Is storing secret keys (internal use passwords and such) on iPhone source code and project resources (such as plist files) secure?
Obviously nothing is 100% secure, but can this information be extracted easily from an installed app?
How do you recommend storing these keys to use them in the source code?
Just in case, this question is not about storing user passwords.
Found basically the same question with a longer discussion:
How would you keep secret data secret in an iPhone application?
To sump up: it seems there's no official way to securely store secret keys in the app binary.
Sorry for posting a duplicate question.
A lot depends on what you mean by secure. For normal device use it could be considered secure in that there is no way for a user to access it. However all bets are off for a jail-broken device which has complete access to the filesystem. So viewing a plist file in your application bundle is trivial on a jail-broken phone.
You might consider the use of the keychain which in theory would be safer and also has the advantage that the data will survive a reinstallation of your app. As before on a jail broken device nothing can be considered to be 100% secure but it depends how much trouble you want to go to.
Related
here is the things: there are some data sensitive which be stored in the device using NSCoding serialization.
I'd like to know is there a way the other people can find the key and unarchived the serialized object file to get data?
Thanks for help.
It is not safe to store sensitive data just using NSCoding. The NSCoded values are not encrypted in any way - you don't even need to know the keys - you can just look at a stored file directly and easily see the values if they are strings.
Sensitive data (particularly API access keys that provide privileged access to back-end web services or financial information) ideally should not be kept on the client device at all. Even when encrypted. In the extreme case, a black hat who has your app installed on their device can mount a man-in-the-middle attack and snoop on your internet traffic with your server. Instead you should a device-specific token approach if concerned about security so you can revoke a token if necessary without affecting other users.
If really concerned, you should look at two factor authentication in addition to the token.
Here is an intro for further reading.
It depends. Each application is given its own 'sandbox' on the filesystem. On a device that has not been jailbroken, an app cannot look outside of its own sandbox. However, when a user connects their device to a Mac or PC, it is possible to use utility applications such as iExplorer (http://www.macroplant.com/iexplorer/) to access the sandbox of each app on their device.
is the data stored on an iPad/iPhone encrypted?
I assume that the iPad/iPhone has an advanced pass code (not just the 4-digit code).
So my question is if data that my custom app stores in the device is encrypted or not (if no special methods are taken in the source code of the app). Would an attacker be able to read the data? What if he jailbreaks the device?
Thanks!
The answer is no if you don't apply any encrypting technique on it. You can try to use iExplorer to browse all the sandboxes of your device's applications. You may get surprised about the security of many apps out there.
I am just starting getting familiar with security in iOS, but from what I read and understood from Apple's IOS Security whitepaper, files are encrypted by per file encryption keys and those are encrypted by class keys assigned by the application that owns the files (which are sandboxed with the application). And then, the files access depends on the protection policy you assigned in your application.
However, from this answer, it is unclear if the encryption is always on, or just when the device if off or unlocked.
In any case, the above applies from non jailbreaked systems (not sure if they do for jailbreaked ones as well).
According to Apple documentation and other documentation I have read about on disk encryption on an iOS device, it seems that in order to take advantage of the advanced encryption of the device the user must have a passcode enabled so that when you use the NSDataWritingFileProtectionComplete attribute it will encrypt.
What if the user does not have a passcode set but I still want to ensure the files are encrypted? What options are there for this scenario?
Thanks!
Flea
iOS includes several APIs for encrypting data. The automatic on-disk encryption is a user-selected option that lets the user encrypt all the data written to the device's secondary storage. If you need your data to be encrypted whether or not the user chooses to turn on that option, encrypt the data yourself using one of the options provided.
Unless you really know what you're doing (and even if you think you do, you probably don't), it's generally a better idea to use the provided APIs which you can expect to have been written and reviewed by experts.
If you plan to distribute your app outside the US, and you use encryption, you will have to comply with the US Bureau of Commerce restrictions. If you use Apple's provided APIs and you are only using encryption to protect your content, you will be able to distribute your app internationally (according to Apple's iTunesConnect FAQ.)
However, if you write the encryption yourself you will have to go through a review process with the US government.
I've written more than one app that encrypts content on a server so it can be protected even after it has been downloaded to the device.
Even Apple's encryption doesn't prevent someone from making an unencrypted backup or mounting the device as a filesystem and taking the media files your app might have downloaded.
So, to protect your content you must encrypt it yourself. And, you must only decrypt it in ram and never as a temporary file in flash memory (which could be copied off the device.) This makes serving encrypted movies and PDFs a bit challenging. I use a decrypting web server thread; however, there are more modern approaches including a file-level delegate approach that might work better.
So I am working on a test app that downloads files locally to the app file storage sandbox. Some of these files may be sensitive and need to be protected. My app has a login mechanism, so you wouldn't be able to access the files if you didn't have a login, so my main concern is the ability to sniff the contents (Perhaps on a jailbroken device??).
Now I was wondering if the best method to protecting these files is to encrypt each one independently? Or perhaps there is a way to encrypt the whole sandbox? Or is it encrypted by default? Has anyone ever done anything like this before?
I apologize for the long string of questions, I am trying to gather as much info about this as possible before making a design decision...
Thanks!
You might want to look into the File Protection mechanisms in iOS 4 and later. That provides a way to mark a file as "protected" so it will be stored encrypted on disk at all times, only accessible when the device is unlocked (with a passcode).
See also this question
You can encrypt the whole sandbox using the OS if you target iPhone 4 with OS 4.x. Even then, iOS has this concept of an 'escrow keychain' which is basically a cache of passwords and can he potentially hacked into. As far as I am aware, Mail is the only app that encrypts everything.
In order to encrypt your application data in this way, you just need to set the appropriate NSFileProtectionKey as documented in NSFileManager. But, as mentioned, this is not entirely secure.
You could try a custom category on the file manager that encrypts files based on your own requirement so that you have encrypted documents. The choice is yours.
I want to create an app which holds sensitive information (imagine it's bank account details, thought it's not). The user enters this information on a form the first time the app starts up. I want this info to be saved, and available, any time the user uses the app (without having to enter a password). However, if the iPhone has a password lock on it, and is stolen, I don't want the data to be easily accessible from the file system.
What is the best way of encrypting or obfuscating the data? There is not a lot of data, just a dozen NSStrings from the UITextFields on the form.
I'm aware there are encryption export restrictions on the iPhone for non-US developers (I am in UK), so I would prefer to avoid going jumping through any of Apple's app submission hoops to get it on the store.
Why not use the built in Keychain Services? That's what it is for.
EDIT: There an article in SDKDevFAQ.com about Keychain Services that points to a tutorial and sample code on github. Also, check out this blog entry about using the Keychain.
I don't know if a jailbroken iPhone device lets you read NSUserDefaults from other applications or not. If not, you could just store your information in there instead of as a file.
Alternatively, you could generate some salt based on (but not equal to) the device ID, and simply XOR it with the bytes of the strings. As long as your algorithm to generate the salt isn't trivial and the strings aren't too long, the data will be fairly safe. Without getting into heavier encryption stuff, you can't guarantee too much more than "fairly safe".