1、依赖软件包：
yum install wgetgcc-yyum install -y zlib-devel openssl-devel yum install pam-devel libselinux-devel zlib-devel openssl-devel -y
2、下载安装包OpenSSH8.4上传至服务器或wget直接下载
wget https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.4p1.tar.gz
3、删除低版本OpenSSH的的rpm包
rpm -e--nodeps`rpm -qa | grep openssh`
4、安装openssh
（1）.解压
tar -zxvf openssh-8.4p1.tar.gz cd openssh-8.4p1
（2）.配置
./configure --prefix=/usr --sysconfdir=/etc/ssh --with-md5-passwords--with-pam--with-zlib--with-tcp-wrappers--with-ssl-dir=/usr/local/ssl --without-hardening
（3）.编译安装
makemake install
（4）赋权
chmod600 /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_ecdsa_key /etc/ssh/ssh_host_ed25519_key
（5）复制配置文件并设置允许root用户远程登录
cp-a contrib/redhat/sshd.init /etc/init.d/sshd cp-a contrib/redhat/sshd.pam /etc/pam.d/sshd.pam chmod u+x /etc/init.d/sshd vim /etc/ssh/sshd_config
1.修改#PermitRootLogin prohibit-password项，去掉注释#并把prohibit-password改为yes，修改后即为PermitRootLogin yes
2.去掉注释#PasswordAuthentication yes变为PasswordAuthentication yes
（6）添加添加自启服务ssh到开机启动项
chkconfig --add sshd chkconfig sshd on
（7）重启服务
systemctl restart sshd
（8）查看下安装结果：
ssh-V
