[https://letsencrypt.org/][1] is a Certificate Authority (CA) that provides free SSL Certs.

I have a Domain in Salesforce that I'd like to get an SSL Certificate for, and I created a CA Signed Certificate in Salesforce's Certificate and Key Management, and I downloaded the Certificate Signing Request (csr).

I [installed][2] letsencrypt on a Linux box (with [Advice for using letsencrypt for Windows Users][4]), and tried to generate a SSL Certificate with the following command using the csr, but I am getting an error.

	~/letsencrypt $ ./letsencrypt-auto --csr subdomain_mydomain_com.csr

[It has been noted][3] that to use letsencrypt with a csr, the csr has to:

 1. Be in der format
 2. Contain a subjectAltName (SAN)

But I can't figure out how to add a SAN in Salesforce before creating a CA Signed Certificate nor converting the csr to der format.  (I can't change a csr once it's been signed.)

Has anyone figured out how to use letsencrypt with Salesforce?

  [1]: https://letsencrypt.org/
  [2]: https://letsencrypt.org/howitworks/
  [3]: https://www.tty1.net/blog/2015/using-letsencrypt-in-manual-mode_en.html
  [4]: https://community.letsencrypt.org/t/advice-for-windows-users-successfully-implementing-le/7666