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-rw-r--r--engine/classes/ElggCrypto.php208
-rw-r--r--engine/lib/actions.php27
-rw-r--r--engine/lib/admin.php2
-rw-r--r--engine/lib/upgrades/2013060900-1.8.15-site_secret-404fc165cf9e0ac9.php13
4 files changed, 248 insertions, 2 deletions
diff --git a/engine/classes/ElggCrypto.php b/engine/classes/ElggCrypto.php
new file mode 100644
index 000000000..b6a8b2024
--- /dev/null
+++ b/engine/classes/ElggCrypto.php
@@ -0,0 +1,208 @@
+<?php
+/**
+ * ElggCrypto
+ *
+ * @package Elgg.Core
+ * @subpackage Crypto
+ *
+ * @access private
+ */
+class ElggCrypto {
+
+ /**
+ * Character set for temp passwords (no risk of embedded profanity/glyphs that look similar)
+ */
+ const CHARS_PASSWORD = 'bcdfghjklmnpqrstvwxyz2346789';
+
+ /**
+ * Generate a string of highly randomized bytes (over the full 8-bit range).
+ *
+ * @param int $length Number of bytes needed
+ * @return string Random bytes
+ *
+ * @author George Argyros <argyros.george@gmail.com>
+ * @copyright 2012, George Argyros. All rights reserved.
+ * @license Modified BSD
+ * @link https://github.com/GeorgeArgyros/Secure-random-bytes-in-PHP/blob/master/srand.php Original
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the <organization> nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL GEORGE ARGYROS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+ public function getRandomBytes($length) {
+ /**
+ * Our primary choice for a cryptographic strong randomness function is
+ * openssl_random_pseudo_bytes.
+ */
+ $SSLstr = '4'; // http://xkcd.com/221/
+ if (function_exists('openssl_random_pseudo_bytes')
+ && (version_compare(PHP_VERSION, '5.3.4') >= 0 || substr(PHP_OS, 0, 3) !== 'WIN')) {
+ $SSLstr = openssl_random_pseudo_bytes($length, $strong);
+ if ($strong) {
+ return $SSLstr;
+ }
+ }
+
+ /**
+ * If mcrypt extension is available then we use it to gather entropy from
+ * the operating system's PRNG. This is better than reading /dev/urandom
+ * directly since it avoids reading larger blocks of data than needed.
+ * Older versions of mcrypt_create_iv may be broken or take too much time
+ * to finish so we only use this function with PHP 5.3.7 and above.
+ * @see https://bugs.php.net/bug.php?id=55169
+ */
+ if (function_exists('mcrypt_create_iv')
+ && (version_compare(PHP_VERSION, '5.3.7') >= 0 || substr(PHP_OS, 0, 3) !== 'WIN')) {
+ $str = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
+ if ($str !== false) {
+ return $str;
+ }
+ }
+
+ /**
+ * No build-in crypto randomness function found. We collect any entropy
+ * available in the PHP core PRNGs along with some filesystem info and memory
+ * stats. To make this data cryptographically strong we add data either from
+ * /dev/urandom or if its unavailable, we gather entropy by measuring the
+ * time needed to compute a number of SHA-1 hashes.
+ */
+ $str = '';
+ $bits_per_round = 2; // bits of entropy collected in each clock drift round
+ $msec_per_round = 400; // expected running time of each round in microseconds
+ $hash_len = 20; // SHA-1 Hash length
+ $total = $length; // total bytes of entropy to collect
+
+ $handle = @fopen('/dev/urandom', 'rb');
+ if ($handle && function_exists('stream_set_read_buffer')) {
+ @stream_set_read_buffer($handle, 0);
+ }
+
+ do {
+ $bytes = ($total > $hash_len)? $hash_len : $total;
+ $total -= $bytes;
+
+ //collect any entropy available from the PHP system and filesystem
+ $entropy = rand() . uniqid(mt_rand(), true) . $SSLstr;
+ $entropy .= implode('', @fstat(@fopen( __FILE__, 'r')));
+ $entropy .= memory_get_usage() . getmypid();
+ $entropy .= serialize($_ENV) . serialize($_SERVER);
+ if (function_exists('posix_times')) {
+ $entropy .= serialize(posix_times());
+ }
+ if (function_exists('zend_thread_id')) {
+ $entropy .= zend_thread_id();
+ }
+
+ if ($handle) {
+ $entropy .= @fread($handle, $bytes);
+ } else {
+ // Measure the time that the operations will take on average
+ for ($i = 0; $i < 3; $i++) {
+ $c1 = microtime(true);
+ $var = sha1(mt_rand());
+ for ($j = 0; $j < 50; $j++) {
+ $var = sha1($var);
+ }
+ $c2 = microtime(true);
+ $entropy .= $c1 . $c2;
+ }
+
+ // Based on the above measurement determine the total rounds
+ // in order to bound the total running time.
+ $rounds = (int) ($msec_per_round * 50 / (int) (($c2 - $c1) * 1000000));
+
+ // Take the additional measurements. On average we can expect
+ // at least $bits_per_round bits of entropy from each measurement.
+ $iter = $bytes * (int) (ceil(8 / $bits_per_round));
+
+ for ($i = 0; $i < $iter; $i++) {
+ $c1 = microtime();
+ $var = sha1(mt_rand());
+ for ($j = 0; $j < $rounds; $j++) {
+ $var = sha1($var);
+ }
+ $c2 = microtime();
+ $entropy .= $c1 . $c2;
+ }
+ }
+
+ // We assume sha1 is a deterministic extractor for the $entropy variable.
+ $str .= sha1($entropy, true);
+
+ } while ($length > strlen($str));
+
+ if ($handle) {
+ @fclose($handle);
+ }
+
+ return substr($str, 0, $length);
+ }
+
+ /**
+ * Generate a random string of specified length.
+ *
+ * Uses supplied character list for generating the new string.
+ * If no character list provided - uses Base64 URL character set.
+ *
+ * @param int $length Desired length of the string
+ * @param string|null $chars Characters to be chosen from randomly. If not given, the Base64 URL
+ * charset will be used.
+ *
+ * @return string The random string
+ *
+ * @throws InvalidArgumentException
+ *
+ * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license http://framework.zend.com/license/new-bsd New BSD License
+ *
+ * @see https://github.com/zendframework/zf2/blob/master/library/Zend/Math/Rand.php#L179
+ */
+ public static function getRandomString($length, $chars = null) {
+ if ($length < 1) {
+ throw new InvalidArgumentException('Length should be >= 1');
+ }
+
+ if (empty($chars)) {
+ $numBytes = ceil($length * 0.75);
+ $bytes = self::getRandomBytes($numBytes);
+ $string = substr(rtrim(base64_encode($bytes), '='), 0, $length);
+
+ // Base64 URL
+ return strtr($string, '+/', '-_');
+ }
+
+ $listLen = strlen($chars);
+
+ if ($listLen == 1) {
+ return str_repeat($chars, $length);
+ }
+
+ $bytes = self::getRandomBytes($length);
+ $pos = 0;
+ $result = '';
+ for ($i = 0; $i < $length; $i++) {
+ $pos = ($pos + ord($bytes[$i])) % $listLen;
+ $result .= $chars[$pos];
+ }
+
+ return $result;
+ }
+}
diff --git a/engine/lib/actions.php b/engine/lib/actions.php
index 56936f582..8047914ac 100644
--- a/engine/lib/actions.php
+++ b/engine/lib/actions.php
@@ -364,16 +364,19 @@ function generate_action_token($timestamp) {
}
/**
- * Initialise the site secret hash.
+ * Initialise the site secret (32 bytes: "z" to indicate format + 186-bit key in Base64 URL).
*
* Used during installation and saves as a datalist.
*
+ * Note: Old secrets were hex encoded.
+ *
* @return mixed The site secret hash or false
* @access private
* @todo Move to better file.
*/
function init_site_secret() {
- $secret = md5(rand() . microtime());
+ $secret = 'z' . ElggCrypto::getRandomString(31);
+
if (datalist_set('__site_secret__', $secret)) {
return $secret;
}
@@ -400,6 +403,26 @@ function get_site_secret() {
}
/**
+ * Get the strength of the site secret
+ *
+ * @return string "strong", "moderate", or "weak"
+ * @access private
+ */
+function _elgg_get_site_secret_strength() {
+ $secret = get_site_secret();
+ if ($secret[0] !== 'z') {
+ $rand_max = getrandmax();
+ if ($rand_max < pow(2, 16)) {
+ return 'weak';
+ }
+ if ($rand_max < pow(2, 32)) {
+ return 'moderate';
+ }
+ }
+ return 'strong';
+}
+
+/**
* Check if an action is registered and its script exists.
*
* @param string $action Action name
diff --git a/engine/lib/admin.php b/engine/lib/admin.php
index 7f82108c0..f36f29668 100644
--- a/engine/lib/admin.php
+++ b/engine/lib/admin.php
@@ -236,6 +236,7 @@ function admin_init() {
elgg_register_action('admin/site/update_advanced', '', 'admin');
elgg_register_action('admin/site/flush_cache', '', 'admin');
elgg_register_action('admin/site/unlock_upgrade', '', 'admin');
+ elgg_register_action('admin/site/regenerate_secret', '', 'admin');
elgg_register_action('admin/menu/save', '', 'admin');
@@ -291,6 +292,7 @@ function admin_init() {
elgg_register_admin_menu_item('configure', 'settings', null, 100);
elgg_register_admin_menu_item('configure', 'basic', 'settings', 10);
elgg_register_admin_menu_item('configure', 'advanced', 'settings', 20);
+ elgg_register_admin_menu_item('configure', 'advanced/site_secret', 'settings', 25);
elgg_register_admin_menu_item('configure', 'menu_items', 'appearance', 30);
elgg_register_admin_menu_item('configure', 'profile_fields', 'appearance', 40);
// default widgets is added via an event handler elgg_default_widgets_init() in widgets.php
diff --git a/engine/lib/upgrades/2013060900-1.8.15-site_secret-404fc165cf9e0ac9.php b/engine/lib/upgrades/2013060900-1.8.15-site_secret-404fc165cf9e0ac9.php
new file mode 100644
index 000000000..b5b614762
--- /dev/null
+++ b/engine/lib/upgrades/2013060900-1.8.15-site_secret-404fc165cf9e0ac9.php
@@ -0,0 +1,13 @@
+<?php
+/**
+ * Elgg 1.8.15 upgrade 2013060900
+ * site_secret
+ *
+ * Description
+ */
+
+$strength = _elgg_get_site_secret_strength();
+
+if ($strength !== 'strong') {
+ elgg_add_admin_notice('weak_site_key', elgg_echo("upgrade:site_secret_warning:$strength"));
+}