Using more secure token

This commit is contained in:
Antonin 2015-04-02 11:58:35 +02:00
parent 09ca8b28a7
commit c4cc36b076

View File

@ -5,14 +5,17 @@ class Token {
private $time; private $time;
private $value; private $value;
private $length;
private static $codeAlphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789';
function __construct() { function __construct($length = 64) {
$this->length = $length;
$this->time = time() + TOKEN_TIME; $this->time = time() + TOKEN_TIME;
$this->value = $this->generate(); $this->value = $this->generate();
} }
private function generate() { private function generate() {
return sha1(uniqid(mt_rand(), true)); return self::getToken($this->length);
} }
public function getTime() { public function getTime() {
@ -31,5 +34,58 @@ class Token {
return $value === $this->value; return $value === $this->value;
} }
/**
* Get a secure token if possible, or a less secure one if not.
*
* @param int $length The token length
* @param bool $crypto_strong If passed, tells if the token is "cryptographically strong" or not.
* @return string
*/
public static function getToken($length, &$crypto_strong = false) {
if (function_exists('openssl_random_pseudo_bytes')) {
openssl_random_pseudo_bytes(1, $crypto_strong); // Fake use to see if the algorithm used was "cryptographically strong"
return self::getSecureToken($length);
}
return self::getUnsecureToken($length);
}
public static function getUnsecureToken($length) {
$string = '';
mt_srand();
for ($i = 0; $i < $length; $i++) {
$string .= self::$codeAlphabet[mt_rand() % strlen(self::$codeAlphabet)];
}
return $string;
}
/**
* @author http://stackoverflow.com/a/13733588
*/
public static function getSecureToken($length){
$token = "";
for($i=0;$i<$length;$i++){
$token .= self::$codeAlphabet[self::crypto_rand_secure(0,strlen(self::$codeAlphabet))];
}
return $token;
}
/**
* @author http://us1.php.net/manual/en/function.openssl-random-pseudo-bytes.php#104322
*/
private static function crypto_rand_secure($min, $max) {
$range = $max - $min;
if ($range < 0) return $min; // not so random...
$log = log($range, 2);
$bytes = (int) ($log / 8) + 1; // length in bytes
$bits = (int) $log + 1; // length in bits
$filter = (int) (1 << $bits) - 1; // set all lower bits to 1
do {
$rnd = hexdec(bin2hex(openssl_random_pseudo_bytes($bytes)));
$rnd = $rnd & $filter; // discard irrelevant bits
} while ($rnd >= $range);
return $min + $rnd;
}
} }