• VsFTPd

Installer le paquet de la distribution Cf. Gestionnaire paquets GNU/Linux.

Exemple avec deux comptes utilisateurs locaux standard nommés userlocal1 et userlocal2. Le compte userlocal1 doit pouvoir accéder au serveur FTP mais pas userlocal2.

Sauvegarde du fichier de configuration.

cd /etc/vsftpd
cp -p vsftpd.conf vsftpd.conf.orig

Changer les options suivantes avec les valeurs spécifiées.

ftpd_banner=Authorized access only.
anonymous_enable=NO #Desactivation des access anonymes
local_enable=YES #Autoriser les comptes locaux a se connecter
local_umask=002 #par défaut à 022. Pour permettre l'écriture des comptes membres du même groupe
idle_session_timeout=3600 #Monter la valeur par defaut de desactivation de session FTP
chroot_list_enable=YES #Activation d'une liste de compte chroote
chroot_list_file=/etc/vsftpd/chroot_list #Fichier de list de compte chroote
nopriv_user=ftp #Execution du service vsftpd avec un autre compte utilisateur. Utilisation du compte ftp amene par le paquet client qui est en /sbin/nologin.
userlist_enable=YES #Activation de la liste des utilisateurs interdit. Pas de demande de password
dual_log_enable=YES #Activation de deux logs
log_ftp_protocol=YES #Activation du log FTP (connexion)
vsftpd_log_file=/var/log/vsftpd.log #selection du chemin du log des connexions. Chemin par défaut pris en compte dans le logrotate par défaut. 

xferlog_file=/var/log/xferlog #selection du chemin du log des transferts FTP. Chemin par défaut pris en compte dans le logrotate par défaut.
pasv_enable=YES #activation mode passif
pasv_min_port=52000 #plage min des ports clients passif
pasv_max_port=54000 #plage max des ports clients passif

Création du fichier /etc/vsftpd/chroot_list avec la liste des comptes chrootes.

userlocal1

Ajout des comptes qui ne doivent pas pouvoir se connecter en FTP dans /etc/vsftpd/ftpusers. Avec uniquement cette liste, le mot de passe est quand même demandé. Erreur : login incorrect.

# Users that are not allowed to login via ftp
root
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
nobody
userlocal2

Ajout des comptes qui ne doivent jamais pouvoir se connecter en FTP dans /etc/vsftpd/user_list. Un utilisateur dans cette liste sera automatiquement interdit. La demande de mot de passe n'est pas demandé.

# vsftpd userlist
# If userlist_deny=NO, only allow users in this file
# If userlist_deny=YES (default), never allow users in this file, and
# do not even prompt for a password.
# Note that the default vsftpd pam config also checks /etc/vsftpd/ftpusers
# for users that are denied.
root
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
nobody
userlocal2

Démarrer le service.

/etc/init.d/vsftpd start

L'ajouter au démarrage du système.

chkconfig --list vsftpd
chkconfig vsftpd on

# Example config file /etc/vsftpd/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
#anonymous_enable=YES
anonymous_enable=NO
#
# Uncomment this to allow local users to log in.
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES
#
dual_log_enable=YES
# The target log file can be vsftpd_log_file or xferlog_file.
# This depends on setting xferlog_std_format parameter
xferlog_enable=YES
#
log_ftp_protocol=YES
vsftpd_log_file=/var/log/vsftpd.log
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# The name of log file when xferlog_enable=YES and xferlog_std_format=YES
# WARNING - changing this filename affects /etc/logrotate.d/vsftpd.log
#xferlog_file=/var/log/xferlog
#
# Switches between logging into vsftpd_log_file and xferlog_file files.
# NO writes to vsftpd_log_file, YES to xferlog_file
xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
idle_session_timeout=3600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
nopriv_user=ftp
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that on some FTP servers, ASCII support allows a denial of service
# attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
# predicted this attack and has always been safe, reporting the size of the
# raw file.
# ASCII mangling is a horrible feature of the protocol.
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
#ftpd_banner=Welcome to blah FTP service.
ftpd_banner=Bienvenue sur le serveur FTP du Sifec.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd/banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
chroot_list_enable=YES
# (default follows)
chroot_list_file=/etc/vsftpd/chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
listen=YES
#
# This directive enables listening on IPv6 sockets. To listen on IPv4 and IPv6
# sockets, you must run two copies of vsftpd whith two configuration files.
# Make sure, that one of the listen options is commented !!
#listen_ipv6=YES

pam_service_name=vsftpd
userlist_enable=YES
tcp_wrappers=YES

• /var/log/xferlog : log des transactions.
• /var/log/vsftpd.log : log des connexions.

Tester la connexion avec les comptes utilisateurs.

Modification de la rotation des logs pour éviter de saturer le filesystem /var. Conservation des 4 derniers jours et compression des logs.

/etc/logrotate.d/vsftpd

/var/log/vsftpd.log {
    # ftpd doesn't handle SIGHUP properly
    daily
    compress
    missingok
}

/var/log/xferlog {
    # ftpd doesn't handle SIGHUP properly
    daily
    compress
    missingok
}

• Cf. Test FTP.