How to create a link in a site that will login another site?

Question

There is a simple site, let's call it http://foo.com/ , with a simple user/pass form that sends a post request to http://foo.com/login.php to login the user.

How to create a link in another site, say http://foo_autologin.com/ , that will login with a pre-determined password on http://foo.com/ and open it, logged in, in another tab?

Answer 1

You can have http://foo_autologin.php (doesn't have to be php, can be html) use Javascript to open a new window pointed to a file called proxy_login.php or something. Then use CURL to post the login credentials to http://foo.com . Checkout Curl Documentation and look in the examples.