jQuery Validate plugin - password check - minimum requirements - Regex

Question

I've got a little problem with my password-checker.

There's got a registration form with some fields. I use jQuery Validate plugin to validate user-inputs.

It all works except the password-validation:

The password should meet some minimum requirements:

• minimum length: 8 -> I just use 'minlength: 8'
• at least one lower-case character
• at least one digit
• Allowed Characters: A-Z a-z 0-9 @ * _ - . !

At the moment I use this code to validate the password:

$.validator.addMethod("pwcheck",
function(value, element) {
   return /^[A-Za-z0-9d=!-@._*]+$/.test(value);
});

This Code works for the allowed characters but not for minimum requirements. I know that you can use for example (?=.*[a-z]) for a lower-case-requirement. But I just don't get it to work.

If I add (?=.*[a-z]) the whole code doesn't work anymore. I need to know how to properly add the code to the existing one.

Thank you for your answers!

This is the complete code

<script>
                $(function() {
                    $("#regform").validate({
                        rules: {
                            forename: {
                                required: true
                            },
                            surname: {
                                required: true
                            },
                            username: {
                                required: true
                            },
                            password: {
                                required: true,
                                pwcheck: true,
                                minlength: 8
                            },
                            password2: {
                                required: true,
                                equalTo: "#password"
                            },
                            mail1: {
                                required: true,
                                email: true
                            },
                            mail2: {
                                required: true,
                                equalTo: "#mail1"
                            }
                        },
                        messages: {
                            forename: {
                                required: "Vornamen angeben"
                            },
                            surname: {
                                required: "Nachnamen angeben"
                            },
                            username: {
                                required: "Usernamen angeben"
                            },
                            password: {
                                required: "Passwort angeben",
                                pwcheck: "Das Passwort entspricht nicht den Kriterien!",
                                minlength: "Das Passwort entspricht nicht den Kriterien!"
                            },
                            password2: {
                                required: "Passwort wiederholen",
                                equalTo: "Die Passw?rter stimmen nicht überein"
                            },
                            mail1: {
                                required: "Mail-Adresse angeben",
                                email: "ungültiges Mail-Format"
                            },
                            mail2: {
                                required: "Mail-Adresse wiederholen",
                                equalTo: "Die Mail-Adressen stimmen nicht überein"
                            }
                        }
                    });

                    $.validator.addMethod("pwcheck",
                        function(value, element) {
                            return /^[A-Za-z0-9d=!-@._*]+$/.test(value);
                    });
                });
                </script>

Answer 1

If I add (?=.*[a-z]) the whole code doesn't work anymore.

Add it here:

/^(?=.*[a-z])[A-Za-z0-9d=!-@._*]+$/

However, it's much easier to do this without a lookahead:

$.validator.addMethod("pwcheck", function(value) {
   return /^[A-Za-z0-9d=!-@._*]*$/.test(value) // consists of only these
       && /[a-z]/.test(value) // has a lowercase letter
       && /d/.test(value) // has a digit
});