Code signing for macOS - quick start version

Creating the App Store Connect API key

Signing macOS applications requires Apple Developer Program membership.

It is recommended to create a dedicated App Store Connect API key for Codemagic in App Store Connect. To do so:

Log in to App Store Connect and navigate to Users and Access > Integrations » App Store Connect API.
Click on the + sign to generate a new API key.
Enter the name for the key and select an access level. We recommend choosing App Manager access rights, read more about Apple Developer Program role permissions here.
Click Generate.
As soon as the key is generated, you can see it added to the list of active keys. Click Download API Key to save the private key for later. Note that the key can only be downloaded once.

Take note of the Issuer ID above the table of active keys as well as the Key ID of the generated key as these will be required when setting up the Apple Developer Portal integration in the Codemagic UI.

Automatic vs Manual code signing

Signing macOS apps requires a Signing certificate (App Store development or distribution certificate in .p12 format) and a Provisioning profile. In Manual code signing you save these files as Codemagic Environment variables and manually reference them in the appropriate build steps.

In Automatic code signing, Codemagic takes care of Certificate and Provisioning profile management for you. Based on the certificate private key that you provide, Codemagic will automatically fetch the correct certificate from the App Store or create a new one if necessary.

Certificate types

There are several certificate types you can choose to sign your macOS app, depending on the distribution method you plan to use.

MAC_APP_DEVELOPMENT certificate allows you to build your app for internal testing and debugging.
MAC_APP_DISTRIBUTION certificate is used to sign a Mac app before submitting it to the Mac App Store
MAC_INSTALLER_DISTRIBUTION is used to sign and submit a Mac Installer Package to the Mac App Store
DEVELOPER_ID_APPLICATION is used to sign a Mac app before distributing it outside the Mac App Store
DEVELOPER_ID_INSTALLER is used to sign a Mac Installer Package before distributing it outside the Mac App Store

For example, in order to publish to Mac App Store, the application must be signed with a Mac App Distribution certificate using a Mac App Store provisioning profile. If you want to create a .pkg Installer package, you must use a Mac Installer Distribution certificate.

Obtaining the certificate private key

To enable Codemagic to automatically fetch or create the correct signing certificate on your behalf, you need to provide the corresponding certificate private key. You then have to save that key as a Codemagic environment variable.

Create a new key
Use an existing key

You can create a new 2048 bit RSA key by running the command below in your terminal:

ssh-keygen -t rsa -b 2048 -m PEM -f ~/Desktop/mac_distribution_private_key -q -N ""

This new private key will be used to create a new Mac App Distribution certificate in your Apple Developer Program account if there isn’t one that already matches this private key.

On the Mac which created the Mac App Distribution certificate, open the Keychain Access, located in the Applications and Utilities folder.
Select the appropriate certificate entry.
Right-click on it to select “Export.”
In the export prompt window that appears, make sure the file format is set to Personal Information Exchange (.p12)"**.
Give the file a name such as “MAC_DISTRIBUTION”, choose a location and click Save.
On the next prompt, leave the password empty and click OK.
Use the following openssl command to export the private key:

openssl pkcs12 -in MAC_DISTRIBUTION.p12 -nodes -nocerts | openssl rsa -out mac_distribution_private_key

When prompted for the import password, just press enter. The private key will be written to a file called mac_distribution_private_key in the directory where you ran the command.

Configuring environment variables

Open your Codemagic app settings, and go to the Environment variables tab.
Enter CERTIFICATE_PRIVATE_KEY as the Variable name.
Open the file mac_distribution_private_key with a text editor and copy the entire contents of the file, including the -----BEGIN RSA PRIVATE KEY----- and -----END RSA PRIVATE KEY----- tags. Alternatively, you can run the following command on the file:
```
  cat mac_distribution_private_key | pbcopy
```
Paste into the Variable value field.
Enter a variable group name, e.g. appstore_credentials. Click the button to create the group.
Make sure the Secure option is selected so that the variable can be protected by encryption.
Click the Add button to add the variable.
Run the following command on the App Store Connect API key file that you downloaded earlier (in our example saved as codemagic_api_key.p8) to copy its content to clipboard:
```
cat codemagic_api_key.p8 | pbcopy
```
Create a new Environment variable APP_STORE_CONNECT_PRIVATE_KEY and paste the value from clipboard.
Create variable APP_STORE_CONNECT_KEY_IDENTIFIER. The value is the Key ID field from App Store Connect > Users and Access > Keys.
Create variable APP_STORE_CONNECT_ISSUER_ID. The value is the Issuer ID field from App Store Connect > Users and Access > Keys.

Tip: Store all the of these variables in the same group so they can be imported to codemagic.yaml workflow at once.

Environment variables have to be added to the workflow either individually or as a group. Modify your codemagic.yaml file by adding the following:

workflows:
  macos-workflow:
    name: macOS Workflow
    environment:
      groups:
        - appstore_credentials

Automatic code signing

To code sign the app, add the following commands in the scripts section of the configuration file, after all the dependencies are installed, right before the build commands.

    scripts:
      - name: Set up keychain to be used for code signing using Codemagic CLI 'keychain' command
        script: keychain initialize
      - name: Fetch signing files
        script: | 
          app-store-connect fetch-signing-files "$BUNDLE_ID" \
            --platform MAC_OS \
            --type MAC_APP_STORE \
            --create
      - name: Fetch Mac Installer Distribution certificates
        script: |  
            app-store-connect certificates list --type MAC_APP_DISTRIBUTION --save || \
            app-store-connect certificates create --type MAC_APP_DISTRIBUTION --save
      - name: Set up signing certificate
        script: keychain add-certificates
      - name: Set up code signing settings on Xcode project
        script: xcode-project use-profiles

Instead of specifying the exact bundle ID, you can use "$(xcode-project detect-bundle-id)".

Based on the specified bundle ID and provisioning profile type, Codemagic will fetch or create the relevant provisioning profile and certificate to code sign the build.

Creating the Installer package

To package your application into an .pkg Installer package and sign it with the Mac Installer Distribution certificate, use the following script:

  scripts:
    - name: Package application
      script: | 
      set -x
    
      # Command to find the path to your generated app, may be different
      APP_NAME=$(find $(pwd) -name "*.app")  
      cd $(dirname "$APP_NAME")
    
      PACKAGE_NAME=$(basename "$APP_NAME" .app).pkg
      xcrun productbuild --component "$APP_NAME" /Applications/ unsigned.pkg  # Create and unsigned package

      # Find the installer certificate common name in keychain
      INSTALLER_CERT_NAME=$(keychain list-certificates \
        | jq '.[]
        | select(.common_name
        | contains("Mac Developer Installer"))
        | .common_name' \
        | xargs)
      
      xcrun productsign --sign "$INSTALLER_CERT_NAME" unsigned.pkg "$PACKAGE_NAME" # Sign the package
    
      rm -f unsigned.pkg                                                       # Optionally remove the not needed unsigned package

Note: Don’t forget to specify the path to your generated package in the artifacts section.

Notarizing macOS applications

Notarization is a process where Apple verifies your application to make sure it has a Developer ID code signature and does not contain malicious content. All apps distributed outside the Mac App Store have to be notarized.

Notarizing an app during the Codemagic build process is possible using the altool command as follows:

xcrun altool --notarize-app -f <file> --primary-bundle-id <bundle_id>
           {-u <username> [-p <password>] | --apiKey <api_key> --apiIssuer <issuer_id>}
           [--asc-provider <name> | --team-id <id> | --asc-public-id <id>]