密码强度验证Java

Question

I need to write a program to check the strength of a password based on following conditions and output the type of password as "Too short", "Weak", "Medium" or "Strong"

Conditions: 1) Password should be 8 characters long 2) it should contain at least one uppercase and one lowercase letter 3) it should contain one or more of these special characters: ~, !, @, #, $, %, ^, &, * 4) it should contain one or more digits in it The output is defined as: if first condition fails, then output = "Too short" if only two conditions including first one

is met, then output = "Weak" if only three conditions including first one is met, then output = "Medium" if all four conditions are met, then output = "Strong" Below is the code I have written:

class PasswordStrengthValidation
{
    public static void main(String[] args)
    {
        // TODO Auto-generated method stub
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter the password");
        String inputPassword = scan.next();
        int uppercase = 0;
        int lowercase = 0;
        int specialcharacters = 0;
        int digits = 0;
        char[] Password = inputPassword.toCharArray();
        for (int index = 0; index < inputPassword.length(); index++)
        {
            if (Character.isUpperCase(Password[index]))
            {
                uppercase = 1;
            }
            if (Character.isLowerCase(Password[index]))
            {
                lowercase = 1;
            }
            if (Character.isDigit(Password[index]))
            {
                digits = 1;
            }
        }
        if (inputPassword.contains("~") || inputPassword.contains("!") || inputPassword.contains("@")
            || inputPassword.contains("#") || inputPassword.contains("$") || inputPassword.contains("%")
            || inputPassword.contains("^") || inputPassword.contains("&") || inputPassword.contains("*")) ;
        {
            specialcharacters = 1;
        }
        if (inputPassword.length() < 8)

            System.out.println("Too Short");

        if (inputPassword.length() >= 8 && (((uppercase == 1) && (lowercase == 1)) || (digits == 1) || (specialcharacters == 1)))

            System.out.println("Weak");

        if ((inputPassword.length() >= 8 && (((uppercase == 1) && (lowercase == 1)) || (digits == 1) && (specialcharacters == 1)))
            &&
            (inputPassword.length() >= 8 && (((uppercase == 1) && (lowercase == 1)) && (digits == 1) || (specialcharacters == 1))))

            System.out.println("Medium");

        if (inputPassword.length() >= 8 && (uppercase == 1) && (lowercase == 1) && (digits == 1) && (specialcharacters == 1))

            System.out.println("Strong");

    }
}

However when I try to implement the below code by giving an input of "Password" which falls under the "Weak" category I get the output as Weak followed by Medium. Can someone please help me as to where am I going wrong. Thanks in advance!

Answer 1

I suggest use a regex

if (inputPassword.matches("^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!@#\$%\^&\*])(?=.{8,})")){
    System.out.println("Strong");
} else if (inputPassword.matches("^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.{8,})")){
    System.out.println("Medium");
} else if (inputPassword.matches("^(?=.*[a-z])(?=.*[0-9])(?=.{8,})")){
    System.out.println("Weak");
} else if (inputPassword.matches("^(?=.*[A-Z])(?=.*[0-9])(?=.{8,})")){
    System.out.println("Weak");
} // etc

you can adjust conditions removing or change conditions in the expression

• (?=.*[az]) The string must contain at least 1 lowercase alphabetical character

• (?=.*[AZ]) The string must contain at least 1 uppercase
  alphabetical character

• (?=.*[0-9]) The string must contain at least 1 numeric character

• (?=.[!@#\\$%\\^&]) The string must contain at least one special character, but we are escaping reserved RegEx characters to avoid conflict

• (?=.{8,}) The string must be eight characters or longer