Code Signing

The cryptographic process verifying software authenticity and integrity. Gatekeeper and iOS security rely on code signing to ensure apps are from trusted sources.

What to Know

Code signing is the cornerstone of Apple’s security model, preventing malware and unauthorized software from executing on devices. Every app, script, and system component must be signed by a trusted developer certificate before macOS or iOS will allow it to run. This creates a verifiable chain of trust from Apple’s root certificate authorities down to individual developers, ensuring that software hasn’t been tampered with after publication and comes from a known source.

For IT admins, code signing impacts software deployment strategies: unsigned or improperly signed packages will be blocked by Gatekeeper, requiring manual overrides or proper signing infrastructure. Understanding code signing is essential for troubleshooting app installation failures, managing developer certificates, and maintaining security policies that don’t inadvertently block legitimate software.

Common Scenarios

Enterprise IT: Internal custom applications and scripts must be signed with a valid Developer ID certificate to avoid Gatekeeper blocks on employee devices. IT teams either sign packages themselves using an Apple Developer account or configure policies to allow specific unsigned apps, though the latter weakens security posture.

MSP: When deploying client-specific software or custom automation scripts, MSPs must ensure all packages are properly signed or documented as exceptions. Unsigned software triggers security warnings that generate support tickets and erode user trust in IT-deployed tools.

Education: Schools deploying educational software from smaller vendors may encounter apps that lack proper notarization or code signing. IT staff must balance security requirements with the need to support specialized educational tools, often requiring explicit policy exceptions for specific apps.

In Addigy

Addigy’s software deployment tools automatically handle code signing verification during package installation. If an app fails to install due to signature issues, Addigy’s logs provide detailed error messages indicating whether the signature is invalid, expired, or untrusted. Admins can also deploy configuration profiles to manage Gatekeeper settings and allowlist specific apps, though Addigy recommends proper code signing over policy exceptions whenever possible.