CentOS 7 OpenSSH 升级教程：从基础到8.4p1部署

OpenSSH升级
  上传软件包
1.安装telnet服务
  yum -y install telnet-server* telnet  xinetd    
  ###vi /etc/xinetd.d/telnet （将其中disable字段的yes改为no以启用telnet服务  centos7 没有这个）
  mv /etc/securetty /etc/securetty.old    #允许root用户通过telnet登录 
  systemctl start telnet.socket && systemctl enable telnet.socket  #启动telnet服务 
  systemctl enable xinetd.service  #使telnet服务开机启动，避免升级过程中服务器意外重启后无法远程登录
2.备份路径    
  #cp /etc/pam.d/sshd /tmp
  mkdir /etc/sshbak
  cp -rf  /etc/ssh/* /etc/sshbak                 #备份原来的ssh配置文件
  cp -rf  /etc/init.d/sshd /etc/init.d/sshdbak   #备份原来的ssh启用脚本
  卸载openssh: for i in $(rpm -qa |grep openssh);do rpm -e $i --nodeps;done
3.安装基础依赖包
  yum install  -y gcc gcc-c++ glibc make autoconf openssl openssl-devel pcre-devel pam* zlib*
4.解压openssh-8.1p1.tar.gz
  #tar zvxf openssh-8.4p1.tar.gz 
  进入解压目录
  cd openssh-8.4p1
  配置openssh
  ./configure --prefix=/usr --sysconfdir=/etc/ssh
  rm -rf /etc/ssh
  编译安装
  make && make install
5.复制启动脚本到/etc/init.d
  cp -rp  contrib/redhat/sshd.init /etc/init.d/sshd
  cp -rp  contrib/redhat/sshd.pam /etc/pam.d/sshd.pam
  chmod +x /etc/init.d/sshd
  mv  /usr/lib/systemd/system/sshd.service  /tmp