Regex to validate passwords with characters restrictions

Question

I need to validate a password with these rules:

• 6 to 20 characters
• Must contain at least one digit;
• Must contain at least one letter (case in

Answer 1

^(?=.*\d)(?=.*[a-zA-Z])[a-zA-Z0-9!@#$%&*]{6,20}$

Answer 2

Regex could be:-

^(?=.*\d)(?=.*[a-zA-Z])[a-zA-Z0-9!@#$%&*]{6,20}$

How about this in Javascript:-

function checkPwd(str) {
    if (str.length < 6) {
        return("too_short");
    } else if (str.length > 20) {
        return("too_long");
    } else if (str.search(/\d/) == -1) {
        return("no_num");
    } else if (str.search(/[a-zA-Z]/) == -1) {
        return("no_letter");
    } else if (str.search(/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\_\+]/) != -1) {
        return("bad_char");
    }
    return("ok");
}

Also check out this

Answer 3

I'm not completely sure I have this right, but since your last requirement is "Can contain the following characters: !@#$%&*" I am assuming that other special characters are not allowed. In other words, the only allowed characters are letters, digits, and the special characters !@#$%&*.

If this is the correct interpretation, the following regex should work:

^((?=.*\d)(?=.*[a-zA-Z])[a-zA-Z0-9!@#$%&*]{6,20})$

Note that I changed your character class [A-z] to [a-zA-Z], because [A-z] will also include the following characters: [\]^_`

I also added beginning and end of string anchors to make sure you don't get a partial match.