Implements StoredObjectManager for local storage

src/Bundle/ChillDocStoreBundle/Service/Cryptography/KeyGenerator.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\DocStoreBundle\Service\Cryptography;
+
+use Base64Url\Base64Url;
+use Chill\DocStoreBundle\Service\StoredObjectManagerInterface;
+use Random\Randomizer;
+
+class KeyGenerator
+{
+    private readonly Randomizer $randomizer;
+
+    public function __construct()
+    {
+        $this->randomizer = new Randomizer();
+    }
+
+    /**
+     * @return array{alg: string, ext: bool, k: string, key_ops: list<string>, kty: string}
+     */
+    public function generateKey(string $algo = StoredObjectManagerInterface::ALGORITHM): array
+    {
+        if (StoredObjectManagerInterface::ALGORITHM !== $algo) {
+            throw new \LogicException(sprintf("Algorithm '%s' is not supported.", $algo));
+        }
+
+        $key = $this->randomizer->getBytes(128);
+
+        return [
+            'alg' => 'A256CBC',
+            'ext' => true,
+            'k' => Base64Url::encode($key),
+            'key_ops' => ['encrypt', 'decrypt'],
+            'kty' => 'oct',
+        ];
+    }
+
+    /**
+     * @return list<int<0, 255>>
+     */
+    public function generateIv(): array
+    {
+        $iv = [];
+        for ($i = 0; $i < 16; ++$i) {
+            $iv[] = unpack('C', $this->randomizer->getBytes(8))[1];
+        }
+
+        return $iv;
+    }
+}

src/Bundle/ChillDocStoreBundle/Service/StoredObjectManagerInterface.php

@@ -18,6 +18,8 @@ use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
 
 interface StoredObjectManagerInterface
 {
+    public const ALGORITHM = 'AES-256-CBC';
+
     /**
      * @param StoredObject|StoredObjectVersion $document if a StoredObject is given, the last version will be used
      */