About software update certificates

To ensure their integrity, Apple uses a certificate to sign both automatic and manually downloadable software updates.

This article has been archived and is no longer updated by Apple.

When an Apple software update (automatic or manual) is installing, it must be signed by Apple's certificate. This ensures that the update has not been altered in any way. Any alterations to the software update will invalidate the certificate signature.

To view the certificate of a manually downloaded software update, open it and click the padlock icon in the upper right corner of the installer window. Note: You can't view an automaticupdate's certificate, such as an update installed via Software Update.

Learn more

Click here for details about Lion Server and Mac OS X v10.6 Server's Software Update service.

How to install a manually downloaded software update with an expired certificate.

When a certificate is issued, it comes with an expiration date. After that date has passed, the certificate expires and you will see an alert: "This certificate has expired".

The life of the certificate is set when the certificate is generated. They can be valid for 1, 5, or 10 years, or whatever the certificate generator has been configured for.

If an automatic software update has an expired certificate as shown below, you can download the manual equivalent of the update from Apple Support Downloads, then follow the steps below depending on your OS version.

  • For OS X Lion:
    • Open the manually-downloaded update, then click "Continue" and follow the onscreen instructions.
  • For Mac OS X Snow Leopard:
    • Open "Software Update…", install available updates until it reports "Your software is up to date."
    • Open the manually-downloaded update, then click "Continue" and follow the onscreen instructions.

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