Redhat7安装VNC服务端和FTP服务端实现远程控制

心已赠人 2022-06-08 02:06 446阅读 0赞

VNC作为一种非常成熟使用方便的远程桌面系统，使用非常广泛

首先要注意在安装Redhat的时候要安装图形化界面GNU——KDE和FTP服务器

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安装VNC的过程非常简单

1、首先将光盘放入光驱，观察光驱的挂载点，然后将本地的yum源指向光驱。

假设现在的光驱挂载点为 /run/media/alex/RHEL-7.2 Server.x86\_64/，太长了所以我使用软连接把这个目录连接到了/opt/rhel下面（ln -s   /run/media/alex/RHEL-7.2\\ Server.x86\_64/  /opt/rhel），那么现在需要在/etc/yum.repos.d/目录下建立一个新文件，rhel-source.repo,内容如下。

[base]
    name=Red Hat Enterprise Linux $releasever - $basearch - Source
    baseurl=file:///opt/rhel
    enabled=1
    gpgcheck=1
    gpgkey=file:///opt/rhel/RPM-GPG-KEY-redhat-release

这个文件就指明了一个名为“base”的yum源，它指向光盘（并非光盘里面的Packages文件夹），使用baseurl=file...这种方式可以指向本地的文件。同时这里也可以支持http或者ftp格式，可以在局域网内搭建yum源服务器。

同时gpg证书也指向光盘中的gpg证书。注意如果光盘不是自动挂载的，或者你只有一个.iso文件，那么也可以把这个.iso文件上传到Redhat服务器上，然后使用mount -o loop xxx.iso的方式进行挂载。

配置完成之后刷新一下yum

yum clean all
    yum update

如果配置的路径正确，那么此处会更新yum源，如果路径填写错误或者挂载出现问题，跑不了几行就会报ERROR

有了光盘的yum源之后再安装就轻而易举了，首先检查一下VNC是否被安装过了

rpm -qa vnc*

如果没有输出说明没有被安装过，那么我们现在就可以安装了

yum -y install vnc*

如果你之前yum配置的没有问题，那么此时安装应该是非常顺畅

依赖关系解决
    
    ====================================================================================================================================================
     Package                                  架构                            版本                                  源                             大小
    ====================================================================================================================================================
    正在安装:
     tigervnc                                 x86_64                          1.3.1-3.el7                           base                          210 k
     tigervnc-server                          x86_64                          1.3.1-3.el7                           base                          202 k
    为依赖而安装:
     fltk                                     x86_64                          1.3.0-13.el7                          base                          654 k
     tigervnc-icons                           noarch                          1.3.1-3.el7                           base                           35 k
    
    事务概要
    ====================================================================================================================================================
    安装  2 软件包 (+2 依赖软件包)
    
    总下载量：1.1 M
    安装大小：2.6 M

安装完毕之后，配置一个密码就可以用了。下面这个密码就是客户端连接所用的密码，和本地user的密码可以不同

vncpasswd

下面就可以启动VNC服务器了，注意当前命令行是哪个用户那么远程登录之后就是哪个用户，权限也是一致的

vncserver

每次执行都会新建一个vnc服务端，第一个使用5901端口，第二个5902以此类推。

windows做客户端的话，只需要安装一个VNCViewer，填入IP和端口，写上上面录入的密码就可以登录图形化界面

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安装FTP不复杂，但是装FTP主要就是为了在SSH之外查看和修改服务器上的文件的，一般都会做成匿名访问，拥有很高的权限，可以查看，修改，删除任意一个服务器上的文件。主要任务就是修改配置文件/etc/vsftpd/vsftpd.conf,修改后如下

###     ###

### 普通用户、root用户访问配置文件（推荐）： ###

如果需要使用root用户密码登录，或者其他用户根据自己的权限登录，可以做如下配置

# 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=No
    #
    # 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_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
    #
    # 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=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=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
    userlist_deny=NO
    tcp_wrappers=YES
    local_root=/
    chroot_local_user=YES

其中比较重要的有下面几项

1、让user\_list文件生效，并只允许这个列表中的用户登录，并禁止匿名用户登录

userlist\_enable=YES

userlist\_deny=NO

anonymous\_enable=NO

注意同时要将/etc/vsftpd/ftpuser文件里面的root删掉，因为ftpuser这个文件是个黑名单

2、设置用户登录后的默认目录，如果不修改默认是用户的HOME，但是这样在使用curl的时候容易出现550 Failed to change directory.的报错，如下

curl ftp://192.166.1.21/home/ -u admin:admin -v
    * About to connect() to 192.168.1.2 port 21 (#0)
    *   Trying 192.168.1.2...
    * Connected to 192.166.1.21 (192.166.1.21) port 21 (#0)
    < 220 (vsFTPd 2.2.2)
    > USER alex
    < 331 Please specify the password.
    > PASS 123456
    < 230 Login successful.
    > PWD
    < 257 "/home/alex"
    * Entry path is '/home/alex'
    > CWD home
    * ftp_perform ends with SECONDARY: 0
    < 550 Failed to change directory.
    * Server denied you to change to the given directory
    * Connection #0 to host 192.166.1.21 left intact
    curl: (9) Server denied you to change to the given directory

因为默认目录为home的话，那我如果在curl home就相当于/home/alex/home目录，是默认根目录的相对目录，所以我们为了方便需要把默认目录改成根目录/,方法如下

local\_root=/

chroot\_local\_user=YES

3、使用vsftpd直接监控21端口，而不是通过xinetd转发

LISTEN=YES

同时删除掉/etc/xinetd.d/下面和ftp有关的配置，但是如果你习惯于使用xinetd，那么就将LISTEN=YES注释掉，防止端口冲突，同时重启xinetd。

4、还有就是selinux导致的权限问题，上文说可以通过setenforce 0 来关闭selinux，但是这样可能会影响其他安全，但是如果不关闭selinux，就会报530 Login incorrect

curl ftp://192.168.1.21/home/admin/ -u admin:admin -s -v
    * About to connect() to 192.168.1.2 port 21 (#0)
    *   Trying 192.168.1.2...
    * Connected to 192.168.1.2 (192.168.1.2) port 21 (#0)
    < 220 (vsFTPd 2.0.5)
    > USER alex
    < 331 Please specify the password.
    > PASS alex
    < 530 Login incorrect.
    * Access denied: 530
    * Closing connection 0

所以我们要有选择的关闭selinux，首先通过命令查看selinux里对ftp的限制

[root@localhost ~]# getsebool -a | grep ftpd
    allow_ftpd_anon_write --> off
    allow_ftpd_full_access --> off
    allow_ftpd_use_cifs --> off
    allow_ftpd_use_nfs --> off
    ftpd_connect_db --> off
    ftpd_use_passive_mode --> off

我们发现多数权限都是off状态，这里要开启一项就可以不用关闭selinux了，如下

[root@localhost ~]# setsebool -P allow_ftpd_full_access 1
    [root@localhost ~]# getsebool -a | grep ftpd
    allow_ftpd_anon_write --> off
    allow_ftpd_full_access --> on
    allow_ftpd_use_cifs --> off
    allow_ftpd_use_nfs --> off
    ftpd_connect_db --> off

### 匿名用户上传下载配置文件（风险高）： ###

有些时候我们并不想搞得特别复杂，越简单越直接越好，最好匿名用户登录以后可以有像root一样的权限，随便下载删除文件，经常用在测试系统上。

# 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
    
    
    local_root=/
    chroot_local_user=YES
    anon_root=/
    
    
    #
    # 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
    anon_world_readable_only=NO
    anon_umask=022
    anon_other_write_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.
    # 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
    #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. 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=YES
    tcp_wrappers=YES

启动vsftpd的命令是：

service vsftpd restart

既然给了这么大的权限，所以干脆把selinux和防火墙也全都关掉。然后就可以自由的操作FTP了。

方法1：修改/etc/selinux/config文件中的SELINUX="" 为 disabled ，然后重启。

方法2：用命令setenforce 0，无需重启。（setenforce的格式：setenforce \[ Enforcing | Permissive | 1 | 0 \]）

如果你不想任何一个人通过浏览器就可以匿名访问你的FTP主机，那么可以加上下面两行，只允许除root以外的限定用户通过账号密码登录

userlist_deny=NO
    userlist_file=/etc/vsftpd/user_list

然后你可以修改/etc/vsftpd/user\_list来限定访问的用户，注意考虑/etc/vsftpd/ftpusers这个文件里面记录了黑名单。

最后要注意要对相应的要通过FTP传输的文件赋予相关访问权限。

比如如下三个文件：

-rw-------.   1 root root   126 9\u6708  12 18:39 ftpusers
    -rw-------.   1 root root   366 9\u6708  12 18:41 user_list
    -rw-------.   1 root root  5206 9\u6708  12 19:08 vsftpd.conf
    -rwxr--rw-.   1 root root   338 8\u6708   3 2015 vsftpd_conf_migrate.sh

那么对于FTP用户来说，只能读取 vsftpd\_conf\_migrate.sh这一个文件，其余三个文件均无法读写。原因是

\-rw------- 前三个是文件所有者的权限，中间三个是与文件所有者同组的权限，最后三位是其他用户的权限，FTP属于其他用户（如果你使用Linux的用户登录，那么要注意是否同组的问题），所以最后三位需要为rw-,一般执行如下命令

chmod o+r+w -R /xxx/xxx/*

意思就是对于其他用户（o）对某个目录下所有文件和递归后的文件，全部添加r和w权限，当然这样也是比较危险的。

另外RedHat安装完毕之后会自动打开防火墙，封锁除22以外的所有端口，所以还需要把防火墙暂时关闭

systemctl stop firewalld

永久关闭

systemctl disable firewalld

开启防火墙

systemctl enable firewalld

[Center]: /images/20220608/a09d88bbef144f368ef09f09ca5ed683.png
[Center 1]: /images/20220608/9593bf3b13cf459382c02dc0d2dda576.png
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