php curl - sending form data to external website

I have a login form set up on my domain (eg: www.example.com/login).

When the user enters their login information, I need those details to be passed through a login form on an external website and the user directed to the application that they are logging into.

So to add the user steps to this: 1. User enters login information on www.example.com/login 2. User is directed to and has access to application on www.external.com/application without having to re-enter login details at www.external.com/login

The problem is, I'm not sure how to go about doing this. I found some references to cURL which from what I could gather is the best approach to take.开发者_如何学C

Any help with this would be appreciated .. I'm a PHP novice! Also ... the application on the external website is ASP.NET (I'm not sure if this has any factor on getting this to work).

Thanks for your help, Mark.

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Depending on how your application works, what could work is have your login form on example.com/login point to external.com/application

so your form tag would look like this:

<form action="external.com/application" method="post">

Now your external.com/application will have to be setup to accept the data from the login form. When the form is submitted the browser should direct itself to external.com/application.

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This is a possible approach :

• On www.example.com/login, do a classic login form which is submitted on itself

• On www.example.com/login, when a $_POST is detected :

  • check that the credentials are good
  • if yes, store within a table in you db server an hash dedicated to this user (by hashing his id/user/etc... whatever you wish)
  • redirect to www.external.com/login?hash=the_generated_hash

• On www.example.com/verifyHash.php:

  • create a simple php file that take a hash in $_GET and echo "true" if this hash exists in your db

• on www.external.com/login

  • check that a hash is passed in $_GET
  • if yes, do a simple $result = file_get_contents("www.example.com/verifyHash.php?hash=$_GET["hash"]");
  • if the result is true then you can assume that the user has valid credentials.

Of course, you can optimize this whole thing by passing a user id along your hash, by implementing some security when your asking remotly verifyHash, etc...