feat: add key:rotate command

Author: paulbalandan

system/Commands/Encryption/RotateKey.php

@@ -0,0 +1,271 @@
+<?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\Commands\Encryption;
+
+use CodeIgniter\CLI\AbstractCommand;
+use CodeIgniter\CLI\Attributes\Command;
+use CodeIgniter\CLI\CLI;
+use CodeIgniter\CLI\Input\Option;
+use Config\Paths;
+
+/**
+ * Rotates the encryption key, demoting the current key to `previousKeys`.
+ */
+#[Command(
+    name: 'key:rotate',
+    description: 'Rotates the encryption key, demoting the current key to `encryption.previousKeys` in the `.env` file.',
+    group: 'Encryption',
+)]
+class RotateKey extends AbstractCommand
+{
+    /**
+     * @var list<string>
+     */
+    private const VALID_PREFIXES = ['hex2bin', 'base64'];
+
+    protected function configure(): void
+    {
+        $this
+            ->addOption(new Option(
+                name: 'force',
+                shortcut: 'f',
+                description: 'Skip the key rotation confirmation.',
+            ))
+            ->addOption(new Option(
+                name: 'length',
+                description: 'The length of the random string for the new key, in bytes.',
+                requiresValue: true,
+                default: '32',
+            ))
+            ->addOption(new Option(
+                name: 'prefix',
+                description: 'Prefix for the new key (either hex2bin or base64).',
+                requiresValue: true,
+                default: 'hex2bin',
+            ))
+            ->addOption(new Option(
+                name: 'keep',
+                description: 'Maximum number of previous keys to retain. Older keys are dropped. 0 means unlimited.',
+                requiresValue: true,
+                default: '0',
+            ));
+    }
+
+    protected function interact(array &$arguments, array &$options): void
+    {
+        $prefix = $this->getUnboundOption('prefix', $options);
+
+        if (is_string($prefix) && ! in_array($prefix, self::VALID_PREFIXES, true)) {
+            $options['prefix'] = CLI::prompt('Please provide a valid prefix to use.', self::VALID_PREFIXES, 'required');
+        }
+
+        if ($this->hasUnboundOption('force', $options)) {
+            return;
+        }
+
+        if (env('encryption.key', '') === '') {
+            return;
+        }
+
+        if (CLI::prompt('Rotate encryption key? The current key will be moved to `previousKeys`.', ['n', 'y']) === 'y') {
+            $options['force'] = null; // simulate the presence of the --force option
+        }
+    }
+
+    protected function execute(array $arguments, array $options): int
+    {
+        $prefix = $options['prefix'];
+
+        if (! in_array($prefix, self::VALID_PREFIXES, true)) {
+            CLI::error(sprintf('Invalid prefix "%s". Use either "hex2bin" or "base64".', $prefix));
+
+            return EXIT_ERROR;
+        }
+
+        $currentKey = env('encryption.key', '');
+
+        if ($currentKey === '') {
+            CLI::error('No existing `encryption.key` to rotate. Run `spark key:generate` first.');
+
+            return EXIT_ERROR;
+        }
+
+        if ($options['force'] === false) {
+            if ($this->isInteractive()) {
+                CLI::error('Key rotation cancelled.');
+            } else {
+                CLI::error('Key rotation aborted.');
+                CLI::error('If you want, use the "--force" option to force the rotation.');
+            }
+
+            return EXIT_ERROR;
+        }
+
+        $keep = $options['keep'];
+
+        if (! is_numeric($keep) || (int) $keep < 0) {
+            CLI::error('The --keep option must be a non-negative integer.');
+
+            return EXIT_ERROR;
+        }
+
+        $length = $options['length'];
+
+        if (! is_numeric($length) || (int) $length < 1) {
+            CLI::error('The --length option must be a positive integer.');
+
+            return EXIT_ERROR;
+        }
+
+        $previousKeys = $this->mergePreviousKeys($currentKey, $this->parsePreviousKeys(), (int) $keep);
+
+        // Write previousKeys first. If the subsequent `key:generate` call fails,
+        // the worst case is a stale-but-still-decryptable `.env` (the rotated-out
+        // key is preserved on disk).
+        if (! $this->writePreviousKeys($previousKeys)) {
+            CLI::error('Error in writing `encryption.previousKeys` to `.env` file.');
+
+            return EXIT_ERROR;
+        }
+
+        // Clear `encryption.previousKeys` from all env sources so the DotEnv
+        // reload triggered by `key:generate` picks up the new value (DotEnv's
+        // `setVariable()` skips vars that are already set).
+        putenv('encryption.previousKeys');
+        unset($_ENV['encryption.previousKeys']);
+        service('superglobals')->unsetServer('encryption.previousKeys');
+
+        $exitCode = $this->callSilently('key:generate', options: [
+            'force'  => null,
+            'prefix' => $prefix,
+            'length' => $length,
+        ]);
+
+        if ($exitCode !== EXIT_SUCCESS) {
+            return $exitCode; // @codeCoverageIgnore
+        }
+
+        $count = count($previousKeys);
+
+        CLI::write(sprintf(
+            'Encryption key rotated. %d %s retained for decryption fallback.',
+            $count,
+            $count === 1 ? 'previous key' : 'previous keys',
+        ), 'green');
+        CLI::write('Re-encrypt existing data with the new key when ready.', 'yellow');
+
+        return EXIT_SUCCESS;
+    }
+
+    /**
+     * Reads the existing `encryption.previousKeys` from the environment as a
+     * comma-separated list, ignoring blank entries.
+     *
+     * @return list<string>
+     */
+    private function parsePreviousKeys(): array
+    {
+        $raw = env('encryption.previousKeys', '');
+
+        if (! is_string($raw) || $raw === '') {
+            return [];
+        }
+
+        return array_values(array_filter(
+            array_map(trim(...), explode(',', $raw)),
+            static fn (string $v): bool => $v !== '',
+        ));
+    }
+
+    /**
+     * Prepends the rotated-out key, deduplicates while preserving newest-first order,
+     * and optionally caps the list length.
+     *
+     * @param list<string> $existing
+     *
+     * @return list<string>
+     */
+    private function mergePreviousKeys(string $currentKey, array $existing, int $keep): array
+    {
+        $merged = [$currentKey, ...$existing];
+        $seen   = [];
+        $result = [];
+
+        foreach ($merged as $key) {
+            if (isset($seen[$key])) {
+                continue;
+            }
+
+            $seen[$key] = true;
+            $result[]   = $key;
+        }
+
+        if ($keep > 0) {
+            $result = array_slice($result, 0, $keep);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Replaces or inserts the `encryption.previousKeys` line in the `.env` file.
+     * `key:generate` is responsible for the file's existence and the
+     * `encryption.key` line; this method only touches `encryption.previousKeys`.
+     *
+     * @param list<string> $previousKeys
+     */
+    private function writePreviousKeys(array $previousKeys): bool
+    {
+        $envFile = ((new Paths())->envDirectory ?? ROOTPATH) . '.env'; // @phpstan-ignore nullCoalesce.property
+
+        if (! is_file($envFile)) {
+            return false; // @codeCoverageIgnore
+        }
+
+        if (! is_writable($envFile)) {
+            return false;
+        }
+
+        $contents = (string) file_get_contents($envFile);
+        $value    = implode(',', $previousKeys);
+
+        // Match an actual setting line, not a substring buried in a comment. The optional
+        // `export` prefix mirrors what DotEnv accepts.
+        $previousKeysPattern = '/^(\h*(?:export\h+)?encryption\.previousKeys\h*=\h*)[^\r\n]*$/m';
+
+        if (preg_match($previousKeysPattern, $contents) === 1) {
+            $contents = (string) preg_replace($previousKeysPattern, '$1' . $value, $contents, 1);
+
+            return file_put_contents($envFile, $contents) !== false;
+        }
+
+        // Insert right after the `encryption.key` line so the two stay grouped.
+        $injected = (string) preg_replace(
+            '/^(\h*(?:export\h+)?encryption\.key\h*=\h*[^\r\n]*)$/m',
+            "$1\nencryption.previousKeys = {$value}",
+            $contents,
+            1,
+        );
+
+        if ($injected === $contents) {
+            // @codeCoverageIgnoreStart
+            // Fallback: append to the end. Shouldn't trigger because `key:generate`
+            // writes the `encryption.key` line just before this method runs.
+            $injected = $contents . "\nencryption.previousKeys = {$value}";
+            // @codeCoverageIgnoreEnd
+        }
+
+        return file_put_contents($envFile, $injected) !== false;
+    }
+}