Sigurnosno pitanje, molimo odgovorite:");
DEFINE('MATHGUARD_FIELD_ANSWER', md5("hotelskalaa_answer".(date("d")*date("W")*date("W")))); // change this immediatelly to something else. eg. myanswer123
DEFINE('MATHGUARD_FIELD_CODE', md5("hotelskalaa_code".(date("d")*date("W")))); // change this immediatelly to something else. eg. mysecretcodefield
/** SETTINGS - you can easily modify these constants **/
class MathGuard {
/** you can also modify $output to your needs **/
function produceOutput($prime) {
$a = rand() % 10; // generates the random number
$b = rand() % 10; // generates the random number
$code = MathGuard :: generateCode($a, $b, $prime);
// please don't remove the backlink, thank you
$output = MATHGUARD_QUESTION .
"
";
return $output;
}
/** function that converts the decimal number to line of 3 random characters
* @param $dec decimal number that is being converted to line of 3 random characters
* */
function decToBin($dec) {
$pattern = "123456789ABCDEFGHIJKLMNOPQRTSTUWXYZ"; //without zero, it was interpreted as an empty space
$output = " ";
$i = 0;
do {
if ($dec % 2) {
$rand = rand() % 34;
$output {
2 - $i }
= $pattern {
$rand };
} else {
$output {
2 - $i }
= " ";
}
$dec = (int) ($dec / 2);
$i++;
} while ($dec > 0);
$output = str_replace(" ", " ", $output);
return $output;
}
/** function that renders a final 3x5 matrix consisting of random characters
* @param $a random number a that renders to the 3x5 matrix consisting of random characters
* @param $b random number b that renders to the 3x5 matrix consisting of random characters
* */
function renderExpression($a, $b) {
$number = array (
array (
7,
5,
5,
5,
7
),
array (
2,
6,
2,
2,
7
),
array (
7,
1,
7,
4,
7
),
array (
7,
1,
7,
1,
7
),
array (
4,
5,
7,
1,
1
),
array (
7,
4,
7,
1,
7
),
array (
7,
4,
7,
5,
7
),
array (
7,
1,
1,
1,
1
),
array (
7,
5,
7,
5,
7
),
array (
7,
5,
7,
1,
7
)
);
$plus = array (
0,
2,
7,
2,
0
);
$eq = array (
0,
7,
0,
7,
0
);
$output = "\n\n";
for ($line = 0; $line < 5; $line++) {
$output .= MathGuard :: decToBin($number[$a][$line]) . " " . MathGuard :: decToBin($plus[$line]) . " " . MathGuard :: decToBin($number[$b][$line]) . " " . MathGuard :: decToBin($eq[$line]) . "\n";
$output = str_replace("0", " ", $output);
}
return nl2br($output);
}
/** A main hashing function: concat of user's answer, hour and the additional prime number (default 37) */
function encode($input, $prime) {
return md5($input . date("H-d") . $prime);
}
/** This function generates the hash code from the two numbers
* @param $a first number
* @param $b second sumber
* @param $prime additional number to encode with
* */
function generateCode($a, $b, $prime) {
$code = MathGuard :: encode($a + $b, $prime);
return $code;
}
/** This function checks whether the answer and generated security code match
* @param $mathguard_answer answer the user has entered
* @param $mathguard_code hashcode the mathguard has generated
*/
function checkResult($mathguard_answer, $mathguard_code, $prime = 37) {
$mathguard_code = @$_POST[MATHGUARD_FIELD_CODE];
$mathguard_answer = @$_POST[MATHGUARD_FIELD_ANSWER];
// echo("prime; $prime, $mathguard_answer");
$result_encoded = MathGuard :: encode($mathguard_answer, $prime);
if ($result_encoded == $mathguard_code)
return true;
else
return false;
}
/** this function inserts the two math term into your form, the parameter is optional */
function insertQuestion($prime = 37) { //default prime is 37, you can change it when specifying the different parameter
$output = MathGuard :: produceOutput($prime);
echo $output;
}
/** this function returns math expression into your form, the parameter is optional
* quite simmilar to insertQuestion, but returns the output as a text instead of echoing
*/
function returnQuestion($prime = 37) { //default prime is 37, you can change it when specifying the different parameter
$output = MathGuard :: produceOutput($prime);
return $output;
}
}
?>
ENGLISH
