JavaScript 密码强度判断代码

//bitTotal函数
//计算出当前密码当中一共有多少种模式
function bitTotal(num){
modes=0;
for (i=0;i<4;i++){
if (num & 1) modes++;
num>>>=1;
}
return modes;
}

//checkStrong函数
//返回密码的强度级别

function checkStrong(sPW){
if (sPW.length<=4)
return 0; //密码太短
Modes=0;
for (i=0;i<sPW.length;i++){
//测试每一个字符的类别并统计一共有多少种模式.
Modes|=CharMode(sPW.charCodeAt(i));
}

return bitTotal(Modes);

}

//pwStrength函数
//当用户放开键盘或密码输入框失去焦点时,根据不同的级别显示不同的颜色

function pwStrength(pwd){
O_color=”#eeeeee”;
L_color=”#FF0000″;
M_color=”#FF9900″;
H_color=”#33CC00″;
if (pwd==null||pwd==”){
Lcolor=Mcolor=Hcolor=O_color;
}
else{
S_level=checkStrong(pwd);
switch(S_level) {
case 0:
Lcolor=Mcolor=Hcolor=O_color;
case 1:
Lcolor=L_color;
Mcolor=Hcolor=O_color;
break;
case 2:
Lcolor=Mcolor=M_color;
Hcolor=O_color;
break;
default:
Lcolor=Mcolor=Hcolor=H_color;
}
}

document.getElementById(“strength_L”).style.background=Lcolor;
document.getElementById(“strength_M”).style.background=Mcolor;
document.getElementById(“strength_H”).style.background=Hcolor;
return;
}
</script>

<form name=form1 action=”” >
输入密码:<input type=password size=10 onKeyUp=pwStrength(this.value) onBlur=pwStrength(this.value)>
<br>密码强度:
<table width=”217″ border=”1″ cellspacing=”0″ cellpadding=”1″ bordercolor=”#cccccc” height=”23″ style=’display:inline’>
<tr align=”center” bgcolor=”#eeeeee”>
<td width=”33%” id=”strength_L”>弱</td>
<td width=”33%” id=”strength_M”>中</td>
<td width=”33%” id=”strength_H”>强</td>
</tr>
</table>
</form>