구글 OTP 각서버 동일하게 적용

sudo yum -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
sudo yum -y install google-authenticator

sudo vi /etc/pam.d/sshd
	auth required pam_google_authenticator.so nullok
sudo vi /etc/ssh/sshd_config
	ChallengeResponseAuthentication yes
	PasswordAuthentication no

su [사용자]
cd /home/[사용자]
google-authenticator
vi .google_authenticator
	IFOCJJGLRDBTL5UJ3CYVGVEQYP
	" RESETTING_TIME_SKEW 54081899-361 54087293-519 54167743-10
	" RATE_LIMIT 3 30 1626072612
	" WINDOW_SIZE 17
	" DISALLOW_REUSE 54202420
	" TOTP_AUTH
	31115755
	95534382
	85136180
	14377575
	97203041

sudo systemctl restart sshd.service