»Passwort Generator mit hoher Sicherheit

$spec = '';

<?php

function rand_pw($min=4, $max=40, $pwlen=0)
{
	// settings
	$low = 'abcdefghijklmnopqrstuvwxyz';
	$up = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
	$no = '0123456789';
	$spec = '/-_#*+!§()=:.@äöüÄÖÜß';
	// default vars
	$all = $low . $up . $no . $spec;
	$len = strlen($all);
	$pw = '';
	$new = false;
	if ( PHP_VERSION < 4.2 )
	{
		mt_srand(intval((doubleval(microtime()) * 1000003)));
	}
	if ( !$pwlen )
	{
		// 4 is the minimum because of the number of char groups
		// 40 is the maximum because of the performance
		$min = $min < 4 ? 4 : ($min > 40 ? 40 : $min);
		$max = $max < 4 ? 4 : ($max > 40 ? 40 : $max);
		// min may not below max
		$min = $min > $max ? $max : $min;
		// set password length
		$pwlen = mt_rand($min, $max);
	}
	else
	{
		$pwlen = $pwlen < 4 ? 4 : ($pwlen > 40 ? 40 : $pwlen);
	}
	// create password
	for ($i = 1; $i <= $pwlen; $i++)
	{
		$pw .= $all{mt_rand(0, $len)};
	}
	// check for lowercase
	if ( $low && preg_match('/^[^' . $low . ']+$/', $pw) )
	{
		$new = true;
	}
	// check for uppercase
	else if ( $up && preg_match('/^[^' . $up . ']+$/', $pw) )
	{
		$new = true;
	}
	// check for numbers
	else if ( $no && preg_match('/^[^' . $no . ']+$/', $pw) )
	{
		$new = true;
	}
	// check for special chars
	else if ( $spec && preg_match('/^[^' . preg_quote($spec, '/') . ']+$/', $pw) )
	{
		$new = true;
	}
	// count char group appearance
	else
	{
		$ilow = 0;
		$iup = 0;
		$ino = 0;
		$ispec = 0;
		$chars = count_chars($pw);
		foreach ( $chars as $char => $count )
		{
			if ( $low && preg_match('/^[' . $low . ']+$/', chr($char)) )
			{
				if ( $count > 2 )
				{
					$new = true;
					break;
				}
				$ilow = $ilow + $count;
			}
			else if ( $up && preg_match('/^[' . $up . ']+$/', chr($char)) )
			{
				if ( $count > 2 )
				{
					$new = true;
					break;
				}
				$iup = $iup + $count;
			}
			else if ( $no && preg_match('/^[' . $no . ']+$/', chr($char)) )
			{
				if ( $count > 2 )
				{
					$new = true;
					break;
				}
				$ino = $ino + $count;
			}
			else if ( $spec && preg_match('/^[' . preg_quote($spec, '/') . ']+$/', chr($char)) )
			{
				if ( $count > 2 )
				{
					$new = true;
					break;
				}
				$ispec = $ispec + $count;
			}
		}
		// check for minimum appearance per group
		$app = $pwlen > 4 ? floor($pwlen / 5) : 1;
		if ( $ilow < $app || $iup < $app || $ino < $app || $ispec < $app )
		{
			$new = true;
		}
	}
	// obtain new password
	if ( $new )
	{
		$pw = rand_pw($min, $max, $pwlen);
	}
	return $pw;
}

// Passwort zwischen 4 und 10 Zeichen
echo(rand_pw(4, 10));
echo('<br />');
// Passwort mit fixer Länge von 12 Zeichen
echo(rand_pw(12, 12));
echo('<br />');
// resultiert das gleiche (fixe Länge von 12 Zeichen)
echo(rand_pw(0, 0, 12));
echo('<br />');

?>