Php check if password contains special characters

I am currently making some tests with regex. I had an exercise which requested to check for a strong password, which means it should have: at least one number,one lowercase letter, one uppercase letter, no spaces, and at least one character that is not a letter or number. And it should be between 8-16 characters.

I wrote this code:

     = 8 && strlen($pass) < 17)
     {
       if(preg_match("/^\w*(?=\w*\d)(?=\w*[A-Z])(?=\w*[^0-9A-Za-z])(?=\w*[a-z])\w*$/", $pass) )
        echo "$pass => MATCH
";
       else
        echo "$pass => FAIL
";
     }
    else
      echo "$pass => FAIL(because of length)
";
  }
 ?>

The last two should match but they fail. I think the problem stands at

(?=\w*[^0-9A-Za-z])

which is supposed to be the pattern match to have at least one character that is not a letter or a number, but I cant figure out why. I know this strong password is solved in internet but thats not my issue. My issue is why that part of work dont do what is supposed to do.

asked Feb 26, 2017 at 10:17

10

You could split your regex into different checks.

It will allow you to write more readable conditions and to display specific error messages. Although, regexp patterns will be easier to write and to understand.

i.e. :

$errors = array();
if (strlen($pass) < 8 || strlen($pass) > 16) {
    $errors[] = "Password should be min 8 characters and max 16 characters";
}
if (!preg_match("/\d/", $pass)) {
    $errors[] = "Password should contain at least one digit";
}
if (!preg_match("/[A-Z]/", $pass)) {
    $errors[] = "Password should contain at least one Capital Letter";
}
if (!preg_match("/[a-z]/", $pass)) {
    $errors[] = "Password should contain at least one small Letter";
}
if (!preg_match("/\W/", $pass)) {
    $errors[] = "Password should contain at least one special character";
}
if (preg_match("/\s/", $pass)) {
    $errors[] = "Password should not contain any white space";
}

if ($errors) {
    foreach ($errors as $error) {
        echo $error . "\n";
    }
    die();
} else {
    echo "$pass => MATCH\n";
}

Hope it helps.

thenetimp

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answered Feb 26, 2017 at 10:41

JazZJazZ

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2

You can try this:

^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?!.* )(?=.*[^a-zA-Z0-9]).{8,16}$

It covers all your requirment

Explanation

1. (?=.*\d) Atleast a digit
2. (?=.*[a-z]) Atleast a lower case letter
3. (?=.*[A-Z]) Atleast an upper case letter
4. (?!.* ) no space
5. (?=.*[^a-zA-Z0-9]) at least a character except a-zA-Z0-9
6. .{8,16} between 8 to 16 characters

Sample Code:

Run it here

answered Feb 26, 2017 at 10:45

Mustofa RizwanMustofa Rizwan

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5

^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}\S+$

//The rule is at least
   one upper case, one lower case, one digit[0-9], 
   one special character[#?!@$%^&*-] and the minimum length should be 8.

answered Feb 26, 2017 at 10:40

SrikrushnaSrikrushna

3,7651 gold badge36 silver badges45 bronze badges

Use this simple regex to test a strong password

/(?=^.{8,}$)(?=.{0,}[A-Z])(?=.{0,}[a-z])(?=.{0,}\W)(?=.{0,}\d)/g

Javascript:

var password = "Abcdef@1234"
var passwordRegex = /(?=^.{8,}$)(?=.{0,}[A-Z])(?=.{0,}[a-z])(?=.{0,}\W)(?=.{0,}\d)/g

var isStrongPassword = passwordRegex.test(password)

console.log(isStrongPassword, "")

1. Minimum length 8 characters
2. at least 1 uppercase
3. at least 1 lowercase
4. at least 1 special character
5. at least 1 digit

answered Sep 23, 2020 at 10:26

^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[special characters]).{8,16}$

Add special characters as per requirement.

Above code check following conditions

• At least 1 uppercase character
• At least 1 lowercase character
• At least 1 digit
• At least 1 special character

Click here to test

answered Apr 10 at 10:50

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