Uniquely Identify iOS device over multiple users - ios

I have done a lot of research on this so please read the question before marking this as similar to some other question.
Our app needs to uniquely determine an iPhone such that even when user completely wipes a phone, when he runs our app we can be sure that it is the same device. The most important thing is we also need to determine devices over multiple Apple ID users so suggestions containing Keychain access and uniqueVendorID might not work as those change when another user starts using that phone. And as I have read using MAC addresses and old UDID for devices is not longer available as of iOS 6.0. I went through [UIDevice identifierForVendor] but this NSUUID changes when all the app by the same vendor has been uninstalled Reference.
I have looked through these resources:
UIDevice uniqueIdentifier Deprecated - What To Do Now?
and
What is a long-term method I can use to uniquely identify an iOS device?
I can not disclose the nature of work that my app performs due to non-disclosure, but to clarify what I require:
Multiple users might use our app on same phones, I need a way to know that the device user A used before and has reported to have handed over to user B is the same device on which our app was run. Is there any way to achieve this?

There's no way to achieve this.
If it's really the case that different users might use your app on the same device after a factory reset of the device, then what you want is not possible. Apple deprecated UIDevice uniqueIdentifier which would have been the way to do this.

as long as they dont restore/wipe the device identifierForVendor is ok

Related

Best way to uniquely identify iOS device?

I'm aware if the following methods, each which has it'd flaws
UDID
Advertising Identifier
Vendor ID
The problem with UDID is that its deprecated and doesn't even work as of ios7, problem with other two is that the user can change them via software reset of phone or reinstallation of app
Another interesting solution I found is to randomly generate one yourself and then save to keychain to avoid deletion upon app reinstallation however would this work across software resets? And surely there's a very small chance that two devices would randomly generate the same ID?
I think the best option might be to use UDID but I would like to know if, even though the UDID is incorrect as of ios7, is it still unique?
Yet another option is MAC address but as far as I know, there is no API for these
Please advise on the best option
Starting iOS 7 deducing MAC address isn't possible. You can, however, use below:
[[[UIDevice currentDevice] identifierForVendor] UUIDString]
Per Apple Documentation:
The value changes when the user deletes all of that vendor’s apps from
the device and subsequently reinstalls one or more of them. The value
can also when installing test builds using Xcode or when installing an
app on a device using ad-hoc distribution. Therefore, if your app
stores the value of this property anywhere, you should gracefully
handle situations where the identifier changes.

iOS 8 How to get Serialnumber

In our applications the user autentications is based on the serial number.It seems that in ios 8 it is not possible to get the serialnumber.Is any other way?
Thanks in advance.
Apple deprecated access to a unique-per-device UUID (known as uniqueIdentifier as of iOS 6. As of iOS 7, they also blocked access to MAC querying the address, and other sorts of unique identifiers. Sometime between iOS 6 and today, they started rejecting any application that accesses this property.
There are two replacement APIs that might help: on UIDevice, there is identifierForVendor, that is consistent across your apps. And there is also an entire framework, AdSupport, who's job is to provide an identifier that can be used for advertising networks. This identifier has the limitation of people can change it whenever they want, so you cannot rely on it being consistent across multiple launches.
The hint Apple is trying to pass on here is "you cannot consistently, uniquely identify people per device across multiple apps that are not your own".
In addition to zadr excellent explanation I would like to not iCloud as another possible solution:
Simply store a value (as file or key-value) in iCloud. Only disadvantage of this approach is, that you will have to add the iCloud entitlement to your app if your app does not use iCloud yet. On the other hand there are some advantages
Very little / none additional effort necessary if your app already uses iCloud
No additional Frameworsk like AdSupport necessary
The saved value will be consistent between devices and app re-install
More than one app can share the ID by using the same iCloud (ubiquity container)
Of course in some cases this might be a little overdone but in other this can be a handy solution.
I would recommend using uniqueIdentifier as suggested above but saving in keychain. This way its reliably available to you all the time, and can be used to track the user.

Retrieving UDID via private API

I'm looking for a way to retrieve the UDID on devices running iOS 6+ (Enterprise deployment only - no app store limitations).
Calling the (now private) method uniqueIdentifier returns the 'vendorIdentifier' starting with 'FFFFFFF'. Unfortunately thats not what I want.
Any ideas? Is there another private method or something?
Thanks in advance.
I recommend you reading this article. To sum up:
The previously deprecated uniqueIdentifier now works like vendorIdentifier on iOS 7+, so it's no longer usable even for Enterprise Apps
OpenUDID cannot be shared between Applications on iOS 7+ and now can change. It's still usable but no longer recommended.
The vendorIdentifier hasn't changed, but it's not recommended for Enterprise Apps because it can change when updating the App.
The new advertisingIdentifier API is the way to go for new Apps. It's the same for all Apps and should not change frequently, but the user can reset it in the settings page.
Edit: Website udid.io obtains the real Device UDID instead of the obfuscated one if you need it for anything outside your App. If you need the UDID from within the App, see my answer above.
You can get a Unique UDID via this method using private api. Follow this link
Look for the code in accepted answer.
Sorry, but Apple warned it would be deprecated and it has been. I've had the same headache myself.
I can't help you identify the device in the same way Apple do, but you can always generate an unique UUID on app launch and stash that away in KeyChain. It won't be perfect, but it will persist between installations and will be unique to the device. As far as I know, that's the current solution

Finding IMEI number using Objective-C [duplicate]

This question already has answers here:
How to get IMEI on iPhone?
(7 answers)
Closed 2 years ago.
I need to find a way to get the IMEI number of an iPhone device. This question is not a duplicate.
I have gone through several forums including SO, and had no luck finding an answer.
Some say Apple doesn't allow developers to see the IMEI number (SO post), and some say to use UDID instead (SO post). Some say that UDID is deprecated (in iOS 7).
I need to know the following:
1.) Does Apple permit developers to retrieve the IMEI number of the device?
2.) How can i programatically do it?
3.) In case if Apple doesn't allow developers to gather the IMEI number, do they provide any other unique number for the device?
4.) Some suggest to use Telephony framework. If i do so, will apple reject my application?
Apple does not allow you to identify a device any more.
UDID, MAC address and all other device identifiers are no longer accessible or allowed by Apple.
Apple suggest that you use either UUID (which you will need to store your self or), identifierForVendor or advertisingIdentifier.
Apple is now also rejecting app that use the advertisingIdentifier and not showing any advertisements apps.
Any means to get the IMEI number are using private methods, which is also not allowed by Apple anymore. And your mobile app might/will get rejected because of this.
Unfortunately, there is no way to get a unique identifier for a device which will always remain the same. Apple no longer allows you to access the UDID. And in iOS 7, all devices' MAC addresses return the same value, so that is no longer useful either.
However, iOS does now give access to two types of identifiers which can be used to identify a device. They are:
Vendor ID - [UIDevice identifierForVendor]. This is a unique identifier which is the same for all apps from the same vendor or company. It will remain the same, so long as the user has at least one app from the vendor installed on their device. So if you have 3 apps, the vendor ID will remain the same unless the user uninstalls all three apps, and then reinstalls. This is not so useful if you only have one app - if the user deletes it and then reinstalls it, it will change.
Advertiser ID - [UIDevice advertisingIdentifier]. This is a unique identifier meant for advertising purposes. But if you use it for non-advertising purposes they, for the most part, won't care. Under most circumstances, the advertising identifier will not change, even if the user deletes and reinstalls the app. However, there is an option in the iOS settings to reset the advertising identifier, which will change it. This is meant to that users can choose to disassociate themselves from any advertising information which has been collected about them. But this is a very advanced setting and I doubt that many users would do this frequently enough that it would be a problem for you.
You can obtain IMEI using private frameworks -See this Question but probably your app will be rejected from app store then.
If you want to obtain some device identifier to use in your application you must use uniqueIdentifier property defined in UIDevice class
(Available in iOS 6.0 and later):
NSString *UDID = [[[UIDevice currentDevice] identifierForVendor] UUIDString];
You can save UUID in keychain and user it as unique number. It won't change until user will reset iOS.
If you want to obtain the IMEI there is no way (on a non-jailbroken device). If you wish to identify the user take a look at this answer. Please pay attention to all documentation/answers written before iOS7 since things have changed.

iOS6 UDID - What advantages does identifierForVendor have over identifierForAdvertising?

Apple is changing their privacy settings for iOS6 and deprecating device UUIDs (UDIDs). According to a WWDC presentation and the docs there are two replacements for the UDIDs, both in the UIDevice class:
-identifierForVendor
ID that is identical between apps from the same developer.
Erased with removal of the last app for that Team ID.
Backed up.
-identifierForAdvertising
Unique to the device.
Available to all applications; used for advertising — iAd has converted from UDID for iOS 6 and later.
Reset with "Erase All Content & Settings".
Backed up.
It seems to me that -identifierForVendor is inferior to -identifierForAdvertising since it would get reset on last uninstall of an app from a vendor and by "erase all contents & settings".
What advantages does -identifierForVendor have over -identifierForAdvertising?
Important Note:
Apple just released iOS 6.0 and the NDA has been lifted.
For developers who preemptively included code that referenced
[[UIDevice currentDevice] identifierForAdvertising]
this method has NOT been included on iOS 6. If you use the above method, your app will (most likely) crash and be rejected!
Instead, Apple has created a new class ASIdentifierManager , which includes the method advertisingIdentifier. Here's the apple docs on it:
Users can limit the use of ad tracking on their phone. See this article on the opt-out mechanism under Settings > General > About > Advertising.
The new ASIdentifierManager class has a property advertisingTrackingEnabled, which returns true or false depending if the user has limited ad tracking. Even though the device's advertising identifier is returned by the advertisingIdentifier property regardless of opt-out, you aren't supposed to use the identifier if the user has opted-out.
So the advantage of identifierForVendor is that you'll always have access to and the right to use this id for the phone regardless of user's opt-in or opt-out for advertising tracking.
I suspect that Apple will simply reject your app if you use identifierForAdvertising for anything that is not advertising-related (i.e., if you send the identifierForAdvertising to your own servers even though you're not an advertising network or if you send the identifierForAdvertising in the same request with other data that could potentially identify an individual).
If my suspicion is correct, the advantage of identifierForVendor over identifierForAdvertising is that it won't get your app rejected.
They are two different ids meant for two different purposes.
I would think that the identifierForVendor would be the one to use to do things that require the app linking to a specific user / device such as provide push notifications and updating the user's app data serverside (like their score or whatever other data is being stored for them).
The identifierForAdvertising should be used for things such as targeted advertising and also to check the effectiveness of a particular ad campaign (check to see which devices installed apps due to a particular ad).
Use the VendorID.
This is a very enlightening article http://www.doubleencore.com/2013/04/unique-identifiers/
To create a uniqueString based on unique identifier of device in iOS 6:
#import <AdSupport/ASIdentifierManager.h>
NSString *uniqueString = [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];
NSLog(#"uniqueString: %#", uniqueString);
Those APIs are so badly designed, that clearly says - Apple does not want us to identify user devices.
Just look at the identifierForVendor description.
It is erased if the user erases all apps from the same vendor. :(
It is not reliable - can return nil (documentation advices to "wait" for some time if this happens. :(
They did not use obvious solution, which works anytime and does not rely on installs/removes - return SHA-1 (or any other hash) of internal hardware device id concatenated with Team ID.
identifierForAdvertising is probably superior in terms of tracking but might be subject to present or future opt-out by the user. On the other hand identifierForVendor is not as likely to be subject of the user.
The important thing to know is that the backup of the identifierForVendor can only be restored to the same device. If the backup is restored to a difference device the identifier is cleared.
User can change identifierForAdvertising any time in Settings,
identifierForVendor changes after reinstall app, if no more apps on device from this vendor.
Here is alternative and the best solution for get or persistent, cross-install Device Identifier:
description: https://blog.onliquid.com/persistent-device-unique-identifier-ios-keychain/
code: https://gist.github.com/miguelcma/e8f291e54b025815ca46

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