php如何防止页面中的敏感信息被提取

今天在逛　二十四画生　的bolg的时候发现他提到＂在asp.net中如何防止用户的敏感信息如email地址经常会被一些工具自动提取，一些非法用户就会利用所提取的Email大肆发送垃圾邮件＂．偶有心得，觉得这个办法非常不错，于是花了几分钟将其转换为php代码以备用．
　　代码清单如下：

php代码清单：
function CloakText($str)
{
//
$tmpStr = "";
$strLength = strlen($str);
for($i=0; $i < $strLength; $i++)
{
if($i != $strLength-1)
$tmpStr .= ord($str[$i]) . ",";
else
$tmpStr .= ord($str[$i]);
}
//
$tmpStr = "/r/n<script language=/"javascript/">/r/n<!--/r/ndocument.write(String.fromCharCode(" . $tmpStr;
$tmpStr .= "))/r/n// -->/r/n</script>/r/n";

return $tmpStr;
}

echo (CloakText("ahao_150@163.com"));

得到输出结果如下：

<script language="javascript">
<!--
document.write(String.fromCharCode(97,104,97,111,95,49,53,48,64,49,54,51,46,99,111,109))
// -->
</script>

相应的vb.net与c#代码如下以做比较：

VB.NET:
Public Function CloakText()Function CloakText(ByVal PersonalInfo As String) As String

If Not PersonalInfo Is Nothing Then
Dim sb As New StringBuilder

' convert to ASCII character codes，将字符串转换成ASCII编码字符串形式
sb.Remove(0, sb.Length)
Dim StringLength As Integer = PersonalInfo.Length - 1
For i As Integer = 0 To StringLength
sb.Append(Asc(PersonalInfo.Substring(i, 1)).ToString)
If i < StringLength Then
sb.Append(",")
End If
Next

' build script block
Dim sbScript As New StringBuilder

sbScript.Append(vbCrLf & "<script language=""javascript"">" & vbCrLf)
sbScript.Append("<!-- " & vbCrLf)
'fromCharCode 方法：从一些 Unicode 字符值中返回一个字符串。
sbScript.Append(" document.write(String.fromCharCode(" & sb.ToString & "))" & vbCrLf)
sbScript.Append("// -->" & vbCrLf)
sbScript.Append("</script>" & vbCrLf)

Return sbScript.ToString
Else
Return Null.NullString
End If

End Function

c#:

public string CloakText(string text)
{
StringBuilder sb = new StringBuilder();

sb.Append("<script language=/"javascript/">/n<!--");
System.Text.ASCIIEncoding asciiEncoding = new ASCIIEncoding();
byte[] bytes = new byte[text.Length];
int count = asciiEncoding.GetBytes(text,0,text.Length,bytes,0);
for(int i=0;i<count;i++)
{
sb.Append((int)bytes[i]);
if(i<count-1)
{
sb.Append(",");
}
}

sb.Append("/n-->/n</script>");
return sb.ToString();
}