如何实现SSH通过扫二维码登录Linux服务器

#安装epel
yum install -y epel-release.noarch &> /dev/null
yum makecache  &> /dev/null
#安装google authenticator
yum install -y google-authenticator.x86_64 &> /dev/null

echo -e "\033[31mDo you want me to update your "/root/.google_authenticator" file? (y/n) y"
echo -e "\033[31m你希望我更新你的“/root/.google_authenticator”文件吗(y/n)？\033[0m"
echo -e "\033[31mDo you want to disallow multiple uses of the same authentication"
echo -e "\033[31mtoken? This restricts you to one login about every 30s, but it increases"
echo -e "\033[31myour chances to notice or even prevent man-in-the-middle attacks (y/n) y"
echo -e "\033[31m你希望禁止多次使用同一个验证令牌吗?这限制你每次登录的时间大约是30秒， 但是这加大了发现甚至防止中间人攻ji的可能性(y/n)?\033[0m"
echo -e "\033[31mBy default, a new token is generated every 30 seconds by the mobile app."
echo -e "\033[31mIn order to compensate for possible time-skew between the client and the server,"
echo -e "\033[31mwe allow an extra token before and after the current time. This allows for a"
echo -e "\033[31mtime skew of up to 30 seconds between authentication server and client. If you"
echo -e "\033[31mexperience problems with poor time synchronization, you can increase the window"
echo -e "\033[31mfrom its default size of 3 permitted codes (one previous code, the current"
echo -e "\033[31mcode, the next code) to 17 permitted codes (the 8 previous codes, the current"
echo -e "\033[31mcode, and the 8 next codes). This will permit for a time skew of up to 4 minutes"
echo -e "\033[31mbetween client and server."
echo -e "\033[31mDo you want to do so? (y/n) y"
echo -e "\033[31m默认情况下，令牌保持30秒有效;为了补偿客户机与服务器之间可能存在的时滞，\033[0m"
echo -e "\033[31m我们允许在当前时间前后有一个额外令牌。如果你在时间同步方面遇到了问题， 可以增加窗口从默认的3个可通过验证码增加到17个可通过验证码，\033[0m"
echo -e "\033[31m这将允许客户机与服务器之间的时差增加到4分钟。你希望这么做吗(y/n)?\033[0m"
echo -e "\033[31mIf the computer that you are logging into isn't hardened against brute-force"
echo -e "\033[31mlogin attempts, you can enable rate-limiting for the authentication module."
echo -e "\033[31mBy default, this limits attackers to no more than 3 login attempts every 30s."
echo -e "\033[31mDo you want to enable rate-limiting? (y/n) y"
echo -e "\033[31m如果你登录的那台计算机没有经过固化，以防范运用蛮力的登录企图，可以对验证模块\033[0m"
echo -e "\033[31m启用尝试次数限制。默认情况下，这限制攻ji者每30秒试图登录的次数只有3次。 你希望启用尝试次数限制吗(y/n)?\033[0m"
echo -e "\033[32m 在App Store 搜索Google Authenticator 进行App安装 \033[0m"

expect << EOF
spawn google-authenticator
expect {
    "y/n" {send "y\n";exp_continue}
    "y/n" {send "y\n"}
    "y/n" {send "y\n"}
    "y/n" {send "y\n"}
}
EOF

#/etc/pam.d/sshd文件，修改或添加下行保存
#auth required pam_google_authenticator.so
sed -i '1a\auth       required     pam_google_authenticator.so' /etc/pam.d/sshd
#编辑/etc/ssh/sshd_config找到下行
#ChallengeResponseAuthentication no
#更改为
#ChallengeResponseAuthentication yes
sed -i 's/ChallengeResponseAuthentication no/ChallengeResponseAuthentication yes/' /etc/ssh/sshd_config

#重启SSH服务
systemctl restart sshd