php的sso单点登录实现方法，代码实例！

1.首页登录页面index.php（是你当前项目首页）

<?php  
header('Content-Type:text/html; charset=utf-8');  
$sso_address = 'http://www.mysso.com/sso/login.php'; //你SSO所在的域名,不是当前项目地址  
$callback_address = 'http://'.$_SERVER['HTTP_HOST']  
                    .str_replace('index.php','',$_SERVER['SCRIPT_NAME'])  
                    .'callback.php'; //callback地址用于回调设置cookie
if(isset($_COOKIE['sign'])){
    exit("欢迎您{$_COOKIE['sign']} <a href='{$sso_address}?logout=1'>退出</a>");  
}else{  
    echo '您还未登录 <a href="'.$sso_address.'?callback='.$callback_address.'">点此登录</a>';
}  
?> 
<iframe src="<?php echo $sso_address ?>?callback=<?php echo $callback_address ?>" frameborder="0"  width="0" height="0"></iframe>

2.当前项目的中间件用来赋值cookie和清空cookie的文件callback.php

<?php  
header('Content-Type:text/html; charset=utf-8');  
if(empty($_GET)){ 
    exit('您还未登录');  
}else{  
    foreach($_GET as $key=>$val){  
        setcookie($key,$val,0,'');  
    }  
    header("location:index.php");  
}

3.很重要的文件login.php（是sso登录也要放在第三方网站下面）

<?php  
header('Content-Type:text/html; charset=utf-8');  
if(isset($_GET['logout'])){ 
    setcookie('sign','',-300);  
    unset($_GET['logout']);  
    header('location:http://www.zjx.com/sso/callback.php?sign'); //注意替换成你项目的域名
} 
 
if(isset($_POST['username']) && isset($_POST['password'])){ 
    setcookie('sign',$_POST['username'],0,'');  
    header("location:".$_POST['callback']."?sign={$_POST['username']}");  
} 
 
if(empty($_COOKIE['sign'])){
?> 
 
<form method="post">  
<p>用户名：<input type="text" name="username" /></p>  
<p>密  码：<input type="password" name="password" /></p>  
<input type="hidden" name="callback" value="<?php echo $_GET['callback']; ?>" />  
<input type="submit" value="登录" />  
</form> 
 
 
<?php  
}else{  
    $query = http_build_query($_COOKIE);  
    echo "系统检测到您已登录 {$_COOKIE['sign']} <a href='{$_GET['callback']}?{$query}''>授权</a> <a href='?logout'>退出</a>";  
}

原理:

根据你第三方登录页面输入的信息，判断是否用户正确信息，然后记录到cookie里面，然后带上加密的sign，跳转回去中间件文件callback.php,然后解密，进行当前项目的cookie进行赋值，然后跳转回首页，并且实现登录了！