fix(federation): allows equal signs in federation id

Signed-off-by: Maxence Lange <[email protected]>

Author: ArtificialOwl

lib/private/Federation/CloudIdManager.php

@@ -106,7 +106,10 @@ public function resolveCloudId(string $cloudId): ICloudId {
 			$user = substr($id, 0, $lastValidAtPos);
 			$remote = substr($id, $lastValidAtPos + 1);
 
-			$this->userManager->validateUserId($user);
+			// We accept slightly more chars when working with federationId than with a local userId.
+			// We remove those eventual chars from the UserId before using
+			// the IUserManager API to confirm its format.
+			$this->userManager->validateUserId(str_replace('=', '-', $user));
 
 			if (!empty($user) && !empty($remote)) {
 				$remote = $this->ensureDefaultProtocol($remote);

tests/lib/Federation/CloudIdManagerTest.php

@@ -91,6 +91,10 @@ public function cloudIdProvider(): array {
 			['[email protected]/cloud/', 'test', 'example.com/cloud', '[email protected]/cloud'],
 			['[email protected]/cloud/index.php', 'test', 'example.com/cloud', '[email protected]/cloud'],
 			['[email protected]@example.com', '[email protected]', 'example.com', '[email protected]@example.com'],
+
+			// Equal signs are not valid on Nextcloud side, but can be used by other federated OCM compatible servers
+			['[email protected]', 'test==', 'example.com', '[email protected]'],
+			['[email protected]', '==', 'example.com', '[email protected]'],
 		];
 	}