Fix login flow form actions

So fun fact. Chrome considers a redirect after submitting a form part of
the form actions. Since we redirect to a new protocol (nc://login/).
Causing the form submission to work but the redirect failing hard.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

core/Controller/ClientFlowLoginController.php

@@ -195,7 +195,10 @@ public function showAuthPickerPage($clientIdentifier = '') {
 		);
 		$this->session->set(self::stateName, $stateToken);
 
-		return new StandaloneTemplateResponse(
+		$csp = new Http\ContentSecurityPolicy();
+		$csp->addAllowedFormActionDomain('nc://*');
+
+		$response = new StandaloneTemplateResponse(
 			$this->appName,
 			'loginflow/authpicker',
 			[
@@ -209,6 +212,9 @@ public function showAuthPickerPage($clientIdentifier = '') {
 			],
 			'guest'
 		);
+
+		$response->setContentSecurityPolicy($csp);
+		return $response;
 	}
 
 	/**
@@ -234,7 +240,10 @@ public function grantPage($stateToken = '',
 			$clientName = $client->getName();
 		}
 
-		return new StandaloneTemplateResponse(
+		$csp = new Http\ContentSecurityPolicy();
+		$csp->addAllowedFormActionDomain('nc://*');
+
+		$response = new StandaloneTemplateResponse(
 			$this->appName,
 			'loginflow/grant',
 			[
@@ -248,6 +257,9 @@ public function grantPage($stateToken = '',
 			],
 			'guest'
 		);
+
+		$response->setContentSecurityPolicy($csp);
+		return $response;
 	}
 
 	/**

tests/Core/Controller/ClientFlowLoginControllerTest.php

@@ -186,6 +186,9 @@ public function testShowAuthPickerPageWithOcsHeader() {
 			],
 			'guest'
 		);
+		$csp = new Http\ContentSecurityPolicy();
+		$csp->addAllowedFormActionDomain('nc://*');
+		$expected->setContentSecurityPolicy($csp);
 		$this->assertEquals($expected, $this->clientFlowLoginController->showAuthPickerPage());
 	}
 
@@ -245,6 +248,9 @@ public function testShowAuthPickerPageWithOauth() {
 			],
 			'guest'
 		);
+		$csp = new Http\ContentSecurityPolicy();
+		$csp->addAllowedFormActionDomain('nc://*');
+		$expected->setContentSecurityPolicy($csp);
 		$this->assertEquals($expected, $this->clientFlowLoginController->showAuthPickerPage('MyClientIdentifier'));
 	}