sending challenge on paste creation, adding logic to store and check it on view requests

This commit is contained in:
El RIDO 2019-06-28 21:33:52 +02:00
parent d0c8975b89
commit 79db7ddafc
No known key found for this signature in database
GPG key ID: 0F5C940A6BD81F92
13 changed files with 247 additions and 14 deletions

View file

@ -26,6 +26,9 @@
},
"time_to_live": {
"@type": "pb:RemainingSeconds"
},
"challenge": {
"@type": "pb:Challenge"
}
}
}

View file

@ -4229,7 +4229,9 @@ jQuery.PrivateBin = (function($, RawDeflate) {
// prepare server interaction
ServerInteraction.prepare();
ServerInteraction.setCryptParameters(TopNav.getPassword());
const key = CryptTool.getSymmetricKey(),
password = TopNav.getPassword();
ServerInteraction.setCryptParameters(password, key);
// set success/fail functions
ServerInteraction.setSuccess(showCreatedPaste);
@ -4250,7 +4252,10 @@ jQuery.PrivateBin = (function($, RawDeflate) {
TopNav.getOpenDiscussion() ? 1 : 0,
TopNav.getBurnAfterReading() ? 1 : 0
]);
ServerInteraction.setUnencryptedData('meta', {'expire': TopNav.getExpiration()});
ServerInteraction.setUnencryptedData('meta', {
'expire': TopNav.getExpiration(),
'challenge': CryptTool.getCredentials(key, password)
});
// prepare PasteViewer for later preview
PasteViewer.setText(plainText);

View file

@ -92,6 +92,9 @@
"@type": "dp:Second",
"@minimum": 1
},
"Challenge": {
"@type": "pb:Base64"
},
"CipherParameters": {
"@container": "@list",
"@value": [

View file

@ -276,9 +276,7 @@ class Controller
// accessing this method ensures that the paste would be
// deleted if it has already expired
$paste->get();
if (
Filter::slowEquals($deletetoken, $paste->getDeleteToken())
) {
if ($paste->isDeleteTokenCorrect($deletetoken)) {
// Paste exists and deletion token is valid: Delete the paste.
$paste->delete();
$this->_status = 'Paste was properly deleted.';
@ -315,9 +313,20 @@ class Controller
try {
$paste = $this->_model->getPaste($dataid);
if ($paste->exists()) {
// handle challenge response
if (!$paste->isTokenCorrect($this->_request->getParam('token'))) {
// we send a generic error to avoid leaking information
// about the existance of a burn after reading pastes
// this avoids an attacker being able to poll, if it has
// been read by the intended recipient or not
$this->_return_message(1, self::GENERIC_ERROR);
return;
}
$data = $paste->get();
if (array_key_exists('salt', $data['meta'])) {
unset($data['meta']['salt']);
foreach (array('salt', 'challenge') as $key) {
if (array_key_exists($key, $data['meta'])) {
unset($data['meta'][$key]);
}
}
$this->_return_message(0, $dataid, (array) $data);
} else {

View file

@ -67,6 +67,13 @@ class FormatV2
if (!($ct = base64_decode($message['ct'], true))) {
return false;
}
// - (optional) challenge
if (
!$isComment && array_key_exists('challenge', $message['meta']) &&
!base64_decode($message['meta']['challenge'], true)
) {
return false;
}
// Make sure some fields have a reasonable size:
// - initialization vector

View file

@ -14,6 +14,7 @@ namespace PrivateBin\Model;
use Exception;
use PrivateBin\Controller;
use PrivateBin\Filter;
use PrivateBin\Persistence\ServerSalt;
/**
@ -23,6 +24,14 @@ use PrivateBin\Persistence\ServerSalt;
*/
class Paste extends AbstractModel
{
/**
* Token for challenge/response.
*
* @access protected
* @var string
*/
protected $_token = '';
/**
* Get paste data.
*
@ -32,6 +41,11 @@ class Paste extends AbstractModel
*/
public function get()
{
// return cached result if one is found
if (array_key_exists('adata', $this->_data) || array_key_exists('data', $this->_data)) {
return $this->_data;
}
$data = $this->_store->read($this->getId());
if ($data === false) {
throw new Exception(Controller::GENERIC_ERROR, 64);
@ -48,10 +62,16 @@ class Paste extends AbstractModel
unset($data['meta']['expire_date']);
}
// check if non-expired burn after reading paste needs to be deleted
// check if non-expired burn after reading paste needs to be deleted,
// but don't delete it if an incorrect token was sent
if (
(
(array_key_exists('adata', $data) && $data['adata'][3] === 1) ||
(array_key_exists('burnafterreading', $data['meta']) && $data['meta']['burnafterreading'])
) && (
!array_key_exists('challenge', $data['meta']) ||
$this->_token === $data['meta']['challenge']
)
) {
$this->delete();
}
@ -94,6 +114,12 @@ class Paste extends AbstractModel
$this->_data['meta']['created'] = time();
$this->_data['meta']['salt'] = serversalt::generate();
// if a challenge was sent, we store the HMAC of paste ID & challenge
if (array_key_exists('challenge', $this->_data['meta'])) {
$this->_data['meta']['challenge'] = hash_hmac(
'sha256', $this->getId(), base64_decode($this->_data['meta']['challenge'])
);
}
// store paste
if (
@ -201,6 +227,40 @@ class Paste extends AbstractModel
(array_key_exists('opendiscussion', $this->_data['meta']) && $this->_data['meta']['opendiscussion']);
}
/**
* Check if paste challenge matches provided token.
*
* @access public
* @param string $token
* @throws Exception
* @return bool
*/
public function isTokenCorrect($token)
{
$this->_token = $token;
if (!array_key_exists('challenge', $this->_data['meta'])) {
$this->get();
}
if (array_key_exists('challenge', $this->_data['meta'])) {
return Filter::slowEquals($token, $this->_data['meta']['challenge']);
}
// paste created without challenge, accept every token sent
return true;
}
/**
* Check if paste salt based HMAC matches provided delete token.
*
* @access public
* @param string $deletetoken
* @throws Exception
* @return bool
*/
public function isDeleteTokenCorrect($deletetoken)
{
return Filter::slowEquals($deletetoken, $this->getDeleteToken());
}
/**
* Sanitizes data to conform with current configuration.
*

View file

@ -71,7 +71,7 @@ if ($MARKDOWN):
endif;
?>
<script type="text/javascript" data-cfasync="false" src="js/purify-1.0.11.js" integrity="sha512-p7UyJuyBkhMcMgE4mDsgK0Lz70OvetLefua1oXs1OujWv9gOxh4xy8InFux7bZ4/DAZsTmO4rgVwZW9BHKaTaw==" crossorigin="anonymous"></script>
<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-JTOr7OLbpnUePy6e/3tj28v3L4Cf1Xvoo1WQVRmJbBAcBK2skOsz4vBkC0RbeRkaObPIYXuv5egrFYseABbuZA==" crossorigin="anonymous"></script>
<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-tQGC7Jwx3TVRu69OGEmWl0K6lwDmgh5of3xU1Xbo4U0EY1Sv9qyUMQaOgGnMET3WMu9kbuZHsPnf7d9tTXhbsQ==" crossorigin="anonymous"></script>
<!--[if IE]>
<style type="text/css">body {padding-left:60px;padding-right:60px;} #ienotice {display:block;}</style>
<![endif]-->

View file

@ -49,7 +49,7 @@ if ($MARKDOWN):
endif;
?>
<script type="text/javascript" data-cfasync="false" src="js/purify-1.0.11.js" integrity="sha512-p7UyJuyBkhMcMgE4mDsgK0Lz70OvetLefua1oXs1OujWv9gOxh4xy8InFux7bZ4/DAZsTmO4rgVwZW9BHKaTaw==" crossorigin="anonymous"></script>
<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-JTOr7OLbpnUePy6e/3tj28v3L4Cf1Xvoo1WQVRmJbBAcBK2skOsz4vBkC0RbeRkaObPIYXuv5egrFYseABbuZA==" crossorigin="anonymous"></script>
<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-tQGC7Jwx3TVRu69OGEmWl0K6lwDmgh5of3xU1Xbo4U0EY1Sv9qyUMQaOgGnMET3WMu9kbuZHsPnf7d9tTXhbsQ==" crossorigin="anonymous"></script>
<!--[if IE]>
<style type="text/css">body {padding-left:60px;padding-right:60px;} #ienotice {display:block;}</style>
<![endif]-->

View file

@ -155,7 +155,7 @@ class Helper
public static function getPastePost($version = 2, array $meta = array())
{
$example = self::getPaste($version, $meta);
$example['meta'] = array('expire' => $example['meta']['expire']);
$example['meta'] = array_merge(array('expire' => $example['meta']['expire']), $meta);
return $example;
}

View file

@ -366,6 +366,30 @@ class ControllerTest extends PHPUnit_Framework_TestCase
$this->assertEquals(1, $paste['adata'][2], 'discussion is enabled');
}
/**
* @runInSeparateProcess
*/
public function testCreateInvalidFormat()
{
$options = parse_ini_file(CONF, true);
$options['traffic']['limit'] = 0;
Helper::createIniFile(CONF, $options);
$paste = Helper::getPasteJson(2, array('challenge' => '$'));
$file = tempnam(sys_get_temp_dir(), 'FOO');
file_put_contents($file, $paste);
Request::setInputStream($file);
$_SERVER['HTTP_X_REQUESTED_WITH'] = 'JSONHttpRequest';
$_SERVER['REQUEST_METHOD'] = 'POST';
$_SERVER['REMOTE_ADDR'] = '::1';
ob_start();
new Controller;
$content = ob_get_contents();
ob_end_clean();
$response = json_decode($content, true);
$this->assertEquals(1, $response['status'], 'outputs error status');
$this->assertFalse($this->_data->exists(Helper::getPasteId()), 'paste exists after posting data');
}
/**
* @runInSeparateProcess
*/
@ -784,6 +808,56 @@ class ControllerTest extends PHPUnit_Framework_TestCase
$this->assertFalse($this->_data->exists(Helper::getPasteId()), 'paste successfully deleted');
}
/**
* @runInSeparateProcess
*/
public function testReadBurnAfterReadingWithToken()
{
$token = base64_encode(hash_hmac(
'sha256', Helper::getPasteId(), random_bytes(32)
));
$burnPaste = Helper::getPaste(2, array('challenge' => $token));
$burnPaste['adata'][3] = 1;
$this->_data->create(Helper::getPasteId(), $burnPaste);
$this->assertTrue($this->_data->exists(Helper::getPasteId()), 'paste exists before deleting data');
$_SERVER['QUERY_STRING'] = Helper::getPasteId() . '&token=' . $token;
$_GET[Helper::getPasteId()] = '';
$_GET['token'] = $token;
$_SERVER['HTTP_X_REQUESTED_WITH'] = 'JSONHttpRequest';
ob_start();
new Controller;
$content = ob_get_contents();
ob_end_clean();
$response = json_decode($content, true);
$this->assertEquals(0, $response['status'], 'outputs status');
$this->assertFalse($this->_data->exists(Helper::getPasteId()), 'paste successfully deleted');
}
/**
* @runInSeparateProcess
*/
public function testReadBurnAfterReadingWithIncorrectToken()
{
$token = base64_encode(hash_hmac(
'sha256', Helper::getPasteId(), random_bytes(32)
));
$burnPaste = Helper::getPaste(2, array('challenge' => base64_encode(random_bytes(32))));
$burnPaste['adata'][3] = 1;
$this->_data->create(Helper::getPasteId(), $burnPaste);
$this->assertTrue($this->_data->exists(Helper::getPasteId()), 'paste exists before deleting data');
$_SERVER['QUERY_STRING'] = Helper::getPasteId() . '&token=' . $token;
$_GET[Helper::getPasteId()] = '';
$_GET['token'] = $token;
$_SERVER['HTTP_X_REQUESTED_WITH'] = 'JSONHttpRequest';
ob_start();
new Controller;
$content = ob_get_contents();
ob_end_clean();
$response = json_decode($content, true);
$this->assertEquals(1, $response['status'], 'outputs status');
$this->assertTrue($this->_data->exists(Helper::getPasteId()), 'paste not deleted');
}
/**
* @runInSeparateProcess
*/

View file

@ -21,6 +21,10 @@ class FormatV2Test extends PHPUnit_Framework_TestCase
$paste['ct'] = '$';
$this->assertFalse(FormatV2::isValid($paste), 'invalid base64 encoding of ct');
$paste = Helper::getPastePost();
$paste['meta']['challenge'] = '$';
$this->assertFalse(FormatV2::isValid($paste), 'invalid base64 encoding of ct');
$paste = Helper::getPastePost();
$paste['ct'] = 'bm9kYXRhbm9kYXRhbm9kYXRhbm9kYXRhbm9kYXRhCg==';
$this->assertFalse(FormatV2::isValid($paste), 'low ct entropy');

View file

@ -268,10 +268,48 @@ class ModelTest extends PHPUnit_Framework_TestCase
$paste->setData($pasteData);
$paste->store();
$paste = $paste->get();
$paste = $this->_model->getPaste(Helper::getPasteId())->get();
$this->assertEquals((float) 300, (float) $paste['meta']['time_to_live'], 'remaining time is set correctly', 1.0);
}
public function testToken()
{
$pasteData = Helper::getPastePost();
$pasteData['meta']['challenge'] = base64_encode(random_bytes(32));
$token = hash_hmac(
'sha256', Helper::getPasteId(), base64_decode($pasteData['meta']['challenge'])
);
$this->_model->getPaste(Helper::getPasteId())->delete();
$paste = $this->_model->getPaste(Helper::getPasteId());
$this->assertFalse($paste->exists(), 'paste does not yet exist');
$paste = $this->_model->getPaste();
$paste->setData($pasteData);
$paste->store();
$paste = $this->_model->getPaste(Helper::getPasteId());
$this->assertTrue(
$paste->isTokenCorrect($token),
'token is accepted after store and retrieval'
);
}
public function testDeleteToken()
{
$pasteData = Helper::getPastePost();
$this->_model->getPaste(Helper::getPasteId())->delete();
$paste = $this->_model->getPaste(Helper::getPasteId());
$this->assertFalse($paste->exists(), 'paste does not yet exist');
$paste = $this->_model->getPaste();
$paste->setData($pasteData);
$paste->store();
$deletetoken = $paste->getDeleteToken();
$paste = $this->_model->getPaste(Helper::getPasteId());
$this->assertTrue($paste->isDeleteTokenCorrect($deletetoken), 'delete token is accepted after store and retrieval');
}
/**
* @expectedException Exception
* @expectedExceptionCode 64
@ -287,6 +325,20 @@ class ModelTest extends PHPUnit_Framework_TestCase
$paste->getComment(Helper::getPasteId())->delete();
}
/**
* @expectedException Exception
* @expectedExceptionCode 75
*/
public function testInvalidFormat()
{
$pasteData = Helper::getPastePost();
$pasteData['adata'][1] = 'foo';
$this->_model->getPaste(Helper::getPasteId())->delete();
$paste = $this->_model->getPaste();
$paste->setData($pasteData);
}
public function testPurge()
{
$conf = new Configuration;

View file

@ -130,6 +130,22 @@ class RequestTest extends PHPUnit_Framework_TestCase
$this->assertEquals('read', $request->getOperation());
}
public function testApiReadWithToken()
{
$this->reset();
$id = $this->getRandomId();
$_SERVER['REQUEST_METHOD'] = 'GET';
$_SERVER['HTTP_ACCEPT'] = 'application/json, text/javascript, */*; q=0.01';
$_SERVER['QUERY_STRING'] = $id . '&token=foo';
$_GET[$id] = '';
$_GET['token'] = 'foo';
$request = new Request;
$this->assertTrue($request->isJsonApiCall(), 'is JSON Api call');
$this->assertEquals($id, $request->getParam('pasteid'));
$this->assertEquals('foo', $request->getParam('token'));
$this->assertEquals('read', $request->getOperation());
}
public function testApiDelete()
{
$this->reset();