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Serveur ftp avec vsftpd 1 : Mise en place.

Serveur ftp avec vsftpd 1 : Mise en place.

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Voici comment je me suis mont� un serveur FTP afin de pouvoir agr�menter mon Weblog avec quelques t�l�chargements......et pr�cision, je veux que n'importe qui puisse prendre les fichiers mis a dispo, mais je ne veux pas qu'il puisse faire n'importe quoi, juste les t�l�charger !

Comme d'habitude, nous somme sur une Ubuntu, une 7.10 cette fois mais �a fonctionne comme la 7.04, commen�ons par installer vsftpd

Code BASH :

 moi@ma-machine:-$ sudo apt-get install vsftpd

Et bien sur sur Linux, quasiment tout se passe dans le fichier de configuration, celui ci se trouve dans le r�pertoire /etc, il nous faut l'editer :

Code BASH :

 moi@ma-machine:-$ sudo vi /etc/vsftpd.conf

Ce qui nous renvois :

Code BASH :

# Example config file /etc/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.
 #
 #
 # Run standalone?  vsftpd can run either from an inetd or as a standalone
 # daemon started from an initscript.
 listen=YES
 #
 # Run standalone with IPv6?
 # Like the listen parameter, except vsftpd will listen on an IPv6 socket
 # instead of an IPv4 one. This parameter and the listen parameter are mutually
 # exclusive.
 #listen_ipv6=YES
 #
 # Allow anonymous FTP? (Beware - allowed by default if you comment this out).
 anonymous_enable=YES
 #
 # Uncomment this to allow local users to log in.
 local_enable=NO
 #
 # 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
 #
 # Activate logging of uploads/downloads.
 xferlog_enable=YES
 
 # 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
 #
 # You may override where the log file goes if you like. The default is shown
 # below.
 #xferlog_file=/var/log/vsftpd.log
 #
 # If you want, you can have your log file in standard ftpd xferlog format
 #xferlog_std_format=YES
 #
 # You may change the default value for timing out an idle session.
 #idle_session_timeout=600
 #
 # 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
 #
 # 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 the small furtiv one FTP service.
 #
 # 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 restrict local users to their home directories.  See the FAQ for
 # the possible risks in this before using chroot_local_user or
 #chroot_list_enable below.
 chroot_local_user=NO
 #
 # 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
 #
 #
 # Debian customization
 #
 # Some of vsftpd's settings don't fit the Debian filesystem layout by
 # default.  These settings are more Debian-friendly.
 #
 # This option should be the name of a directory which is empty.  Also, the
 # directory should not be writable by the ftp user. This directory is used
 # as a secure chroot() jail at times vsftpd does not require filesystem
 # access.
 secure_chroot_dir=/var/run/vsftpd
 #
 # This string is the name of the PAM service vsftpd will use.
 pam_service_name=vsftpd
 #
 # This option specifies the location of the RSA certificate to use for SSL
 # encrypted connections.
 rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
 #
 # This option specifies the location of the RSA key to use for SSL
 # encrypted connections.
 rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key

Voici les options importantes a retenir pour un acc�s avec l'utilisateur "''anonymous''" de fa�on relativement s�curis�e, bien sur, �tant donn� que nous utilisons un acc�s anonyme, on ne peut garantir a 100% la s�curit� du syst�me !

Code BASH :

 listen=YES
 anonymous_enable=YES
 local_enable=NO
 local_umask=022
 write_enable=NO
 xferlog_file=YES
 chroot_list_enable=YES
 chroot_list_file=/etc/vsftpd.chroot_list
 ftpd_banner=Welcome to the small furtiv one's FTP service

Description des options a retenir :

listen=YES--> Permet de d�finir si le serveur est en ''standalone'' ou lanc� par un super deamon comme ''xinetd''.
anonymous_enable=YES--> On accepte les connexions anonymes.
Local_enable=NO--> On refuse les connexions locales, pour l'exemple, je n'en ai pas besoin donc je refuse !
local_umask=022--> Permet de d�finir les droit sur les dossiers et fichiers du /home du ftp =>022 donne des permissions en 644 sur les fichiers et 755 sur les dossiers.
write_enable=NO--> On interdit toutes actions d'ecriture.
xferlog_file=YES--> On ecrit un log sur les fichiers.
chroot_list_enable=YES--> On active la liste des utilisateur qui seront enferm�s.
chroot_list_file=/etc/vsftpd.chroot_list--> c'est dans cette liste, qu'il faut cr�er, que l'on nomme les futur prisonniers ! dans notre cas, mentionner : anonymous
ftpd_banner=Welcome to the small furtiv one's FTP service--> Me semble important car on peut y mettre d'�ventuelles infos sur des mises a jours etc....

Il existe de nombreuses autres options, vsftpd est plein de possibilit�s, on peut par exemple d�finir le nombre de connexion maxi sur le serveur gr�ce a l'option max_clients=, ou encore limiter le nombre de connexion par adresse ip gr�ce a max_per_ip=, et puis nous n'avons vu que la config pour une utilisation en anonyme, mais avec des utilisateurs d�clar�s, vsftpd se montre particuli�rement performant, notamment gr�ce au base de donn�es berkeley pour l'authentification....Nous verrons cela dans un futur article.

Voici les liens qui m'ont aid� dans ma tache :

Le site d'Andesi pour une config avec utilisateur virtuels et authentification

Ecrit par: le furtif, Le: 12/10/08