Using enterprise iOS apps for more than 12 months without reinstalling with new Provisioning Profile

Question

We are building iOS apps for distribution in our own internal App Store using an Enterprise Developer Account from Apple. For building, we need to generate a provisioning profile, which expires 12 months from the creation. After expiration, the app doesn't work on the devices (crashes immediately because of expired Provisioning Profile), and each device needs to reinstall a new build of the app.

How can we provide our users an user friendly workflow in which they do not have to cope with crashing apps after 12 months?

Thanks in advance,

Bas

Answer 1

The expiration of provisioning profiles is a hassle with enterprise distributed apps. And it is something that will require ongoing maintenance from your internal development team, mobile support teams.

First, I want to point out that you don't mention certificates. Because they only expire every 3 years now (as of this writing - originally they expired every year), developers often forget about them. However, their expiration is actually more troublesome than the profiles. When a profile expires, you simply need to get another valid profile on the device. This can be done in multiple ways. You can use an mobile device management (MDM) solution to push just a new profile. Or if another app with a valid profile (that uses a wildcard ID) has been pushed to the device more recently, this can also get a valid profile on the device.

If the certificate expires, you will actually need to re-build the app with the new certificate. Old builds signed with the expired cert will not run unless. Technically, you can resign the old IPA, but the main thing to note is that the actual binary is invalid and will not work until a new binary with a proper code signing is generated. Fortunately this is only every 3 years, so it is less frequent, but I can almost promise you when it happens you will have a mess on your hands if you don't plan for it. Again, as with the provisioning profile, you could handle this by using MDM to push something new to the device. In this case, you would use MDM to actually replace the while app, not just the profile. A little more work, but it could be done.

Of course, there are reasons you may not want to use MDM. Cost could be a concern. Employees may not want the company to manage their personal devices (if these apps are going on personal devices). Ability to manage the MDM infrastructure / workload. If MDM is not a great solution for your organization, I would recommend another approach that isn't as ideal from a user experience, but could solve your problem. You could built your apps to be self-updating. In other words, on launch, your app checks a server to see if a new version is available. If so, it prompts the user to update. This wouldn't require the device to be managed, and you could easily build a shared framework to make this easy for app developers. One downside to this approach is if the user doesn't launch the app between the time you post the new version (with new profile / cert) and the time the profile or cert expires, the app will not launch, so the auto-update functionality can't run to tell the user to get a new version. It will just appear to the user as if the app is crashing. That is the one UX problem with this approach. But if you can manage that, it can provide an alternative to the MDM route.

Answer 2

You can manage this with an MDM server. Essentially the workflow looks something like this:

User installs MDM Profile and Accepts the prompts to allow the MDM Server to install apps.

The MDM Server is able to manage the device according to the permissions set in the MDM Profile. Apps managed by the MDM Server can then be installed and removed arbitrarily.

A quick google search for iOS MDM Server should get you headed in the right direction. Pricing for various paid options is somewhere around $15 / device / year, last time I looked into this (about a year ago). But there are one or two reasonable open source MDM Servers available as well.