1. 安装telnet
yum -y install xinetd telnet-server
配置/etc/xinetd.d/telnet
cat > /etc/xinetd.d/telnet <<EOF
service telnet
{
disable = yes
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
}
EOF
配置telnet登录的终端类型
cat >> /etc/securetty <<EOF
pts/0
pts/1
pts/2
pts/3
EOF
启动telnet
systemctl enable xinetd –now
systemctl enable telnet.socket –now
2. 下载安装包
wget http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.8p1.tar.gz
wget https://www.openssl.org/source/openssl-1.1.1j.tar.gz –no-check-certificate
wget http://www.zlib.net/zlib-1.2.12.tar.gz
3. 安装zlib
tar -zxvf zlib-1.2.12.tar.gz
cd zlib-1.2.12
./configure –prefix=/usr/local/zlib
make && make install
4. 安装openssl
tar -zxvf openssl-1.1.1j.tar.gz
cd openssl-1.1.1j
./config –prefix=/usr/local/ssl -d shared
make && make install
echo ‘/usr/local/ssl/lib’ >> /etc/ld.so.conf
ldconfig -v
openssl version -a
5. 安装openssh
tar -zxvf openssh-8.8p1.tar.gz
cd openssh-8.8p1
./configure –prefix=/usr/local/openssh –with-zlib=/usr/local/zlib –with-ssl-dir=/usr/local/ssl
make && make install
#sshd_config文件修改
echo ‘PermitRootLogin yes’ >>/usr/local/openssh/etc/sshd_config
echo ‘PubkeyAuthentication yes’ >>/usr/local/openssh/etc/sshd_config
echo ‘PasswordAuthentication yes’ >>/usr/local/openssh/etc/sshd_config
# 备份原有文件，并将新的配置复制到指定目录
mv /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
cp /usr/local/openssh/etc/sshd_config /etc/ssh/sshd_config
mv /usr/sbin/sshd /usr/sbin/sshd.bak
cp /usr/local/openssh/sbin/sshd /usr/sbin/sshd
mv /usr/bin/ssh /usr/bin/ssh.bak
cp /usr/local/openssh/bin/ssh /usr/bin/ssh
mv /usr/bin/ssh-keygen /usr/bin/ssh-keygen.bak
cp /usr/local/openssh/bin/ssh-keygen /usr/bin/ssh-keygen
mv /etc/ssh/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub.bak
cp /usr/local/openssh/etc/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub
# 修改systemd参数（去掉Type或改为Type=simple）
vim /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
[Service]
#Type=notify
Type=simple
EnvironmentFile=/etc/sysconfig/sshd
ExecStart=/usr/sbin/sshd -D $OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
RestartSec=42s
[Install]
WantedBy=multi-user.target
重启sshd服务
systemctl daemon-reload
systemctl restart sshd
systemctl status sshd
# 验证是否升级成功
ssh -V
