self-service-password，即SSP，可以达到openldap中用户自助修改密码的目的
CentOS Linux release 7.7.1908
OpenLDAP: slapd 2.4.44
yum 安装SSP
方法一，适用于国服：
下载【noarch/self-service-password-1.2-1.el7.noarch.rpm】
cat > /etc/yum.repos.d/ltb-project.repo << EOF
[ltb-project-noarch]
name=LTB project packages (noarch)
baseurl=https://ltb-project.org/rpm/7/noarch
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-LTB-project
EOFyum install -y noarch/self-service-password-1.2-1.el7.noarch.rpm方法二，适用于外服：
yum install -y https://ltb-project.org/rpm/7/noarch/self-service-password-1.2-1.el7.noarch.rpm