Installation d'un serveur FTP

J'ai eu beaucoup de mal à installer mon serveur FTP (tout ça pour pouvoir lancer la mise à jour automatique de Wordpress 3 !) - et je suis sûr qu'il n'est pas encore tout à fait bien configuré... Mais bon, voici ce que j'ai fait :

Je suis sous Ubuntu Server 10.04 - j'ai opté pour proftpd donc sudo aptitude install proftpd

Ajout des règles iptables :

sudo iptables -A INPUT -p tcp -i eth0 --dport ftp -j ACCEPT
sudo iptables -A OUTPUT -p tcp -o eth0 --sport ftp -j ACCEPT

Édition du fichier /etc/proftpd/proftpd.conf :

AllowOverwrite on
AuthAliasOnly on

# Choose here the user alias you want !!!!
UserAlias utilisateur_pour_le_ftp utilisateur_normal

ServerName                      "LeNomDeVotreChoix"
ServerType                      standalone
DeferWelcome                    on

MultilineRFC2228 on
DefaultServer                   on
ShowSymlinks                    off

TimeoutNoTransfer 600
TimeoutStalled 100
TimeoutIdle 2200

DisplayChdir                    .message
ListOptions                     "-l"

RequireValidShell               off

TimeoutLogin 20

RootLogin                       off

# It's better for debug to create log files ;-)
ExtendedLog                     /var/log/ftp.log
TransferLog                     /var/log/xferlog
SystemLog                       /var/log/syslog.log

#DenyFilter                     \*.*/

# I don't choose to use /etc/ftpusers file (set inside the users you want to ban, not useful for me)
UseFtpUsers off

# Allow to restart a download
AllowStoreRestart               on

# Port 21 is the standard FTP port, so you may prefer to use another port for security reasons (choose here the port you want)
Port                            21
To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances 8

# Set the user and group that the server normally runs at.
User                  nobody
Group                 nogroup

# Umask 022 is a good standard umask to prevent new files and dirs
# (second parm) from being group and world writable.
Umask                           022     022

PersistentPasswd                off

MaxClients 8
MaxClientsPerHost 8
MaxClientsPerUser 8
MaxHostsPerUser 8

# Display a message after a successful login
AccessGrantMsg "welcome !!!"
# This message is displayed for each access good or not
ServerIdent                  on       "you're at home"

# Set /home/FTP-shared directory as home directory
DefaultRoot /home/user_normal

# Lock all the users in home directory, ***** really important *****
DefaultRoot ~

MaxLoginAttempts    5

AllowUser user_normal

<Directory /home/utilisateur_normal>
Umask 000 000
AllowOverwrite on
<Limit ALL>
Order Allow,Deny
AllowUser utilisateur_normal
Deny ALL

Lancer proftpd :

sudo service proftpd start

Je me suis basé sur ce lien pour la configuration de proftpd et sur celui-ci pour les règles iptables