Hello, I have an Apple Developer Enterprise account, and Apple Support has already enabled MDM for my account. I successfully downloaded and installed my MDM Vendor Certificate (it shows up in Keychain as MDM Vendor: [My Company Name] with its private key). Here’s what I’ve done so far: Exported the Vendor Certificate + private key as a .p12, then converted to .pem and .key using OpenSSL. Generated an unsigned CSR with CN=com.apple.mgmt.External.<UUID> using OpenSSL. Attempted to sign the CSR using: my Vendor certificate the Vendor private key Apple Worldwide Developer Relations (WWDR) intermediate certificate OpenSSL smime -sign command with DER output Problem: Every time I try to upload the vendor-signed CSR to the Apple Push Certificates Portal, I get an error (CSR rejected). Sometimes OpenSSL even fails with “unable to load certificates” depending on how the WWDR certificate is included. My Questions: What is the correct OpenSSL command and certificate chain Apple expects for signing the CSR? Do I need to include any additional intermediates besides WWDR? Is there an official Apple reference example for generating the vendor-signed CSR that the Push Certificates Portal will accept? Any guidance from the community (or someone who has successfully done this end-to-end) would be greatly appreciated. Thank you, Sergio Sanchez
