1 files changed, 109 insertions, 0 deletions
diff --git a/extlib/Auth/OpenID/CryptUtil.php b/extlib/Auth/OpenID/CryptUtil.php
new file mode 100644
index 000000000..aacc3cd39
--- /dev/null
+++ b/extlib/Auth/OpenID/CryptUtil.php
@@ -0,0 +1,109 @@
+<?php
+
+/**
+ * CryptUtil: A suite of wrapper utility functions for the OpenID
+ * library.
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: See the COPYING file included in this distribution.
+ *
+ * @access private
+ * @package OpenID
+ * @author JanRain, Inc. <openid@janrain.com>
+ * @copyright 2005-2008 Janrain, Inc.
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
+ */
+
+if (!defined('Auth_OpenID_RAND_SOURCE')) {
+    /**
+     * The filename for a source of random bytes. Define this yourself
+     * if you have a different source of randomness.
+     */
+    define('Auth_OpenID_RAND_SOURCE', '/dev/urandom');
+}
+
+class Auth_OpenID_CryptUtil {
+    /**
+     * Get the specified number of random bytes.
+     *
+     * Attempts to use a cryptographically secure (not predictable)
+     * source of randomness if available. If there is no high-entropy
+     * randomness source available, it will fail. As a last resort,
+     * for non-critical systems, define
+     * <code>Auth_OpenID_RAND_SOURCE</code> as <code>null</code>, and
+     * the code will fall back on a pseudo-random number generator.
+     *
+     * @param int $num_bytes The length of the return value
+     * @return string $bytes random bytes
+     */
+    function getBytes($num_bytes)
+    {
+        static $f = null;
+        $bytes = '';
+        if ($f === null) {
+            if (Auth_OpenID_RAND_SOURCE === null) {
+                $f = false;
+            } else {
+                $f = @fopen(Auth_OpenID_RAND_SOURCE, "r");
+                if ($f === false) {
+                    $msg = 'Define Auth_OpenID_RAND_SOURCE as null to ' .
+                        ' continue with an insecure random number generator.';
+                    trigger_error($msg, E_USER_ERROR);
+                }
+            }
+        }
+        if ($f === false) {
+            // pseudorandom used
+            $bytes = '';
+            for ($i = 0; $i < $num_bytes; $i += 4) {
+                $bytes .= pack('L', mt_rand());
+            }
+            $bytes = substr($bytes, 0, $num_bytes);
+        } else {
+            $bytes = fread($f, $num_bytes);
+        }
+        return $bytes;
+    }
+
+    /**
+     * 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;
+    }
+}
+
+?>
+\ No newline at end of file