How do I resolve the CodeSign error: CSSMERR_TP_NOT_TRUSTED?

How do I resolve the CodeSign error: CSSMERR_TP_NOT_TRUSTED?

The Xcode build error titled "CSSMERR_TP_NOT_TRUSTED" is a common problem that arises when Trust Settings have been mistakenly modified for any of the iOS Development related certificates that follow:

iPhone Developer: <your_name>

iPhone Distribution: <your_name>

Apple Worldwide Developer Relations Certification Authority

To confirm diagnosis of this error open Keychain Access app > Certificates "Category" and individually select each of the above certificates taking note of the status in the header pane. A Green Circle with White Checkmark indicates a healthy certificate, while a Blue Circle with White Plus sign indicates an unhealthy certificate and cause of the error.

Use the following steps to troubleshoot the issue -

1) Ensure that the Apple Inc. Root Certificate is installed in your keychain. If not, it can be downloaded here.

2) Ensure the Apple Worldwide Developer Relations Certification Authority certificate is installed in your keychain. If not, it can be downloaded from the bottom link on the Provisioning Portal website > Certificates tab .

3) First try and restore Trust settings to the proper value "Use System Defaults". To do that, double click on that certificate to expand the Trust section, and select "Use System Defaults". If after doing that the Blue Circle with White Plus sign does not automatically change to a Green Circle with White Checkmark, the problem is not yet fixed and you‘ll need to continue to the following step to resolve the issue.

4) Certificate Trust Settings are inherited from any duplicate certificates that may exist in other keychains. Therefore, if you have multiple copies of these iOS Development related certificates in different Keychains, you‘ll need to restore the Trust Settings to "Use System Defaults" on all copies of those certificates in all of your Keychains to fully resolve the problem. See the "Keychains" side bar in Keychain Access app for all of the Keychains to check, e.g. "login", "System", "System Roots", and any others.

5) if after restoring the Trust Settings to "Use System Defaults" for all of your iOS Development related certificates the error persists, you‘ll need to remove/delete all iOS Development related certificates that are still exhibiting the Blue Circle with White Plus sign in the header pane. To do that, follow the remaining steps in this list.

• 5a) For all iOS Development related certificates that still exhibit the Blue Circle with White Plus sign in the header pane, Ctrl-click and delete the certificate. Be sure to delete all copies of this certificate from all Keychains.

• 5b) Reinstall the deleted certificates. If the certificate deleted was the "Apple Worldwide Developer Relations Certification Authority" it can be re-download from the iOS Portal > Certificates within the "Certificates" sidebar and the link reading "*If you do not have the WWDR intermediate certificate installed, click here to download now". After it is downloaded, double-click it to install it into the Keychain.

• 5c) If the certificates deleted were either the "iPhone Developer: <your_name>" or "iPhone Distribution: <your_name>" use Provisioning Profile Refresh to have Xcode download fresh copies of those certificates and install them into your Keychain on your behalf.

After performing the above steps your certificates should show a Green Circle with White Checkmark with status "This certificate is valid" and avoid the CSSMERR_TP_NOT_TRUSTED Xcode build error.