I'd like to use Keychain Services for iOS to store the OAuth access token and refresh token that my app need to perform Web services requests. I've been reading the Keychain Services Programming Guide and I downloaded the GenericKeychain sample code, but I'm getting confused:
Code provided in document is different from the sample code... which approach should I follow?
I read somewhere that you need to enable Data Protection in Member Center for the App ID and its associated provisioning profile. However, I didn't read anything about enabling Data Protection in Xcode for the target's capabilities, and it seems that I could access the keychain anyway... this is weird, but I guess I should enable Data Protection in the Xcode project as well, right? Where is this Data Protection stuff described in Apple's docs? Is it somewhere said that I need to enable it for Keychain management? I don't find it...
Samples I found use the kSecClassGenericPassword class for the keychain items. Since I want to manage OAuth related information, is there any better class I should use? Maybe kSecClassInternetPassword? What is the difference with kSecClassGenericPassword?
Is it recommended to instantiate a kind of KeychainWrapper class, or would it be better to access keychain related methods as class methods?
Thanks in advance
Q3:
According to Apple
documentation
You use Internet passwords for accessing servers and websites over the Internet, and generic passwords for any other password-protected service (such as a database or scheduling application).
Related
We have an enterprise iOS SDK that uses Keychain to store highly sensitive information. These information are not available to the client's app.
I've always thought that you need a key to fetch the associated value from the Keychain. But recently, I found out you can ask Keychain to return all the stored keys in Keychain (IMHO, this is a bad design).
Since the client's app can easily fetch all the Keychain elements, I'd really like to create a separate Keychain store for the SDK only. I've looked over SO questions but never found an answer.
TL;DR:
How to create a separate Keychain store in iOS?
You can't.
The security boundary for the KeyChain is the app (Or the KeyChain identifier across multiple apps from the same developer if you enable KeyChain sharing).
Once your framework is embedded in the client app, it is part of the client app. It doesn't have its own context or process space or anything to distinguish its code from the client code.
If code in your framework puts something in the KeyChain then, to iOS, it is the client app that has put something in the KeyChain, and there is no reason to keep a secret from itself.
Even if you could create a KeyChain just for your framework, presumably the code that puts the information in the KeyChain is in your framework, so an attacker could just decompile your framework to obtain the information.
I'm developing an iOS app that uses Cognito User Pools / Federated Identities, Mobile Analytics, and S3 to manage various features of the app, and recently I have become concerned for the security of these features. I already use IAM roles to control the services unauthenticated vs authenticated users have access to, but most of these services use strings (e.g. user pool app client id or user pool app client secret for User Pools, or app id for Mobile Analytics) to give the app access to that service.
What are the best practices to securely store these strings on the device to be used when necessary? Is it even necessary to secure these strings since the app is using IAM roles?
If it is necessary to securely store the strings, I have read that using the CommonCrypto library to encrypt strings before putting them in the keychain is best, but I'm not sure what key to use for encryption since my user needs unauthenticated access to those services. Any advice would be tremendously helpful.
This is a common problem to any mobile app. If someone really wants to, it's not difficult to decompile the app and scrape the keys from it. It's great that you are using IAM roles to restrict feature usage. This will limit the blast radius of attackers, but not necessarily prevent them.
Wth user pools you also get a globally unique identifier which can be used with IAM to restrict what S3 you can use key pre-fixes (which act similar to folders) to limit the objects that users can access to pre-fixes with their unique identifier. You can refer to https://mobile.awsblog.com/post/Tx1OSMBRHZVM9V0/Understanding-Amazon-Cognito-Authentication-Part-3-Roles-and-Policies (Using user pools as the provider, which will use the identity id as the prefix). Depending on how you structure your app you could use this so each user can only modify their own objects. I don't think Analytics has any way of restricting like this... because it wouldn't really make sense for it.
As far as securing your ID's there are things you can do to help mitigate, but there is no fool proof way to prevent someone taking it. You could for instance have the app make a call to your server for the ID... but then an attacker could just call the server. You could encrypt it, which might make it more difficult for an attacker to get, but you have to keep the key somewhere and if the app could get it so could someone who decompiles the app. Unless your app users get some sort of password from outside the app and put it in there isn't a complete way to lock it against attackers.
Hope this helps.
I'm struggling to find the exact details on this, so I'm hoping to get some help here. I'm looking for some information regarding the underlying storage mechanism of the iOS shared NSHTTPCookieStorage:
When cookies are stored using the shared NSHTTPCookieStorage, is there any encryption provided by default, such as the use of the keychain services? Or are the cookies simply stored in plaintext using NSUserDefaults?
I understand that the cookies are stored within an app's sandbox, so that other apps will not have access, but is my understanding correct that someone with physical access to the device can easily access an app's cookies and their values (especially if they are stored unencrypted)?
If one had to handle some sensitive data in cookies but wanted to utilise the default cookie handling/storage (shared NSHTTPCookieStorage) of the NSURLSession APIs for instance, what would then be the best option?
Sorry, I know I've asked 3 separate questions but any help on this would be greatly appreciated.
Thanks.
I don't know how cookies specifically are stored, but all application files are encrypted on iOS, with an AES256 key specific to the app. Those keys are derived from other keys that ultimately come from the "secure enclave" within the CPU chip, which will only release the keys when the user unlocks the device. (Apple has a pretty comprehensive security white-paper for iOS that describes this in detail.)
For this reason it's quite difficult to access files on iOS, even with physical access, unless you can get the device's passcode and unlock it. The regular cookie storage is probably secure enough for your purposes.
As you know many apps use keychain to save user login name and password, but is it really safe? especially on device jail break mode. So another solution is to use Outh2 protocol to save those confidential infomation on server side which needs many changes on both client and server side (for my app).
How do you guys handle this tough issue? Anyone who knows please share and thanks in advance.
Keychain:
It has two level encryption options
lock screen passcode as the encryption key
key generated by and stored on the device)
But when the device is jailbroken its not safe too.
oAuth:
Eventhough you store credentials in server you'll have to save the OAuth TOKEN in client side there is no place better than keychain to store it in client side.So now comes possibility of extracting the TOKEN on jailbroken device.
As far as I know in most apps they use one of these approaches.
If you need those data to be very very secure.
Suggestions:
Store OAuth token in server not in client
Store the Encrypted Credentials in Keychain and store the encryption key in server.This approach would be easy for you since you said adopting OAuth is hard for you.
Note:
There are some open source libraries available which detects if the device you run or app is cracked if so you can take action like deactivating TOKEN,deleting critical resources,locking app etc.
I was just reading through some source code for an iOS application and I'm curious about the security of the same. It seems that the access group of an application can be specified in the entitlements it was built with. However, if a user unknowingly installs malware which tries to be part of a particular group and read the data stored in the storage, isn't it a security issue?
Is the Apple Application Screening process the only thing that stops the above attack? Or is there some permission management concept that im missing out? Thanks!
No, this is not a security risk. Provisioning profiles determine which access groups apps are allowed to claim access to, and provisioning profiles must be signed by Apple in order to function. Apple will only let you claim access to access groups created by other apps in your developer account.
The other answerer is mistaken; he/she links to a tool which is only for jailbroken devices and must be run as root, bypassing the standard iOS security mechanisms which apply to most devices.
Yes, it's a security hole. For example, this tool can dump all the sensitive info in the keychain, including Wi-Fi and mail/facebook/any passwords off of your device.