Certificate Transparency MDM payload settings for Apple devices
Use the Certificate Transparency payload to control the behaviour of Certificate Transparency enforcement on iPhone, iPad, Mac or Apple TV devices. This custom payload doesn’t require MDM or the device’s serial number to appear in Apple School Manager, Apple Business Manager or Apple Business Essentials.
iOS, iPadOS, macOS, tvOS, watchOS 10 and visionOS 1.1 have Certificate Transparency requirements in order for TLS certificates to be trusted. Certificate Transparency involves submitting your server’s public certificate to a log that’s available to the public. If you use certificates for internal-only servers, you may not be able to show those servers and so won’t be able to use Certificate Transparency. As a result, the Certificate Transparency requirements will cause certificate trust failures for your users.
This payload allows device administrators to selectively lower the Certificate Transparency requirements for internal domains and servers to avoid those trust failures on devices communicating with the internal servers.
The Certificate Transparency payload supports the following. For more information, see Payload information.
Supported payload identifier: com.apple.security.certificatetransparency
Supported operating systems and channels: iOS, iPadOS, Shared iPad device, macOS device, tvOS, watchOS 10, visionOS 1.1.
Supported enrolment types: User Enrolment, Device Enrolment, Automated Device Enrolment.
Duplicates allowed: True — more than one Certificate Transparency payload can be delivered to a device.
Apple Support article: Apple’s Certificate Transparency policy
Certificate Transparency policy on the Chromium Project website
You can use the settings in the table below with the Certificate Transparency payload.
Setting | Description | Required | |||||||||
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Disable Certificate Transparency enforcement for specific certificates | Select this option to permit private, untrusted certificates by disabling the enforcement of Certificate Transparency. The certificates to be disabled must contain (1) the algorithm that was used by the issuer to sign the certificate and (2) the public key that’s associated with the identity the certificate is issued to. For the specific values you need, see the rest of this table. | No. | |||||||||
Algorithm | The algorithm that was used by the issuer to sign the certificate. The value must be “sha256”. | Yes, if Disable Certificate Transparency enforcement for specific certificates is used. | |||||||||
Hash of | The public key associated with the identity the certificate is issued to. | Yes, if Disable Certificate Transparency enforcement for specific certificates is used. | |||||||||
Disable specific domains | A list of domains where certificate transparency is disabled. A leading full stop can be used to match subdomains, but a domain matching rule must not match all domains within a top-level domain. (“.com” and “.co.uk” aren’t allowed, but “.betterbag.com” and “.betterbag.co.uk” are allowed). | No. | |||||||||
Note: Each MDM vendor implements these settings differently. To learn how various Certificate Transparency settings are applied to your devices, consult your MDM vendor’s documentation.
How to create the hash of subjectPublicKeyInfo
In order for Certificate Transparency enforcement to be disabled when this policy is set, the subjectPublicKeyInfo hash must be one of the following:
The first method to disable Certificate Transparency enforcement |
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A hash of the server leaf certificate’s |
The second method to disable Certificate Transparency enforcement |
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The third method to disable Certificate Transparency enforcement |
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How to generate the specified data
In the subjectPublicKeyInfo dictionary, use the following commands:
PEM encoded certificate:
openssl x509 -pubkey -in example_certificate.pem -inform pem | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | base64DER encoded certificate:
openssl x509 -pubkey -in example_certificate.der -inform der | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | base64
If your certificate doesn’t have a .pem or .der extension, use the following file commands to identify its encoding type:
file example_certificate.crtfile example_certificate.cer
To view a complete example of this custom payload, see the Certificate Transparency custom payload example.