Linux Server Security, Second Edition

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Chapter 4: Secure Remote Administration

much of the stuff we fling over networks as possible, we leverage this flexibility as

fully as we can.

Getting and Installing OpenSSH

Nowadays, OpenSSH is a standard package on all Linux distributions: it’s that

important. Accordingly, the simplest way to get OpenSSH is to install it from your

Linux CD-ROMs. Just be sure to also check your distribution’s web site for updates,

or run your distribution’s online-update tool (e.g., apt-get, yast2, up2date, etc.) to

make sure you’re using your distribution’s newest OpenSSH package. OpenSSH has

had some serious security vulnerabilities over the years.

OpenSSH’s official web site is http://www.openssh.com. This is the place to go for the

very latest version of OpenSSH, both in source-code and RPM forms, and also for

OpenSSL, which is required by OpenSSH. Also required is zlib, available at http://

www.zlib.net.

You may or may not get by with RPM packages, depending mainly on whether the

RPMs you wish to install were created for your distribution. (Mandrake, Red Hat,

SUSE, and a number of other distributions can use RPMs, but not always

interchangeably.) If for some reason your distribution doesn’t provide its own

OpenSSH RPMs, even in a “contrib.” (end-user contributed) directory, you’re best

off compiling ...