今天遇到的一些關於vsftp的坑！！！

原由：最近在搗鼓Linux，配置vsftp的時候發現權限問題很坑，頭疼了一天，發現了一點小問題

 

常見的身份驗證方式：

1.使用系統的用戶認證

例如vsftp這種軟件，若是想創建一個能夠登陸FTP的用戶咱們建議不要給予該用戶能夠登陸系統shell的權限

useradd -s /sbin/nologin xxx

使用段代碼咱們能夠指定該用戶沒有登陸系統shell的權限可是他能夠做爲一個用戶登陸FTP，默認狀況下該用戶登陸到FTP服務器的目錄實在本身的家目錄下，那咱們若是想給用戶指定他登陸到FTP服務所在的固定目錄，那咱們能夠在新建用戶的時候加入-d參數指定用戶的家目錄就能夠實現

2.使用軟件自己的身份驗證機制

例如samba這樣的軟件，他雖然也須要在Linux系統創建用戶可是真正的身份驗證服務是由samba自己提供的，咱們只須要在系統上創建帳戶而後使用smbpasswd -a給新建的用戶建立密碼

3.使用有公信力的第三方機構

例如Kerberos這樣的認證服務器，也能夠提供身份認證

 

接下來講我遇到的坑

放上小弟的配置文件

# 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
allow_writeable_chroot=YES
# 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=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.
# 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=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/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. The vsftpd.conf(5) man page explains
# the behaviour when these options are disabled.
# 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
local_root=/var/ftp
#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=NO
#
# 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=YES

 

 

關於文件夾的屬主和屬組

 

 

 本人實測的兩個Linux系統，Ubuntu16.04和redhat7.6

在Ubuntu裏面安裝vsftp成功以後默認建立的用戶和組都是ftp

而Redhat默認建立的用戶和組是vsftp

 

 

 Ubuntu

 

 

 Redhat

 

本人一直以爲不能由於方便就把selinux關了，因此通過測試，只有打開ftpd_full_access的bool值設置爲on的時候能夠實現正常的ftp功能，若是要容許任意用戶上傳文件的話須要打開ftpd_anon_write,若是要使用FTP的被動模式須要打開ftpd_use_passive_mode

打開的語句能夠參照

setsebool -P ftpd_full_access 1

 

 

 同理咱們也要在防火牆上放行FTP這個服務

 

 

 命令參考

firewall-cmd --add-service=ftp
firewall-cmd --add-service=ftp --permanent

firewall-cmd --reload

如上第一條是臨時放行FTP服務，重啓以後失效，第二條是寫進底層，重啓以後任然生效可是必須重啓才能夠生效，因此一二條搭配使用，或者執行二三條也能夠達到一樣的效果

 

而後就是關於目錄的文件夾權限設置，在Redhat上推薦把/var/ftp目錄的權限設置爲755，屬主和屬組設置成vsftp

本地用戶上傳的文件權限通常爲644，文件夾通常爲755，這是由於配置文件中默認的權限掩碼umask=022的做用

 

暫時就這些，大佬們多多指正