VSFTPD： very secure ftp
非常安全的FTP服务器软件，因为FTP是非常古老的软件，而且还是基于明文传输的，没有任何加密技术，所以就产生了vsftpd.
基于tcp链接的，监听在21端口上。
程序配置文件：
/etc/vsftpd/vsftpd.conf
[root@localhost ftp]# service vsftpd start Starting vsftpd for vsftpd: [ OK ] [root@localhost ftp]# netstat -ntlp Active Internet connections (only servers) tcp 0 0 0.0.0.0:21 0.0.0.0:* LISTEN 42268/vsftpd
ftp的用户有三种：
1、匿名用户：映射至某个固定的系统用户： ftp vsftp
2、本地用户：也就是系统用户，root，daemon
3、虚拟用户：基于某种认证方式登录的匿名用户，认证方式有：nsswtich(名称服务转换)、pam(插入式认证模块)
实验：通过pam_mysql来连接mysql，获取mysql上的用户账号密码，登录ftp
1、安装pam_mysql驱动
[root@localhost src]# yum -y install pam-devel mysql-devel [root@localhost src]# tar -xf pam_mysql-0.7RC1.tar.gz [root@localhost src]# cd pam_mysql-0.7RC1 [root@localhost pam_mysql-0.7RC1]# ./configure --with-mysql=/usr --with-pam=/usr [root@localhost pam_mysql-0.7RC1]# make && make install [root@localhost pam_mysql-0.7RC1]# cd /lib/security/ [root@localhost security]# ls pam_mysql.la pam_mysql.so //生成pam连接mysql驱动
2、授权账号，创建用户表，让pam读取表里的账号密码
mysql> grant all on pam.* to ‘pamuser‘@localhost identified by "123456"; Query OK, 0 rows affected (0.03 sec) mysql> create table pamuser(id int not null primary key, name char(30) not null, password char(48) binary not null); Query OK, 0 rows affected (0.01 sec mysql> desc pamuser -> ; +----------+----------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+----------+------+-----+---------+-------+ | id | int(11) | NO | PRI | NULL | | | name | char(30) | NO | | NULL | | | password | char(48) | NO | | NULL | | +----------+----------+------+-----+---------+-------+ 3 rows in set (0.00 sec)
3、给表中插入数据，包括账号密码
mysql> insert into pamuser(id,name,password) values (1,‘tom‘,password("magedu"));
Query OK, 1 row affected (0.00 sec)
mysql> insert into pamuser(id,name,password) values (2,‘jerry‘,password("jerry"));
Query OK, 1 row affected (0.00 sec)
mysql> select * from pamuser;
+----+-------+-------------------------------------------+
| id | name | password |
+----+-------+-------------------------------------------+
| 2 | jerry | *09FB9E6E2AA0750E9D8A8D22B6AA8D86C85BF3D0 |
| 1 | tom | *6B8CCC83799A26CD19D7AD9AEEADBCD30D8A8664 |
+----+-------+-------------------------------------------+
2 rows in set (0.00 sec)4、创建映射用户
[root@localhost security]# useradd -s /nologin -d /ftproot vuser [root@localhost security]# id vuser uid=501(vuser) gid=501(vuser) groups=501(vuser)
5、编辑配置文件，指明虚拟用户访问时对应的映射用户
[root@localhost security]# vim /etc/vsftpd/vsftpd.conf guest_enable=YES guest_username=vuser //添加这两个语句
6、编写虚拟用户认证的文件
[root@localhost pam.d]# vim /etc/pam.d/vsftpd.conf auth required /lib/security/pam_mysql.so user=pamuser passwd=123456 host=localhost db=pam table=pamuser usercolumn=name passwdcolumn=password crypt=2 account required /lib/security/pam_mysql.so user=pamuser passwd=123456 host=localhost db=pam table=pamuser usercolumn=name passwdcolumn=password crypt=2
7、修改vsftpd的配置文件
[root@localhost pam.d]# vim /etc/vsftpd/vsftpd.conf pam_service_name=vsftpd.conf //把vsftpd修改为vsftpd.conf anon_upload_enable=YES //允许匿名用户上传 anon_mkdir_write_enable=YES //允许匿名用户创建文件 anon_other_write_enable=YES //允许匿名用户删除及重命名操作
8、重启vsftpd服务，验证虚拟用户能否登录ftp
[root@www ~]# ftp 172.18.250.76 Connected to 172.18.250.76 (172.18.250.76). 220 (vsFTPd 2.2.2) Name (172.18.250.76:root): tom 331 Please specify the password. Password: 230 Login successful. //ok，能登录 Remote system type is UNIX. Using binary mode to transfer files. ftp> ls 227 Entering Passive Mode (172,18,250,76,115,157). 150 Here comes the directory listing. 226 Transfer done (but failed to open directory). //这不能显示vuser的家目录，只要修改权限就行
修改vuser的家目录的权限，并修改家目录下的子目录，让匿名用户能在此目录下创建上传
[root@localhost /]# chmod go+rx ftproot/ [root@localhost ftproot]# chown vuser upload/
再次测试登录。。
ftp> ls 227 Entering Passive Mode (172,18,250,76,69,54). 150 Here comes the directory listing. drwxr-xr-x 2 501 0 4096 Apr 18 05:32 upload 226 Directory send OK.
ftp> cd upload 250 Directory successfully changed. ftp> mkdir tom.txt //能创建 257 "/upload/tom.txt" created ftp> lcd /etc //切换到Linux主机上的etc目录 Local directory now /etc ftp> put fstab //能上传 local: fstab remote: fstab 227 Entering Passive Mode (172,18,250,76,222,184). 150 Ok to send data. 226 Transfer complete. 805 bytes sent in 0.00111 secs (726.53 Kbytes/sec) [root@www ~]# ftp 172.18.250.76 Connected to 172.18.250.76 (172.18.250.76). 220 (vsFTPd 2.2.2) Name (172.18.250.76:root): jerry //jerry登录也没问题 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> ls 227 Entering Passive Mode (172,18,250,76,234,145). 150 Here comes the directory listing. drwxr-xr-x 3 501 0 4096 Apr 18 08:53 upload 226 Directory send OK.
如果希望tom能有上传功能，jerry没有，怎么办
思路： 禁止所有匿名用户上传功能，只单独开放tom能上传
[root@localhost /]# vim /etc/vsftpd/vsftpd.conf #anon_upload_enable=YES user_config_dir=/etc/vsftpd/vsftpd.conf.d/ //让服务去读取这里定义的权限 [root@localhost /]# cd /etc/vsftpd/ [root@localhost vsftpd]# mkdir vsftpd.conf.d [root@localhost vsftpd]# cd vsftpd.conf.d/ [root@localhost vsftpd.conf.d]# vim tom anon_upload_enable=YES
在测试下。。。。
[root@www ~]# ftp 172.18.250.76 Connected to 172.18.250.76 (172.18.250.76). 220 (vsFTPd 2.2.2) Name (172.18.250.76:root): tom 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> cd upload 250 Directory successfully changed. ftp> ls 227 Entering Passive Mode (172,18,250,76,233,150). 150 Here comes the directory listing. -rw------- 1 501 501 805 Apr 18 08:53 fstab drwx------ 2 501 501 4096 Apr 18 08:53 tom.txt 226 Directory send OK. ftp> lcd /etc Local directory now /etc ftp> put issue //tom上传文件 local: issue remote: issue 227 Entering Passive Mode (172,18,250,76,158,39). 150 Ok to send data. 226 Transfer complete. 47 bytes sent in 0.000309 secs (152.10 Kbytes/sec) //上传文件OK
[root@www ~]# ftp 172.18.250.76 Connected to 172.18.250.76 (172.18.250.76). 220 (vsFTPd 2.2.2) Name (172.18.250.76:root): jerry 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> cd upload 250 Directory successfully changed. ftp> lcd /etc Local directory now /etc ftp> put issue //jerry上传文件 local: issue remote: issue 227 Entering Passive Mode (172,18,250,76,24,97). 550 Permission denied. //上传文件失败，被拒绝
除了定义上传之外，还可以定义创建，删除，重命名等权限，方法和上面上传的方法一样。
原文地址：http://lanxianting.blog.51cto.com/7394580/1767113
