I need to figure out if a password meets several conditions, but not all.
Has to include 3 out 4 conditions
a) A-Z
b) a-z
c) 0-9
d) !*?$%&
So it's correct if the password has a capital letter, a lower letter and a numnber or instead of the number a special char, ...
Is this possible without writing several OR conditions (a+b+c OR a+b+d OR a+c+d OR b+c+d) ?
I'd avoid the issue of using a single regular expression, and simply combine the simple regular expressions together into an array, test the entered-password against that array of expressions using Array.prototype.filter() to create a new array from those matches where the individual regular expressions test true (using RegExp.prototype.test()):
function validateConditions (string, n) {
// individual tests:
var capital = /[A-Z]/, // any letter, from the characters A-Z (inclusive)
lower = /[a-z]/, // any letter, from the characters a-z (inclusive)
numeric = /\d/, // any number character
special = /[!*?$%&]/, // any of these special characters
// an array of those simple tests:
tests = [capital, lower, numeric, special],
// filtering the array of tests (to create a new array 'success'):
success = tests.filter(function (validate) {
// if the string tests true (RegExp.test returns a Boolean value):
if (validate.test(string)) {
// we return true (though any value would be fine, since
// we're only checking the length of the 'success' array):
return true;
}
});
// making sure that the 'success' array has a length equal to, or greater
// than the required number ('n') of matches:
return success.length >= n;
}
// adding an event-listener to the 'test' element, which runs on 'keyup':
document.getElementById('test').addEventListener('keyup', function (e) {
// logging the returned Boolean of validateConditions():
console.log(validateConditions(e.target.value, 3));
});
References:
This website might give some answers too: http://www.zorched.net/2009/05/08/password-strength-validation-with-regular-expressions/
On a side note: Use of symbols, lowercase, uppercase, numbers does increase entropy, but length is much more important. The CorrectHorseBatteryStaple (http://xkcd.com/936/) example was a big eye-opener to me.
Look into using regular expression lookaheads and see if you can hack together a beast of a regex. I checked google for "regex password complexity" and found similar questions to yours, so I'd start there.
