gencert.sh for Mattermost 

Generate a self-signed x509v3 certificate for use with multiple URLs / IPs.

Generate Certificates 

Default values 

CRT_CN="client.com" CRT_SAN="DNS.1:www.client.com,DNS.2:admin.client.com,IP.1:192.168.1.10,IP.2:10.0.0.234" gencert.sh

Custom values 

You may change the CRT_CN and CRT_SAN values of the above command based on your needs.

Additionally you may use any of the following environment variables :

  • CRT_C : Country value

  • CRT_L : Locality value

  • CRT_O : Organization value

  • CRT_OU : Organizational Unit value

  • CRT_CN : Common Name value

  • CRT_SAN : SubjectAltName value

Result 

The command will generate two files:

  • pkcs#8 private key : mattermost-x509.key

  • x509v3 certificate : mattermost-x509.crt

You can confirm the certificate content by using the following standard x509 command:

openssl x509 -in mattermost-x509.crt -noout -text

Secure/Unsecure Certificates 

The generated private key is passwordless by default.

You can secure/unsecure the certificates using standard pkcs8 commands:

# secure
openssl pkcs8 -in mattermost-x509.key -topk8 -v2 des3 -out mattermost-x509.secure.key

# unsecure
openssl pkcs8 -in mattermost-x509.secure.key -topk8 -nocrypt -out mattermost-x509.key

Additional Reading 

Below are additional guides and documentation for optional reading: