1cat AddTrustExternalCARoot.crt COMODORSAAddTrustCA.crt COMODORSADomainValidationSecureServerCA.crt >> cert-chain.pem NOTE: This is the inverse of "Creating an SSL Bundle out of Comodo Positive SSL" which seems valid as well. Not sure if it's valid in any order.

Given this list of files given by Comodo 1Root CA Certificate - AddTrustExternalCARoot.crt 2Intermediate CA Certificate - USERTrustRSAAddTrustCA.crt 3Intermediate CA Certificate - SectigoRSADomainValidationSecureServerCA.crt 4Your PositiveSSL Multi-Domain Certificate - 285695299.crt Do the following: 1cat 285695299.crt …