Based on EzSocial v1.01 add-on for OsCommerce 2.3 Written by Christopher Trigg.
Easy and friendly way to add social logins to your site. Uses PHP for backend work to login and CSS to display buttons
Base module which installs a social login box on your login.php page; and
Sub-modules for each social login provider.
No core files overwritten, just upload then follow installation instructions.
Requires you to create an app for each provider you require (Facebook, Google, LinkedIn) - instructions are included.
You can also add other providers such as Twitter, Instagram, Github, Microsoft, Yahoo etc with minimal effort (some technical knowledge required)
Support thread at https://forums.oscommerce.com/topic/411306-ezsocial-for-osc234bs-v10a/