better random number generator

git-svn-id: https://silmor.de/svn/softmagic/smoke/trunk@609 6e3c4bff-ac9f-4ac1-96c5-d2ea494d3e33

diff --git a/www/inc/classes/random.php b/www/inc/classes/random.php
index 62ec275..32b9eac 100644 (file)
--- a/www/inc/classes/random.php
+++ b/www/inc/classes/random.php
@@ -23,36 +23,44 @@ function randseedfile($fn,$sz)
 }
 
 //get current random seed
-$RANDSEED="".microtime();
+$RANDSEED="";
 $RANDCTR=0;
-if($db->canUseDb())$RANDSEED.=$db->getConfig("randseed");
-if(file_exists("/dev/urandom"))randseedfile("/dev/urandom",64);
-if(file_exists("/dev/random"))randseedfile("/dev/random",16);
-if(isset($_SERVER["UNIQUE_ID"]))$RANDSEED.=$_SERVER["UNIQUE_ID"];
 
-/**add some seed into the random function*/
-function randseed($rand)
+//initialize random seed
+function randseedinit()
 {
-       global $RANDSEED;
-       $RANDSEED.=$rand;
+       global $RANDSEED,$_SERVER;
+       //very basic initialization
+       $RANDSEED.=microtime().uniqid("",true);
+       //attempt to use OpenSSL
+       if (function_exists('openssl_random_pseudo_bytes')) {
+               $RANDSEED .= openssl_random_pseudo_bytes(64, $strong);
+               // if it was strong, be happy and leave
+               if($strong === true) {
+                       return;
+               }
+       }
+       //attempt to use /dev/(u)random
+       if(file_exists("/dev/urandom"))randseedfile("/dev/urandom",64);
+       else if(file_exists("/dev/random"))randseedfile("/dev/random",20);
+       //last resort: get what we got from apache
+       if(isset($_SERVER["UNIQUE_ID"]))$RANDSEED.=$_SERVER["UNIQUE_ID"];
 }
 
-/**return $bits bits of random data*/
+/**return $bits bits of random data as hex string*/
 function getRandom($bits)
 {
        //number of digits...
        $bits/=4;
        //init
-       global $RANDSEED,$db,$RANDCTR;
-       $ret="";$ctr=0;
+       global $RANDSEED,$RANDCTR;
+       if($RANDSEED=="")randseedinit();
+       $ret="";
        //get string
        while(strlen($ret)<$bits){
                $ret.=sha1($RANDSEED.microtime().$RANDCTR);
                $RANDCTR++;
        }
-       //rewrite seed to DB
-       $RANDSEED=sha1($RANDSEED.microtime().$ret.$RANDCTR);$RANDCTR=0;
-       $db->setConfig("randseed",$RANDSEED);
        //return
        return substr($ret,0,$bits);
 }