1、依赖软件包：
yum install wget gcc -y yum 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.gz3、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
make make install
（4）赋权
chmod 600 /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：