In a future version of macOS, notarization will be required by default

Notarization gives users more confidence that the Developer ID-signed software you distribute has been checked by Apple for malicious components. Notarization is not App Review. The Apple notary service is an automated system that scans your software for malicious content, checks for code-signing issues, and returns the results to you quickly. If there are no issues, the notary service generates a ticket for you to staple to your software; the notary service also publishes that ticket online where Gatekeeper can find it.

When the user first installs or runs your software, the presence of a ticket (either online or attached to the executable) tells Gatekeeper that Apple notarized the software. Gatekeeper then places descriptive information in the initial launch dialog to help the user make an informed choice about whether to launch the app.

You can notarize several different types of software deliverables, including:

• macOS apps

• Non-app bundles, such as kernel extensions

• Disk images (UDIF format)

• Flat installer packages

Notarization also protects your users if your Developer ID signing key is exposed. The notary service maintains an audit trail of the software distributed using your signing key. If you discover unauthorized versions of your software, you can work with Apple to revoke the tickets associated with those versions.

Notarization requires Xcode 10 or later. Building a new app for notarization requires macOS 10.13.6 or later. Uploading and stapling an app requires macOS 10.12 or later.

Apple’s notary service requires you to adopt the following protections:

• Enable code-signing for all of the executables you distribute.

• Enable the Hardened Runtime capability for your executable targets, as described in Enable hardened runtime.

• Use a “Developer ID” application, kernel extension, or installer certificate for your code-signing signature. (Don’t use a Mac Distribution or local development certificate.) For more information, see Create, export, and delete signing certificates.

• Include a secure timestamp with your code-signing signature. (The Xcode distribution workflow includes a secure timestamp by default. For custom workflows, include the --timestamp option when running the codesign tool.)

• Don’t include the com.apple.security.get-task-allow entitlement with the value set to any variation of true. If your software hosts third-party plug-ins and needs this entitlement to debug the plug-in in the context of a host executable, see Avoid the Get-Task-Allow Entitlement.

• Link against the macOS 10.9 or later SDK.

Apple recommends that you notarize all of the software that you’ve distributed, including older releases, and even software that doesn’t meet all of these requirements or that is unsigned. Apple’s notary service uses a variety of methods, including telemetry, to determine which of the above rules to relax for preexisting software. For more information, see Notarize Your Preexisting Software.

When you enable the extra security enforced by the hardened runtime, as notarization requires, this impacts both your app and any plug-ins that your app hosts. Plug-ins don’t declare their own entitlements. Instead, they inherit the entitlements of the host process. Therefore, a host app must include all the entitlements that prospective plug-ins require, even when the plug-ins are notarized separately.

For example, if a plug-in employs deep integration with the host executable via C function pointer overrides, or uses a JavaScript engine for custom workflows, the host executable must declare the Allow Unsigned Executable Memory Entitlement or Allow Execution of JIT-compiled Code Entitlement, respectively. In some cases, a plug-in fails to even load if the host executable lacks the proper entitlement.

Also include resource access entitlements, like the Address Book or Location access entitlements, and the related purpose strings, that support your app’s plug-ins. For example, if a Print Dialog Extension (PDE) that provides fax services wants to access a user’s contact list, the host executable must declare the Address Book Entitlement and include the NSContactsUsageDescription purpose string in its Information Property List for the plug-in to operate.

For a complete list of hardened runtime entitlements, see Hardened Runtime Entitlements. For information about usage strings, see Accessing Protected Resources.

Before distributing your app directly to customers, your Account Holder must sign the app with your Developer ID. Xcode’s Organizer window includes a workflow for generating a distributable version of your app. In Xcode 10 and later, this workflow includes an option to notarize your app automatically. To notarize your app using this workflow, do the following:

1. Open your Xcode project.

2. Create an archive of your app.

3. Open Xcode’s Organizer window.

4. In the Archives tab, select the archive you created.

5. Click Distribute App to view the distribution options.

6. Choose Developer ID for your method of distribution.

7. Click Next.

8. Choose Upload to send your archive to the Apple notary service.

9. Click Next.

When you click Next, Xcode uploads your archive to the notary service. When the upload is complete, the notary service begins the scanning process, which usually takes less than an hour. While the notary service scans your software, you can continue to prepare your archive for distribution. For example, you can export the archive and perform any final testing that you require prior to making your software available to customers.

When the notarization process finishes, Xcode downloads the ticket and staples it to your archive. At that point, export your archive again to receive a distributable version of your software that includes the notary ticket.

For more information about how to use the Xcode UI to upload your software, see Upload a macOS app to be notarized.

Notarizing your preexisting software lets Gatekeeper warn users when they try to run it. It also helps the notary service distinguish your legitimate software from variants that have been tampered with. You can notarize an existing disk image, installer package, or ZIP archive containing your app.

To notarize your preexisting software, do the following:

1. Make Xcode 10 your active Xcode installation. (If you’re not sure whether Xcode 10 is the active installation, use the xcode-select command-line to make it active. For information about how to use this tool, see the man page for it, as described in Reading UNIX Manual Pages.)

2. Upload your software to the Apple notary service, as described in Upload Your App to the Notarization Service.

3. Staple the returned ticket to your existing software, as described in Staple the Ticket to Your Distribution.

For tips on how to resolve issues that can occur during notarization, see Resolving Common Notarization Issues.

If you use an automated build system, you can integrate the notarization process into your existing build scripts. The altool and stapler command-line tools (included with Xcode) allow you to upload your software to the Apple notary service, and to staple the resulting ticket to your executable.

For information about how to incorporate notarization into your custom build scripts, see Customizing the Notarization Workflow.