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Check if request is sent from official ownCloud client 

There are authentication backends such as Shibboleth that do send no Basic Auth credentials for DAV requests. This means that the ownCloud DAV backend would consider these requests coming from an untrusted source and require higher levels of security checks. (e.g. a CSRF check)

While an elegant solution would rely on authenticating via token (so that one can properly ensure that the request came indeed from a trusted client) this is a okay'ish workaround for this problem until we have something more reliable in the authentication code.
This commit is contained in:
Lukas Reschke 2016-03-23 19:31:17 +01:00
parent 4b3af9dfe7
commit cc8c0b6a90
3 changed files with 242 additions and 36 deletions
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82
apps/dav/lib/connector/sabre/auth.php
View File

@ -30,6 +30,7 @@
namespace OCA\DAV\Connector\Sabre;
use Exception;
use OC\AppFramework\Http\Request;
use OCP\IRequest;
use OCP\ISession;
use OCP\IUserSession;
@ -48,6 +49,8 @@ class Auth extends AbstractBasic {
private $userSession;
/** @var IRequest */
private $request;
/** @var string */
private $currentUser;
/**
* @param ISession $session
@ -130,7 +133,46 @@ class Auth extends AbstractBasic {
$msg = $e->getMessage();
throw new ServiceUnavailable("$class: $msg");
}
}
}
/**
* Checks whether a CSRF check is required on the request
*
* @return bool
*/
private function requiresCSRFCheck() {
// GET requires no check at all
if($this->request->getMethod() === 'GET') {
return false;
}
// Official ownCloud clients require no checks
if($this->request->isUserAgent([
Request::USER_AGENT_OWNCLOUD_DESKTOP,
Request::USER_AGENT_OWNCLOUD_ANDROID,
Request::USER_AGENT_OWNCLOUD_IOS,
])) {
return false;
}
// If not logged-in no check is required
if(!$this->userSession->isLoggedIn()) {
return false;
}
// POST always requires a check
if($this->request->getMethod() === 'POST') {
return true;
}
// If logged-in AND DAV authenticated no check is required
if($this->userSession->isLoggedIn() &&
$this->isDavAuthenticated($this->userSession->getUser()->getUID())) {
return false;
}
return true;
}
/**
* @param RequestInterface $request
@ -139,27 +181,33 @@ class Auth extends AbstractBasic {
* @throws NotAuthenticated
*/
private function auth(RequestInterface $request, ResponseInterface $response) {
// If request is not GET and not authenticated via WebDAV a requesttoken is required
if($this->userSession->isLoggedIn() &&
$this->request->getMethod() !== 'GET' &&
!$this->isDavAuthenticated($this->userSession->getUser()->getUID())) {
if(!$this->request->passesCSRFCheck()) {
$forcedLogout = false;
if(!$this->request->passesCSRFCheck() &&
$this->requiresCSRFCheck()) {
// In case of a fail with POST we need to recheck the credentials
if($this->request->getMethod() === 'POST') {
$forcedLogout = true;
} else {
$response->setStatus(401);
throw new \Sabre\DAV\Exception\NotAuthenticated('CSRF check not passed.');
}
}
if (\OC_User::handleApacheAuth() ||
//Fix for broken webdav clients
($this->userSession->isLoggedIn() && is_null($this->session->get(self::DAV_AUTHENTICATED))) ||
//Well behaved clients that only send the cookie are allowed
($this->userSession->isLoggedIn() && $this->session->get(self::DAV_AUTHENTICATED) === $this->userSession->getUser()->getUID() && $request->getHeader('Authorization') === null)
) {
$user = $this->userSession->getUser()->getUID();
\OC_Util::setupFS($user);
$this->currentUser = $user;
$this->session->close();
return [true, $this->principalPrefix . $user];
if($forcedLogout) {
$this->userSession->logout();
} else {
if (\OC_User::handleApacheAuth() ||
//Fix for broken webdav clients
($this->userSession->isLoggedIn() && is_null($this->session->get(self::DAV_AUTHENTICATED))) ||
//Well behaved clients that only send the cookie are allowed
($this->userSession->isLoggedIn() && $this->session->get(self::DAV_AUTHENTICATED) === $this->userSession->getUser()->getUID() && $request->getHeader('Authorization') === null)
) {
$user = $this->userSession->getUser()->getUID();
\OC_Util::setupFS($user);
$this->currentUser = $user;
$this->session->close();
return [true, $this->principalPrefix . $user];
}
}
if (!$this->userSession->isLoggedIn() && in_array('XMLHttpRequest', explode(',', $request->getHeader('X-Requested-With')))) {

193
apps/dav/tests/unit/connector/sabre/auth.php
View File

@ -198,10 +198,7 @@ class Auth extends TestCase {
$this->assertFalse($this->invokePrivate($this->auth, 'validateUserPass', ['MyTestUser', 'MyTestPassword']));
}
/**
* @expectedException \Sabre\DAV\Exception\NotAuthenticated
* @expectedExceptionMessage CSRF check not passed.
*/
public function testAuthenticateAlreadyLoggedInWithoutCsrfTokenForNonGet() {
$request = $this->getMockBuilder('Sabre\HTTP\RequestInterface')
->disableOriginalConstructor()
@ -210,27 +207,182 @@ class Auth extends TestCase {
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->once())
->expects($this->any())
->method('isLoggedIn')
->will($this->returnValue(true));
$this->request
->expects($this->any())
->method('getMethod')
->willReturn('POST');
$this->session
->expects($this->once())
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue(null));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->once())
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('MyWrongDavUser'));
$this->userSession
->expects($this->once())
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
->expects($this->once())
->method('passesCSRFCheck')
->willReturn(false);
$expectedResponse = [
false,
"No 'Authorization: Basic' header found. Either the client didn't send one, or the server is mis-configured",
];
$response = $this->auth->check($request, $response);
$this->assertEquals([true, 'principals/users/MyWrongDavUser'], $response);
$this->assertSame($expectedResponse, $response);
}
public function testAuthenticateAlreadyLoggedInWithoutCsrfTokenAndCorrectlyDavAuthenticated() {
$request = $this->getMockBuilder('Sabre\HTTP\RequestInterface')
->disableOriginalConstructor()
->getMock();
$response = $this->getMockBuilder('Sabre\HTTP\ResponseInterface')
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->any())
->method('isLoggedIn')
->willReturn(true);
$this->request
->expects($this->any())
->method('getMethod')
->willReturn('PROPFIND');
$this->request
->expects($this->any())
->method('isUserAgent')
->with([
'/^Mozilla\/5\.0 \([A-Za-z ]+\) (mirall|csyncoC)\/.*$/',
'/^Mozilla\/5\.0 \(Android\) ownCloud\-android.*$/',
'/^Mozilla\/5\.0 \(iOS\) ownCloud\-iOS.*$/',
])
->willReturn(false);
$this->session
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue('LoggedInUser'));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('LoggedInUser'));
$this->userSession
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
->expects($this->once())
->method('passesCSRFCheck')
->willReturn(false);
$this->auth->check($request, $response);
}
/**
* @expectedException \Sabre\DAV\Exception\NotAuthenticated
* @expectedExceptionMessage CSRF check not passed.
*/
public function testAuthenticateAlreadyLoggedInWithoutCsrfTokenAndIncorrectlyDavAuthenticated() {
$request = $this->getMockBuilder('Sabre\HTTP\RequestInterface')
->disableOriginalConstructor()
->getMock();
$response = $this->getMockBuilder('Sabre\HTTP\ResponseInterface')
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->any())
->method('isLoggedIn')
->willReturn(true);
$this->request
->expects($this->any())
->method('getMethod')
->willReturn('PROPFIND');
$this->request
->expects($this->any())
->method('isUserAgent')
->with([
'/^Mozilla\/5\.0 \([A-Za-z ]+\) (mirall|csyncoC)\/.*$/',
'/^Mozilla\/5\.0 \(Android\) ownCloud\-android.*$/',
'/^Mozilla\/5\.0 \(iOS\) ownCloud\-iOS.*$/',
])
->willReturn(false);
$this->session
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue('AnotherUser'));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('LoggedInUser'));
$this->userSession
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
->expects($this->once())
->method('passesCSRFCheck')
->willReturn(false);
$this->auth->check($request, $response);
}
public function testAuthenticateAlreadyLoggedInWithoutCsrfTokenForNonGetAndDesktopClient() {
$request = $this->getMockBuilder('Sabre\HTTP\RequestInterface')
->disableOriginalConstructor()
->getMock();
$response = $this->getMockBuilder('Sabre\HTTP\ResponseInterface')
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->any())
->method('isLoggedIn')
->will($this->returnValue(true));
$this->request
->expects($this->any())
->method('getMethod')
->willReturn('POST');
$this->request
->expects($this->any())
->method('isUserAgent')
->with([
'/^Mozilla\/5\.0 \([A-Za-z ]+\) (mirall|csyncoC)\/.*$/',
'/^Mozilla\/5\.0 \(Android\) ownCloud\-android.*$/',
'/^Mozilla\/5\.0 \(iOS\) ownCloud\-iOS.*$/',
])
->willReturn(true);
$this->session
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue(null));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('MyWrongDavUser'));
$this->userSession
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
->expects($this->once())
->method('passesCSRFCheck')
->willReturn(false);
$this->auth->check($request, $response);
}
public function testAuthenticateAlreadyLoggedInWithoutCsrfTokenForGet() {
@ -241,26 +393,26 @@ class Auth extends TestCase {
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->exactly(2))
->expects($this->any())
->method('isLoggedIn')
->will($this->returnValue(true));
$this->session
->expects($this->once())
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue(null));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->once())
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('MyWrongDavUser'));
$this->userSession
->expects($this->once())
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
->expects($this->once())
->expects($this->any())
->method('getMethod')
->willReturn('GET');
@ -268,7 +420,6 @@ class Auth extends TestCase {
$this->assertEquals([true, 'principals/users/MyWrongDavUser'], $response);
}
public function testAuthenticateAlreadyLoggedInWithCsrfTokenForGet() {
$request = $this->getMockBuilder('Sabre\HTTP\RequestInterface')
->disableOriginalConstructor()
@ -277,22 +428,22 @@ class Auth extends TestCase {
->disableOriginalConstructor()
->getMock();
$this->userSession
->expects($this->exactly(2))
->expects($this->any())
->method('isLoggedIn')
->will($this->returnValue(true));
$this->session
->expects($this->exactly(2))
->expects($this->any())
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue(null));
$user = $this->getMockBuilder('\OCP\IUser')
->disableOriginalConstructor()
->getMock();
$user->expects($this->exactly(2))
$user->expects($this->any())
->method('getUID')
->will($this->returnValue('MyWrongDavUser'));
$this->userSession
->expects($this->exactly(2))
->expects($this->any())
->method('getUser')
->will($this->returnValue($user));
$this->request
@ -368,6 +519,10 @@ class Auth extends TestCase {
->method('get')
->with('AUTHENTICATED_TO_DAV_BACKEND')
->will($this->returnValue('MyTestUser'));
$this->request
->expects($this->once())
->method('getMethod')
->willReturn('GET');
$httpRequest
->expects($this->atLeastOnce())
->method('getHeader')

3
lib/private/appframework/http/request.php
View File

@ -59,6 +59,9 @@ class Request implements \ArrayAccess, \Countable, IRequest {
// Android Chrome user agent: https://developers.google.com/chrome/mobile/docs/user-agent
const USER_AGENT_ANDROID_MOBILE_CHROME = '#Android.*Chrome/[.0-9]*#';
const USER_AGENT_FREEBOX = '#^Mozilla/5\.0$#';
const USER_AGENT_OWNCLOUD_IOS = '/^Mozilla\/5\.0 \(iOS\) ownCloud\-iOS.*$/';
const USER_AGENT_OWNCLOUD_ANDROID = '/^Mozilla\/5\.0 \(Android\) ownCloud\-android.*$/';
const USER_AGENT_OWNCLOUD_DESKTOP = '/^Mozilla\/5\.0 \([A-Za-z ]+\) (mirall|csyncoC)\/.*$/';
const REGEX_LOCALHOST = '/^(127\.0\.0\.1|localhost)$/';
protected $inputStream;