(PECL crack >= 0.1)
crack_check — Performs an obscure check with the given password
$dictionary
, string $password
)$password
, string $username = ""
, string $gecos = ""
, resource $dictionary = NULL
)Performs an obscure check with the given password on the specified dictionary. The alternative signature also takes into account the username and the GECOS information.
This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.
dictionaryThe crack lib dictionary. If not specified, the last opened dictionary is used.
passwordThe password to be checked.
usernameThe username of the account with the password.
gecosThe GECOS information associated with the user account.
Returns TRUE if password is strong, or FALSE otherwise.
| Version | Description |
|---|---|
| 0.3 |
The username, gecos and
dictionary parameters were added to the
alternative signature.
|
In addition to the usual checks crack can also check for similarities between the password and a username and gecos field (the gecos field normally contains the person's full name on unix systems).
There is a third format for the function call which supplies these additional parameters:
bool crack_check (string $password, string $username, string $gecos, resource $dictionary)
This is true of PECL crack version 0.4, I'm not sure about earlier versions.
If you need to test a password with cracklib but don't have the necessary module available in PHP, you can use a function like this.
It requires the command line cracklib-check binary in /usr/sbin, but changing its location is trivial.
The $message variable will contain cracklib's complaint (if there is one)
You'll want to wrap your invocation of this function in a try...catch block.
<?php
function cracklibCheck($password, &$message)
{
// Clean up password
$password=str_replace("\r", "", $password);
$password=str_replace("\n", "", $password);
// Run password through cracklib-check
exec("echo ".escapeshellarg($password)." | /usr/sbin/cracklib-check 2>/dev/null", $output, $return_var);
// Check it ran properly
if($return_var==0)
{
if(preg_match("/^.*\: ([^:]+)$/", $output[0], $matches))
{
// Check response
if(strtoupper($matches[1])=="OK")
{
// Password is strong
$message="";
return(true);
}
else
{
// Cracklib doesn't like it
$message=$matches[1];
return(false);
}
}
else
{
// Badly formatted response from cracklib-check.
throw new Exception("Didn't understand cracklib-check response.");
}
}
else
{
// Some sort of execution error
throw new Exception("Failed to run cracklib-check.");
}
}
?>
