function test_cryptrand()
{
// It's possible, but HIGHLY unlikely that a correct
// implementation will fail by returning the same number twice
$s = Auth_OpenID_CryptUtil::getBytes(32);
$t = Auth_OpenID_CryptUtil::getBytes(32);
$this->assertEquals(Auth_OpenID::bytes($s), 32);
$this->assertEquals(Auth_OpenID::bytes($t), 32);
$this->assertFalse($s == $t);
}
/**
* Produce a string of length random bytes, chosen from chrs. If
* $chrs is null, the resulting string may contain any characters.
*
* @param integer $length The length of the resulting
* randomly-generated string
* @param string $chrs A string of characters from which to choose
* to build the new string
* @return string $result A string of randomly-chosen characters
* from $chrs
*/
function randomString($length, $population = null)
{
if ($population === null) {
return Auth_OpenID_CryptUtil::getBytes($length);
}
$popsize = strlen($population);
if ($popsize > 256) {
$msg = 'More than 256 characters supplied to ' . __FUNCTION__;
trigger_error($msg, E_USER_ERROR);
}
$duplicate = 256 % $popsize;
$str = "";
for ($i = 0; $i < $length; $i++) {
do {
$n = ord(Auth_OpenID_CryptUtil::getBytes(1));
} while ($n < $duplicate);
$n %= $popsize;
$str .= $population[$n];
}
return $str;
}
/**
* Make a new association.
*/
function createAssociation($dumb = true, $assoc_type = 'HMAC-SHA1')
{
$secret = Auth_OpenID_CryptUtil::getBytes(
Auth_OpenID_getSecretSize($assoc_type));
$uniq = base64_encode(Auth_OpenID_CryptUtil::getBytes(4));
$handle = sprintf('{%s}{%x}{%s}', $assoc_type, intval(time()), $uniq);
$assoc = Auth_OpenID_Association::fromExpiresIn(
$this->SECRET_LIFETIME, $handle, $secret, $assoc_type);
if ($dumb) {
$key = $this->dumb_key;
} else {
$key = $this->normal_key;
}
$this->store->storeAssociation($key, $assoc);
return $assoc;
}
/**
* Returns a random number in the specified range. This function
* accepts $start, $stop, and $step values of arbitrary magnitude
* and will utilize the local large-number math library when
* available.
*
* @param integer $start The start of the range, or the minimum
* random number to return
* @param integer $stop The end of the range, or the maximum
* random number to return
* @param integer $step The step size, such that $result - ($step
* * N) = $start for some N
* @return integer $result The resulting randomly-generated number
*/
function rand($stop)
{
static $duplicate_cache = array();
// Used as the key for the duplicate cache
$rbytes = $this->longToBinary($stop);
if (array_key_exists($rbytes, $duplicate_cache)) {
list($duplicate, $nbytes) = $duplicate_cache[$rbytes];
} else {
if ($rbytes[0] == "") {
$nbytes = Auth_OpenID::bytes($rbytes) - 1;
} else {
$nbytes = Auth_OpenID::bytes($rbytes);
}
$mxrand = $this->pow(256, $nbytes);
// If we get a number less than this, then it is in the
// duplicated range.
$duplicate = $this->mod($mxrand, $stop);
if (count($duplicate_cache) > 10) {
$duplicate_cache = array();
}
$duplicate_cache[$rbytes] = array($duplicate, $nbytes);
}
do {
$bytes = "" . Auth_OpenID_CryptUtil::getBytes($nbytes);
$n = $this->binaryToLong($bytes);
// Keep looping if this value is in the low duplicated range
} while ($this->cmp($n, $duplicate) < 0);
return $this->mod($n, $stop);
}
