Suppose, I have two domain 1. example1.com 2. example2.com I have SSL certificates for this two domain. For example1.com example1.crt and example1.key and for example2.com example2.crt and example2.key Is there a way to combine these two certificates to one crt and one key file ? I want to use the single certificate in the classic load balancer.


  • 2
    No, you can't merge them. Get a single replacement certificate with a Subject Alternative Name extension consisting of both example1.com and example2.com. You could conceivably ask one of the issuers to re-issue the certificate with both SAN entries, but it's probably easier to get a replacement. – garethTheRed Nov 18 '18 at 8:48
  • How can I get a replacement certificate with Subject Alternative Name ? If I provide the certificate authority the certificate and key files for both the domain, will they provide me a single certificate ? – gloom700 Nov 18 '18 at 8:52
  • It will be problem If the issuers are different – gloom700 Nov 18 '18 at 8:54
  • You do not provide them with either. You provide them with a certificate signing request (csr), the key file you always retain, and do not share with anyone. The CSR includes the common name (CN) and the Subject Alternative Name (SAN) that you would like. They will take the CSR and sign a certificate for you, which will include the CN and SAN you specified. – ColtonCat Nov 18 '18 at 9:41
  • Yes, it will be a major problem if the issuers are different. Do they have to be different though? A single certificate from one issuer is your only option. – garethTheRed Nov 18 '18 at 16:12

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