Get the proper UID

Some user backends (like the database backend) allow us to obtain a user
case insensitive. However the UID itself is case sensitive.

Example:
* create a user User1
* login as User1
  - This results the data/User1 folder to be created etc
* now have some code somewhere that obtains the userFolder (from
IRootFolder) but pas in 'uSER1' as uid
  - The code will check if that is a valid user. And in this case it is
  since User1 and uSER1 both map to the same user
  - However the the UID in the user object is used for the folder a new
  folder fill be create data/uSER1

With this PR this is avoided now. Since we obtain the real UID casing in
the backend before creating the user object.

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

2 files changed, 17 insertions, 1 deletions

diff --git a/lib/private/User/Database.php b/lib/private/User/Database.php
index 8c00060e196..3db96fa02e2 100644
--- a/lib/private/User/Database.php
+++ b/lib/private/User/Database.php
@@ -65,6 +65,7 @@ use OCP\User\Backend\ICountUsersBackend;
 use OCP\User\Backend\ICreateUserBackend;
 use OCP\User\Backend\IGetDisplayNameBackend;
 use OCP\User\Backend\IGetHomeBackend;
+use OCP\User\Backend\IGetRealUIDBackend;
 use OCP\User\Backend\ISetDisplayNameBackend;
 use OCP\User\Backend\ISetPasswordBackend;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
@@ -80,7 +81,8 @@ class Database extends ABackend
 	           IGetDisplayNameBackend,
 	           ICheckPasswordBackend,
 	           IGetHomeBackend,
-	           ICountUsersBackend {
+	           ICountUsersBackend,
+	           IGetRealUIDBackend {
 	/** @var CappedMemoryCache */
 	private $cache;
 
@@ -473,6 +475,15 @@ class Database extends ABackend
 				}
 			}
 		}
+	}
+
+	public function getRealUID(string $uid): string {
+		if (!$this->userExists($uid)) {
+			throw new \RuntimeException($uid . ' does not exist');
+		}
 
+		return $this->cache[$uid]['uid'];
 	}
+
+
 }
diff --git a/lib/private/User/Manager.php b/lib/private/User/Manager.php
index c9aa17b8bc2..7f9691073c9 100644
--- a/lib/private/User/Manager.php
+++ b/lib/private/User/Manager.php
@@ -38,6 +38,7 @@ use OCP\IGroup;
 use OCP\IUserBackend;
 use OCP\IUserManager;
 use OCP\IConfig;
+use OCP\User\Backend\IGetRealUIDBackend;
 use OCP\UserInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
@@ -151,6 +152,10 @@ class Manager extends PublicEmitter implements IUserManager {
 	 * @return \OC\User\User
 	 */
 	protected function getUserObject($uid, $backend, $cacheUser = true) {
+		if ($backend instanceof IGetRealUIDBackend) {
+			$uid = $backend->getRealUID($uid);
+		}
+
 		if (isset($this->cachedUsers[$uid])) {
 			return $this->cachedUsers[$uid];
 		}