[TOC] （注：ssh7.4升级ssh8.1p，配置文件可以不用替换，值得注意的是:ssh7.4以下版本PermitRootLogin默认yes， ssh8.1p版本PermitRootLogin默认是prohibit-password，即禁止root用密码登录） #### 开启telnet `yum install xinetd telnet-server -y` ``` systemctl enable xinetd systemctl enable telnet.socket ``` ``` systemctl start telnet.socket systemctl start xinetd ``` `netstat -lntp|grep 23` ``` vi /etc/pam.d/remote 注释第一行 #auto required pam_securetty.so ``` `telnet ip` telnet远程登录成功 #### 编译openssh-8.1p1 1.tar zxvf openssh-8.1p1.tar.gz 2.chown -R root.root /tmp/openssh-8.1p1 3.chattr -i /etc/ssh/sshd_config 4.rm -rf /etc/ssh/* 5.cd /tmp/openssh-8.1p1 6.yum install -y openssl-devel pam-devel zlib-devel 7.(./configure --prefix=/usr/ --sysconfdir=/etc/ssh --with-zlib --with-md5-passwords --with-pam && make && make install) 8.sed -i "s/#PermitRootLogin prohibit-password/PermitRootLogin yes/" /etc/ssh/sshd_config 9.sed -i "s/#UseDNS no/UseDNS no/" /etc/ssh/sshd_config 9.1 sed -i "s/#UsePAM no/UsePAM yes/" /etc/ssh/sshd_config 10.cp -a /tmp/openssh-8.1p1/contrib/redhat/sshd.init /etc/init.d/sshd 11.cp -a /tmp/openssh-8.1p1/contrib/redhat/sshd.pam /etc/pam.d/sshd.pam（这步不需要） 12.chmod +x /etc/init.d/sshd 13.chkconfig --add sshd 14.systemctl enable sshd 15.mv /usr/lib/systemd/system/sshd.service /root/ 16.chkconfig sshd on 17./etc/init.d/sshd restart 18.netstat -lntp|grep sshd|grep 22 19.setenforce 0 20.sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config