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今天在网上瞎逛又看到了一个不错的东西。 有些程序员如果没有很好的在 javascript中解析 json数据,往往会直接 eval把json转成js对象,这时候如果json的数据中包含了被注入的恶意数据,则可能导致代码注入的问题。 正确的做法是 分割出json里包含的特殊字符,然后再解析为对象 http://json.org/json2.js 中是通过正则来完成的。// We split the second stage into 4 regexp operations in order to work around// crippling inefficiencies in IE's and Safari's regexp engines. First we// replace the JSON backslash pairs with '@' (a non-JSON character). Second, we// replace all simple value tokens with ']' characters. Third, we delete all// open brackets that follow a colon or comma or that begin the text. Finally,// we look to see that the remaining characters are only whitespace or ']' or// ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval. if (/^[\],:{}\s]*$/.test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@').replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']').replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) {// In the third stage we use the eval function to compile the text into a// JavaScript structure. The '{' operator is subject to a syntactic ambiguity// in JavaScript: it can begin a block or an object literal. We wrap the text// in parens to eliminate the ambiguity. j = eval('(' + text + ')');目前不少写的好的框架和js解析函数都取用了这种做法。 所以,以后千万别直接eval了。
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