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 requester, you will need the GNOME
libraries and headers.

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

Alternatly Jim Knoble <jmknoble@pobox.com> has written an excellent X11
passphrase requester. This is maintained seperatly at:

http://www.pobox.com/~jmknoble/jmk/


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/

GNU Make:
ftp://ftp.gnu.org/gnu/make/

OpenSSH has only been tested with GNU make. It may work with other
'make' programs, but you are on your own.

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.

If you are using PAM, you will need to manually install a PAM control
file as "/etc/pam.d/sshd" (or wherever your system prefers to keep
them). A generic PAM configuration is included as "sshd.pam.generic",
you may need to edit it before using it on your system.

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). The file argument refers to the EGD pool file, not the 
EGD program itself. Please refer to the EGD documentation.

--with-kerberos4 will enable Kerberos IV support. You will need to
have the Kerberos libraries and header files installed for this to
work.

--with-afs will enable AFS support. You will need to have the Kerberos
IV and the AFS libraries and header files installed for this to work.

--with-skey will enable S/Key one time password support. You will need
the S/Key libraries and header files installed for this to work.

--with-tcp-wrappers will enable TCP Wrappers (/etc/hosts.allow|deny)
support. You will need libwrap.a and tcpd.h installed.

--with-md5-passwords will enable the use of MD5 passwords. Enable this
if your operating system uses MD5 passwords without using PAM.

If you need to pass special options to the compiler or linker, you
can specify these as enviornment variables before running ./configure.
For example:

CFLAGS="-O -m486" LFLAGS="-s" ./configure

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.

To generate a host key, issue the following command: (replacing
/etc/ssh/ssh_host_key with an appropriate path)

/usr/bin/ssh-keygen -b 1024 -f /etc/ssh/ssh_host_key -N ''

Replacing /etc/ssh with the correct path to the configuration directory.
(${prefix}/etc or whatever you specified with --sysconfdir during 
configuration)

If you have configured OpenSSH with EGD support, ensure that EGD is
running and has collected some Entropy.

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

4. Problems?
------------

If you experience problems compiling, installing or running OpenSSH. 
Please refer to the "reporting bugs" section of the webpage at
http://violet.ibs.com.au/openssh/