Set proper permissions on link share

If we do not allow public upload we should limit the permissions on
links shares upon retrieval.

* Added unit test
* Allow fetching federated shares by token as well

lib/private/Share20/Manager.php

@@ -976,7 +976,17 @@ class Manager implements IManager {
 	public function getShareByToken($token) {
 		$provider = $this->factory->getProviderForType(\OCP\Share::SHARE_TYPE_LINK);
 
-		$share = $provider->getShareByToken($token);
+		try {
+			$share = $provider->getShareByToken($token);
+		} catch (ShareNotFound $e) {
+			//Ignore
+		}
+
+		// If it is not a link share try to fetch a federated share by token
+		if ($share === null) {
+			$provider = $this->factory->getProviderForType(\OCP\Share::SHARE_TYPE_REMOTE);
+			$share = $provider->getShareByToken($token);
+		}
 
 		if ($share->getExpirationDate() !== null &&
 			$share->getExpirationDate() <= new \DateTime()) {
@@ -984,6 +994,14 @@ class Manager implements IManager {
 			throw new ShareNotFound();
 		}
 
+		/*
+		 * Reduce the permissions for link shares if public upload is not enabled
+		 */
+		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK &&
+			!$this->shareApiLinkAllowPublicUpload()) {
+			$share->setPermissions($share->getPermissions() & ~(\OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE));
+		}
+
 		return $share;
 	}
 

tests/lib/share20/managertest.php

@@ -2084,6 +2084,25 @@ class ManagerTest extends \Test\TestCase {
 		$this->assertSame($share, $res);
 	}
 
+	public function testGetShareByTokenPublicSharingDisabled() {
+		$share = $this->manager->newShare();
+		$share->setShareType(\OCP\Share::SHARE_TYPE_LINK)
+			->setPermissions(\OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE);
+
+		$this->config->method('getAppValue')->will($this->returnValueMap([
+			['core', 'shareapi_allow_public_upload', 'yes', 'no'],
+		]));
+
+		$this->defaultProvider->expects($this->once())
+			->method('getShareByToken')
+			->willReturn('validToken')
+			->willReturn($share);
+
+		$res = $this->manager->getShareByToken('validToken');
+
+		$this->assertSame(\OCP\Constants::PERMISSION_READ, $res->getPermissions());
+	}
+
 	public function testCheckPasswordNoLinkShare() {
 		$share = $this->getMock('\OCP\Share\IShare');
 		$share->method('getShareType')->willReturn(\OCP\Share::SHARE_TYPE_USER);