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Update csrf token function, provide support for those without openssl #7

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Merged
alexweissman merged 1 commit into from
Apr 18, 2014
Merged

Update csrf token function, provide support for those without openssl #7

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35 changes: 26 additions & 9 deletions models/class.user.php
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Original file line number Diff line number Diff line change
Expand Up @@ -139,16 +139,33 @@ public function checkPermission($permission)
public function csrf_token($regen = false)
{
if($regen === true) {
//we need to give the user a token
unset($_SESSION["csrf_token"]);
$max = mt_rand(0, mt_getrandmax());//get a max number from mt_rand
do{
$result = floor($max*(hexdec(bin2hex(openssl_random_pseudo_bytes(4)))/0xffffffff));//generate a random 32 bit int with the seed from mt_rand
//*make sure token is set, if so unset*//
if(isset($_SESSION["__csrf_token"])) {
unset($_SESSION["__csrf_token"]);
}
if (function_exists('openssl_random_pseudo_bytes')) {
$rand_num = openssl_random_pseudo_bytes(16);//pull 16 bytes from /dev/random
}else{
/*
RYO(Roll Your Own) random number gen.
only used in the event openssl isn't available
*/
$rand = array();
for($i = 0; $i < 64; $i++) {
$random = mt_rand(rand(0,65012), mt_getrandmax());//get a random number between rand(0,65012) and mt rand max
$rand[$i] = mt_rand($i, $random); //add an array key of $i and a value of a number between $i and the first random number
}
$rand = array_sum(shuffle($rand)); //shuffle the random number, then sum the values
$rand_num = str_shuffle($rand * 64); //multiply the rand number by 64 and shuffle the string.
}
if(isset($rand_num)) {
$build_string = $rand_num . $this->hash_pw . time();
if(isset($build_string)) {
$_SESSION["__csrf_token"] = hash('whirlpool', str_shuffle($build_string));
$this->csrf_token = $_SESSION["__csrf_token"];
return $this->csrf_token;
}
}
while($result == $max);
$_SESSION["csrf_token"] = hash("sha256", $max . $this->username . $this->hash_pw);//hash the 32bit int, username, and password into the csrf token.
$this->csrf_token = $_SESSION["csrf_token"];
return $this->csrf_token;
}else{
//the user already has a token
return $this->csrf_token;
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