Multiple Password Generation

baffled_in_UK

Hi,

I'm creating a user database and at the site launch I intend to generate passwords for each member and then mail them out. I do this by looping around the member table and for each member I call run the function. The problem I am having is that each script I use (taken from free sites), generates the same password for every member. The latest script looks like this :

function genpassword($length){ 

srand((double)microtime()*100000); 

$vowels = array("a", "e", "i", "o", "u"); 
$cons = array("b", "c", "d", "g", "h", "j", "k", "l", "m", "n", "p", "r", "s", "t", "u", "v", "w", "tr", 
"cr", "br", "fr", "th", "dr", "ch", "ph", "wr", "st", "sp", "sw", "pr", "sl", "cl"); 

$num_vowels = count($vowels); 
$num_cons = count($cons); 

for($i = 0; $i < $length; $i++){ 
    $password .= $cons[rand(0, $num_cons - 1)] . $vowels[rand(0, $num_vowels - 1)]; 
} 

return substr($password, 0, $length); 
}

I'm fairly sure it's because the script is using the same time once it starts so therefore I'm getting the same result. How can I adjust this so that it will generate different values whilst the time doesn't change.

Thanks

drawmack

comment out the srand function, or move it outside the function and into the main program

baffled_in_UK

Just done it but the same thing is happening.

drawmack

why don't you generate a password bassed on something else. Like maybe their username and email address?

baffled_in_UK

Thanks for replying.

The user name is their email address but I was also hoping someone would be able to give me a solution.

pjleonhardt

yeah... this is a problem ive had as well... as far as i have found, if you are using the time as a seed for the random generator, if u call the random function too fast, and starts on the same seed again youll keep getting the same result. I am stumped for a solution as well

drawmack

I just ran this function, as you have it in the first post, on my server in a loop 1000 times. Only four of the passwords repeated and each of those only once. So I got 996 unique passwords out of 1000. Since I'm just putting this into an array I can easily use the in_array function to ensure uniqueness. Like so

<?php
$passwords_needed = 1000;
$password_length = 6;
$passwords = array();
while(count($passwords) < $passwords_needed) {
    $temp = genpassword($password_length);
    if(!in_array($temp,$passwords)) {
        array_push($passwords,$temp);
    } //end if
} //end while
?>

and just for argument sake the script that I ran on my server as a test is attached.