/**
* Derive a key from the supplied arguments
*
* @param string $password The password to derive from
* @param string $salt The salt string to use
* @param int $iterations The number of iterations to use
* @param int $length The size of the string to generate
*
* @return string The derived key
*/
public function derive($password, $salt, $iterations, $length)
{
$size = Hash::getHashSize($this->hash);
$len = ceil($length / $size);
$result = '';
for ($i = 1; $i <= $len; $i++) {
$tmp = hash_hmac($this->hash, $salt . pack('N', $i), $password, true);
$res = $tmp;
for ($j = 1; $j < $iterations; $j++) {
$tmp = hash_hmac($this->hash, $tmp, $password, true);
$res ^= $tmp;
}
$result .= $res;
}
return substr($result, 0, $length);
}
public function testIsSecureDefault()
{
$this->assertEquals(false, Hash::isSecure('foobarbaz'));
}