php单点登陆简单实现 (iframe方式)

有四个网站分别为： 
www.a.com
www.b.com
www.c.com
www.sso.com
需求是如果我们在sso登陆后，其他网站也会显示登陆中，不需要重复登陆，退出时，其他网站也会失效。
 
解决流程如下：
1、我们需要统一这四个站的session存储方式。 (session共享，保存到mysql中)
2、登陆和退出的请求统一由sso这个站处理。(其他站全部跳转到sso上)
3、当用户在sso.com登陆时，我们在验证完用户名和密码正确后，通过获取session_id和生成一段skey加密串保存到user表的相应字段中。然后跳转到一个中间页面，访页面通过iframe的方式引入a.com，b.com，和c.com。
<iframe src="http://www.a.com/sso.php?sessid=xxx&skey=xxx" width="0" height="0" frameborder="0">
</iframe>
<iframe src="http://www.b.com/sso.php?sessid=xxx&skey=xxx" width="0" height="0" frameborder="0">
</iframe>
<iframe src="http://www.c.com/sso.php?sessid=xxx&skey=xxx" width="0" height="0" frameborder="0">
</iframe>
(*传给a，b，c这三个站的sessid是经过加密的，为了安全。)
 
4、a，b，c这三个站的sso.php拿到sessid和skey解密后得到session_id，然后到user表中进行比对，如果正确，设置当前会话的session_id，然后session_start()，因为四个站的session是共享的，所以a，b ，c三个站就拿到了在sso上登陆时存储的会话数据。
//sessid是sso.com上产生的session_id
session_id(sessid);
session_start();
具体的代码如下：
www.sso.com/index.php
<?php
header('Content-Type:text/html;charset=utf-8');
require_once './DBSession.php';
session_start();

if(array_key_exists('userInfo', $_SESSION) && !empty($_SESSION['userInfo'])) {
    $userInfo = $_SESSION['userInfo'];
    echo '欢迎', $userInfo['name'], '<br />';
    echo '<a href="./logout.php">退出</a>';
} else {
    header('Location: ./login.html');
}
www.sso.com/login.html
<!DOCTYPE HTML>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
    * {padding:0;margin:0;}
    .loginForm {450px;height:auto;margin:100px auto 0 auto;}
    .loginForm table {100%;border-collapse:collapse;}
    .loginForm table td, .loginForm table th {border:1px solid #dcdcdc;padding:5px;}
    </style>
</head>
<body>
    <form action="./login.php" method="post" class="loginForm">
        <table>
            <tr>
                <th colspan="2">用户登陆</th>
            </tr>
            <tr>
                <td>用户名：</td>
                <td><input type="text" name="uname" value="" /></td>
            </tr>
            <tr>
                <td>密码：</td>
                <td><input type="password" name="upwd" value="" /></td>
            </tr>
            <tr>
                <td> </td>
                <td><input type="submit" name="submit" value="登陆" /></td>
            </tr>
        </table>
    </form>
</body>
</html>
www.sso.com/login.php
<?php
require_once './DBSession.php';
require_once './DB.php';
session_start();

if(!empty($_POST)) {
    $uname = !empty($_POST['uname']) ? trim($_POST['uname']) : '';
    $upwd = !empty($_POST['upwd']) ? trim($_POST['upwd']) : '';

    $upwd = md5($upwd);
    $ret = mysql_query("select `id`,`name` from `user` where `name`='{$uname}' and `pwd`='{$upwd}';", $db);
    $data = mysql_fetch_assoc($ret);
    if($data) {
        $userInfo = array(
            'id' => $data['id'],
            'name' => $data['name'],
        );
        $_SESSION['userInfo'] = $userInfo;
        //通过用户ID，用户名和时间戳的md5生成skey
        $skey = md5($data['id'] . $data['name'] .  time());
        $sessId = session_id();

        $userId = $data['id'];
        $ret = mysql_query("update `user` set `sessid`='$sessId', `skey`='$skey' where `id`={$userId};", $db);
        if(mysql_affected_rows($db)) {

            //取skey前三个字符和后三个字符生成key
            $key = substr($skey, 0, 3) . substr($skey, -1, 3);
            $lifeTime = ini_get('session.gc_maxlifetime');
            $sessId = authcode($sessId, 'ENCODE', $key, $lifeTime);

            $appSSOUrl = array(
                'http://www.a.com/sso.php',
                'http://www.b.com/sso.php',
                'http://www.c.com/sso.php',
            );
            
            require 'iframe.php';
        }
    } else {
        header('Location: ./login.html');
    }
}
www.sso.com/iframe.php
<!DOCTYPE HTML>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <?php foreach($appSSOUrl as $item) { ?>
    <iframe src="<?php echo $item . '?sessid=' . $sessId . '&skey=' . $skey;?>" width="0" height="0" frameborder="0"></iframe>
    <?php } ?>
</body>
<script type="text/javascript">
    window.onload = function() {
         location.href = 'index.php';
    };
</script>
</html>
www.sso.com/logout.php
<?php
require_once './DBSession.php';
require_once './DB.php';

session_start();

if(array_key_exists('userInfo', $_SESSION) && !empty($_SESSION['userInfo'])) {
    $uid = $_SESSION['userInfo']['id'];

    $ret = mysql_query("update `user` set `sessid`='', `skey`='' where id={$uid}", $db);
    if(session_destroy()) {
        header('Location: ./login.html');
    }
}
www.a.com/index.php
<?php
header('Content-Type:text/html;charset=utf-8');
require_once './DBSession.php';
session_start();

if(array_key_exists('userInfo', $_SESSION) && !empty($_SESSION['userInfo'])) {
    $userInfo = $_SESSION['userInfo'];
    echo '欢迎', $userInfo['name'], '<br />';
    echo '<a href="http://www.sso.com/logout.php">退出</a>';
} else {
    header('Location: http://www.sso.com/login.html');
}
www.a.com/sso.php
<?php
require_once './DBSession.php';
require_once './DB.php';

$sessid = !empty($_GET['sessid']) ? trim($_GET['sessid']) : '';
$skey = !empty($_GET['skey']) ? trim($_GET['skey']) : '';

if(empty($sessid) || empty($skey)) {
    exit;
}

$key = substr($skey, 0, 3) . substr($skey, -1, 3);
$sessid = authcode($sessid, 'DECODE', $key);
if(!empty($sessid)) {
    $ret = mysql_query("select count(*) as num from user where sessid='{$sessid}' and skey='{$skey}'");
    $row = mysql_fetch_assoc($ret);
    if($row['num']) {
        session_id($sessid);
        session_start();
    }
} else {
    header('Location: http://www.sso.com/login.html');
}
b和c站的文件跟a站是一样的，只需复制a站即可，这里就不重复了。
 
DBSession.php代码：
<?php
class DBSession {
    protected $db = null;
    protected $lifeTime = 0;
    protected $sessTable = '';

    public function __construct($db, $sessTable) {
        $this->db = $db;
        $this->sessTable = $sessTable;
        $this->lifeTime = ini_get('session.gc_maxlifetime');

        ini_set('session.save_handler', 'user');
        session_set_save_handler(
            array($this, "open"),
            array($this, "close"),
            array($this, "read"),
            array($this, "write"),
            array($this, "destroy"),
            array($this, "gc")
        );
        register_shutdown_function('session_write_close');
    }

    public function open($savePath, $sessName) {
        return true;
    }

    public function close() {
        $this->gc($this->lifeTime); 
        return true;
    }

    public function read($sessId) {
        $time = time();
        $ret = mysql_query("SELECT `data` FROM `{$this->sessTable}` WHERE `sid`='{$sessId}' AND `expire` > {$time};", $this->db);
        if($ret) {
           $row = mysql_fetch_assoc($ret);
           return $row['data']; 
        }
        return ''; 
    }

    public function write($sessId, $sessData) {
        $expire = time() + $this->lifeTime;
        $sessData = mysql_real_escape_string($sessData);
        
        $ret = mysql_query("SELECT COUNT(*) AS cnt FROM `{$this->sessTable}` WHERE `sid`='{$sessId}';", $this->db);
        $row = mysql_fetch_assoc($ret);
        if($row['cnt']) {
            $sql = "UPDATE `{$this->sessTable}` SET `data`='{$sessData}', `expire`={$expire} WHERE `sid`='{$sessId}';";
        } else {
            $sql = "INSERT INTO `{$this->sessTable}` (`sid`,`expire`,`data`) VALUES('{$sessId}',{$expire},'{$sessData}');";
        }
        mysql_query($sql, $this->db);
        if(mysql_affected_rows($this->db)) {
            return true;
        }
        return false;
    }

    public function destroy($sessId) {
        mysql_query("DELETE FROM `{$this->sessTable}` WHERE `sid`='{$sessId}';", $this->db); 
        if(mysql_affected_rows($this->db)) {
            return true;
        }
        return false;
    }

    public function gc($lifeTime) {
        $time = time();
        mysql_query("DELETE FROM `{$this->sessTable}` WHERE `expire` < {$time};", $this->db); 
        return mysql_affected_rows($this->db);
    }
}

$sessDb = mysql_connect('127.0.0.1', 'root', '') or die('connect error');
mysql_select_db('test', $sessDb) or ('select db error');
mysql_query('set names utf8', $sessDb);
new DBSession($sessDb, 'session');
session表结构如下：
CREATE TABLE `session` (
`sid` varchar(32) NOT NULL DEFAULT '' COMMENT 'session_id',
`expire` int(11) NOT NULL COMMENT '过期时间',
`data` text COMMENT 'session数据',
PRIMARY KEY (`sid`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='session表';
DB.php文件代码如下：
<?php
$db = mysql_connect('127.0.0.1', 'root', '') or die('connect error');
mysql_select_db('test', $db) or ('select db error');
mysql_query('set names utf8', $db);
user表结构如下：
CREATE TABLE `user` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '用户ID',
  `name` varchar(32) NOT NULL DEFAULT '' COMMENT '用户名',
  `pwd` varchar(32) NOT NULL DEFAULT '' COMMENT '用户密码(md5)',
  `sessid` varchar(32) NOT NULL DEFAULT '' COMMENT 'session_id(未加密)',
  `skey` varchar(32) NOT NULL DEFAULT '' COMMENT '安全码',
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='用户表';
加密解密函数authcode(取自Discuz)代码如下：
function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0){
    if($operation == 'DECODE') {
        $string = str_replace('[a]','+',$string);
        $string = str_replace('[b]','&',$string);
        $string = str_replace('[c]','/',$string);
    }
    $ckey_length = 4;
    $key = md5($key ? $key : 'livcmsencryption');
    $keya = md5(substr($key, 0, 16));
    $keyb = md5(substr($key, 16, 16));
    $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
    $cryptkey = $keya.md5($keya.$keyc);
    $key_length = strlen($cryptkey);
    $string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
    $string_length = strlen($string);
    $result = '';
    $box = range(0, 255);
    $rndkey = array();
    for($i = 0; $i <= 255; $i++) {
        $rndkey[$i] = ord($cryptkey[$i % $key_length]);
    }
    for($j = $i = 0; $i < 256; $i++) {
        $j = ($j + $box[$i] + $rndkey[$i]) % 256;
        $tmp = $box[$i];
        $box[$i] = $box[$j];
        $box[$j] = $tmp;
    }
    for($a = $j = $i = 0; $i < $string_length; $i++) {
        $a = ($a + 1) % 256;
        $j = ($j + $box[$a]) % 256;
        $tmp = $box[$a];
        $box[$a] = $box[$j];
        $box[$j] = $tmp;
        $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
    }
    if($operation == 'DECODE') {
        if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
            return substr($result, 26);
        } else {
            return '';
        }
    } else {
        $ustr = $keyc.str_replace('=', '', base64_encode($result));
        $ustr = str_replace('+','[a]',$ustr);
        $ustr = str_replace('&','[b]',$ustr);
        $ustr = str_replace('/','[c]',$ustr);
        return $ustr;
    }
}
我们通过在sso.com上登陆
php单点登陆简单实现 (iframe方式) - 怀素真 - 因上努力 果上随缘
登成功后会跳转到index.php
php单点登陆简单实现 (iframe方式) - 怀素真 - 因上努力 果上随缘
 然后我们访问a.com，b.com ，c.com查看
php单点登陆简单实现 (iframe方式) - 怀素真 - 因上努力 果上随缘
我们点击任一网站退出，其他网站都已退出。
 
原理其实很简单，我们统一了四个站的session存储方式，然后让a,b,c三个站拿到用户在sso上登陆的会话id。这样会话信息就共享了。不过实现的很粗糙，仅供学习使用。
 
参考资料：

http://www.zhihu.com/question/19779937

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原文地址：https://www.cnblogs.com/jkko123/p/6294579.html