update

v4_ci4/system/Encryption/KeyRotationDecorator.php

@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Encryption;
+
+use CodeIgniter\Encryption\Exceptions\EncryptionException;
+use SensitiveParameter;
+
+/**
+ * Key Rotation Decorator
+ *
+ * Wraps any EncrypterInterface implementation to provide automatic
+ * fallback to previous encryption keys during decryption. This enables
+ * seamless key rotation without requiring re-encryption of existing data.
+ */
+class KeyRotationDecorator implements EncrypterInterface
+{
+    /**
+     * @param EncrypterInterface $innerHandler The wrapped encryption handler
+     * @param list<string>       $previousKeys Array of previous encryption keys
+     */
+    public function __construct(
+        private readonly EncrypterInterface $innerHandler,
+        private readonly array $previousKeys,
+    ) {
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * Encryption always uses the inner handler's current key.
+     */
+    public function encrypt(#[SensitiveParameter] $data, #[SensitiveParameter] $params = null)
+    {
+        return $this->innerHandler->encrypt($data, $params);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * Attempts decryption with current key first. If that fails and no
+     * explicit key was provided in $params, tries each previous key.
+     *
+     * @throws EncryptionException
+     */
+    public function decrypt($data, #[SensitiveParameter] $params = null)
+    {
+        try {
+            return $this->innerHandler->decrypt($data, $params);
+        } catch (EncryptionException $e) {
+            // Don't try previous keys if an explicit key was provided
+            if (is_string($params) || (is_array($params) && isset($params['key']))) {
+                throw $e;
+            }
+
+            if ($this->previousKeys === []) {
+                throw $e;
+            }
+
+            foreach ($this->previousKeys as $previousKey) {
+                try {
+                    $previousParams = is_array($params)
+                        ? array_merge($params, ['key' => $previousKey])
+                        : $previousKey;
+
+                    return $this->innerHandler->decrypt($data, $previousParams);
+                } catch (EncryptionException) {
+                    continue;
+                }
+            }
+
+            throw $e;
+        }
+    }
+
+    /**
+     * Delegate property access to the inner handler.
+     *
+     * @return array|bool|int|string|null
+     */
+    public function __get(string $key)
+    {
+        if (method_exists($this->innerHandler, '__get')) {
+            return $this->innerHandler->__get($key);
+        }
+
+        return null;
+    }
+
+    /**
+     * Delegate property existence check to inner handler.
+     */
+    public function __isset(string $key): bool
+    {
+        if (method_exists($this->innerHandler, '__isset')) {
+            return $this->innerHandler->__isset($key);
+        }
+
+        return false;
+    }
+}