部署telnet，防止ssh啟動失敗
1、關閉防火牆或者開放23端口
2、安裝啟動服務，並開啟root訪問
yum install -y telnet-server.x86_64 yum install -y telnet.x86_64 yum install -y xinetd.x86_64 systemctl enable xinetd.service systemctl enable telnet.socket systemctl start telnet.socket systemctl start xinetd mv /etc/securetty /etc/securetty.bak
部署open-ssh
#備份與卸載
mkdir /etc/ssh_oldbak/ mv /etc/ssh/* /etc/ssh_oldbak/ rpm -e `rpm -qa |grep openssh`
#安裝依賴 yum install -y gcc gcc-c++ glibc make autoconf openssl openssl-devel pcre-devel pam-devel yum install -y pam* zlib*
#編譯安裝 cd openssh-7.9p1/ ./configure -prefix=/usr -sysconfdir=/etc/ssh -with-md5-passwords -with-pam -with-ssl-dir=/usr/include/openssl -without-hardening make && make install
#將原來備份的配置文件拷貝回來
mv /etc/ssh/sshd_config /etc/ssh/sshd_config.bak cp /etc/ssh_oldbak/sshd_config /etc/ssh/sshd_config
#從程序包拷貝可執行文件
cp contrib/redhat/sshd.init /etc/init.d/sshd chmod +x /etc/init.d/sshd
#添加到自啟動 chkconfig --add sshd chkconfig sshd on
修改配置文件
vi /usr/lib/systemd/system/sshd.service[Unit] Description=OpenSSH server daemon Documentation=man:sshd(8) man:sshd_config(5) # After=network.target sshd-keygen.service # Wants=sshd-keygen.service After=network.target [Service] # Type=notify # EnvironmentFile=/etc/sysconfig/sshd # ExecStart=/usr/sbin/sshd -D $OPTIONS ExecStart=/usr/sbin/sshd # ExecReload=/bin/kill -HUP $MAINPID # KillMode=process # Restart=on-failure # RestartSec=42s [Install] WantedBy=multi-user.target
修改配置文件
vi /etc/ssh/sshd_config設置如下：
PermitRootLogin yes
PasswordAuthentication yes
注銷sshd的配置文件（sshd_config）的如下配置:
#GSSAPIAuthentication yes
#GSSAPICleanupCredentials yes
#UsePAM yes
重啟服務
systemctl restart sshd
systemctl enable sshd
----------------------------openssl 升級-----------------------------------------
1、如上第一步，先部署telnet
2、升級OpenSSl
1、查看原版本
openssl version -a
2、解壓安裝
tar zxvf openssl-1.1.1c.tar.gzcd openssl-1.0.1g
cd openssl-1.1.1c
./config --prefix=/usr/local/openssl #檢查環境
./config -t
make #編譯
make install #編譯安裝
cd /usr/local
ldd /usr/local/openssl/bin/openssl #檢查函數庫
echo "/usr/local/openssl/lib" >> /etc/ld.so.conf #添加所缺函數庫
ldconfig -v #更新函數庫
openssl/bin/openssl version #查看新安裝的版本
which openssl #查看舊版本openssl命令在哪里
mv /bin/openssl /usr/bin/openssl.old #將舊版本openssl移除
ln -s /usr/local/openssl/bin/openssl /usr/bin/openssl #新版本制作軟鏈接
openssl version 最后查看版本，更新完畢