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vsftpd实现上传和下载的权限分离

作者:海无涯  发布日期:2013-10-24 10:05:50

要求:ftp上架设两下目录:

upload:只能上传文件,并且上传不能到下载,而且存在相同的文件时上传也失败

download:只能下载文件.

 

平台:RHEL6.4 ,关闭selinux。

下面是vsftpd.conf的配置:


# 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 
# 
# 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_world_readable_only=NO 
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 
local_root=/var/ftp
# 
# 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 
# 
# 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=user1    //实现在上传后不能下载的关键 
# 
# 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=YES 
#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. 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

在/var/ftp创建新两件夹:

[root@paylmrh6 ftp]# pwd

/var/ftp

[root@paylmrh6 ftp]# ll

total 8

drwxr-xr-x. 2 root root 4096 Oct 23 11:49 download

drwxrwxrwx. 2 root root 4096 Oct 23 14:00 upload

 

 

重启vsftpd就可完成。

注:user1用户是存在的

上传后不能下载和删除的原理:(upload目录中上传)

local_umask=022 //匿名用户上传后的文件权限为700

chown_uploads=YES //开上传后更改所有者的功能

chown_username=user1 //上传后文件所有者变为了user1,而匿名用户对文件的权限为0,无任何权限。所以不能下载,更改等。

上传后的文件权限为:

-rw-------. 1 user1 ftp 2355 Oct 23 13:52 linux4.txt

 

 

只能下载:(download目录)

很明显,download目录的权限为755,匿名属于others,只能读取文件的内容。而且是download目录中是文件的other权限为r才能下载.


Tag标签: vsftpd  
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