MA-E3xx では、sshd がインストールされていますので、セキュアなファイル転送として SFTP プロトコルが利用できます。
組み込み機器などで、どうしても FTP プロトコルしか使用できないというような場合のため、FTPサーバを導入方法を紹介します。
Ubuntu Linux に用意されている、FTPサーバのパッケージを検索してみます。
user1@plum:~$ sudo apt-cache search ftpd [sudo] password for user1: tftpd-hpa - HPA's tftp server vsftpd - lightweight, efficient FTP server written for security atftpd - advanced TFTP server auth2db-filters - Auth2db defaults filters pack ccze - A robust, modular log coloriser fail2ban - ban hosts that cause multiple authentication errors ftp-ssl - The FTP client with SSL or TLS encryption support ftpd - File Transfer Protocol (FTP) server ftpd-ssl - FTP server with SSL encryption support gadmin-proftpd - GTK+ configuration tool for proftpd gadmin-proftpd-dbg - GTK+ configuration tool for proftpd debug package gadmintools - GTK+ server administration tools (meta-package) gosa-plugin-pureftpd - pureftpd plugin for GOsa? gosa-plugin-pureftpd-schema - LDAP schema for GOsa? pureftpd plugin heimdal-servers - Heimdal Kerberos - server programs inetutils-ftpd - File Transfer Protocol server libnet-tftpd-perl - Perl extension for Trivial File Transfer Protocol Server muddleftpd - A flexible and efficient FTP daemon mysqmail-pure-ftpd-logger - real-time logging system in MySQL - Pure-FTPd traffic-logger nordugrid-arc-gridftpd - ARC GridFTP server owftpd - FTP daemon providing access to 1-Wire networks prelude-lml - Security Information Management System [ Log Agent ] proftpd-basic - Versatile, virtual-hosting FTP daemon - binaries proftpd-dev - Versatile, virtual-hosting FTP daemon - development files proftpd-doc - Versatile, virtual-hosting FTP daemon - documentation proftpd-mod-autohost - ProFTPD module mod_autohost proftpd-mod-case - ProFTPD module mod_case proftpd-mod-clamav - ProFTPD module mod_clamav proftpd-mod-dnsbl - ProFTPD module mod_dnsbl proftpd-mod-fsync - ProFTPD module mod_fsync proftpd-mod-geoip - Versatile, virtual-hosting FTP daemon - GeoIP module proftpd-mod-ldap - Versatile, virtual-hosting FTP daemon - LDAP module proftpd-mod-msg - ProFTPD module mod_msg proftpd-mod-mysql - Versatile, virtual-hosting FTP daemon - MySQL module proftpd-mod-odbc - Versatile, virtual-hosting FTP daemon - ODBC module proftpd-mod-pgsql - Versatile, virtual-hosting FTP daemon - PostgreSQL module proftpd-mod-sqlite - Versatile, virtual-hosting FTP daemon - SQLite3 module proftpd-mod-tar - ProFTPD module mod_tar proftpd-mod-vroot - ProFTPD module mod_vroot pure-ftpd - Secure and efficient FTP server pure-ftpd-common - Pure-FTPd FTP server (Common Files) pure-ftpd-ldap - Secure and efficient FTP server with LDAP user authentication pure-ftpd-mysql - Secure and efficient FTP server with MySQL user authentication pure-ftpd-postgresql - Secure and efficient FTP server with PostgreSQL user authentication pureadmin - Gtk graphic front-end for PureFTPd pyftpd - ftp daemon with advanced features python-pyftpdlib - Python FTP server library tcllib - Standard Tcl Library tftpd - Trivial file transfer protocol server twoftpd - a simple secure efficient FTP server (programs) twoftpd-run - a simple secure efficient FTP server uec-provisioning-tftpd - the UEC Provisioning TFTP server yasat - simple stupid audit tool user1@plum:~$
TFTP1)も検索されてしまっていますが、 有名なFTPサーバとして、下記が導入できるようです。
“the most secure”, “fastest” という謳い文句が魅力的なので、vsftpd を導入してみます。
apt-get コマンドでインストールします。
user1@plum:~$ sudo apt-get install vsftpd [sudo] password for user1: Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: vsftpd 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 99.8 kB of archives. After this operation, 298 kB of additional disk space will be used. Get:1 http://ports.ubuntu.com/ubuntu-ports/ trusty-updates/main vsftpd armhf 3.0.2-1ubuntu2.14.04.1 [99.8 kB] Fetched 99.8 kB in 1s (53.9 kB/s) Preconfiguring packages ... Selecting previously unselected package vsftpd. (Reading database ... 17590 files and directories currently installed.) Preparing to unpack .../vsftpd_3.0.2-1ubuntu2.14.04.1_armhf.deb ... Unpacking vsftpd (3.0.2-1ubuntu2.14.04.1) ... Processing triggers for ureadahead (0.100.0-16) ... Setting up vsftpd (3.0.2-1ubuntu2.14.04.1) ... vsftpd start/running, process 1398 Processing triggers for ureadahead (0.100.0-16) ... localepurge: Disk space freed in /usr/share/locale: 0 KiB localepurge: Disk space freed in /usr/share/man: 0 KiB Total disk space freed by localepurge: 0 KiB user1@plum:~$
これでインストールできました。 プロセスが立ち上がっているか確認してみます。
user1@plum:~$ ps ax|grep vsftp 1398 ? Ss 0:00 /usr/sbin/vsftpd 1446 pts/1 S+ 0:00 grep --color=auto vsftp user1@plum:~$
どのポートでlistenしているか確認してみます。
user1@plum:~$ netstat -l -4 -t Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:ftp *:* LISTEN tcp 0 0 *:domain *:* LISTEN tcp 0 0 *:ssh *:* LISTEN tcp 0 0 *:50040 *:* LISTEN tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:http *:* LISTEN user1@plum:~$
“ftp” (TCP/21) で listen していることがわかります。
別の機器から、FTPで接続してみます。
user1@plum:~$ ftp 192.168.253.35 Connected to 192.168.253.35. 220 (vsFTPd 3.0.2) Name (192.168.253.35:user1): user1 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> quit 221 Goodbye. user1@plum:~$
接続できることが確認できました。
apt-get コマンドで導入することで、とりあえず使用することができるようになりました。
しかし、このままですと、インターネットに接続した場合、世界中のどこからでもアクセスできるようになってしまい、
セキュリティ上問題があります。
インターネットに接続して利用する場合、Firewall を設定し、アドレスなどで接続を制限することを 強く お勧めします。
Ubuntu の vsftpd の設定ファイルは、/etc/vsftpd.conf です。
内容についてのドキュメントは、http://manpages.ubuntu.com/manpages/trusty/en/man5/vsftpd.conf.5.html になります。
デフォルトでは、下記のように設定されています。
# 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? (Disabled by default) 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 # # If enabled, vsftpd will display directory listings with the time # in your local time zone. The default is to display GMT. The # times returned by the MDTM FTP command are also affected by this # option. use_localtime=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. # Note that the default log file location is /var/log/xferlog in this case. #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 blah 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=YES # # 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(). # (Warning! chroot'ing can be very dangerous. If using chroot, make sure that # the user does not have write access to the top level directory within the # chroot) #chroot_local_user=YES #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 # # Customization # # Some of vsftpd's settings don't fit the filesystem layout by # default. # # 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/empty # # 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