Missing signature is validated inside the SignatureStrategy

Author: tg666

src/ImageServer/LocalImageServer.php

@@ -148,12 +148,7 @@ private function validateSignature(RequestInterface $request, string $path): voi
         $signatureParameterName = $this->imageStorage->getConfig()[Config::SIGNATURE_PARAMETER_NAME];
         assert(is_string($signatureParameterName));
 
-        $token = $request->getQueryParameter($signatureParameterName) ?? '';
-        assert(is_string($token));
-
-        if (empty($token)) {
-            throw new SignatureException('Missing signature in request.');
-        }
+        $token = (string) ($request->getQueryParameter($signatureParameterName) ?? '');
 
         if (!$signatureStrategy->verifyToken($token, $path)) {
             throw new SignatureException('Request contains invalid signature.');

src/Security/SignatureStrategy.php

@@ -35,6 +35,10 @@ public function verifyToken(string $token, string $path): bool
             return true;
         }
 
+        if ('' === $token) {
+            return false;
+        }
+
         return hash_equals($token, $this->doCreateToken(path: $path));
     }