changing version string

This fixes issue 2.7 of https://defuse.ca/audits/zerobin.htm, and thus
(with commit a24212afda90ca3e4b4ff5ce30d2012709b58a28) also issue 2.8.

(cherry picked from commit 0b4db7ece313dd268e51fc47a0293a649927558a)

Conflicts:
	index.php

CHANGELOG.md

@@ -63,4 +63,7 @@
     * ADDED: Better json checking (including entropy).
     * ADDED: Added version to js/css assets URLs in order to prevent some abusive caches to serve an obsolete version of these files when ZeroBin is upgraded.
     * "Burn after reading" option has been moved out of Expiration combo to a separate checkbox. Reason is: You can prevent a read-once paste to be available ad vitam eternam on the net.
+  * **Alpha 0.19 (2013-07-05)**:
+    * Corrected XSS security flaw which affected IE<10. Other browsers were not affected.
+    * Corrected spacing display in IE<10.
 

README.md

@@ -1,4 +1,4 @@
-ZeroBin 0.18 Alpha
+ZeroBin 0.19 Alpha
 
 ==== THIS IS ALPHA SOFTWARE - USE AT YOUR OWN RISKS ====
 

css/zerobin.css

@@ -1,4 +1,4 @@
-/* ZeroBin 0.18 - http://sebsauvage.net/wiki/doku.php?id=php:zerobin */
+/* ZeroBin 0.19 - http://sebsauvage.net/wiki/doku.php?id=php:zerobin */
 
 
 /*  CSS Reset from YUI 3.4.1 (build 4118) - Copyright 2011 Yahoo! Inc. All rights reserved.

index.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 // change this, if your php files and data is outside of your webservers document root

js/zerobin.js

@@ -6,7 +6,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 // Immediately start random number generator collector.
@@ -152,6 +152,9 @@ function pasteID() {
     return window.location.search.substring(1);
 }
 
+function htmlEntities(str) {
+    return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
+}
 /**
  * Set text of a DOM element (required for IE)
  * This is equivalent to element.text(text)
@@ -161,9 +164,9 @@ function pasteID() {
 function setElementText(element, text) {
     // For IE<10.
     if ($('div#oldienotice').is(":visible")) {
-        // IE<10 do not support white-space:pre-wrap; so we have to do this BIG UGLY STINKING THING.
-        element.text(text.replace(/\n/ig,'{BIG_UGLY_STINKING_THING__OH_GOD_I_HATE_IE}'));
-        element.html(element.text().replace(/{BIG_UGLY_STINKING_THING__OH_GOD_I_HATE_IE}/ig,"\n<br />"));
+        // IE<10 does not support white-space:pre-wrap; so we have to do this BIG UGLY STINKING THING.
+        var html = htmlEntities(text).replace(/\n/ig,"\r\n<br>");
+        element.html('<pre>'+html+'</pre>');
     }
     // for other (sane) browsers:
     else {
@@ -306,6 +309,7 @@ function send_comment(parentid) {
     });
 }
 
+
 /**
  *  Send a new paste to server
  */
@@ -314,7 +318,17 @@ function send_data() {
     if ($('textarea#message').val().length == 0) {
         return;
     }
+
+    // If sjcl has not collected enough entropy yet, display a message.
+    if (!sjcl.random.isReady())
+    {
+        showStatus('Sending paste (Please move your mouse for more entropy)...', spin=true);
+        sjcl.random.addEventListener('seeded', function(){ send_data(); }); 
+        return; 
+    }
+    
     showStatus('Sending paste...', spin=true);
+
     var randomkey = sjcl.codec.base64.fromBits(sjcl.random.randomWords(8, 0), 0);
     var cipherdata = zeroCipher(randomkey, $('textarea#message').val());
     var data_to_send = { data:           cipherdata,
@@ -425,10 +439,9 @@ function stateExistingPaste() {
   */
 function rawText()
 {
-    history.pushState(document.title, document.title, 'document.txt');
-    var paste = $('div#cleartext').text();
-    var newDoc = document.open('text/plain', 'replace');
-    newDoc.write(paste);
+    var paste = $('div#cleartext').html();
+    var newDoc = document.open('text/html', 'replace');
+    newDoc.write('<pre>'+paste+'</pre>');
     newDoc.close();
 }
 

lib/auto.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 spl_autoload_register('auto::loader');

lib/filter.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**
@@ -50,4 +50,35 @@ class filter
         }
         return number_format($size, ($i ? 2 : 0), '.', ' ') . ' ' . $iec[$i];
     }
+
+    /**
+     * validate paste ID
+     *
+     * @access public
+     * @param  string $dataid
+     * @return bool
+     */
+    public static function is_valid_paste_id($dataid)
+    {
+        return (bool) preg_match('#\A[a-f\d]{16}\z#', $dataid);
+    }
+
+    /**
+     * fixed time string comparison operation to prevent timing attacks
+     * https://crackstation.net/hashing-security.htm?=rd#slowequals
+     *
+     * @access public
+     * @param  string $a
+     * @param  string $b
+     * @return bool
+     */
+    public static function slow_equals($a, $b)
+    {
+        $diff = strlen($a) ^ strlen($b);
+        for($i = 0; $i < strlen($a) && $i < strlen($b); $i++)
+        {
+            $diff |= ord($a[$i]) ^ ord($b[$i]);
+        }
+        return $diff === 0;
+     }
 }

lib/persistence.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**
@@ -105,7 +105,7 @@ abstract class persistence
     {
         self::_initialize();
         $file = self::$_path . '/' . $filename;
-        file_put_contents($file, $data);
+        file_put_contents($file, $data, LOCK_EX);
         chmod($file, 0705);
         return $file;
     }

lib/serversalt.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**
@@ -39,9 +39,16 @@ class serversalt extends persistence
     public static function generate()
     {
         $randomSalt = '';
+        if (function_exists('mcrypt_create_iv'))
+        {
+            $randomSalt = bin2hex(mcrypt_create_iv(256, MCRYPT_DEV_URANDOM));
+        }
+        else // fallback to mt_rand()
+        {
             for($i = 0; $i < 16; ++$i) {
                 $randomSalt .= base_convert(mt_rand(), 10, 16);
             }
+        }
         self::$_salt = $randomSalt;
         return self::$_salt;
     }

lib/sjcl.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**

lib/trafficlimiter.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**

lib/vizhash16x16.php

@@ -8,7 +8,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:vizhash_gd
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.0.4 beta ZeroBin 0.18
+ * @version   0.0.4 beta ZeroBin 0.19
  */
 
 /**

lib/zerobin.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**
@@ -20,7 +20,7 @@ class zerobin
     /*
      * @const string version
      */
-    const VERSION = 'Alpha 0.18';
+    const VERSION = 'Alpha 0.19';
 
     /**
      * @access private
@@ -272,8 +272,8 @@ class zerobin
             $pasteid  = $_POST['pasteid'];
             $parentid = $_POST['parentid'];
             if (
-                !preg_match('/\A[a-f\d]{16}\z/', $pasteid) ||
-                !preg_match('/\A[a-f\d]{16}\z/', $parentid)
+                !filter::is_valid_paste_id($pasteid) ||
+                !filter::is_valid_paste_id($parentid)
             ) $this->_return_message(1, 'Invalid data.');
 
             // Comments do not expire (it's the paste that expires)
@@ -340,18 +340,21 @@ class zerobin
     private function _delete($dataid, $deletetoken)
     {
         // Is this a valid paste identifier?
-        if (preg_match('\A[a-f\d]{16}\z', $dataid))
+        if (!filter::is_valid_paste_id($dataid))
         {
+            $this->_error = 'Invalid paste ID.';
+            return;
+        }
+
         // Check that paste exists.
         if (!$this->_model()->exists($dataid))
         {
             $this->_error = 'Paste does not exist, has expired or has been deleted.';
             return;
         }
-        }
 
         // Make sure token is valid.
-        if ($deletetoken != hash_hmac('sha1', $dataid , serversalt::get()))
+        if (filter::slow_equals($deletetoken, hash_hmac('sha1', $dataid , serversalt::get())))
         {
             $this->_error = 'Wrong deletion token. Paste was not deleted.';
             return;
@@ -372,8 +375,12 @@ class zerobin
     private function _read($dataid)
     {
         // Is this a valid paste identifier?
-        if (preg_match('#\A[a-f\d]{16}\z#', $dataid))
+        if (!filter::is_valid_paste_id($dataid))
         {
+            $this->_error = 'Invalid paste ID.';
+            return;
+        }
+
         // Check that paste exists.
         if ($this->_model()->exists($dataid))
         {
@@ -426,7 +433,6 @@ class zerobin
             $this->_error = 'Paste does not exist or has expired.';
         }
     }
-    }
 
     /**
      * Display ZeroBin frontend.

lib/zerobin/abstract.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**

lib/zerobin/data.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**

lib/zerobin/db.php

@@ -7,7 +7,7 @@
  * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
  * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
  * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
- * @version   0.18
+ * @version   0.19
  */
 
 /**

tst/filter.php

@@ -44,4 +44,25 @@ class filterTest extends PHPUnit_Framework_TestCase
         $this->assertEquals('1.00 YiB', filter::size_humanreadable(1024 * $exponent));
         $this->assertEquals('1.21 YiB', filter::size_humanreadable(1234 * $exponent));
     }
+
+    public function testPasteIdValidation()
+    {
+        $this->assertTrue(filter::is_valid_paste_id('a242ab7bdfb2581a'), 'valid paste id');
+        $this->assertFalse(filter::is_valid_paste_id('foo'), 'invalid hex values');
+        $this->assertFalse(filter::is_valid_paste_id('../bar/baz'), 'path attack');
+    }
+
+    public function testSlowEquals()
+    {
+        $this->assertTrue(filter::slow_equals('foo', 'foo'), 'same string');
+        $this->assertFalse(filter::slow_equals('foo', true), 'string and boolean');
+        $this->assertFalse(filter::slow_equals('foo', 0), 'string and integer');
+        $this->assertFalse(filter::slow_equals('123foo', 123), 'string and integer');
+        $this->assertFalse(filter::slow_equals('123foo', '123'), 'different strings');
+        $this->assertFalse(filter::slow_equals('6', ' 6'), 'strings with space');
+        $this->assertFalse(filter::slow_equals('4.2', '4.20'), 'floats as strings');
+        $this->assertFalse(filter::slow_equals('1e3', '1000'), 'integers as strings');
+        $this->assertFalse(filter::slow_equals('9223372036854775807', '9223372036854775808'), 'large integers as strings');
+        $this->assertFalse(filter::slow_equals('61529519452809720693702583126814', '61529519452809720000000000000000'), 'larger integers as strings');
+    }
 }

tst/mcrypt_mock.php

@@ -0,0 +1,17 @@
+<?php
+
+define('MCRYPT_DEV_URANDOM', 1);
+
+function mcrypt_create_iv($int, $flag)
+{
+    $randomSalt = '';
+    for($i = 0; $i < 16; ++$i) {
+        $randomSalt .= base_convert(mt_rand(), 10, 16);
+    }
+    // hex2bin requires an even length, pad if necessary
+    if (strlen($randomSalt) % 2)
+    {
+        $randomSalt = '0' . $randomSalt;
+    }
+    return hex2bin($randomSalt);
+}

tst/phpunit.xml

@@ -1,6 +1,7 @@
 <phpunit bootstrap="bootstrap.php" colors="true">
 	<testsuite name="ZeroBin Test Suite">
 		<directory suffix=".php">./</directory>
+		<exclude>mcrypt_mock.php</exclude>
 	</testsuite>
 	<filter>
 		<whitelist>

tst/vizhash16x16.php

@@ -37,5 +37,10 @@ class vizhash16x16Test extends PHPUnit_Framework_TestCase
         $this->assertEquals('image/png', $finfo->file($this->_file));
         $this->assertNotEquals($pngdata, $vz->generate('2001:1620:2057:dead:beef::cafe:babe'));
         $this->assertEquals($pngdata, $vz->generate('127.0.0.1'));
+
+        // generating new salt
+        $salt = serversalt::get();
+        require 'mcrypt_mock.php';
+        $this->assertNotEquals($salt, serversalt::generate());
     }
 }