Add mitigation against BREACH

While BREACH requires the following three factors to be effectively exploitable we should add another mitigation:

1. Application must support HTTP compression
2. Response most reflect user-controlled input
3. Response should contain sensitive data

Especially part 2 is with ownCloud not really given since user-input is usually only echoed if a CSRF token has been passed.

To reduce the risk even further it is however sensible to encrypt the CSRF token with a shared secret. Since this will change on every request an attack such as BREACH is not feasible anymore against the CSRF token at least.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/private/server.php b/lib/private/server.php
index 618431ff2d4..9eea7c45376 100644
--- a/lib/private/server.php
+++ b/lib/private/server.php
@@ -409,6 +409,7 @@ class Server extends SimpleContainer implements IServerContainer {
 					'requesttoken' => $requestToken,
 				],
 				$this->getSecureRandom(),
+				$this->getCrypto(),
 				$this->getConfig(),
 				$stream
 			);