1. Prerequisites
----------------

You will need working installations of Zlib and OpenSSL.

Zlib:
http://www.cdrom.com/pub/infozip/zlib/

OpenSSL:
http://www.openssl.org/

OpenSSH can utilise Pluggable Authentication Modules (PAM) if your system
supports it. PAM is standard on Redhat and Debian Linux and on Solaris.

PAM:
http://www.kernel.org/pub/linux/libs/pam/

If you wish to build the GNOME passphrase requestor, you will need the GNOME
libraries and headers.

GNOME:
http://www.gnome.org/

If you are planning to use OpenSSH on a Unix which lacks a Kernel random
number generator (/dev/urandom), you will need to install the Entropy
Gathering Daemon (or similar). You will also need to specify the 
--with-egd-pool option to ./configure.

EGD:
http://www.lothar.com/tech/crypto/


2. Building / Installation
--------------------------

To install OpenSSH with default options:

./configure
make
make install

This will install the OpenSSH binaries in /usr/local/bin, configuration files
in /usr/local/etc, the server in /usr/local/sbin, etc. To specify a different
installation prefix, use the --prefix option to configure:

./configure --prefix=/opt
make
make install

Will install OpenSSH in /opt/{bin,etc,lib,sbin}. You can also override 
specific paths, for example:

./configure --prefix=/opt --sysconfdir=/etc/ssh
make
make install

This will install the binaries in /opt/{bin,lib,sbin}, but will place the
configuration files in /etc/ssh.

There are a few other options to the configure script:

--enable-gnome-askpass will build the GNOME passphrase dialog. You need a 
working installation of GNOME, including the development headers, for this
to work.

--with-random=/some/file allows you to specify an alternate source of 
random numbers (the default is /dev/urandom). Unless you are absolutly 
sure of what you are doing, it is best to leave this alone.

--with-egd-pool=/some/file allows you to enable Entropy Gathering Daemon 
support and to specify a EGD pool socket. You will need to use this if your
Unix does not support the /dev/urandom device (or similar).

--without-askpass will disable X11 password requestor support in ssh-add


3. Configuration
----------------

The runtime configuration files are installed by in ${prefix}/etc or 
whatever you specified as your --sysconfdir (/usr/local/etc by default).

The default configuration should be instantly usable, though you should 
review it to ensure that it matches your security requirements.

For more information on configuration, please refer to the manual pages 
for sshd, ssh and ssh-agent.