Portable OpenSSH - Installation instructions

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1. Prerequisites

   You will need working installations of Zlib and OpenSSL (version 0.9.5a or later). Redhat Linux RPMS of OpenSSL are available in the support/ subdirectory of the OpenSSH mirror sites.

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

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

   Alternatively, Jim Knoble has written an excellent X11 passphrase requester. This is maintained separately.

   If you are planning to use OpenSSH on a Unix which lacks a Kernel random number generator (/dev/urandom), you may want to install the Entropy Gathering Daemon (or similar). You will also need to specify the --with-egd-pool option to ./configure. OpenSSH 2.0 includes some peliminary built-in randomness collection, but it is not as well tested as EGD.

   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 contrib/sshd.pam.generic, you may need to edit it before using it on your system. If you are using a recent version of Redhat Linux, the config file in contrib/redhat/sshd.pam should be more useful.

   There are a few other options to the configure script:

   --with-rsh=PATH

   Specifies the path to your rsh program. Normally ./configure will search the current $PATH for rsh. You may need to specify this option if rsh is not in your path or has a different name.

   --without-pam

   Disables PAM support. PAM is automatically detected and switched on if found.

   --with-random=/some/file

   Specifies 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

   Enables Entropy Gathering Daemon support and to specify a EGD pool socket. You may want 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-lastlog=FILE

   Specifies the location of the lastlog file. ./configure searches a few locations for lastlog, but may not find it if lastlog is installed in a different place.

   --without-lastlog

   Disables lastlog support entirely.

   --with-kerberos4=PATH

   Enables Kerberos IV support. You will need to have the Kerberos libraries and header files installed for this to work. Use the optional PATH argument to specify the root of your Kerberos installation.

   --with-afs=PATH

   Enables AFS support. You will need to have the Kerberos IV and the AFS libraries and header files installed for this to work. Use the optional PATH argument to specify the root of your AFS installation. AFS requires Kerberos support to be enabled.

   --with-skey

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

   --with-tcp-wrappers

   Enables TCP Wrappers (/etc/hosts.allow|deny) support. You will need libwrap.a and tcpd.h installed.

   --with-md5-passwords

   Enables the use of MD5 passwords. Enable this if your operating system uses MD5 passwords without using PAM.

   --with-utmpx

   Enables utmpx support. utmpx support is automatic for some platforms.

   --without-shadow

   Disables shadow password support.

   --with-ipaddr-display

   Forces the use of a numeric IP address in the $DISPLAY environment variable. Some broken systems need this.

   --with-default-path=PATH

   allows you to specify a default $PATH for sessions started by sshd. This replaces the standard path entirely. Use this if you have troubles with the server not finding scp.

   --with-pid-dir=PATH

   Specifies the directory in which the ssh.pid file is created.

   --with-xauth=PATH

   Specifies the location of the xauth binary

   --with-ipv4-default

   Instructs OpenSSH to use IPv4 by default for new connections. Normally OpenSSH will try attempt to lookup both IPv6 and IPv4 addresses. On Linux/glibc-2.1.2 this causes long delays in name resolution. If this option is specified, you can still attempt to connect to IPv6 addresses using the command line option -6.

   --with-ssl-dir=DIR

   Allows you to specify where your OpenSSL libraries are installed.

   --with-4in6

   Check for IPv4 in IPv6 mapped addresses and convert them to real (AF_INET) IPv4 addresses. Works around more IPv6 quirks on Linux.

   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" LIBS="-lrubbish" LD="/usr/foo/ld" ./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, run "make host-key". Alternately you can do so manually using the following commands:

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