16.1. Linux SSH2 Client/Server

Since Linux is all about choices we have provided as an alternative the commercial verion of OpenSSH, The SSH2 and these installation instructions assume

• Commands are Unix-compatible.

• The source path is /var/tmp, other paths are possible.

• Installations were tested on Red Hat Linux 6.1 and 6.2.

• All steps in the installation will happen in super-user account root.

• SSH2 version number is 2.0.13

Packages that you need can be downloaded from:

SSH2 Homepage:http://www.ssh.org/

You must be sure to download: ssh-2.0.13.tar.gz

once you have got the Tarballs, It is a good idea to make a list of files on the system before you install ssh2, and one afterwards, and then compare them using diff to find out what file it placed where. Simply run find /* > SSH1 before and find /* > SSH2 after you install the software, and use diff SSH1 SSH2 > SSH-Installed to get a list of what changed.

Before you Compile, you need to decompress the tarball tar.gz.

[root@deep] /#cp ssh-version.tar.gz /var/tmp [root@deep] /#cd /var/tmp [root@deep ]/tmp#tar xzpf ssh-version.tar.gz

You need to Compile and Optimize so move into the new SSH2 directory and type the following commands on your terminal:

CC="egcs" \ CFLAGS="-O9 -funroll-loops -ffast-math -malign-double -mcpu=pentiumpro -march=pentiumpro -fomit-frame-pointer -fno-exceptions" \ ./configure \ --prefix=/usr \ --without-ssh-agent1-compat \ --disable-suid-ssh-signer \ --disable-tcp-port-forwarding \ --disable-X11-forwarding \ --enable-tcp-nodelay \ --with-libwrap

This tells SSH2 to set itself up for this particular hardware setup as follows:

• Leave out ssh-agent1 compatibility.

• Install ssh-signer without suid bit.

• Disable port forwarding support.

• Disable X11 forwarding support.

• Enable TCP_NODELAY socket option.

• Compile in libwrap tcp_wrappers support.

[root@deep ]/ssh-2.0.13#make clean [root@deep ]/ssh-2.0.13# make [root@deep ]/ssh-2.0.13# make install [root@deep ]/ssh-2.0.13#rm -f /usr/bin/ssh-askpass

The make clean, command erase all previous traces of a compilation so as to avoid any mistakes,

The make command compiles all source files into executable binaries,

The make install command installs the binaries and any supporting files into the appropriate locations.

Please don't forget to cleanup after work:

[root@deep] /#cd /var/tmp [root@deep ]/tmp#rm -rf ssh-version/ ssh-version.tar.gz

The rm command as used above will remove all the source files we have used to compile and install SSH2. It will also remove the SSH2 compressed archive from the /var/tmp directory.