SSTP is Microsofts Remote Access Solution (RAS) for PPP over SSL. It can be used instead of PPTP or L2TP, and is only available with Windows Vista/7 connecting to a Windows 2008 Server. The advantage of SSTP compared to PPTP and L2TP is that it cannot be easily blocked by firewalls since the traffic is transmitted over HTTPS on port 443.
In Ubuntu Linux we can connect to SSTP by using SSTP-Client project on SourceForge.
To install SSTP-Client on Ubuntu add PPA repository:
sudo add-apt-repository ppa:eivnaes/network-manager-sstp
Then update package list and install packages sstp-client, network-manager-sstp by commands:
sudo apt update sudo apt install sstp-client network-manager-sstp
Package network-manager-sstp is used only on Linux with graphic interface, on console Linux You don’t need to install this package.
To convert .CRT certificate to .PEM certificate use command:
openssl x509 -in mycert.crt -out mycert.pem -outform PEM