Set up code signing for iOS projects

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Basic configuration of iOS projects

This document assumes that you already have an iOS project building correctly on CircleCI using our recommended best practices. It also assumes that you use Bundler and Fastlane, and have a Gemfile, Appfile and Fastfile checked into your repository.

If you have not yet configured your iOS project on CircleCI, you can find the configuration instructions in the Testing iOS Applications document.

CircleCI only officially supports Fastlane Match for code signing. Other methods may be used, but are not guaranteed to work and are unsupported.

Set up Fastlane Match

Code signing must be configured to generate ad-hoc distributions of your app and App Store builds.

Fastlane Match is one of the Fastlane tools, and it allows for seamless configuration for code signing in both your local development environment and on CircleCI. Fastlane Match stores all of your code signing certificates and provisioning profiles in a git repository/AWS S3 Bucket/Google Cloud Storage, and downloads and installs the necessary certificates and profiles when required.

In this example configuration, we will set up and use a git repository for storage.

To set up Fastlane Match:

On your local machine, open Terminal and navigate to the root directory of your repository
Run bundle exec fastlane match init
Follow the instructions to configure the Match repository
After the above is complete, run bundle exec fastlane match development to generate and install the Development certificates and profiles
Then, run bundle exec fastlane match adhoc to generate and install the Ad-hoc distribution certificates and profiles.

Prepare your Xcode project for use with Fastlane Match

Before setting up Match you must ensure that the code signing settings in your Xcode project are configured as follows:

Signing & Capabilities -> Signing uncheck Automatically manage signing for both Debug and Release
Signing & Capabilities -> Provisioning Profile choose the appropriate profile created by Fastlane Match (for example, match adhoc com.circleci.helloworld)

Add Match to the Fastlane lane

On CircleCI, Fastlane Match will need to be run every time you build and sign your app. The easiest way to do this is to add the match action to the lane which builds your app.

For the match action to work correctly, you must add setup_circle_ci to before_all in your Fastfile. This ensures that a temporary Fastlane keychain with full permissions is used. Without using this you may see build failures or inconsistent results.

# fastlane/Fastfile
default_platform :ios

platform :ios do
  before_all do
    setup_circle_ci
  end

  desc "Build and run tests"
  lane :test do
    scan
  end

  desc "Ad-hoc build"
  lane :adhoc do
    match(type: "adhoc")
    gym(export_method: "ad-hoc")
  end
  ...
end

Add a user key to the CircleCI project

To enable Fastlane Match to download the certificates and the keys from GitHub, it is necessary to add a user key with access to both the project repository and the certificates / keys repository to the CircleCI project.

To add a user key:

In the CircleCI application, go to your project’s settings by clicking the Project Settings button (top-right on the Pipelines page of the project).
On the Project Settings page, click on SSH Keys (vertical menu on the left).
Click the Add User Key button and follow the steps to authorize CircleCI

This action will give the CircleCI project the same GitHub permissions as the user who will be clicking the Authorize with GitHub button.

In your Matchfile, the git_url should be an SSH URL ( in the git@github.com:... format), rather than a HTTPS URL. Otherwise you may see authentication errors when you attempt to use match. For example:

git_url("git@github.com:fastlane/certificates")
app_identifier("tools.fastlane.app")
username("user@fastlane.tools")

It is best practice to create a machine user with access to just the project repository and the keys repository, and use that machine user to create a user key to reduce the level of GitHub access granted to the CircleCI project.

After you have added a user key, CircleCI will be able to checkout both the project repository and the Fastlane Match repository from GitHub.

Add the Match passphrase to the project

To enable Fastlane Match to decrypt the certificates and profiles stored in the GitHub repository, it is necessary to add the encryption passphrase that you configured in the Match setup step to the CircleCI project’s environment variables.

In the project settings on CircleCI, click on Environment Variables and add the MATCH_PASSWORD variable. Set its value to your encryption passphrase. The passphrase will be stored encrypted at rest.

Build and code-sign the app on CircleCI

After you have configured Match and added its invocation into the appropriate lane, you can run that lane on CircleCI. The following config.yml will create an Ad-hoc build every time you push to the development branch:

# .circleci/config.yml
version: 2.1
jobs:
  build-and-test:
    macos:
      xcode: 14.2.0
    steps:
      # ...
      - run: bundle exec fastlane test

  adhoc:
    macos:
      xcode: 14.2.0
    steps:
      # ...
      - run: bundle exec fastlane adhoc

workflows:
  build-test-adhoc:
    jobs:
      - build-and-test
      - adhoc:
          filters:
            branches:
              only: development
          requires:
            - build-and-test

Sample configuration files

The best practice configuration for setting up code signing for iOS projects is as follows:

# fastlane/fastfile
default_platform :ios

platform :ios do
  before_all do
    setup_circle_ci
  end

  desc "Runs all the tests"
  lane :test do
    scan
  end

  desc "Ad-hoc build"
  lane :adhoc do
    match(type: "adhoc")
    gym(export_method: "ad-hoc")
  end
end

# .circleci/config.yml
version: 2.1
jobs:
  build-and-test:
    macos:
      xcode: 14.2.0
    environment:
      FL_OUTPUT_DIR: output
      FASTLANE_LANE: test
    steps:
      - checkout
      - run: bundle install
      - run:
          name: Fastlane
          command: bundle exec fastlane $FASTLANE_LANE
      - store_artifacts:
          path: output
      - store_test_results:
          path: output/scan

  adhoc:
    macos:
      xcode: 14.2.0
    environment:
      FL_OUTPUT_DIR: output
      FASTLANE_LANE: adhoc
    steps:
      - checkout
      - run: bundle install
      - run:
          name: Fastlane
          command: bundle exec fastlane $FASTLANE_LANE
      - store_artifacts:
          path: output

workflows:
  build-test-adhoc:
    jobs:
      - build-and-test
      - adhoc:
          filters:
            branches:
              only: development
          requires:
            - build-and-test

By setting the FL_OUTPUT_DIR: environment, that will tell Fastlane to output the Xcode and Fastlane logs to that directory, so they get uploaded as artifacts for ease in troubleshooting.