Password integrity

[karldesign]

Hi all,

 

I am doing a registration for a website and want to check the password meets the following requirements:

 

1) 6 chars at least

2) A-Z/a-z/0-9 only (no characters)

 

I have worked out how to check for (1) - if(strlen($_POST['formPassword']) < 6) - and I just need to work out how to check for just letters and numbers (2).

 

Any help would be great...

[karldesign]

Does anyone know if this will be enough..?

 

if(!eregi("[a-z0-9]", $_POST['formPassword'])){
//invalid - not text or numbers
}
else if(eregi(" ", $_POST['formPassword'])){
//invalid - has space
}

[Orio]

The best way to check if a string is alphanumeric (Has only letters/numbers) imo is using ctype_alnum(). Example:

 

<?php

$str = '12abCD19z4';
if (ctype_alnum($str)) {
echo "Letters or digits only";

?>

 

 

In the tests I've made in the past, this function was faster than using preg_match() ot eregi().

If you still wanna go for the eregi() way:

 

<?php

if(eregi("^[0-9a-z]{6,}$", $_POST['formPassword']))
echo "Letters or digits only, and six chars at least";

?>

 

This would also check if the string has at least 6 chars

 

 

Orio.

[karldesign]

this allows such characters as '@' though... I don't want users to be able to select anythin but letters or numbers...

 

the ctype_alnum() function works fine though. thanks