vsftpd 설정

늘 써오던 vsftp를 제대로 쓰기위에 늘 Conf파일 정리를 해야하면서 미뤄오던 작업을 오늘 하게되었다



OS는 Cent OS 6.3 이다



일단  Vsftp를 yum으로 설치하고 /etc/vsftpd/vsftpd.conf 파일을 확인해보자

====================================================================

 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=NO : 익명의 사용자를 사용할것인가에 대한 옵션이다 ( 그냥 접속했을때 허용할것인가…)

#

# Uncomment this to allow local users to log in.

local_enable=YES : 로컬 사용자 즉 리눅스 사용자를 사용할것인가

#

# Uncomment this to enable any form of FTP write command.

write_enable=YES : 쓰기 허용할 것인가?

#

# 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 : 파일의 실행 권한을 제거 하기 위한 umask 값을 지정

#

# 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 : 익명의 사용자에게 업로드 권한 부여 여부

#

# Uncomment this if you want the anonymous FTP user to be able to create

# new directories.

#anon_mkdir_write_enable=YES : 익명의 사용자에게 디렉토리 생성권한 부여 여부

#

# Activate directory messages – messages given to remote users when they

# go into a certain directory.

dirmessage_enable=YES

#

# The target log file can be vsftpd_log_file or xferlog_file.

# This depends on setting xferlog_std_format parameter

xferlog_enable=YES : 파일 전송 로그의 잔류 여부

#

# 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

#

# The name of log file when xferlog_enable=YES and xferlog_std_format=YES

# WARNING – changing this filename affects /etc/logrotate.d/vsftpd.log

#xferlog_file=/var/log/xferlog

#

# Switches between logging into vsftpd_log_file and xferlog_file files.

# NO writes to vsftpd_log_file, YES to xferlog_file

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().

chroot_local_user=NO : 사실 이부분이 집중적으로 정리를 하고 싶었던 부분이다. 

chroot_list_enable=YES : 이부분은 하단에서 정리!!!!!

# (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. To listen on IPv4 and IPv6

# sockets, 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=YES

tcp_wrappers=YES

==============================================================

1. chroot_local_user=NO

이것은 사용자가 자신의 디렉토리를 최상위 디렉토리로 인식시킬것인지에 대한 내용이다

내 생각에는 결국 자신의 디렉토리만 접근 시킬것인지를 묻는것이다.

YES 는 사용자 디렉토리만 접근하는것이고

NO 를 하면 상위 디렉토리 뿐만 아니라 접근 권한이 있는 디렉토리는 다 접근이 가능하다


2. chroot_list_enable=YES

ㄱ) chroot_local_user=NO 로 했을경우에는 위의 설명처럼 상위로 접근이 가능하다 

그럴때 이 옵션을 YES로 했을 경우 3의 chroot_list_file=

주석을 풀어주어야 하며 아래의 3의 경로 처럼  /etc/vsftpd/chroot_list에 있는

사용자들은 접근하지 못한다.

ㄴ) 반대로 chroot_local_user=YES로 했을경우에는 1번의 설명처럼 사용자들은 자기의 폴더만 

접근이 가능하다 

이때 기본적으로 2번 항목은 주석이 되어 있어야 전체 사용자가 적용을 받고

풀려있을 경우에는 ㄱ)과 반대로 3의 파일에 들어있는 사용자만 상위로 접근이 가능하다


# (default follows)

3. chroot_list_file=/etc/vsftpd/chroot_list


+++++++++++++++++++++++++++++++++++++++++ 


항상 이옵션을 할때면 헷갈렸고 검색을 해서 한참을 읽어야 이해가 되곤했다


틀림없이 이 글을 읽고있는 사람이라면 공감할것이라 생각된다…(나만 그런가….ㅋㅋ)


그래서 난 직접 경우를 테스트해보고 올린다.


어리석게도 ㅋㅋㅋ