This certificate has an invalid issuer keychain

Question

I do have private key(my_ca.key) and public key(my_cert.crt) which is signed by DigiCert. Now I want to generate the SSL certificate (version 3) and sign it by my private ke

Answer 1

1. Download https://developer.apple.com/certificationauthority/AppleWWDRCA.cer and double-click to install to Keychain.
2. Select "View" -> "Show Expired Certificates" in Keychain app.
3. Confirm "Certificates" category is selected.
4. Remove expired Apple Worldwide Developer Relations Certificate Authority certificates from "login" tab and "System" tab.

Here's Apple's answer.

Thanks for bringing this to the attention of the community and apologies for the issues you’ve been having. This issue stems from having a copy of the expired WWDR Intermediate certificate in both your System and Login keychains. To resolve the issue, you should first download and install the new WWDR intermediate certificate (by double-clicking on the file). Next, in the Keychain Access application, select the System keychain. Make sure to select “Show Expired Certificates” in the View menu and then delete the expired version of the Apple Worldwide Developer Relations Certificate Authority Intermediate certificate (expired on February 14, 2016). Your certificates should now appear as valid in Keychain Access and be available to Xcode for submissions to the App Store.

You can also check on https://forums.developer.apple.com/thread/37208

For more detail refer https://developer.apple.com/support/certificates/expiration/