Question

I need a regex to test a users password for the following:

Must be minimum 8 characters with alphanumeric format, no more than 4 consecutive numbers, no id in the password (i.e. cannot use: 1234, 9876, abcd, or 1234abvc)

I am using ^([a-zA-Z0-9!@#$*%]{8,15})$ currently and it works great, but doesn’t account for the consecutive characters piece. I’m not sure how to add that to the mix.

Any help would be great!

Answer 1

If you want to solve it with regex, just add an negative lookahead assertion. You can test it here

^(?!.*\d{4,}.*)([a-zA-Z0-9!@#$*%]{8,})$

The added part (?!.*\d{4,}.*) does not consume your string, it just checks if there are 4 or more numbers in a row and if so, its false.

Why do you want to limit the passwords to 15 characters? I removed this in my example.