原由:最近在捣鼓Linux,配置vsftp的时候发现权限问题很坑,头疼了一天,发现了一点小问题linux
常见的身份验证方式:shell
1.使用系统的用户认证服务器
例如vsftp这种软件,若是想创建一个能够登陆FTP的用户咱们建议不要给予该用户能够登陆系统shell的权限session
useradd -s /sbin/nologin xxx
使用段代码咱们能够指定该用户没有登陆系统shell的权限可是他能够做为一个用户登陆FTP,默认状况下该用户登陆到FTP服务器的目录实在本身的家目录下,那咱们若是想给用户指定他登陆到FTP服务所在的固定目录,那咱们能够在新建用户的时候加入-d参数指定用户的家目录就能够实现app
2.使用软件自己的身份验证机制socket
例如samba这样的软件,他虽然也须要在Linux系统创建用户可是真正的身份验证服务是由samba自己提供的,咱们只须要在系统上创建帐户而后使用smbpasswd -a给新建的用户建立密码async
3.使用有公信力的第三方机构tcp
例如Kerberos这样的认证服务器,也能够提供身份认证ide
接下来讲我遇到的坑测试
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
关于文件夹的属主和属组
本人实测的两个Linux系统,Ubuntu16.04和redhat7.6
在Ubuntu里面安装vsftp成功以后默认建立的用户和组都是ftp
而Redhat默认建立的用户和组是vsftp
Ubuntu
Redhat
本人一直以为不能由于方便就把selinux关了,因此通过测试,只有打开ftpd_full_access的bool值设置为on的时候能够实现正常的ftp功能,若是要容许任意用户上传文件的话须要打开ftpd_anon_write,若是要使用FTP的被动模式须要打开ftpd_use_passive_mode
打开的语句能够参照
setsebool -P ftpd_full_access 1
同理咱们也要在防火墙上放行FTP这个服务
命令参考
firewall-cmd --add-service=ftp firewall-cmd --add-service=ftp --permanent firewall-cmd --reload
如上第一条是临时放行FTP服务,重启以后失效,第二条是写进底层,重启以后任然生效可是必须重启才能够生效,因此一二条搭配使用,或者执行二三条也能够达到一样的效果
而后就是关于目录的文件夹权限设置,在Redhat上推荐把/var/ftp目录的权限设置为755,属主和属组设置成vsftp
本地用户上传的文件权限通常为644,文件夹通常为755,这是由于配置文件中默认的权限掩码umask=022的做用
暂时就这些,大佬们多多指正