[Linux] CentOS 7 FTP 설정

1. vsftpd package 설치

[root@localhost ~]# yum -y install vsftpd

2. ftp 설정

[root@localhost ~]# vi /etc/vsftpd/vsftpd.conf

- 해당 파일 default 내용

Line 102 / 104 주석 해제

->chroot_list 에 있는 계정 접속 허용

      1 # Example config file /etc/vsftpd/vsftpd.conf
      2 #
      3 # The default compiled in settings are fairly paranoid. This sample file
      4 # loosens things up a bit, to make the ftp daemon more usable.
      5 # Please see vsftpd.conf.5 for all compiled in defaults.
      6 #
      7 # READ THIS: This example file is NOT an exhaustive list of vsftpd options.
      8 # Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
      9 # capabilities.
     10 #
     11 # Allow anonymous FTP? (Beware - allowed by default if you comment this out).
     12 anonymous_enable=YES
     13 #
     14 # Uncomment this to allow local users to log in.
     15 # When SELinux is enforcing check for SE bool ftp_home_dir
     16 local_enable=YES
     17 #
     18 # Uncomment this to enable any form of FTP write command.
     19 write_enable=YES
     20 #
     21 # Default umask for local users is 077. You may wish to change this to 022,
     22 # if your users expect that (022 is used by most other ftpd's)
     23 local_umask=022
     24 #
     25 # Uncomment this to allow the anonymous FTP user to upload files. This only
     26 # has an effect if the above global write enable is activated. Also, you will
     27 # obviously need to create a directory writable by the FTP user.
     28 # When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
     29 #anon_upload_enable=YES
     30 #
     31 # Uncomment this if you want the anonymous FTP user to be able to create
     32 # new directories.
     33 #anon_mkdir_write_enable=YES
     34 #
     35 # Activate directory messages - messages given to remote users when they
     36 # go into a certain directory.
     37 dirmessage_enable=YES
     38 #
     39 # Activate logging of uploads/downloads.
     40 xferlog_enable=YES
     41 #
     42 # Make sure PORT transfer connections originate from port 20 (ftp-data).
     43 connect_from_port_20=YES
     44 #
     45 # If you want, you can arrange for uploaded anonymous files to be owned by
     46 # a different user. Note! Using "root" for uploaded files is not
     47 # recommended!
     48 #chown_uploads=YES
     49 #chown_username=whoever
     50 #
     51 # You may override where the log file goes if you like. The default is shown
     52 # below.
     53 #xferlog_file=/var/log/xferlog
     54 #
     55 # If you want, you can have your log file in standard ftpd xferlog format.
     56 # Note that the default log file location is /var/log/xferlog in this case.
     57 xferlog_std_format=YES
     58 #
     59 # You may change the default value for timing out an idle session.
     60 #idle_session_timeout=600
     61 #
     62 # You may change the default value for timing out a data connection.
     63 #data_connection_timeout=120
     64 #
     65 # It is recommended that you define on your system a unique user which the
     66 # ftp server can use as a totally isolated and unprivileged user.
     67 #nopriv_user=ftpsecure
     68 #
     69 # Enable this and the server will recognise asynchronous ABOR requests. Not
     70 # recommended for security (the code is non-trivial). Not enabling it,
     71 # however, may confuse older FTP clients.
     72 #async_abor_enable=YES
     73 #
     74 # By default the server will pretend to allow ASCII mode but in fact ignore
     75 # the request. Turn on the below options to have the server actually do ASCII
     76 # mangling on files when in ASCII mode. The vsftpd.conf(5) man page explains
     77 # the behaviour when these options are disabled.
     78 # Beware that on some FTP servers, ASCII support allows a denial of service
     79 # attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
     80 # predicted this attack and has always been safe, reporting the size of the
     81 # raw file.
     82 # ASCII mangling is a horrible feature of the protocol.
     83 #ascii_upload_enable=YES
     84 #ascii_download_enable=YES
     85 #
     86 # You may fully customise the login banner string:
     87 #ftpd_banner=Welcome to blah FTP service.
     88 #
     89 # You may specify a file of disallowed anonymous e-mail addresses. Apparently
     90 # useful for combatting certain DoS attacks.
     91 #deny_email_enable=YES
     92 # (default follows)
     93 #banned_email_file=/etc/vsftpd/banned_emails
     94 #
     95 # You may specify an explicit list of local users to chroot() to their home
     96 # directory. If chroot_local_user is YES, then this list becomes a list of
     97 # users to NOT chroot().
     98 # (Warning! chroot'ing can be very dangerous. If using chroot, make sure that
     99 # the user does not have write access to the top level directory within the
    100 # chroot)
    101 #chroot_local_user=YES
    102 chroot_list_enable=YES
    103 # (default follows)
    104 chroot_list_file=/etc/vsftpd/chroot_list
    105 #
    106 # You may activate the "-R" option to the builtin ls. This is disabled by
    107 # default to avoid remote users being able to cause excessive I/O on large
    108 # sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
    109 # the presence of the "-R" option, so there is a strong case for enabling it.
    110 #ls_recurse_enable=YES
    111 #
    112 # When "listen" directive is enabled, vsftpd runs in standalone mode and
    113 # listens on IPv4 sockets. This directive cannot be used in conjunction
    114 # with the listen_ipv6 directive.
    115 listen=YES
    116 #
    117 # This directive enables listening on IPv6 sockets. By default, listening
    118 # on the IPv6 "any" address (::) will accept connections from both IPv6
    119 # and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6
    120 # sockets. If you want that (perhaps because you want to listen on specific
    121 # addresses) then you must run two copies of vsftpd with two configuration
    122 # files.
    123 # Make sure, that one of the listen options is commented !!
    124 listen_ipv6=NO
    125
    126 pam_service_name=vsftpd
    127 userlist_enable=YES
    128 tcp_wrappers=YES

 

*수정 ( 2022.04.05 )

115 : listen = NO -> listen = YES

124 : llisten_ipv6=YES -> llisten_ipv6=NO

 

* 수정 ( 2022.04.05 )

설정 이슈 인지 아래 내용 적용시 

500 OOPS: vsftpd: refusing to run with writable root inside chroot() 발생.

해당 list 내용 제거

 

chroot_list 계정 추가 ( root , user1 , user 2 .. )

[root@localhost ~]# vi /etc/vsftpd/chroot_list

 

root
user1
user2
~
~
~
~
-- INSERT --

 

root으로 접속시 안되는 경우 아래 경로 에서 root 을 제거하면 된다.

[root@localhost ~]# vi /etc/vsftpd/ftpusers
[root@localhost ~]# vi /etc/vsftpd/user_list

-> 위 내용을 진행하지 않으면 530 Permission denied 를 보게 된다.

응답:	530 Please login with USER and PASS.
상태:	보안되지 않은 서버입니다. TLS를 통한 FTP를 지원하지 않습니다.
명령:	USER root
응답:	530 Permission denied.
오류:	서버에 연결하지 못함

 

 

3. 방화벽 해제

[root@localhost ~]# firewall-cmd --permanent --add-service=ftp
success
[root@localhost ~]# firewall-cmd --permanent --add-port=21/tcp
success
[root@localhost ~]# firewall-cmd --reload
success

 

4. FTP 실행

[root@localhost ~]# systemctl start vsftpd
[root@localhost ~]# systemctl status vsftpd
● vsftpd.service - Vsftpd ftp daemon
   Loaded: loaded (/usr/lib/systemd/system/vsftpd.service; disabled; vendor preset: disabled)
   Active: active (running) since Fri 2022-04-01 01:59:31 EDT; 4min 38s ago
  Process: 10268 ExecStart=/usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf (code=exited, status=0/SUCCESS)
 Main PID: 10269 (vsftpd)
   CGroup: /system.slice/vsftpd.service
           └─10269 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf

Apr 01 01:59:31 localhost.localdomain systemd[1]: Starting Vsftpd ftp daemon...
Apr 01 01:59:31 localhost.localdomain systemd[1]: Started Vsftpd ftp daemon.

5. 접속 확인 ( Windows10 - Filezilla )

호스트( IP or DNS ) , 계정, 패스워드 , 포트 ( 22 ) 입력 후 연결 하면 아래와 같이 접속 된다.