Ensure payload is always base64url encoded

src/Base64UrlUtil.php

@@ -0,0 +1,17 @@
+<?php
+declare(strict_types=1);
+
+namespace BauerKirch\CoronaWarnAppEventRegistration;
+
+class Base64UrlUtil
+{
+    public static function encode(string $input): string
+    {
+        return str_replace(['+', '/', '='], ['-', '_', ''], base64_encode($input));
+    }
+
+    public static function decode(string $input): string
+    {
+        return base64_decode(str_replace(['-', '_'], ['+', '/'], $input));
+    }
+}

src/QRCodePayloadGenerator.php

@@ -72,7 +72,7 @@ public function generatePayload(LocationType $locationType, string $description,
 
         try {
             $payload->setVendorData($locationData->serializeToString());
-            return base64_encode($payload->serializeToString());
+            return Base64UrlUtil::encode($payload->serializeToString());
         } catch (\Exception $e) {
             throw new GenerateException($e);
         }

src/QRCodePayloadReader.php

@@ -32,7 +32,7 @@ public function readPayload(string $payload): QRCodePayloadDto
         $internalPayload = new QRCodePayload();
         $internalLocationData = new CWALocationData();
         try {
-            $internalPayload->mergeFromString(base64_decode($payload));
+            $internalPayload->mergeFromString(Base64UrlUtil::decode($payload));
             $internalLocationData->mergeFromString($internalPayload->getVendorData());
         } catch (\Exception $e) {
             throw new ReadException($e);