OpenSSH for Windows

Notes from OpenSSH for Windows site -

"OpenSSH for Windows is a free package that installs a minimal OpenSSH server and client utilities in the Cygwin package without needing the full Cygwin installation.

The OpenSSH for Windows package provides full SSH/SCP/SFTP support. SSH terminal support provides a familiar Windows Command prompt, while retaining Unix/Cygwin-style paths for SCP and SFTP."

To setup OpenSSH on a Windows PC follow the instructions below -

Extract setupssh.exe from the OpenSSH download and install using default settings - this will install the required files to the C:\Program Files\OpenSSH\ directory.

Start a command prompt and enter the following -
CD "C:\Program Files\OpenSSH\bin" [enter]

Create a group file -

To create a group file (a list of user accounts on the server) for local user accounts, enter the following -
mkgroup -l >> ..\etc\group [enter]
To create a group file for domain users edit the above command and replace the -l switch with -d
mkgroup -d >> ..\etc\group [enter]
To create a group file for local and domain user run both of the above commands - you will however need to edit the C:\Program Files\OpenSSH\etc\group file in a text editor to remove any duplicate entries.

Create a passwd file (it is not possible to login to the server until a passwd file has been created) -

To create a passwd file for a local user account, enter the following (where Administrator is the name of the account to create a passwd for) -
mkpasswd -l -u Administrator >> ..\etc\passwd [enter]
To create a passwd file for all local user accounts, enter the following -
mkpasswd -l >> ..\etc\passwd [enter]
To create a passwd file for a domain user account, enter the following (where domain_username is the name of the domain account to create a passwd for - note from readme file included with the OpenSSH installer "To add domain users from a domain that is not the primary domain of the machine, add the domain name after the user name") -
mkpasswd -d -u domain_username >> ..\etc\passwd [enter]
To create a passwd file for all domain user accounts, enter the following -
mkpasswd -d >> ..\etc\passwd [enter]

In order to allow login via an encrypted key file the OpenSSH configuration file will need to be edited. To create a backup, open C:\Program Files\OpenSSH\etc\sshd_config in notepad and save as C:\Program Files\OpenSSH\etc\sshd_config.bak.

Now replace the text in the configuration file (C:\Program Files\OpenSSH\etc\sshd_config) with the following (use copy and paste - highlight all text in the textbox below and hold the [ctrl]+[c] keys to copy, then [ctrl]+[v] to paste into notepad). See here for changes to the original C:\Program Files\OpenSSH\etc\sshd_config (edited lines are in red) -

#	$OpenBSD: sshd_config,v 1.65 2003/08/28 12:54:34 markus Exp $

# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

#Port 22
#Protocol 2,1
Protocol 2
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
#HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768

# Logging
#obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
PermitRootLogin no

# The following setting overrides permission checks on host key files
# and directories. For security reasons set this to "yes" when running
# NT/W2K, NTFS and CYGWIN=ntsec.
StrictModes no

RSAAuthentication no
PubkeyAuthentication yes
AuthorizedKeysFile /etc/authorized_keys

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication yes
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
IgnoreUserKnownHosts yes
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCreds yes

# Set this to 'yes' to enable PAM authentication (via challenge-response)
# and session processing. Depending on your PAM configuration, this may
# bypass the setting of 'PasswordAuthentication'
#UsePAM yes

#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding no
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#KeepAlive yes
#UseLogin no
UsePrivilegeSeparation no
#PermitUserEnvironment no
#Compression yes
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS yes
#PidFile /var/run/sshd.pid
MaxStartups 10:30:60

# default banner path
Banner /etc/banner.txt

# override default of no subsystems
Subsystem	sftp	/usr/sbin/sftp-server

See here for instructions on creating public and private key files using PuTTYgen.exe.

Assuming the instructions were followed in step 7 and PuTTYgen was used to create the keyfiles, copy authorized_keys to the C:\Program Files\OpenSSH\etc\ directory.

To start the OpenSSH service, open a command prompt and enter the following -
net start opensshd [enter]