FTP サーバ構築

概要

• wordpress をインストールしたが、GUIの管理画面でFTP情報を入力すると楽にインストール作業が行えることが判明
• そのため、FTPサーバを構築する

手順

1. vsftpd インストール・起動
2. 設定ファイルの編集
3. user_list の編集
4. ユーザの作成
5. chroot の設定

#vsftpd インストール・起動 設定

• FTP サーバのインストール

$ sudo yum install -y vsftpd

• FTP サーバの自動起動・起動

$ sudo systemctl enable vsftpd
$ sudo systemctl start vsftpd

設定ファイルの編集

$ sudo cp -p /etc/vsftpd/vsftpd.conf /etc/vsftpd/vsftpd.conf.back
$ sudo vi /etc/vsftpd/vsftpd.conf

以下設定ファイルの設定内容

接続モード	PASVモード
ポート	10000-10100番

etc/vsftpd/vsftpd.conf

# 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.
# When SELinux is enforcing check for SE bool ftp_home_dir
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=077
#
# 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.
# When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
#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=NO
#
# 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/xferlog
#
# 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 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
#
# 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. By default, listening
# on the IPv6 "any" address (::) will accept connections from both IPv6
# and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6
# sockets. If you want that (perhaps because you want to listen on specific
# addresses) then you must run two copies of vsftpd with two configuration
# files.
# Make sure, that one of the listen options is commented !!
listen_ipv6=YES

pam_service_name=vsftpd
userlist_enable=NO
tcp_wrappers=NO

# コピペ
user_config_dir=/etc/vsftpd/chroot_user_conf
pasv_enable=YES
pasv_min_port=10000
pasv_max_port=10100
pasv_address=[IP アドレス]

user_list を編集

• 接続許可するユーザを追加する
• 今回は、 [ftp-hoge] というユーザを追加する

/etc/vsftpd/user_list

# 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.

ftp-hoge

ユーザ作成

• サーバのユーザとして、 [ftp-hoge] を作成する

$ sudo useradd ftp-hoge
$ sudo passwd ftp-hoge

chrootの設定

• ユーザ毎の設定ファイルを作成し、パスを指定する
• ここで作成したファイルのパスが、FTPのルートディレクトリになる

$ sudo mkdir /etc/vsftpd/chroot_user_conf
$ sudo vi /etc/vsftpd/chroot_user_conf/ftp-hoge

ファイルを作成し、以下のように記述する

/etc/vsftpd/chroot_user_conf/ftp-hoge

local_root=[任意のパス]

• FTPのルートディレクトリよりも上へいきたい場合は、以下のファイルを作成し、ユーザ名を記載する。

$ sudo touch /etc/vsftpd/chroot_list

★今回は不要なので、ファイルだけ作成。

終了したら、再起動

$ sudo systemctl restart vsftpd
$ sudo systemctl status vsftpd

AWSのセキュリティグループの設定

• PASVモードで設定しているので、以下のように設定する
• カスタムTCP [10000-10100] で設定をする
• カスタムTCP [21] で設定をする

感想

Wordpress の初の設定で色々必要なんだと実感。
セキュリティ等も鑑みる必要があり、考える事が多いなーという感じ。
FTPは、終了したので接続確認です(^^)