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, 102 insertions, 15 deletions

diff --git a/tests/lib/appframework/http/RequestTest.php b/tests/lib/appframework/http/RequestTest.php
index 10a9e486c97..deb28909869 100644
--- a/tests/lib/appframework/http/RequestTest.php
+++ b/tests/lib/appframework/http/RequestTest.php
@@ -10,6 +10,7 @@
 
 namespace OC\AppFramework\Http;
 
+use OC\Security\Crypto;
 use OCP\Security\ISecureRandom;
 use OCP\IConfig;
 
@@ -53,6 +54,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -85,6 +87,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -96,8 +99,8 @@ class RequestTest extends \Test\TestCase {
 
 
 	/**
-	* @expectedException \RuntimeException
-	*/
+	 * @expectedException \RuntimeException
+	 */
 	public function testImmutableArrayAccess() {
 		$vars = array(
 			'get' => array('name' => 'John Q. Public', 'nickname' => 'Joey'),
@@ -107,6 +110,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -115,8 +119,8 @@ class RequestTest extends \Test\TestCase {
 	}
 
 	/**
-	* @expectedException \RuntimeException
-	*/
+	 * @expectedException \RuntimeException
+	 */
 	public function testImmutableMagicAccess() {
 		$vars = array(
 			'get' => array('name' => 'John Q. Public', 'nickname' => 'Joey'),
@@ -126,6 +130,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -134,8 +139,8 @@ class RequestTest extends \Test\TestCase {
 	}
 
 	/**
-	* @expectedException \LogicException
-	*/
+	 * @expectedException \LogicException
+	 */
 	public function testGetTheMethodRight() {
 		$vars = array(
 			'get' => array('name' => 'John Q. Public', 'nickname' => 'Joey'),
@@ -145,6 +150,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -161,6 +167,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -182,6 +189,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -206,6 +214,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -230,6 +239,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -250,6 +260,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -274,6 +285,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -303,6 +315,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -324,6 +337,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			$vars,
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -347,6 +361,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -358,6 +373,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			\OC::$server->getSecureRandom(),
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -382,6 +398,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -410,6 +427,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -438,6 +456,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -470,6 +489,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -497,6 +517,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -506,10 +527,10 @@ class RequestTest extends \Test\TestCase {
 
 	public function testGetServerProtocolWithProtoValid() {
 		$this->config
-				->expects($this->exactly(2))
-				->method('getSystemValue')
-				->with('overwriteprotocol')
-				->will($this->returnValue(''));
+			->expects($this->exactly(2))
+			->method('getSystemValue')
+			->with('overwriteprotocol')
+			->will($this->returnValue(''));
 
 		$requestHttps = new Request(
 			[
@@ -518,6 +539,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -528,6 +550,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -551,6 +574,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -571,6 +595,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -587,6 +612,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -607,6 +633,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -628,6 +655,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -716,6 +744,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -732,6 +761,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -749,6 +779,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -766,6 +797,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -793,6 +825,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -814,6 +847,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -840,6 +874,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -866,6 +901,7 @@ class RequestTest extends \Test\TestCase {
 				],
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -882,6 +918,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -909,6 +946,7 @@ class RequestTest extends \Test\TestCase {
 		$request = new Request(
 			[],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -924,6 +962,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -944,6 +983,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -964,6 +1004,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -986,6 +1027,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -1008,6 +1050,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -1030,6 +1073,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -1052,6 +1096,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -1105,6 +1150,7 @@ class RequestTest extends \Test\TestCase {
 				]
 			],
 			$this->secureRandom,
+			$this->getMock('\OCP\Security\ICrypto'),
 			$this->config,
 			$this->stream
 		);
@@ -1144,6 +1190,7 @@ class RequestTest extends \Test\TestCase {
 					]
 				],
 				$this->secureRandom,
+				$this->getMock('\OCP\Security\ICrypto'),
 				$this->config,
 				$this->stream
 			])
@@ -1157,17 +1204,25 @@ class RequestTest extends \Test\TestCase {
 	}
 
 	public function testPassesCSRFCheckWithGet() {
+		$crypto = $this->getMock('\OCP\Security\ICrypto');
+		$crypto
+			->expects($this->once())
+			->method('decrypt')
+			->with('1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4', 'secret')
+			->will($this->returnValue('MyStoredRequestToken'));
+
 		/** @var Request $request */
 		$request = $this->getMockBuilder('\OC\AppFramework\Http\Request')
 			->setMethods(['getScriptName'])
 			->setConstructorArgs([
 				[
 					'get' => [
-						'requesttoken' => 'MyStoredRequestToken',
+						'requesttoken' => '1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4:secret',
 					],
 					'requesttoken' => 'MyStoredRequestToken',
 				],
 				$this->secureRandom,
+				$crypto,
 				$this->config,
 				$this->stream
 			])
@@ -1177,17 +1232,25 @@ class RequestTest extends \Test\TestCase {
 	}
 
 	public function testPassesCSRFCheckWithPost() {
+		$crypto = $this->getMock('\OCP\Security\ICrypto');
+		$crypto
+			->expects($this->once())
+			->method('decrypt')
+			->with('1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4', 'secret')
+			->will($this->returnValue('MyStoredRequestToken'));
+
 		/** @var Request $request */
 		$request = $this->getMockBuilder('\OC\AppFramework\Http\Request')
 			->setMethods(['getScriptName'])
 			->setConstructorArgs([
 				[
 					'post' => [
-						'requesttoken' => 'MyStoredRequestToken',
+						'requesttoken' => '1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4:secret',
 					],
 					'requesttoken' => 'MyStoredRequestToken',
 				],
 				$this->secureRandom,
+				$crypto,
 				$this->config,
 				$this->stream
 			])
@@ -1197,17 +1260,24 @@ class RequestTest extends \Test\TestCase {
 	}
 
 	public function testPassesCSRFCheckWithHeader() {
+		$crypto = $this->getMock('\OCP\Security\ICrypto');
+		$crypto
+			->expects($this->once())
+			->method('decrypt')
+			->with('1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4', 'secret')
+			->will($this->returnValue('MyStoredRequestToken'));
 		/** @var Request $request */
 		$request = $this->getMockBuilder('\OC\AppFramework\Http\Request')
 			->setMethods(['getScriptName'])
 			->setConstructorArgs([
 				[
 					'server' => [
-						'HTTP_REQUESTTOKEN' => 'MyStoredRequestToken',
+						'HTTP_REQUESTTOKEN' => '1c637c4147e40a8a8f09428ec2059cebea3480c27b402b4e793c69710a731513|wlXxNUaFqHuQnZr5|e6ab49c9e0e20c8d3607e02f1d8e6ec17ad6020ae10b7d64ab4b0a6318c0875940943a6aa303dc090fea0b4cd5b9fb8bcbecac4308a2bd15d9f369cdc22121a4:secret',
 					],
 					'requesttoken' => 'MyStoredRequestToken',
 				],
 				$this->secureRandom,
+				$crypto,
 				$this->config,
 				$this->stream
 			])
@@ -1216,18 +1286,34 @@ class RequestTest extends \Test\TestCase {
 		$this->assertTrue($request->passesCSRFCheck());
 	}
 
-	public function testPassesCSRFCheckWithInvalidToken() {
+	public function invalidTokenDataProvider() {
+		return [
+			['InvalidSentToken'],
+			['InvalidSentToken:InvalidSecret'],
+			[null],
+			[''],
+		];
+	}
+
+	/**
+	 * @dataProvider invalidTokenDataProvider
+	 * @param string $invalidToken
+	 */
+	public function testPassesCSRFCheckWithInvalidToken($invalidToken) {
+		$crypto = new Crypto($this->config, $this->secureRandom);
+
 		/** @var Request $request */
 		$request = $this->getMockBuilder('\OC\AppFramework\Http\Request')
 			->setMethods(['getScriptName'])
 			->setConstructorArgs([
 				[
 					'server' => [
-						'HTTP_REQUESTTOKEN' => 'MyInvalidSentToken',
+						'HTTP_REQUESTTOKEN' => $invalidToken,
 					],
 					'requesttoken' => 'MyStoredRequestToken',
 				],
 				$this->secureRandom,
+				$crypto,
 				$this->config,
 				$this->stream
 			])
@@ -1243,6 +1329,7 @@ class RequestTest extends \Test\TestCase {
 			->setConstructorArgs([
 				[],
 				$this->secureRandom,
+				$this->getMock('\OCP\Security\ICrypto'),
 				$this->config,
 				$this->stream
 			])