function _drupal_random_bytes in Node.js integration 6
1 call to _drupal_random_bytes()
- nodejs_generate_content_token in ./
nodejs.module - Generate a token for a piece of content.
File
- ./
nodejs.module, line 679
Code
function _drupal_random_bytes($count) {
// $random_state does not use drupal_static as it stores random bytes.
static $random_state, $bytes;
// Initialize on the first call. The contents of $_SERVER includes a mix of
// user-specific and system information that varies a little with each page.
if (!isset($random_state)) {
$random_state = print_r($_SERVER, TRUE);
if (function_exists('getmypid')) {
// Further initialize with the somewhat random PHP process ID.
$random_state .= getmypid();
}
$bytes = '';
}
if (strlen($bytes) < $count) {
// /dev/urandom is available on many *nix systems and is considered the
// best commonly available pseudo-random source.
if ($fh = @fopen('/dev/urandom', 'rb')) {
// PHP only performs buffered reads, so in reality it will always read
// at least 4096 bytes. Thus, it costs nothing extra to read and store
// that much so as to speed any additional invocations.
$bytes .= fread($fh, max(4096, $count));
fclose($fh);
}
// If /dev/urandom is not available or returns no bytes, this loop will
// generate a good set of pseudo-random bytes on any system.
// Note that it may be important that our $random_state is passed
// through hash() prior to being rolled into $output, that the two hash()
// invocations are different, and that the extra input into the first one -
// the microtime() - is prepended rather than appended. This is to avoid
// directly leaking $random_state via the $output stream, which could
// allow for trivial prediction of further "random" numbers.
while (strlen($bytes) < $count) {
$random_state = hash('sha256', microtime() . mt_rand() . $random_state);
$bytes .= hash('sha256', mt_rand() . $random_state, TRUE);
}
}
$output = substr($bytes, 0, $count);
$bytes = substr($bytes, $count);
return $output;
}