CentOS/7/Yum

/etc/yum.repos.d/centos7.repo

ls -l /etc/pki/rpm-gpg
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
rpm -qa gpg-pubkey* | grep -i f4a80eb5

curl --fail -s -o /tmp/RPM-GPG-KEY-CentOS-7 \
   https://vault.centos.org/RPM-GPG-KEY-CentOS-7

rpm --import /tmp/RPM-GPG-KEY-CentOS-7

[base]
name=CentOS-$releasever - Base
baseurl=http://vault.centos.org/7.9.2009/os/$basearch/
gpgcheck=1
enabled=1

[updates]
name=CentOS-$releasever - Updates
baseurl=http://vault.centos.org/7.9.2009/updates/$basearch/
gpgcheck=1
enabled=1

[extras]
name=CentOS-$releasever - Extras
baseurl=http://vault.centos.org/7.9.2009/extras/$basearch/
gpgcheck=1
enabled=1