ca-certificates-mono software package provides Common CA certificates (Mono keystore), you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install ca-certificates-mono
ca-certificates-mono is installed in your system.
Make ensure the ca-certificates-mono package were installed using the commands given below,
$ sudo dpkg-query -l | grep ca-certificates-mono *
You will get with ca-certificates-mono package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Mono/CLI |
| Package | ca-certificates-mono |
| Version | 4.2.1.102+dfsg2-7ubuntu4 |
| Description | Common CA certificates (Mono keystore) |
| Sub Section | Cli-mono |