diff --git a/tests/Unit/Controller/ConfigControllerTest.php b/tests/Unit/Controller/ConfigControllerTest.php
new file mode 100644
index 000000000..d8f384458
--- /dev/null
+++ b/tests/Unit/Controller/ConfigControllerTest.php
@@ -0,0 +1,130 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Jonas Rittershofer <jotoeri@users.noreply.github.com>
+ *
+ * @author Jonas Rittershofer <jotoeri@users.noreply.github.com>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Forms\Tests\Unit\Controller;
+
+use OCA\Forms\Controller\ConfigController;
+
+use OCA\Forms\Service\ConfigService;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\IConfig;
+use OCP\ILogger;
+use OCP\IRequest;
+
+use PHPUnit\Framework\MockObject\MockObject;
+use Test\TestCase;
+
+class ConfigControllerTest extends TestCase {
+
+	/** @var ConfigController */
+	private $configController;
+
+	/** @var ConfigService */
+	private $configService;
+
+	/** @var IConfig|MockObject */
+	private $config;
+
+	/** @var ILogger|MockObject */
+	private $logger;
+
+	/** @var IRequest|MockObject */
+	private $request;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->configService = $this->createMock(ConfigService::class);
+		$this->config = $this->createMock(IConfig::class);
+		$this->logger = $this->createMock(ILogger::class);
+		$this->request = $this->createMock(IRequest::class);
+
+		$this->configController = new ConfigController(
+			'forms',
+			$this->configService,
+			$this->config,
+			$this->logger,
+			$this->request
+		);
+	}
+
+	public function testGetAppConfig() {
+		$this->configService->expects($this->once())
+			->method('getAppConfig')
+			->willReturn([
+				'allow' => 'someConfig',
+				'permit' => 'all'
+			]);
+		
+		$this->assertEquals(new DataResponse([
+			'allow' => 'someConfig',
+			'permit' => 'all'
+		]), $this->configController->getAppConfig());
+	}
+
+	public function dataUpdateAppConfig() {
+		return [
+			'booleanConfig' => [
+				'configKey' => 'allowPermitAll',
+				'configValue' => true,
+				'strConfig' => "true"
+			],
+			'arrayConfig' => [
+				'configKey' => 'allowPermitAll',
+				'configValue' => [
+					"admin",
+					"group1"
+				],
+				'strConfig' => '["admin","group1"]'
+			]
+		];
+	}
+	/**
+	 * @dataProvider dataUpdateAppConfig
+	 *
+	 * @param string $configKey
+	 * @param mixed $configValue
+	 * @param string $strConfig The configValue as json-string
+	 */
+	public function testUpdateAppConfig(string $configKey, $configValue, string $strConfig) {
+		$this->logger->expects($this->once())
+			->method('debug');
+		
+		$this->config->expects($this->once())
+			->method('setAppValue')
+			->with('forms', $configKey, $strConfig);
+
+		$this->assertEquals(new DataResponse(), $this->configController->updateAppConfig($configKey, $configValue));
+	}
+
+	public function testUpdateAppConfig_unknownKey() {
+		$this->logger->expects($this->once())
+			->method('debug');
+		
+		$this->config->expects($this->never())
+			->method('setAppValue');
+
+		$this->assertEquals(new DataResponse('Unknown appConfig key: someUnknownKey', 400), $this->configController->updateAppConfig('someUnknownKey', 'storeThisValue!'));
+	}
+}
diff --git a/tests/Unit/Controller/ShareApiControllerTest.php b/tests/Unit/Controller/ShareApiControllerTest.php
index a1db81019..4392ac9fe 100644
--- a/tests/Unit/Controller/ShareApiControllerTest.php
+++ b/tests/Unit/Controller/ShareApiControllerTest.php
@@ -30,6 +30,7 @@
 use OCA\Forms\Db\FormMapper;
 use OCA\Forms\Db\Share;
 use OCA\Forms\Db\ShareMapper;
+use OCA\Forms\Service\ConfigService;
 use OCA\Forms\Service\FormsService;
 
 use OCP\AppFramework\Db\DoesNotExistException;
@@ -58,6 +59,9 @@ class ShareApiControllerTest extends TestCase {
 	/** @var ShareMapper|MockObject */
 	private $shareMapper;
 
+	/** @var ConfigService|MockObject */
+	private $configService;
+
 	/** @var FormsService|MockObject */
 	private $formsService;
 
@@ -73,6 +77,7 @@ class ShareApiControllerTest extends TestCase {
 	public function setUp(): void {
 		$this->formMapper = $this->createMock(FormMapper::class);
 		$this->shareMapper = $this->createMock(ShareMapper::class);
+		$this->configService = $this->createMock(ConfigService::class);
 		$this->formsService = $this->createMock(FormsService::class);
 		$this->logger = $this->createMock(ILogger::class);
 		$this->request = $this->createMock(IRequest::class);
@@ -91,6 +96,7 @@ public function setUp(): void {
 			'forms',
 			$this->formMapper,
 			$this->shareMapper,
+			$this->configService,
 			$this->formsService,
 			$this->logger,
 			$this->request,
@@ -215,6 +221,10 @@ public function testNewLinkShare(int $shareType, string $shareWith, array $expec
 			->with($share)
 			->willReturn($shareWithId);
 
+		$this->configService->expects($this->once())
+			->method('getAllowPublicLink')
+			->willReturn(true);
+
 		$this->formsService->expects($this->once())
 			->method('getShareDisplayName')
 			->with($shareWithId->read())
@@ -232,7 +242,7 @@ public function testNewLinkShare(int $shareType, string $shareWith, array $expec
 	/**
 	 * Test a random link hash, that is already existing.
 	 */
-	public function testExistingLinkHash() {
+	public function testNewLinkShare_ExistingHash() {
 		$form = new Form();
 		$form->setId('5');
 		$form->setOwnerId('currentUser');
@@ -242,6 +252,10 @@ public function testExistingLinkHash() {
 			->with('5')
 			->willReturn($form);
 
+		$this->configService->expects($this->once())
+			->method('getAllowPublicLink')
+			->willReturn(true);
+
 		$this->secureRandom->expects($this->any())
 			->method('generate')
 			->willReturn('abcdefgh');
@@ -258,6 +272,25 @@ public function testExistingLinkHash() {
 		$this->shareApiController->newShare(5, IShare::TYPE_LINK, '');
 	}
 
+	/**
+	 * Test a random link hash, that is already existing.
+	 */
+	public function testNewLinkShare_PublicLinkNotAllowed() {
+		$form = new Form();
+		$form->setId('5');
+		$form->setOwnerId('currentUser');
+
+		$this->configService->expects($this->once())
+			->method('getAllowPublicLink')
+			->willReturn(false);
+
+		$this->shareMapper->expects($this->never())
+			->method('insert');
+
+		$this->expectException(OCSException::class);
+		$this->shareApiController->newShare(5, IShare::TYPE_LINK, '');
+	}
+
 	/**
 	 * Test an unused (but existing) Share-Type
 	 */
diff --git a/tests/Unit/Service/ConfigServiceTest.php b/tests/Unit/Service/ConfigServiceTest.php
new file mode 100644
index 000000000..d5cc2fc05
--- /dev/null
+++ b/tests/Unit/Service/ConfigServiceTest.php
@@ -0,0 +1,228 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Jonas Rittershofer <jotoeri@users.noreply.github.com>
+ *
+ * @author Jonas Rittershofer <jotoeri@users.noreply.github.com>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Forms\Tests\Unit\Service;
+
+use OCA\Forms\Service\ConfigService;
+
+use OCP\IConfig;
+use OCP\IGroup;
+use OCP\IGroupManager;
+use OCP\ILogger;
+use OCP\IUser;
+use OCP\IUserSession;
+
+use PHPUnit\Framework\MockObject\MockObject;
+use Test\TestCase;
+
+class ConfigServiceTest extends TestCase {
+
+	/** @var ConfigService */
+	private $configService;
+
+	/** @var IConfig|MockObject */
+	private $config;
+
+	/** @var IGroupManager|MockObject */
+	private $groupManager;
+
+	/** @var ILogger|MockObject */
+	private $logger;
+
+	/** @var IUser|MockObject */
+	private $currentUser;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->config = $this->createMock(IConfig::class);
+		$this->groupManager = $this->createMock(IGroupManager::class);
+		$this->logger = $this->createMock(ILogger::class);
+		$userSession = $this->createMock(IUserSession::class);
+
+		$this->currentUser = $this->createMock(IUser::class);
+		$this->currentUser->expects($this->any())
+			->method('getUID')
+			->willReturn('currentUser');
+		$userSession->expects($this->any())
+			->method('getUser')
+			->willReturn($this->currentUser);
+
+		$this->configService = new ConfigService(
+			'forms',
+			$this->config,
+			$this->groupManager,
+			$this->logger,
+			$userSession
+		);
+	}
+
+	public function dataGetAppConfig() {
+		return [
+			'oneFullConfig' => [
+				'strConfig' => [
+					'allowPermitAll' => 'false',
+					'allowPublicLink' => 'false',
+					'creationAllowedGroups' => '["group1", "group2", "nonExisting"]',
+					'restrictCreation' => 'true',
+				],
+				'groupDisplayNames' => [
+					'group1' => 'Group No. 1',
+					'group2' => 'Group No. 2'
+				],
+				'expected' => [
+					'allowPermitAll' => false,
+					'allowPublicLink' => false,
+					'creationAllowedGroups' => [
+						[
+							'groupId' => 'group1',
+							'displayName' => 'Group No. 1'
+						],
+						[
+							'groupId' => 'group2',
+							'displayName' => 'Group No. 2'
+						]
+					],
+					'restrictCreation' => true,
+
+					'canCreateForms' => false
+				]
+			]
+		];
+	}
+	/**
+	 * @dataProvider dataGetAppConfig
+	 *
+	 * @param array $strConfig JSON Config Strings as stored in AppConfig
+	 * @param array $groupDisplayNames DisplayNames for Testing
+	 * @param array $expected
+	 */
+	public function testGetAppConfig(array $strConfig, array $groupDisplayNames, array $expected) {
+		// Default Values are set within getAppValue, thus returning this one.
+		$this->config->expects($this->any())
+			->method('getAppValue')
+			->will($this->returnCallback(function ($appName, $configKey, $defaultVal) use ($strConfig) {
+				return $strConfig[$configKey];
+			}));
+
+
+		// Mock Group formatting
+		$this->groupManager->expects($this->any())
+			->method('get')
+			->will($this->returnCallback(function ($groupId) use ($groupDisplayNames) {
+				if (!array_key_exists($groupId, $groupDisplayNames)) {
+					return [];
+				}
+				$group = $this->createMock(IGroup::class);
+				$group->expects($this->once())
+					->method('getDisplayName')
+					->willReturn($groupDisplayNames[$groupId]);
+				return $group;
+			}));
+
+		// Return currentUser Groups
+		$this->groupManager->expects($this->once())
+			->method('getUserGroupIds')
+			->with($this->currentUser)
+			->willReturn([]);
+
+		$this->assertEquals($expected, $this->configService->getAppConfig());
+	}
+
+	public function dataGetAppConfig_Default() {
+		return [
+			'defaultValues' => [
+				'expected' => [
+					'allowPermitAll' => true,
+					'allowPublicLink' => true,
+					'creationAllowedGroups' => [],
+					'restrictCreation' => false,
+
+					'canCreateForms' => true
+				]
+			]
+		];
+	}
+	/**
+	 * @dataProvider dataGetAppConfig_Default
+	 *
+	 * @param array $expected
+	 */
+	public function testGetAppConfig_Default(array $expected) {
+		// Default Values are set within getAppValue, thus returning this one.
+		$this->config->expects($this->any())
+			->method('getAppValue')
+			->will($this->returnCallback(function ($appName, $configKey, $defaultVal) {
+				return $defaultVal;
+			}));
+
+		$this->assertEquals($expected, $this->configService->getAppConfig());
+	}
+
+	public function dataCanCreateForms() {
+		return [
+			'notRestriced' => [
+				'config' => [
+					'restrictCreation' => 'false',
+				],
+				'expected' => true
+			],
+			'restrictedGroupAllowed' => [
+				'config' => [
+					'restrictCreation' => 'true',
+					'creationAllowedGroups' => '["usersGroup","notUsersGroup"]'
+				],
+				'expected' => true
+			],
+			'restrictedNotInGroup' => [
+				'config' => [
+					'restrictCreation' => 'true',
+					'creationAllowedGroups' => '["notUsersGroup"]'
+				],
+				'expected' => false
+			]
+		];
+	}
+
+	/**
+	 * @dataProvider dataCanCreateForms
+	 *
+	 * @param array $config AppConfig with necessary values
+	 * @param bool $expected
+	 */
+	public function testCanCreateForms(array $config, bool $expected) {
+		$this->config->expects($this->any())
+			->method('getAppValue')
+			->will($this->returnCallback(function ($appName, $configKey, $defaultVal) use ($config) {
+				return $config[$configKey];
+			}));
+
+		$this->groupManager->expects($this->any())
+			->method('getUserGroupIds')
+			->with($this->currentUser)
+			->willReturn(["usersGroup"]);
+		
+		$this->assertEquals($expected, $this->configService->canCreateForms());
+	}
+}
diff --git a/tests/Unit/Service/FormsServiceTest.php b/tests/Unit/Service/FormsServiceTest.php
index 80585a83f..b8e1efbc7 100644
--- a/tests/Unit/Service/FormsServiceTest.php
+++ b/tests/Unit/Service/FormsServiceTest.php
@@ -36,6 +36,7 @@
 use OCA\Forms\Db\Share;
 use OCA\Forms\Db\ShareMapper;
 use OCA\Forms\Db\SubmissionMapper;
+use OCA\Forms\Service\ConfigService;
 
 use OCP\IGroup;
 use OCP\IGroupManager;
@@ -71,6 +72,9 @@ class FormsServiceTest extends TestCase {
 	/** @var SubmissionMapper|MockObject */
 	private $submissionMapper;
 
+	/** @var ConfigService|MockObject */
+	private $configService;
+
 	/** @var IGroupManager|MockObject */
 	private $groupManager;
 
@@ -88,6 +92,7 @@ public function setUp(): void {
 		$this->questionMapper = $this->createMock(QuestionMapper::class);
 		$this->shareMapper = $this->createMock(ShareMapper::class);
 		$this->submissionMapper = $this->createMock(SubmissionMapper::class);
+		$this->configService = $this->createMock(ConfigService::class);
 
 		$this->groupManager = $this->createMock(IGroupManager::class);
 		$this->logger = $this->createMock(ILogger::class);
@@ -109,6 +114,7 @@ public function setUp(): void {
 			$this->questionMapper,
 			$this->shareMapper,
 			$this->submissionMapper,
+			$this->configService,
 			$this->groupManager,
 			$this->logger,
 			$this->userManager,
@@ -435,6 +441,10 @@ public function testGetPermissions(string $ownerId, array $access, array $expect
 			->with(42)
 			->willReturn([]);
 
+		$this->configService->expects($this->any())
+			->method('getAllowPermitAll')
+			->willReturn(true);
+
 		$this->assertEquals($expected, $this->formsService->getPermissions(42));
 	}
 
@@ -536,6 +546,7 @@ public function testPublicCanSubmit() {
 			$this->questionMapper,
 			$this->shareMapper,
 			$this->submissionMapper,
+			$this->configService,
 			$this->groupManager,
 			$this->logger,
 			$this->userManager,
@@ -646,6 +657,10 @@ public function testHasUserAccess(array $accessArray, string $ownerId, bool $exp
 			->with(42)
 			->willReturn($form);
 
+		$this->configService->expects($this->any())
+			->method('getAllowPermitAll')
+			->willReturn(true);
+
 		$this->assertEquals($expected, $this->formsService->hasUserAccess(42));
 	}
 
@@ -673,6 +688,26 @@ public function testHasUserAccess_DirectShare() {
 		$this->assertEquals(true, $this->formsService->hasUserAccess(42));
 	}
 
+	public function testHasUserAccess_PermitAllNotAllowed() {
+		$form = new Form();
+		$form->setAccess([
+			'permitAllUsers' => true,
+			'showToAllUsers' => true,
+		]);
+		$form->setOwnerId('notCurrentUser');
+
+		$this->formMapper->expects($this->once())
+			->method('findById')
+			->with(42)
+			->willReturn($form);
+
+		$this->configService->expects($this->once())
+			->method('getAllowPermitAll')
+			->willReturn(false);
+
+		$this->assertEquals(false, $this->formsService->hasUserAccess(42));
+	}
+
 	public function testHasUserAccess_NotLoggedIn() {
 		$userSession = $this->createMock(IUserSession::class);
 		$userSession->expects($this->once())
@@ -686,6 +721,7 @@ public function testHasUserAccess_NotLoggedIn() {
 			$this->questionMapper,
 			$this->shareMapper,
 			$this->submissionMapper,
+			$this->configService,
 			$this->groupManager,
 			$this->logger,
 			$this->userManager,
@@ -778,9 +814,13 @@ public function testIsSharedFormShown(string $ownerId, int $expires, array $acce
 		$form->setAccess($access);
 
 		$this->formMapper->expects($this->any())
-		->method('findById')
-		->with(42)
-		->willReturn($form);
+			->method('findById')
+			->with(42)
+			->willReturn($form);
+
+		$this->configService->expects($this->any())
+			->method('getAllowPermitAll')
+			->willReturn(true);
 
 		$share = new Share();
 		$share->setShareType($shareType);
@@ -793,6 +833,33 @@ public function testIsSharedFormShown(string $ownerId, int $expires, array $acce
 		$this->assertEquals($expected, $this->formsService->isSharedFormShown(42));
 	}
 
+	public function testIsSharedFormShown_PermitAllNotAllowed() {
+		$form = new Form();
+		$form->setId(42);
+		$form->setOwnerId('notCurrentUser');
+		$form->setExpires(false);
+		$form->setAccess([
+			'permitAllUsers' => true,
+			'showToAllUsers' => true,
+		]);
+
+		$this->formMapper->expects($this->any())
+			->method('findById')
+			->with(42)
+			->willReturn($form);
+
+		$this->configService->expects($this->any())
+			->method('getAllowPermitAll')
+			->willReturn(false);
+
+		$this->shareMapper->expects($this->any())
+			->method('findByForm')
+			->with(42)
+			->willReturn([]);
+
+		$this->assertEquals(false, $this->formsService->isSharedFormShown(42));
+	}
+
 	public function dataIsSharedToUser() {
 		return [
 			'sharedToUser' => [