laravel/documentation/auth/usage.md

Authentication Usage

• Salting & Hashing
• Logging In
• Protecting Routes
• Retrieving The Logged In User
• Logging Out

Note: Before using the Auth class, you must specify a session driver.

Salting & Hashing

If you are using the Auth class, Laravel requires all passwords to be hashed and salted. Web development must be done responsibly. Salted, hashed passwords make a rainbow table attack against your user's passwords impractical.

Don't worry, salting and hashing passwords is easy using the Hash class. The Hash class provides a simple way to hash passwords using the bcrypt hashing algorithm. Check out this example:

$password = Hash::make('secret');

The make method of the Hash class will return a 60 character hashed string.

You can compare an unhashed value against a hashed one using the check method on the Hash class:

if (Hash::check('secret', $hashed_value))
{
    return 'The password is valid!';
}

Note: Before using the Auth class, be sure to create the "password" column on your user table.

Logging In

Logging a user into your application is simple using the login method on the Auth class. Simply pass the username and password of the user to the method. The login method will return true if the credentials are valid. Otherwise, false will be returned:

if (Auth::login('example@gmail.com', 'password'))
{
     return Redirect::to('user/profile');
}

If the user's credentials are valid, the user ID will be stored in the session and the user will be considered "logged in" on subsequent requests to your application.

To determine if the user of your application is logged in, call the check method:

if (Auth::check())
{
     return "You're logged in!";
}

Protecting Routes

It is common to limit access to certain routes only to logged in users. It's a breeze in Laravel using the built-in auth filter. If the user is logged in, the request will proceed as normal; however, if the user is not logged in, they will be redirected to the "login" named route.

To protect a route, simply attach the auth filter:

'GET /admin' => array('before' => 'auth', 'do' => function() {})

Note: You are free to edit the auth filter however you like. A default implementation is located in application/filters.php.

Retrieving The Logged In User

Once a user has logged in to your application, you may easily access the user model via the user method on the Auth class:

return Auth::user()->email;

Note: If the user is not logged in, the user method will return NULL.

Logging Out

Ready to log the user out of your application? It's simple:

Auth::logout();

This method will remove the user ID from the session, and the user will no longer be considered logged in on subsequent requests to your application.