How-to create a PHP Password Generator

13 Comments

1. Good code, but those ‘for’ cycles look like they’re not in place :) For letters, you can use range(‘a’,’z’); and range(‘A’,’Z’);, then for ‘specials’ the cycle could be placed with range(33,47);, same with numbers. They will create array’s with the needed symbols :) It’s more practical, and it looks cleaner, and of course the performance SHOULD be better :)

2. Hi fosron,

   Thanks for the comment, it’s funny I’m sure that I noticed that function before, but never used it :D

   I don’t think that most of the websites will see a big raise in performance. But for those this is the function in a more “compact” format:

   function create_password($pw_length = 8, $use_caps = true, $use_numeric = true, $use_specials = true) {
   	$caps = array();
   	$numbers = array();
   	$num_specials = 0;
   	$reg_length = $pw_length;
   	$pws = array();
   	$chars = range(97, 122); // create a-z
   	if ($use_caps) $caps = range(65, 90); // create A-Z
   	if ($use_numeric) $numbers = range(48, 57); // create 0-9
   	$all = array_merge($chars, $caps, $numbers);
   	if ($use_specials) {
   		$reg_length =  ceil($pw_length*0.75);
   		$num_specials = $pw_length - $reg_length;
   		if ($num_specials > 5) $num_specials = 5;
   		$signs = range(33, 47);
   		$rs_keys = array_rand($signs, $num_specials);	
   		foreach ($rs_keys as $rs) {
   			$pws[] = chr($signs[$rs]);
   		}
   	} 
   	$rand_keys = array_rand($all, $reg_length);
   	foreach ($rand_keys as $rand) {
   		$pw[] = chr($all[$rand]);
   	}	
   	$compl = array_merge($pw, $pws);	
   	shuffle($compl);
   	return implode('', $compl);
   }
   

3. Or, simply:
   $ pear install Text_Password
   and then in your code:

   require_once 'Text/Password.php';
   echo Text_Password::create();

4. Hi Christian,

   sure there are many options. I don’t like PEAR ;)
   Don’t forget many shared hosting provider doesn’t allow pear installs

5. Correction of some errors I’ve made:
   – it should be “strlen($specialSymbols) – 1”
   – $alphabet instead of $alhpabet in the 1st line of the function
   – there is a “‘” repeated with the $alphabet declaration

6. You don’t have to have a hosting provider’s permission to use PEAR packages (hint: they work without PEAR installer).
   As for the code, how about something like this:

   function randomString($length = 16) {
       $alhpabet = 'ABCDEFGHIJKLMNOPORRQSTUWVXYZabcdefghijklmnoprqstuwvxyz0123456789!@#$%^&*?';
       $alphabetLenght = strlen($alphabet) - 1;
       $string = '';
       while($length) {
           $string .= $alphabet[mt_rand(0, $alphabetLenght)];
           --$length;
       }
       return $string;
   }
   

   For a “special symbols in 25% of the password” thing you would have to have a separate variable for those special symbols and then in the loop something like this:

   if (mt_rand(0,3)) {
       $string .= $alphabet[mt_rand(0, $alphabetLenght)];
   } else {
       $string .= $specialSymbols[mt_rand(0, strlen($specialSymbols))];
   }
   

   That won’t guarantee you perfect 25% every time, but statistically it should oscillate around that number (gotta love math!) and it’s much more elegant solution I think.

   1. Hallo Tomek,

      First of all, thanks for posting your PHP code examples. :)

      Why not using PEAR?

      Sure your can download all the PHP classes from the PEAR site.
      I think the best is the PEAR distribution system, so why should I use PEAR? Because there are so many old projects? Yes there are several good maintained projects but, how do I know which project is a good one? If I need to use a PHP “library”, is Zend Framework a good choise too.

      About your function, I used this kind of code very often (short and simple), but the function in this PHP tutorial has much more control about which character I can use.

      Don’t forget this tutorial is supposed to show how stuff works ;)

7. Thanks for sharing a code sample, but please don’t teach people to use bad coding style. Omitting braces is a recipe for disaster here:

   if ($use_caps) for ($ca = 65; $ca <= 90; $ca++) $caps[] = $ca; // create A-Z

   Also, the way of specifying options can get awkward. A bit mask is more elegant here:

   function create_password($options) {
     if ($options & PASSWORD_USE_SPECIALS) {
       /* ... */
     }
   }

   And as said before, don't reinvent the wheel. :-)

   1. Hi Jan,

      Normally I use braces in my code, but for tutorials I try to keep the code as short as possible … :)

      I don’t understand your second comment, do you suggest to use an array for the options? Why do you suggest a constant variable?

8. Nice script. Thanks

   I have one concern with it (sorry, I’m going to be a little bit blunt), but the syntax you use is atrocious and disgusting:

   if ($use_numeric) for ($nu = 48; $nu <= 57; $nu++) $numbers[] = $nu;

   This is acceptable though:

   if ($use_numeric) $numbers = range(48, 57);

   but this is better:

   if ($use_numeric) 
       $numbers = range(48, 57);

   Code readability is very important...

9. Hello Aziz,
   you’re right readability is important, but is also about personal “coding style” ;)
   I see a lot of people coding this way:

   if ($val) 
   {
       echo 'Hello!';
   }
   

   This is something I don’t like.
   Right my IF statement with a FOR loop on a single row without using braces is very short, but I can read this very well:
   if ($use_numeric) $numbers = range(48, 57);

   btw. You see that WordPress gives a new format to posted code as well.

10. Hello Olaf,

    You are right. if we use the single row without using braces like if ($use_numeric) $numbers = range(48, 57);
    is very short. but the beginners can’t able to understood it at first look.

    1. @srisoftwarez,
       I remember me that I had some problems (years ago with notations like:

       $var ($is_true) ? 'cool' : 'not cool';

       But if you need to pass only one value to a variable , it should be fine to use these short notations. If I have 10 statements like this I can choose from 10 rows I need to scroll or 40

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