Cannot update gems through Sophos firewall

Question

I installed Ruby 2.4.1 on Windows 10 and tried to make 
 gem update -- system 
 but get: 
 
 ERROR: SSL verification error at depth 1: self signed certificate in certificate chain (19) 
 ERROR: Root certificate is not trusted (/C=GB/ST=Oxfordshire/O=Sophos/OU=NSG/CN=Sophos SSL CA_C22017KYFKPJ462/emailAddress=support@sophos.com) 
 ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError) SSL_connect returned=1 errno=0 state=error: certificate verify failed ( https://api.rubygems.org/specs.4.8.gz ) 
 
 The problem is our company's Sophos firewall. In order to have an HTTPS access Sophos SSL root certificate must be installed. I did this task in Internet Explorer and now I can connect my web browsers to HTTPS web sites like this link but for Ruby's gem system the SSL certificate must be installed separately, somewhere into gem system. 
 Is this possible and how to do this?

Jaydeep · Answer

Hi banog gull 
 Would you please post this to the correct group XG Firewall ? Or if you can subscribe to the group, I'll move this post there. 
 If you're installing this application, you will need to install the XG SSL CA into your machine's Trusted Root Authority container. Please refer to this KBA Sophos XG Firewall: SSL CA certificate installation guide and check the section Install the Certificate in the local machine&rsquo;s Trusted Root Authority container.