note 53161 deleted from function.md5 by mazzanet

Note Submitter: mina86 dot spamsux at nospam dot projektcode dot org ---- Re: Robert Chapin That's obvious. null is converted into an empty string. Re: tommiboy Ad 1. Even if N is < 128 (but > then another value) there must be a collision since there are more then 2^128 strings of maximum length of 128 bits. Ad 5. Still, 1) programmer should be aware of ever issue in his/her software and 2) it's better not to have a bug then to have it even if it is very unlikely that anyone will use it. Re: IndigoDarkwolf The problem is that if one has a (let say) 15-letter long password containing only letters and digits, the password's MD5 can be cracked using a home computer in no time (well.. it'll take some time but still it's not hard). Re: scott at rocketpack dot net True, md5() returns only lower case letters but still a MD5 hash with upper case letter is still MD5 hash. It all depends on what you will be using this function for. Re: marc at NOSPAM dot giombetti dot com You're not correct. Check that out: <?php function valid_for_x_minutes($x, $opt = '') { return md5($x!=0 ? (ceil(date('i')/$x)*$x) . $opt : time() . $opt); } // Wait till 59 seconds sleep(59 - time()%60); $hash1 = valid_for_x_minutes(1, 'foo'); sleep(2); $hash2 = valid_for_x_minutes(1, 'foo'); echo($hash1 . "\n" . $hash2 . "\n"); ?> Though when $x>10 one minute doesn't make the difference but still better would be: <?php function valid_for_x_minutes($x, $opt = '') { $x = (int)($x * 60); return md5($x!=0 ? ceil(time()/(int)$x) . $opt : time() . $opt); } ?> Which of course wouldn't work for small $x