PHP和Javascript中密码匹配的正则表达式

Question

I have built a regular expression for password policy match, but it is not working as expected

/((?=.\d)(?=.[a-z])(?=.[A-Z])(?=.[@#\$%!])(?!(.)*\1{2,}).{6,20})/

Password must satisfy below rules -> must have 1 digit -> must have 1 upper case letter -> must have 1 lower case letter -> must have 1 special character from given list -> minimum 6 character long -> maximum 20 character long -> Not more than 2 identical characters`

So it matches

aDm!n1, Adw1n@

but it must not match below aaaD!n1, teSt@111

I have searched for this regular expression and found "(?!(.)*\1{2,})" is not working properly

I am not getting why it is not working even though it has lookahead negative assertion.

Thanks in advance

Answer 1

(?:(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#\$%!])(?!.*(.).*\1.*\1).{6,20})

You need this.See demo.

http://regex101.com/r/hQ9xT1/22

Your regex was failing cos

(?!(.)*\1{2,}) will not work as it find consecutive repeated characters and not any character which is three times or more.So use (?!.*(.).*\1.*\1).

var re = /^(?:(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#\$%!])(?!.*(.).*\1.*\1).{6,20})$/gm;
var str = 'aaaD!n1
teSt@111
aDm!n1
Adw1n@';
var m;

while ((m = re.exec(str)) != null) {
if (m.index === re.lastIndex) {
re.lastIndex++;
}
// View your result using the m-variable.
// eg m[0] etc.
}