I have a requirement to remove all API keys and app secrets from the source code of the app we are building. Ideally the keys and app secrets should be sent to the app out of band as a configuration file, through an MDM solution.
Is this possible, and if so how? If not, what is the recommended approach to store this kind of information, such that it cannot be viewed in the source or extracted from the binary?
EDIT: Update
It is possible to send NSUserDefaults to the app via the MDM solution using Managed App Configuration. However, NSUserDefaults is not secure, easily viewed and modified by a casual user.
My plan is to encrypt the NSUserDefaults to prevent this using the common crypto library included in iOS. Is this the best approach to this problem? Should I also be sending a certificate as part of the MDM config?
Any thoughts, comments, and recommendations appreciated before I go too far down this route.
I know it's been a while, but I recently looked into this (not for an MDM application). I don't have any experience with MDM and that may have another solution. The route I chose to go was using CloudKit. It's a 1st party solution, always available whether the user is logged in to iCloud or not and you communicate securely with Apple's servers and only your App can access these keys.
Also depending how you set it up you can easily rotate out keys.
See more info here
Related
I am trying to build a mobile monitoring tool/app for iOS without Jailbreak. The only possible way to perfectly access all installed app's content is through iCloudKit.
Also I found Apple's MDM come a little close to this for BYOD devices but yet accessing individual application's data is not possible.
During all this process, I came across some website fonemonitor and phonemonitor (with and without) who claim to do the same without Jail Break.
So here is my question is it possible to take any application's data if we get access to the users iCloud account? Also, are all public, private and shared data accessible via iCloudKit? As the documentation clearly states private data is untouched.
How does app monitoring work for any iOS Devices through these websites. Any lead would actually help!
When we talk about securing iOS application we often forget to secure most critically sensitive information such as secret, key, token, encryptionKey. This information is stored in iOS binary. So none of your server side security protocol will help you.
There are lots of suggestion that we should not store such information in the app but store in the server and get it via SSL secured web service call. But this is not possible for all application. E.g. if my application does not need web service at all.
In iOS app we have following option to store information.
UserDefault: Not appropriate for this case
String Constant: Not appropriate for this case. Can be reverse
engineer to retrieve or just use strings command
Secure Database: Store in Secure and encrypted Database. But again have responsibility to secure database username and password.
KeyChain: Best to store critical info. But we cannot save information before installing the app. To store in the keychain, we first need to open the app, read from some source and store in the keychain. Not appropriate for our case either.
Custom Hash String Constant: Not to directly use secret, token, key from service provider (mixpanel, paypal), instead use hash version of that information from custom key. This is also not perfect solution. But add complexity during hacking.
Kindly send some awsome solution to this problem.
If you don't want to use your own backend then use Apple. You can configure On Demand Resources and keep data file with your key, token, any secret on Apple server. After first download you can write this data to Keychain which is secure enough. I'm guessing networking between iOS and Apple server is also secure enough.
On-Demand Resources Essentials
Accessing and Downloading On-Demand Resources
1) Internet Connection Required
1.1) Push Notifications
Great way to have a secure data exchange could be to use (silent) push services from Apple, those use the apns and send data through https - more Details 3.1
1.2)
A more or less similar approach is also used when distributing new user certificates to already deployed applications, if a reinstall of the application is no opportunity AND the application requires a working internet connection anyway.
Downside: working network connection required and basically the information is coming to the application, when it is already being executed => seems not to be appropriate for your case. (see step 4)
2) Static data (as there will be no exchange without network connection / communication partner)
Encryption of data with private key being provided in the bundle itself. Whether it is now a string or a hash, which can be reverse engineered with functions you got emebedded in your application.
Since iOS9 it is pretty hard to decompile iOS applications and basically you will mainly have a look into the provided header-files. So if you had such a function, string, hash value or whatever, make sure you got it in your .m-file!
But again: if the information is not device or user specific, just a secret across your own micro environment, valid across all devices, you would have to provide the encrypted data AND the decryption method in the same bundle, if there is no update process / information exchange or something else, you can think of.
Good for encryption:
iOS System.Security https://developer.apple.com/reference/security
or simply openssl
The difference between your described keychain approach is:
You got a value, which WILL be encrypted and stored securely.
(2) describes the approach to have an encrypted and stored (in bundle) semi secure value, which WILL be decrypted
3) Information exchange
You describe critical data, which was hashed by another instance. Great! - Make sure, relly make sure, the instance you are talking to is really the instance you expect to be (Network Hooking prevention with ssl certificate pinning etc, but even here you might have intruder (men-in-the-middle)). And you will (probably) have a certificate being provided in your application bundle, to ensure the authenticity of the communication server - here you go again, data that is supposed to ensure a secure process between certain instances of your micro environment. Nevertheless, this data is being provided in your application's bundle.
3.1 Secure Information Exchange extended - Silent Push
Make use of Apple's servers to exchange your secrets for this purpose. If you just need to exchange small data chunks. I would recommend to use silent push notifications to the user, those do even work without explicit permission from the user. Huge advantage: In case your secrets or keys change, you can inform users as soon as possible about the change. They will likely only need the change, when they receive new data, which should reliably work in most cases. Exception: Data exchange in local networks or via bluetooth, in this case I would recommend to provide a notification to the user to have the requirement to update a local decryption key. Or exchange the key in this format as well. Once again: I am leaking some detailed information about your environment architecture.
Downside: You don't know, whether a user just used your app for the first time, until the user "tells" you so.
https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/APNSOverview.html#//apple_ref/doc/uid/TP40008194-CH8-SW1
3.1 Secure Information Exchange extended - In App Purchase
Use a frree In-App Purchase for the user to get the data to your phone. Good point here: you can provide larger data chunks easily, as this should be an active request by the user, the user does expect certain processing time and should also be aware of the fact to require a working internet connection.
Downside: User would have to select this on purpose. Up until then the app would not work accordinly.
https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/StoreKitGuide/Introduction.html#//apple_ref/doc/uid/TP40008267
So, it just slightly differs from the approach (2) in its basic idea.
In short: Can you provide additional information, what kind of data you need to encrypt/want to store securely and whether you will have a network exchange or not?
Would need some more information here :-)
I would like to emphasize once again that an application on iOS is not that easy to decrypt anymore, even decompiling would not get everything, you expect it to get. For instance decryption tools like dumpdecrypt were only working properly up until iOS 8.4
It seems to me that the best way to do this is using the built in CloudKit. You can save your secrets in the CloudKit Dashboard and then fetch them on startup. Since CloudKit is only a transport layer you'll have to store the app secrets in the KeyChain.
I know you mentioned the KeyChain not being ideal for your use case (not sure why), but this is a good way of not including the secrets in your app. You can't get around fetching your app secrets from another source.
CloudKit access is secured using the system iCloud account and if there is no iCloud account you still access the iCloud servers securely. Another added benefit of this is that you can change your app secrets at any time, so if you want to be even more secure you can implement a rotation schedule.
Learn more about CloudKit
Cocoapods-keys might be a best option.
From cocoapods-keys doc's
Key names are stored in ~/.cocoapods/keys/ and key values in the OS X
keychain. When you run pod install or pod update, an Objective-C class
is created with scrambled versions of the keys, making it difficult to
just dump the contents of the decrypted binary and extract the keys.
At runtime, the keys are unscrambled for use in your app.
The generated Objective-C classes are stored in the Pods/CocoaPodsKeys
directory, so if you're checking in your Pods folder, just add
Pods/CocoaPodsKeys to your .gitignore file. CocoaPods-Keys supports
integration in Swift or Objective-C projects.
Check out this link for installation, usage and more info : https://github.com/orta/cocoapods-keys
I agree with #Lobsterman and believe that the best way will be to use a combination of these.
Don't include the secret information in the app initially.
Deliver the secret key either as in-App purchase content ,on-demand resource or send it through push notification. This will add the benefit of changing the key periodically if you want and the change will take effect without any additional effort.
Add the entry to keychain access once the content is delivered.
If the data is extremely sensitive then it should never be stored offline on device because all devices are crackable. If you still want to store on device then keychain is one option for storing data securely, However it's encryption is based on the pin code of the device. User's are not forced to set a pin, so in some situations the data may not even be encrypted. In addition the users pin code may be easily hacked.
A better solution is to use something like SQLCipher which is a fully encrypted SQLite database. The encryption key can be enforced by the application and separate from the user's pin code.
I have an iOS application that will be distributed to multiple customers, each using their own network infrastructure. I would like to add some certificate pinning capabilities, but I need to do it in a dynamic fashion since I cannot ship the app with the cert/pubkey bundled, as doing so would require a different build for each customer.
My idea is to query the per-client configured HTTPS server on app startup, get the certificate, potentially extract the public key and then pin it.
Is it possible to do this in Swift or Objective-C? I have not been able to find relevant code samples or documentation.
Operationally, it will be a lot easier to manage and recover from misconfigurations if you embed the certificates or keys in the App. If you just pin whatever certificate the server sent to the App the first time, you have no mechanism to support a new certificate once the current one expires or gets rotated. If that's still what you would like to do, I would recommend looking at the HPKP specification, which implements the same mechanism but for browsers: https://www.rfc-editor.org/rfc/rfc7469
Also, if the App servers are not directly under your control, there is a high change that pinning will end up bricking the App, if the server's certificate unexpectedly changes. Will the team building the App be informed about infrastructure/certificate changes on the App/customer servers, so they can release an update just in time? If not, you should not do it.
Its possible. I haven't tried myself, but I think you are looking for something like this.
https://github.com/wultra/ssl-pinning-ios
I've been researching literacy about the secure aspect of the NSUserDefaults leveraged by the ManagedAppConfig capability of iOS.
We are leveraging this "new" iOS capability to configure our enterprise application via various MDM systems used in our customers landscape.
A debate is now raging on how secure it is.
From our side, the only way that we have found to get this information is to actually JailBrake the device. Which of course would be detected by the MDM system.
Any other security vulnerability that we may have missed there ? Anybody looked into the security aspect of this feature ?
Thanks!
Ingrid.
Everything you store un NSUserDefault is easily accessible (with an app like iExplorer for mac, for example). No need to jailbreak. It is all stored in a .plist file in the Library/Preferences folder of your app.
I had to hide some information before, the way I did it was by using Data Encryption. For more information, read the section called Enabling Data Protection
All you would need to do after enabling correct data protection, is to create a file and store your configuration there. By putting the Data Encryption to NSFileProtectionComplete, your file will be visible, put not readable when the device is locked. For this to work, the user must have set a password on his device
I know there are quite a few threads on this, but it seems none of them would satisfy what I am trying to look for. Here's my constraints:
not a hack that uses private API/framework or undocumented
directory access that would run the risk of app being rejected
because of that
being able to share data across different
vendors / app developers
data can persist outside the lifecycle
of the app (even after app is deleted)
UPDATED: I was in general trying to stay away from using a 3rd party cloud-based service to achieve the goal as this would introduce additional external dependency. But if I have to, I was hoping it could satisfy this one constraint
being able to tell which iOS device it is communicating with. It shouldn't have to uniquely identify the device (which will go into that evil UDID discussion route as we all experienced ). But as long as it can differentiate among different iOS devices it should be fine.
I kind of need this too. I use Parse.com as the backend of all my apps — their free tier should satisfy your development needs.
Parse has APIs available for iOS, Android, Windows 8, OS X, JavaScript and .NET, with all your data available on the cloud on any platform (contrary to Core Data and iCloud). They also offer "Cloud Code," which is code you can execute remotely, to process information remotely and get the data back to your app.
You should definitely check Parse.com out for cloud storage for your app. In my experience, it really gets the job done.
For Data Persistence, I think you might want to take a look at FMDB (although if you decide to persist data locally, it will get deleted with your app, but it might help you, anyways). Core Data is an overkill in many cases.
Edit: Parse.com has an "Installation" class, in which all the devices that have your app installed get listed (wether they're running iOS or Android), uniquely, without you having to type any code.
Maybe this blog post by TextExpander authors will help:
Smile has responded to this by discussing the issue with Apple
engineers at WWDC, filing a bug (#14168862), and checking up on the
status of that bug. We also developed a workaround by storing the
TextExpander data in a new place. Reminders requires user consent to
store and retrieve data. Completed reminders are not normally shown in
its interface. Long-past reminders appear at the bottom of the
completed reminders.
TextExpander touch 2.1 (and later) supports storing shared snippet
data in a long-past, completed reminder. We produced an updated SDK
and kept our developers posted on its progress. Our final SDK was
ready within a few hours of the end of Apple's official iOS 7
announcement.
UPDATE (22.11.2013)
This might not be the best way to do that, because TextExpander's team recently had problems with the App Review Team.
Edit: this only works for apps with the same vendor.
You can save a password to the device's keychain, then access that password from any app.
Using the SSKeychain library...
NSString *service = #"com.yourcompany.yourservice";
// read
NSString *password = [SSKeychain passwordForService:service account:#"user"];
// write
[SSKeychain setPassword:password forService:service account:#"user"];
The password string doesn't have a length limit, so encode all your data as a string and save it there. The keychain entry will persist after the user deletes the app.
One of the ways to do this is using THRIFT. This is a data communication protocol that would need a back end server (private) and THRIFT can be compiled into many languages / platforms. There is a meta language to describe the data and then can be thrift compiled into many languages. Write the data definition once and can be used on many platforms.
More information at.
http://thrift.apache.org/
for me (I have 2 apps and a widged) the best solution is using SSKeyChain and do not forget to add Capabilities for your apps like here
or if you don't wanna to use 3rd party library you can use NSUserDefaults and set the group identifier like here but again do not forget to add the group identifier in Capabilities in AppGroups section for all your apps that have share data.