OAuth2.0 refresh token and access token

When we implement OAuth2, we have access token and refresh token. Why do we need both refresh token and access token? Using plain English, below are reasons in simplified version.

For security reason, OAuth2 has both refresh token and access token. access token is something close to one-time password, which is ideally secure. access token may be expired shortly. Refresh token may last for long time and even will not expire until it will be revoked. 

For performance and scalability reason, it better to verify HTTP request on the resource server instead of on central authorization server for every HTTP request.

Basically, access_token is kind of temporary password and refresh_token is pass to get temporary password from central authentication server. "temporary" password, access_token, is verified on resource server.

install phpMyAdmin on CentOS 7

    1  yum update
    2  df
    3  yum -y install mariadb-server mariadb
    4  systemctl start mariadb.service
    5  systemctl enable mariadb.service
    6  mysql_secure_installation
    7  yum -y install httpd
    8  systemctl start httpd.service
    9  systemctl enable httpd.service
   10  firewall-cmd --permanent --zone=public --add-service=http 
   11  firewall-cmd --permanent --zone=public --add-service=https
   12  firewall-cmd --reload
   13  ifconfig 
   14  yum -y install php
   15  systemctl restart httpd.service
   16  cd /var/www/html/
   17  vi info.php
   18  yum -y install php-mysql
   19  yum -y install php-gd php-ldap php-odbc php-pear php-xml php-xmlrpc php-mbstring php-snmp php-soap curl curl-devel
   20  cd /tmp/ 
   21  wget http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
   22  yum install epel-release-latest-7.noarch.rpm 
   23  yum install phpMyAdmin.noarch

install Oracle jdk on CentOS

yum groupinstall -y development

https://www.if-not-true-then-false.com/2014/install-oracle-java-8-on-fedora-centos-rhel/



alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_65/jre/bin/java 200000
 alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.7.0_65/jre/bin/javaws 200000
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64 /usr/lib/jvm/jdk1.7.0_65/jre/lib/amd64/libnpjp2.so 200000
alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0_65/bin/javac 200000
alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.7.0_65/bin/jar 200000



/usr/lib/jvm/jdk1.8.0_25

alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_25/jre/bin/java 300000
alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.8.0_25/jre/bin/javaws 300000
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64 /usr/lib/jvm/jdk1.8.0_25/jre/lib/amd64/libnpjp2.so 300000
alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_25/bin/javac 300000
alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8.0_25/bin/jar 300000
alternatives --install /usr/bin/jvisualvm jvisualvm /usr/lib/jvm/jdk1.8.0_25/bin/jvisualvm 300000


su -i 

wget --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u131-b11/d54c1d3a095b4ff2b6607d096fa80163/jdk-8u131-linux-x64.tar.gz


/usr/lib/jvm/jdk1.8.0_131

alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_131/jre/bin/java 300000
alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.8.0_131/jre/bin/javaws 300000
alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64 /usr/lib/jvm/jdk1.8.0_131/jre/lib/amd64/libnpjp2.so 300000
alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_131/bin/javac 300000
alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8.0_131/bin/jar 300000
alternatives --install /usr/bin/jvisualvm jvisualvm /usr/lib/jvm/jdk1.8.0_131/bin/jvisualvm 300000