You can obtain the latest libssh library from https://www.libssh.org/. If you are proficient in installing C libraries, feel free to give it a go. Otherwise, read on for step-by-step instructions.
Before beginning, be sure that you've first installed the OpenSSL libraries successfully. These are required by the libssh library.
We will need CMake installed in order to build libssh. You can obtain CMake from https://cmake.org/. They provide a nice GUI installer, and you shouldn't run into any difficulties. Make sure you select the option to add CMake to your PATH during installation:
Once you have the CMake tool and the OpenSSL libraries installed, navigate to the libssh website to download the libssh source code. At the time of writing, Version 0.8.7 is the latest, and it is available from https://www.libssh.org/files/0.8/. Download and...