freeipa/install/share/csrgen/rules/syntaxSAN.json

{
  "rules": [
    {
      "helper": "openssl",
      "template": "subjectAltName = @{% call openssl.section() %}{{ datarules|join('\n') }}{% endcall %}",
      "options": {
        "extension": true
      }
    },
    {
      "helper": "certutil",
      "template": "--extSAN {{ datarules|join(',') }}"
    }
  ]
}