been split in to two parts.  One part holds the certificates that will be used for authentication on Wi-Fi networks.   The other part holds certificates that are used for VPN connections, web site connections, and everything else.   Since you *HAVE* to install a certificate in order to securely use a Wi-Fi connection, showing this warning message is pointless.  The other alternative is not to use a certificate to validate the Wi-Fi network, which leaves you WIDE open to anyone doing a man-in-the-middle.   So, the scary warning actually has the potential to make users LESS secure by making them remove the certificates necessary to secure their networks!   Google must recognize this on some level, because they don't show the warning if an app uses the Wifi API to install certificates.
  • When you tap the warning, give useful information --  Right now, when you tap the warning, you are taken to the security settings screen.   This is COMPLETELY useless.   The user is expecting to be given more information on what this warning is all about.   Take them to a screen that explains what the potential issues are with installing a new CA certificate.   Explain clearly what the problem is, and don't try to scare them in to submission.  Try to give the user enough information to allow them to make a good decision about leaving the certificate installed.   Also, provide links to more detailed information so that those that are really curious can really dig in and understand the problems.
  • Allow users to get rid of the warning -- Right now, you can dismiss the warning, but it comes back any time you install another CA cert, or anytime you reboot your device.   This behavior is annoying.   Tell me once, let me decide what to do, and then leave me alone!  Anything else is a bad user experience.   When the user taps the warning to get more information about what it is about, they should also be given two check boxes.   One check box should allow them to dismiss the warning just for the current certificate, the other should allow them to block ever showing it again.   There really are two types of users where this warning is concerned.  There are those that already understand the risks, and those that don't care.   The purpose of the warning to to try to get some of those that don't care to actually start to care.  But, annoying the crap out of them is only going to make them hate the issue so much that they will never care.

If my three suggestions above were implemented, I suspect most people would no longer hate the warning message as much as they do now.   It also gives the power back to the user, which is what I always thought Android was supposed to be about.

I understand that in addition to warning users that they may be causing themselves problems, they are probably also trying to cover their butts should a bunch of users get hacked and complain in the media, or worse, try to sue.   However, I really believe that showing the warning once is more than enough for Google to cover their butts on this.

In the unlikely event that someone from Google reads this, and wants me to put my money where my mouth is, I will offer to submit patches to the AOSP project to implement all of the things above.  HOWEVER, given my previous experiences with submitting patches to AOSP, I will be expecting a promise that the code will eventually be included.   By "eventually", I mean that someone from Google will be assigned to review my code, and comment on it until the code is in the right state to be fully included in AOSP and eventually the main Android builds.   (As an aside, while I have tried not to give out any information on this blog about who I am, I am sure that Google has the ability to look up my e-mail address based on this blog being hosted on Blogger.   There is also someone on the Android dev team that knows me, and someone on the Android security team that knows me.  So, it should be easy enough to verify that I know what I am talking about, and it should be easy to reach out to me.)

Wednesday, November 6, 2013

Android KitKat : Network may be monitored by an unknown third party

Update 1/26/2015 - Google has refused to take this issue seriously.  They have closed several bugs posted on the Android bug tracker.   Fortunately, there are some other people out there that agree that the current implementation is broken.   Unfortunately, Google doesn't seem to think that it is worth fixing.   Since I know a lot of people find this page while looking for information on this annoying warning, I would encourage you to go to the current bug on the Android bug tracker, and star it to show Google that you want this resolved!   Perhaps if enough of us star it, Google will start to pay attention.   You can find the current open bug here.

Let me start by making the disclaimer that these observations are based on an AOSP build of Android KitKat on a Galaxy Nexus.   (My Nexus 5 isn't due for two more days.)   However, things like this that exist in AOSP tend to also exist in the release builds.

Along with all of the great new features in KitKat, Google has introduced what is probably the WORST security hole possible.   A ham-fisted implementation of certificate pinning.

Certificate pinning itself is a good idea.   It verifies that when you visit a web site, it provides you with the same certificate every time.   In general, certificates shouldn't be changing on web sites, and if one does you should be made aware of it.

So, how could certificate pinning be a security hole then?   By creating a situation where a harmless certificate creates a scary, and unnecessary, warning message.  When you install any certificate in to the key store, you get a warning icon in the bar at the top of the screen.   Pulling down the shade presents the following screen :


Let's consider the average user at this point.   Given the revelations about all of the snooping by various governments, it seems that a warning like this would make uninformed users very concerned.   (And, lets face it, there are very few informed users when it comes to 802.1X on Android.)   But, okay, maybe I am freaking out over nothing.  What happens when we tap the warning?


Hmm... Maybe not.   So, the assumption that an uninformed user is to draw based on this is that having any form of third party "trusted credential" installed means that a 3rd party will probably be monitoring my traffic.

I'm going to skip over the obvious irony here that something from Google is warning me that a 3rd party might be monitoring the web sites I visit, and reading my e-mail.  (If the irony is lost on you, you may want to do some research.)

Google seems to be trying to argue that the only safe type of certificate is one that comes pre-installed on your device.   Which is a downright silly argument no matter how you slice it.   But, lets go ahead and let that one slide.   Being the security minded individual that I am, I make sure that all of my network connections are as secure as possible.   So, I make the (probably bad) assumption that purchasing a certificate for my RADIUS server from a public CA will provide me what I need in order to have a secure wireless network.

Once I get the network setup, I try to connect my Android device to the network.   Now, being that we have paid even a little attention to the security issues around wireless networks, we know that we need to validate the server certificate in order to have a secure connection.   No problem, we purchased from a public CA, so we will just select that in the configuration settings.   But, you can't.   The pre-installed certificates on Android can't be used with 802.1X authentication.   Okay, no problem.  I'll just install the CA certificate on my device and then use that.   Oh, what is this scary message?

Now, those of us that understand the meaning of this message will just dismiss it.   But, let's assume that you aren't a techno savvy individual that has enough time to spend learning about security.   This warning is going to freak you out!   If this conversation hasn't happened on a message board yet, it will soon :

"Hey, I got the upgrade to KitKat, and it is great!  But, now I get this warning saying that someone is monitoring my network connection!   How do I make that go away!?  I don't want someone monitoring my network connection!"

"Getting rid of that warning is easy.   Go to Settings->Security->Clear credentials.   After that, the warning will go away."

"Thanks!  The warning is gone.  But now I can't connect to my wifi network!  HELP!"

"Not a problem.  Go in to the configuration for your wifi network and change the 'CA certificate' setting to '(undefined)'.  Problem solved!"

"Perfect!  That solved my problem!  Thanks!"



And somehow Google either didn't consider this case, or they really want to decrease the security of wireless networks.

Anyway, if you happen across this post while looking for how to make this scary looking warning go away, and you use a secure wifi network, please just swipe the warning out of the shade.   It is really nothing to worry about.   (I'll do a follow-up post in the next week or so about how authentication on wifi works and why you should care.)

Edit 11/26/2013 : A coworker pointed out that my blog post was referenced in a bug posted to the Android bug tracker.   The same bug post had a response from someone using an @android.com e-mail address outlining why this issue isn't a problem.   I tested their solutions and wrote about it here.