After deploying https, the following prompt appears when accessing the domain name:

Your connection is not secure

The security configuration used by this website is outdated, which may cause your information (such as passwords, messages, or credit card numbers) to be leaked during transmission to this site.

NET::ERR_SSL_OBSOLETE_VERSION

The reason is that the server's openssl version is too old, and newer browsers will prompt that it is insecure.

Run openssl version -a to view the openssl version.

Openssl 1.0.0h supports SSLv2, SSLv3 and TLSv1.0

Openssl 1.0.1 added support for TLSv1.1 and TLSv1.2
Openssl 1.1.1 begins to support TLS1.3

For upgrading the old version (openssl1.0.2|openssh7.5), see https://www.west.cn/faq/list.asp?unid=1754

Upgrade openssl-1.1.1

cd /usr/local/src
wget -c https://www.openssl.org/source/openssl-1.1.1g.tar.gz
tar zxvf openssl-1.1.1g.tar.gz
cd openssl-1.1.1g
./config --prefix=/usr --shared
make -j4 && make install
openssl version -a

Upgrade openssh8.3p1

cd /usr/local/src
mv /etc/ssh /etc/ssh.bak
yum install -y pam-devel
wget -c https://openbsd.hk/pub/OpenBSD/OpenSSH/portable/openssh-8.3p1.tar.gz
tar zxvf openssh-8.3p1.tar.gz
cd openssh-8.3p1
./configure --sbindir=/usr/sbin/  --bindir=/usr/bin/ --sysconfdir=/etc/ssh  --with-ssl-engine --with-pam
make -j4 && make install
echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config
echo 'Port 22000' >> /etc/ssh/sshd_config
cp -a contrib/redhat/sshd.init /etc/init.d/sshd
cp -a contrib/redhat/sshd.pam /etc/pam.d/sshd.pam
chmod +x /etc/init.d/sshd
chkconfig --add sshd
chkconfig sshd on
service sshd restart

centos7: mv /usr/lib/systemd/system/sshd.service /tmp

              systemctl enable sshd

centos7: systemctl restart sshd.service

Note: If nginx was compiled with a custom openssl path, you also need to recompile nginx.