jQuery password strength checker

Question

I'm quite new to jQuery, and I've written a simple function to check the strength of a password for each keypress.

The idea is that every time a user enters a character, the contents is evaluated to test the strengh of the password they have entered... I'm sure everyone has seen these before.

Anyhow, the logic I have used is that no password begins with a value of 1. When a lower-case character is used, the score increments to 2. When a digit is used the score increments by 1 again, same for when an uppercase character is used and when the password becomes 5 or more characters long.

What is returned is the strength of the password so far as a value from 1 to 5 every time a key is pressed.

So, about my question. The way that I've done it doesn't seem very jQuery like... almost like I may as well have just done straight javascript. Also I was wondering about my logic. Have I done anything done or overlooked something? Any suggestions from smarter people than myself?

Any suggestions or advice would be appreciated.

$(document).ready(function(){

        $("#pass_strength").keyup(function() {

            var strength = 1;

            /*length 5 characters or more*/
            if(this.value.length >= 5) {
                strength++;
            }

            /*contains lowercase characters*/
            if(this.value.match(/[a-z]+/)) {
                strength++;
            }

            /*contains digits*/
            if(this.value.match(/[0-9]+/)) {
                strength++;
            }

            /*contains uppercase characters*/
            if(this.value.match(/[A-Z]+/)) {
                strength++;
            }

            alert(strength);
        });
     });

Solution 1

The best way is to take an existing plugin as TJB suggested.

As to your question about the code itself, a nicer way is to write it like that:

var pass = "f00Bar!";

var strength = 1;
var arr = [/.{5,}/, /[a-z]+/, /[0-9]+/, /[A-Z]+/];
jQuery.map(arr, function(regexp) {
  if(pass.match(regexp))
     strength++;
});

(Modified to correct syntax errors.)

Solution 2

I would suggest evaluating an existing jQuery password strength plugin. (unless your just doing it as an exercise)

Here are a few links I found:

http://www.visual-blast.com/javascript/password-strength-checker/

http://phiras.wordpress.com/2007/04/08/password-strength-meter-a-jquery-plugin/

Solution 3

If you are doing as excersie

Reference: Password Strength Indicator

jQuery Code Used (# denotes what have changed from Benjamin's code)

$.fn.passwordStrength = function( options ){
return this.each(function(){
    var that = this;that.opts = {};
    that.opts = $.extend({}, $.fn.passwordStrength.defaults, options);

    that.div = $(that.opts.targetDiv);
    that.defaultClass = that.div.attr('class');

    that.percents = (that.opts.classes.length) ? 100 / that.opts.classes.length : 100;

    v = $(this)
    .keyup(function(){
        if( typeof el == "undefined" )
        this.el = $(this);
        var s = getPasswordStrength (this.value);
        var p = this.percents;
        var t = Math.floor( s / p );

        if( 100 <= s )
        t = this.opts.classes.length - 1;

        this.div
        .removeAttr('class')
        .addClass( this.defaultClass )
        .addClass( this.opts.classes[ t ] );
    })
    # Removed generate password button creation
});

function getPasswordStrength(H){
    var D=(H.length);

    # Added below to make all passwords less than 4 characters show as weak
    if (D<4) { D=0 }


    if(D>5){
        D=5
    }
    var F=H.replace(/[0-9]/g,"");
    var G=(H.length-F.length);
    if(G>3){G=3}
    var A=H.replace(/\W/g,"");
    var C=(H.length-A.length);
    if(C>3){C=3}
    var B=H.replace(/[A-Z]/g,"");
    var I=(H.length-B.length);
    if(I>3){I=3}
    var E=((D*10)-20)+(G*10)+(C*15)+(I*10);
    if(E<0){E=0}
    if(E>100){E=100}
    return E
}


# Removed generate password function
};

$(document)
.ready(function(){
$('input[name="password2"]').passwordStrength({targetDiv: '#iSM',classes : Array('weak','medium','strong')});

});

Solution 4

On top of gs' answer, you should check the password against common dictionary words (using a hash, probably). Otherwise a weak password like 'Yellow1' will be evaluated as strong by your logic.

Solution 5

function strengthResult(p) {
if(p.length<6 || p.length>18) {
return 'Passwords must be 6-18 characters';
}
var strength = checkStrength(p);
switch(true) {
    case strength<=30:
        return 'Password "'+p+'" ('+strength+') is Very Weak';
        break;
    case strength>30 && strength<=35:
        return 'Password "'+p+'" ('+strength+') is Weak';
        break;
    case strength>35 && strength<=50:
        return 'Password "'+p+'" ('+strength+') is below Average';
        break;        
    case strength>50 && strength<=60:
        return 'Password "'+p+'" ('+strength+') is almost Good';
        break;
    case strength>60 && strength<=70:
        return 'Password "'+p+'" ('+strength+') is Good';
        break;
    case strength>70 && strength<=80:
        return 'Password "'+p+'" ('+strength+') is Very Good';
        break;
    case strength>80 && strength<=90:
        return 'Password "'+p+'" ('+strength+') is Strong';
        break;
    case strength>90 && strength<=100:
        return 'Password "'+p+'" ('+strength+') is Very Strong';
        break;
        default:
				return 'Error';
}
}
function strengthMap(w,arr) {
var c = 0;
var sum = 0;
newArray = arr.map(function(i) {
i = c;
//sum += w-2*i;
sum += w;
c++;
return sum;
});
return newArray[c-1];
}
function checkStrength(p){
var weight;
var extra;
switch(true) {
    case p.length<6:
        return false;
        break;
    case p.length>18:
        return false;
        break;
    case p.length>=6 && p.length<=10:
    		weight = 7;
        extra = 4;
        break;
    case p.length>10 && p.length<=14:
    		weight = 6;
        extra = 3;
        break;
    case p.length>14 && p.length<=18:
    		weight = 5;
        extra = 2.5;
        break;
}
allDigits = p.replace( /\D+/g, '');
allLower = p.replace( /[^a-z]/g, '' );
allUpper = p.replace( /[^A-Z]/g, '' );
allSpecial = p.replace( /[^\W]/g, '' );
if(allDigits && typeof allDigits!=='undefined') {
dgtArray = Array.from(new Set(allDigits.split('')));
dgtStrength = strengthMap(weight,dgtArray);
} else {
dgtStrength = 0;
}
if(allLower && typeof allLower!=='undefined') {
lowArray = Array.from(new Set(allLower.split('')));
lowStrength = strengthMap(weight,lowArray);
} else {
lowStrength = 0;
}
if(allUpper && typeof allUpper!=='undefined') {
upArray = Array.from(new Set(allUpper.split('')));
upStrength = strengthMap(weight,upArray);
} else {
upStrength = 0;
}
if(allSpecial && typeof allSpecial!=='undefined') {
splArray = Array.from(new Set(allSpecial.split('')));
splStrength = strengthMap(weight,splArray);
} else {
splStrength = 0;
}
strength = dgtStrength+lowStrength+upStrength+splStrength;
if(dgtArray.length>0){
strength = strength + extra;
}
if(splStrength.length>0){
strength = strength + extra;
}
if(p.length>=6){
strength = strength + extra;
}
if(lowArray.length>0 && upArray.length>0){
strength = strength + extra;
}
return strength;
}
console.log(strengthResult('5@aKw1'));
console.log(strengthResult('5@aKw13'));
console.log(strengthResult('5@aKw13e'));
console.log(strengthResult('5@aKw13eE'));
console.log(strengthResult('5@aKw13eE!'));
console.log(strengthResult('5@aKw13eE!,'));
console.log(strengthResult('5@aKw13eE!,4'));
console.log(strengthResult('5@aKw13eE!,4D'));
console.log(strengthResult('5@aKw13eE!,4Dq'));
console.log(strengthResult('5@aKw13eE!,4DqJ'));
console.log(strengthResult('5@aKw13eE!,4DqJi'));
console.log(strengthResult('5@aKw13eE!,4DqJi#'));
console.log(strengthResult('5@aKw13eE!,4DqJi#7'));
console.log(strengthResult('5@aKw13eE!,4DqJJ#7'));
console.log(strengthResult('5@aKw33eE!,4DqJJ#7'));

console.log(strengthResult('111111'));
console.log(strengthResult('1111111'));
console.log(strengthResult('11111111'));
console.log(strengthResult('111111111'));
console.log(strengthResult('1111111111'));
console.log(strengthResult('11111111111'));
console.log(strengthResult('111111111111'));
console.log(strengthResult('1111111111111'));
console.log(strengthResult('11111111111111'));
console.log(strengthResult('111111111111111'));
console.log(strengthResult('1111111111111111'));
console.log(strengthResult('11111111111111111'));
console.log(strengthResult('111111111111111111'));

console.log(strengthResult('5@aKw33eE!,4DqJJ#71'));
console.log(strengthResult('11111'));

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