javascript实现的字符串与十六进制表示字符串相互转换方法

2024-05-06 16:23:21

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这篇文章主要介绍了javascript实现的字符串与十六进制表示字符串相互转换方法,涉及javascript字符串转换的相关技巧,在防止SQL注入和XSS中具有一定参考借鉴价值,需要的朋友可以参考下

本文实例讲述了javascript实现的字符串与十六进制表示字符串相互转换方法。分享给大家供大家参考。具体如下：

之所以写这个，是因为发现SQL注入和XSS中经常利用十六进制表示的字符串，比如

SELECT CONCAT(0x68656c6c6f);

得到的是hello

<!DOCTYPE html>

<html>

<head>

<title>Hex-Char Bi-Converter</title>

</head>

<body>

<div class="mainContainer">

<label for="from" id="fromLabel">String</label>

<input type="text" name="from" id="from" />

<input type="button" name="exchange" id="exchange" value="<=>" />

<label for="to" id="toLabel">Hex</label>

<input type="text" name="to" id="to" />

<input type="button" name="convert" id="convert" value="Convert" />

</div>

<script type="text/javascript" src="js/jquery-1.9.1.min.js"></script>

<script type="text/javascript">

var curMode = 0; // curMode: 0 represents String to Hex, 1 from Hex to String

var fromToLabelArray = ["Hex", "String"];

$(function() {

$("#convert").click(function() {

var fromVal = $("#from").val();

var toVal =

curMode === 0

?

strToHexCharCode(fromVal)

:

hexCharCodeToStr(fromVal);

$("#to").val(toVal);

});

$("#exchange").click(function() {

$("#fromLabel").text(fromToLabelArray[curMode]);

$("#toLabel").text(fromToLabelArray[1-curMode]);

curMode = 1 - curMode;

});

});

function strToHexCharCode(str) {

if(str === "")

return "";

var hexCharCode = [];

hexCharCode.push("0x");

for(var i = 0; i < str.length; i++) {

hexCharCode.push((str.charCodeAt(i)).toString(16));

}

return hexCharCode.join("");

}

function hexCharCodeToStr(hexCharCodeStr) {

var trimedStr = hexCharCodeStr.trim();

var rawStr =

trimedStr.substr(0,2).toLowerCase() === "0x"

?

trimedStr.substr(2)

:

trimedStr;

var len = rawStr.length;

if(len % 2 !== 0) {

alert("Illegal Format ASCII Code!");

return "";

}

var curCharCode;

var resultStr = [];

for(var i = 0; i < len;i = i + 2) {

curCharCode = parseInt(rawStr.substr(i, 2), 16); // ASCII Code Value

resultStr.push(String.fromCharCode(curCharCode));

}

return resultStr.join("");

}

</script>

</body>

</html>