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How do I make a .p12 file?

You’ll need a .p12 file to publish your app on the Apple App Store, but the process can be a little confusing. Here’s our updated step-by-step guide for creating one.


You’ll need a few things before getting started:

  • Access to a Mac computer
    NOTE: This is a requirement from Apple
  • An Apple iOS Developer account (https://developer.apple.com/devcenter/ios/index.action)
    • You’ll need your email address and “common name” for this process (e.g. “jo_smith@company.com”, “Jo Smith”)
    • If you’re not sure of your common name, log in to your iOS Developer account and use the name that appears at the top right

The Process

Creating a .p12 file can be a little confusing the first time, as you need to use often un-noticed pieces of software on your computer, as well as the iOS Developer web interface (which has got better in recent years).

We’ve broken the process into three steps below, which should help through the process:


STEP 1: Create a “.certSigningRequest” (CSR) file

  • Open Keychain Access on your Mac (found in Applications/Utilities)
  • In the main Keychain Access window, make sure that you don’t have a private key already selected, otherwise this process will not work correctly
  • From the toolbar, open Keychain Access > Preferences
  • In the pop up window that appears, click the Certificates tab
  • Set both “Online Certificate Status Protocol” and “Certificate Revocation List” to “Off” (as in the screenshot above
  • Close this window
  • Back in the toolbar, open Keychain Access > Certificate Assistant > Request a Certificate From a Certificate Authority
  • Enter the email address and common name that  you used to register in the iOS Developer Program
    NOTE: Common name should be the name of the developer as it appears in your Apple Developer Account
  • Leave the CA Email blank, and make sure “Saved to disk” is selected, and “Let me specify key pair information” is checked
  • Click Continue
  • Choose a filename & destination on your hard drive
    (e.g. “certificate.certSigningRequest”)
  • Click Save
  • In the next window, for “Key Size” choose “2048 bits”
  • For “Algorithm” choose “RSA”
  • Click Continue
  • This will create and save your certSigningRequest file (CSR) to your hard drive. A public and private key will also be created in Keychain Access with the Common Name you entered earlier (e.g. Jo Smith)


STEP 2: Create the “.cer” file in your iOS Developer Account

  • Log on to https://developer.apple.com
  • Click “Certificates, Identifiers & Profiles”
  • Click “Provisioning Profiles” from the left-hand column05
  • In the “Certificates” section at the top of the left-hand panel, click “Production”
  • Click the “Add” (+) button at the top-right of the main panel05b
  • In the main panel, under Production, Choose “App Store and Ad Hoc”06
  • Click Continue07
  • Click “Choose File” & find the CSR file you’ve just made from your hard drive08
  • Click Generate and wait for the file to process09
  • Click Download to get the file, and then click the Done button at the bottom once the download has finished10


STEP 3: Install the .cer and generate the .p12

  • Find the .cer file you’ve just downloaded and double-click. If the certificate hasn’t automatically been installed, you will see the following (otherwise, skip the next two steps):
  • Make sure the drop-down is set to “login”
  • Click Add
  • Open up KeyChain Access again
  • Find the two profiles you created in Step 1 (with the iOS Developer common name)
  • You should now be able to expand the “private key” profile, which should show the certificate you just added
  • Select only these two items (not the public key), by holding SHIFT and clicking both items12b
  • Right click and click “Export 2 items…” from the popup
  • In the next window, make sure the file format is a “.p12” and choose a filename and destination on your hard drive
  • Click Save
  • Finally, you’ll be prompted to set a password – but leave these both blank
  • Click OK
    NOTE: You may be asked for the administrator password of the computer at this stage (possibly twice as there are two files to export), if you do, enter the password and click OK
  • You should now have a .p12 file in your chosen location on your hard drive


That’s it! We hope that helps make the publishing process on the Apple App Store a little easier.

Kieron Gurner
About Kieron Gurner Kieron manages the AppFurnace Support forums, helping our users out with technical questions and JavaScript snippets for their apps.


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