I'm trying to verify GameCenter authentication on an iOS app with GameKit. The fetchItems API returns a URL for the public key needed to do this.

Steps 3 and 4 of that API say:

  1. Use the publicKeyURL on the third-party server to download the public key.
  2. Verify with the appropriate signing authority that Apple signed the public key.

The public key URL I usually get is https://static.gc.apple.com/public-key/gc-prod-5.cer.

On my Mac, I simply download this cert and call X509Certificate2.Verify() in C#, and it returns true. However, calling this function on an Ubuntu server returns false. The error message I get on the server from X509Chain is:

Status information: unable to get local issuer certificate

The cert in question appears to be CN=Symantec Class 3 SHA256 Code Signing CA, OU=Symantec Trust Network, O=Symantec Corporation, C=US.

How do I get this cert on my Ubuntu server, so that I can verify the public key from Apple? Is there a common registry of certs where I can download it?


1 Answer 1


You need to update your root certificate store as in this post:


If I read your question right...looks like you have a copy of the cert?

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