On l’installe
<code bash>apt-get install openssh-server</code>

On édite le message d’accueil
<code bash>nano /etc/issue.net</code>

On édite la config
<code bash>nano /etc/ssh/sshd_config</code>

Il faut éditer les lignes suivantes ( 8, 76, 79 et 98 du fichier dispo ici : <file bash sshd_config.txt[enable_line_numbers=1, highlight_lines_extra="8,76,79,98", skin=sons-of-obsidian]>
# Lignes a modifier : 8, 77, 80, 90


# Package generated configuration file
# See the sshd_config(5) manpage for details

# What ports, IPs and protocols we listen for
Port TON_PORT

# Use these options to restrict which interfaces/protocols sshd will bind to
#ListenAddress ::
#ListenAddress 0.0.0.0
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes

# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 768

# Logging
SyslogFacility AUTH
LogLevel INFO

# Authentication:
LoginGraceTime 120
PermitRootLogin no
StrictModes yes

RSAAuthentication yes
PubkeyAuthentication yes
#AuthorizedKeysFile     %h/.ssh/authorized_keys

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

# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes

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

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

X11Forwarding yes
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
#UseLogin no

# Explications a partir de 3 mauvaises connexions le client a 30% de chances de s'en voir refuser une nouvelle
# Cette probabilite augmente lineairement jusqu'a 60 connexions
# a partir de 60 connexions il ne pourra plus se connecter
MaxStartups 3:30:60

# Permet d'afficher une banniere (ici c'est le contenu du fichier /etc/issue.net qui sera affiche) 
Banner /etc/issue.net

# Allow client to pass locale environment variables
AcceptEnv LANG LC_*

Subsystem sftp /usr/lib/openssh/sftp-server

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes

# Securise les connexions en specifiant une liste des users authorises a se connecter
AllowUsers PSEUDO_USER1 PSEUDO_USER2</file> ) :


Le port par défaut est le 22, mais il est conseillé de le changer.
<code bash [enable_line_numbers=1, start_line_numbers_at=8, skin=sons-of-obsidian]>Port TON_PORT</code>

A partir de 3 mauvaises connexions le client a 30% de chances de s’en voir refuser une nouvelle.\\
Cette probabilité augmente linéairement jusqu’à 60 connexions.\\
A partir de 60 connexions il ne pourra plus se connecter.

<code bash [enable_line_numbers=1, start_line_numbers_at=76, skin=sons-of-obsidian]>MaxStartups 3:30:60</code> 

Permet d’afficher une bannière (ici c’est le contenu du fichier /etc/issue.net qui sera affiché).
<code bash [enable_line_numbers=1, start_line_numbers_at=79, skin=sons-of-obsidian]>Banner /etc/issue.net</code>

Sécurise les connexions en spécifiant une liste des users autorisés a se connecter.
<code bash [enable_line_numbers=1, start_line_numbers_at=98, skin=sons-of-obsidian]>AllowUsers PSEUDO_USER1 PSEUDO_USER2</code>

**On relance ssh**

Cela permet de recharger la config.
<code bash>/etc/init.d/ssh restart</code>

Plus qu’à se connecter (via Putty par exemple) !