Configuring FortiSSLVPN (FortiGate SSL VPN) on Fedora 27 (using Gnome and NetworkManager)
Install required packages:
dnf install NetworkManager-ppp NetworkManager-fortisslvpn NetworkManager-fortisslvpn-gnome NetworkManager-openconnect-gnome openfortivpn
Enable Fedora testing repository and install upgrades for following packages (1.2.6-3 as version 1.2.6-1 contains some bugs):
dnf update NetworkManager-fortisslvpn NetworkManager-fortisslvpn-gnome
After that disable Fedora testing repository.
Create VPN profile using NetworkManager GUI, during creation on IPv4 tab select checkbox:
Use this connection only for resources of its network
In VPN profile settings select "Identity" tab, click "Advanced..." button, in "Security" section under "Trusted Certificate" put SHA256 sum of SSL certificate.
To connect use following command (as normal user) or connect via GUI:
nmcli --ask connection up ConnectionName
If no success, try to connect with the following command using sudo (not as root!):
sudo nmcli --ask connection up ConnectionName