本文实例讲述了Yii2的XSS攻击防范策略。分享给大家供大家参考，具体如下：XSS漏洞修复原
本文实例讲述了Yii2的XSS攻击防范策略。分享给大家供大家参考，具体如下：
XSS 漏洞修复
原则： 不相信客户输入的数据 注意: 攻击代码不一定在<script></script>中
① 将重要的cookie标记为http only, 这样的话Javascript 中的document.cookie语句就不能获取到cookie了. ② 只允许用户输入我们期望的数据。 例如： 年龄的textbox中，只允许用户输入数字。 而数字之外的字符都过滤掉。 ③ 对数据进行Html Encode 处理 ④ 过滤或移除特殊的Html标签， 例如: script, iframe , < for <, > for >, " for ⑤ 过滤JavaScript 事件的标签。例如 "onclick=", "onfocus" 等等。
Yii中的XSS防范
<?php echo CHtml::encode($user->name) ?>
此方法的源码：
/**
* Encodes special characters into HTML entities.
* The [[\yii\base\Application::charset|application charset]] will be used for encoding.
* @param string $content the content to be encoded
* @param boolean $doubleEncode whether to encode HTML entities in `$content`. If false,
* HTML entities in `$content` will not be further encoded.
* @return string the encoded content
* @see decode()
* @see http://www.php.net/manual/en/function.htmlspecialchars.php
*/
public static function encode($content, $doubleEncode = true)
{
return htmlspecialchars($content, ENT_QUOTES | ENT_SUBSTITUTE, Yii::$app->charset, $doubleEncode);
}
htmlspecialchars & htmlentities & urlencode 三者的区别：
http://php.net/manual/zh/function.htmlspecialchars.php http://php.net/manual/zh/function.htmlentities.php http://cn2.php.net/manual/zh/function.urlencode.php
Available flags constants Constant Name Description ENT_COMPAT Will convert double-quotes and leave single-quotes alone. ENT_QUOTES Will convert both double and single quotes. ENT_NOQUOTES Will leave both double and single quotes unconverted. ENT_IGNORE Silently discard invalid code unit sequences instead of returning an empty string. Using this flag is discouraged as it » may have security implications. ENT_SUBSTITUTE Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of returning an empty string. ENT_DISALLOWED Replace invalid code points for the given document type with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of leaving them as is. This may be useful, for instance, to ensure the well-formedness of XML documents with embedded external content. ENT_HTML401 Handle code as HTML 4.01. ENT_XML1 Handle code as XML 1. ENT_XHTML Handle code as XHTML. ENT_HTML5 Handle code as HTML 5.
htmlspecialchars
Convert special characters to HTML entities
string htmlspecialchars (
string $string
[, int $flags = ENT_COMPAT | ENT_HTML401
[, string $encoding = ini_get("default_charset")
[, bool $double_encode = true ]
]
]
)
The translations performed are:
& (ampersand) becomes & " (double quote) becomes " when ENT_NOQUOTES is not set. ' (single quote) becomes ' (or ') only when ENT_QUOTES is set. < (less than) becomes < > (greater than) becomes >
<?php
$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo $new; // <a href='test'>Test</a>
?>
htmlentities
Convert all applicable characters to HTML entities
string htmlentities (
string $string
[, int $flags = ENT_COMPAT | ENT_HTML401
[, string $encoding = ini_get("default_charset")
[, bool $double_encode = true ]
]
]
)
<?php
$str = "A 'quote' is <b>bold</b>";
// Outputs: A 'quote' is <b>bold</b>
echo htmlentities($str);
// Outputs: A 'quote' is <b>bold</b>
echo htmlentities($str, ENT_QUOTES);
?>
urlencode
URL 编码是为了符合url的规范。因为在标准的url规范中中文和很多的字符是不允许出现在url中的。
例如在baidu中搜索"测试汉字"。 URL会变成 http://www.baidu.com/s?wd=%B2%E2%CA%D4%BA%BA%D7%D6&rsv_bp=0&rsv_spt=3&inputT=7477
所谓URL编码就是： 把所有非字母数字字符都将被替换成百分号（%）后跟两位十六进制数，空格则编码为加号（+） 此字符串中除了 -_. 之外的所有非字母数字字符都将被替换成百分号（%）后跟两位十六进制数，空格则编码为加号（+）。此编码与 WWW 表单 POST 数据的编码方式是一样的，同时与 application/x-www-form-urlencoded 的媒体类型编码方式一样。由于历史原因，此编码在将空格编码为加号（+）方面与 RFC1738 编码（参见 rawurlencode()）不同。
<?php
echo '<a href="mycgi?foo=', urlencode($userinput), '">';
?>
<?php
$query_string = 'foo=' . urlencode($foo) . '&bar=' . urlencode($bar);
echo '<a href="mycgi?' . htmlentities($query_string) . '">';
?>