javascript实现的字符串与十六进制表示字符串相互转换方法
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>
希望本文所述对大家的javascript程序设计有所帮助。
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