Proof of concept for encrypted secrets

src/Symfony/Bundle/FrameworkBundle/Command/SecretsAddCommand.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Command;
+
+use Symfony\Bundle\FrameworkBundle\Secret\SecretStorageInterface;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\QuestionHelper;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Question\Question;
+
+final class SecretsAddCommand extends Command
+{
+    protected static $defaultName = 'secrets:add';
+
+    /**
+     * @var SecretStorageInterface
+     */
+    private $secretStorage;
+
+    public function __construct(SecretStorageInterface $secretStorage)
+    {
+        $this->secretStorage = $secretStorage;
+
+        parent::__construct();
+    }
+
+    protected function configure()
+    {
+        $this
+            ->setDescription('Adds a secret with the key.')
+            ->addArgument(
+                'key',
+                InputArgument::REQUIRED
+            )
+            ->addArgument(
+                'secret',
+                InputArgument::REQUIRED
+            )
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $key = $input->getArgument('key');
+        $secret = $input->getArgument('secret');
+
+        $this->secretStorage->putSecret($key, $secret);
+    }
+
+    protected function interact(InputInterface $input, OutputInterface $output)
+    {
+        /** @var QuestionHelper $helper */
+        $helper = $this->getHelper('question');
+
+        $question = new Question('Key of the secret: ', $input->getArgument('key'));
+
+        $key = $helper->ask($input, $output, $question);
+        $input->setArgument('key', $key);
+
+        $question = new Question('Plaintext secret value: ', $input->getArgument('secret'));
+        $question->setHidden(true);
+
+        $secret = $helper->ask($input, $output, $question);
+        $input->setArgument('secret', $secret);
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Command/SecretsGenerateKeyCommand.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Command;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class SecretsGenerateKeyCommand extends Command
+{
+    protected static $defaultName = 'secrets:generate-key';
+
+    protected function configure()
+    {
+        $this
+            ->setDescription('Prints a randomly generated encryption key.')
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $encryptionKey = sodium_crypto_stream_keygen();
+
+        $output->write($encryptionKey, false, OutputInterface::OUTPUT_RAW);
+
+        sodium_memzero($encryptionKey);
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Command/SecretsListCommand.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Command;
+
+use Symfony\Bundle\FrameworkBundle\Secret\SecretStorageInterface;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\Table;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class SecretsListCommand extends Command
+{
+    protected static $defaultName = 'secrets:list';
+
+    /**
+     * @var SecretStorageInterface
+     */
+    private $secretStorage;
+
+    public function __construct(SecretStorageInterface $secretStorage)
+    {
+        $this->secretStorage = $secretStorage;
+
+        parent::__construct();
+    }
+
+    protected function configure()
+    {
+        $this
+            ->setDescription('Lists all secrets.')
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $table = new Table($output);
+        $table->setHeaders(['key', 'plaintext secret']);
+
+        foreach ($this->secretStorage->listSecrets() as $key => $secret) {
+            $table->addRow([$key, $secret]);
+        }
+
+        $table->render();
+    }
+}

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -115,10 +115,29 @@ class Configuration implements ConfigurationInterface
         $this->addRobotsIndexSection($rootNode);
         $this->addHttpClientSection($rootNode);
         $this->addMailerSection($rootNode);
+        $this->addSecretsSection($rootNode);
 
         return $treeBuilder;
     }
 
+    private function addSecretsSection(ArrayNodeDefinition $rootNode)
+    {
+        $rootNode
+            ->children()
+                ->arrayNode('secrets')
+                    ->canBeEnabled()
+                    ->children()
+                        ->scalarNode('encrypted_secrets_dir')->end()
+                        ->scalarNode('encryption_key')->end()
+                        //->scalarNode('public_key')->end()
+                        //->scalarNode('private_key')->end()
+                        ->scalarNode('decrypted_secrets_cache')->end()
+                    ->end()
+                ->end()
+            ->end()
+        ;
+    }
+
     private function addCsrfSection(ArrayNodeDefinition $rootNode)
     {
         $rootNode

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -334,6 +334,7 @@ class FrameworkExtension extends Extension
         $this->registerRouterConfiguration($config['router'], $container, $loader);
         $this->registerAnnotationsConfiguration($config['annotations'], $container, $loader);
         $this->registerPropertyAccessConfiguration($config['property_access'], $container, $loader);
+        $this->registerSecretsConfiguration($config['secrets'], $container, $loader);
 
         if ($this->isConfigEnabled($container, $config['serializer'])) {
             if (!class_exists('Symfony\Component\Serializer\Serializer')) {
@@ -1441,6 +1442,20 @@ class FrameworkExtension extends Extension
         ;
     }
 
+    private function registerSecretsConfiguration(array $config, ContainerBuilder $container, XmlFileLoader $loader)
+    {
+        if (!$this->isConfigEnabled($container, $config)) {
+            $container->removeDefinition('console.command.secrets_add');
+
+            return;
+        }
+
+        $loader->load('secrets.xml');
+
+        $container->getDefinition('secrets.storage.files')->replaceArgument(0, $config['encrypted_secrets_dir']);
+        $container->getDefinition('secrets.storage.files')->replaceArgument(1, $config['encryption_key']);
+    }
+
     private function registerSecurityCsrfConfiguration(array $config, ContainerBuilder $container, XmlFileLoader $loader)
     {
         if (!$this->isConfigEnabled($container, $config)) {

src/Symfony/Bundle/FrameworkBundle/Resources/config/console.xml

@@ -200,5 +200,19 @@
             <argument type="service" id="debug.file_link_formatter" on-invalid="null" />
             <tag name="console.command" command="debug:error-renderer" />
         </service>
+
+        <service id="console.command.secrets_add" class="Symfony\Bundle\FrameworkBundle\Command\SecretsAddCommand">
+            <argument type="service" id="secrets.storage.cache" />
+            <tag name="console.command" command="secrets:add" />
+        </service>
+
+        <service id="console.command.secrets_generate_key" class="Symfony\Bundle\FrameworkBundle\Command\SecretsGenerateKeyCommand">
+            <tag name="console.command" command="secrets:generate-key" />
+        </service>
+
+        <service id="console.command.secrets_list" class="Symfony\Bundle\FrameworkBundle\Command\SecretsListCommand">
+            <argument type="service" id="secrets.storage.cache" />
+            <tag name="console.command" command="secrets:list" />
+        </service>
     </services>
 </container>

src/Symfony/Bundle/FrameworkBundle/Resources/config/secrets.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" ?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
+
+    <services>
+        <service id="secrets.storage.files" class="Symfony\Bundle\FrameworkBundle\Secret\FilesSecretStorage">
+            <argument />
+            <argument />
+        </service>
+
+        <service id="secrets.storage.cache" class="Symfony\Bundle\FrameworkBundle\Secret\CachedSecretStorage">
+            <argument type="service" id="secrets.storage.files" />
+            <argument type="service" id="cache.system" />
+        </service>
+
+        <service id="secrets.env_processor" class="Symfony\Bundle\FrameworkBundle\Secret\SecretEnvVarProcessor">
+            <argument type="service" id="secrets.storage.cache" />
+            <tag name="container.env_var_processor" />
+        </service>
+    </services>
+</container>

src/Symfony/Bundle/FrameworkBundle/Secret/CachedSecretStorage.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Secret;
+
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+
+class CachedSecretStorage implements SecretStorageInterface
+{
+    /**
+     * @var SecretStorageInterface
+     */
+    private $decoratedStorage;
+    /**
+     * @var CacheItemPoolInterface
+     */
+    private $cache;
+
+    public function __construct(SecretStorageInterface $decoratedStorage, CacheItemPoolInterface $cache)
+    {
+        $this->decoratedStorage = $decoratedStorage;
+        $this->cache = $cache;
+    }
+
+    public function getSecret(string $key): string
+    {
+        $cacheItem = $this->cache->getItem('secrets.php');
+
+        if ($cacheItem->isHit()) {
+            $secrets = $cacheItem->get();
+            if (isset($secrets[$key])) {
+                return $secrets[$key];
+            }
+        }
+
+        $this->regenerateCache($cacheItem);
+
+        return $this->decoratedStorage->getSecret($key);
+    }
+
+    public function putSecret(string $key, string $secret): void
+    {
+        $this->decoratedStorage->putSecret($key, $secret);
+        $this->regenerateCache();
+    }
+
+    public function deleteSecret(string $key): void
+    {
+        $this->decoratedStorage->deleteSecret($key);
+        $this->regenerateCache();
+    }
+
+    public function listSecrets(): iterable
+    {
+        $cacheItem = $this->cache->getItem('secrets.php');
+
+        if ($cacheItem->isHit()) {
+            return $cacheItem->get();
+        }
+
+        return $this->regenerateCache($cacheItem);
+    }
+
+    private function regenerateCache(?CacheItemInterface $cacheItem = null): array
+    {
+        $cacheItem = $cacheItem ?? $this->cache->getItem('secrets.php');
+
+        $secrets = [];
+        foreach ($this->decoratedStorage->listSecrets() as $key => $secret) {
+            $secrets[$key] = $secret;
+        }
+
+        $cacheItem->set($secrets);
+        $this->cache->save($cacheItem);
+
+        return $secrets;
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Secret/EncryptedMessage.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Secret;
+
+class EncryptedMessage
+{
+    /**
+     * @var string
+     */
+    private $ciphertext;
+
+    /**
+     * @var string
+     */
+    private $nonce;
+
+    public function __construct(string $ciphertext, string $nonce)
+    {
+        $this->ciphertext = $ciphertext;
+        $this->nonce = $nonce;
+    }
+
+    public function __toString()
+    {
+        return $this->nonce.$this->ciphertext;
+    }
+
+    public function getCiphertext(): string
+    {
+        return $this->ciphertext;
+    }
+
+    public function getNonce(): string
+    {
+        return $this->nonce;
+    }
+
+    public static function createFromString(string $message): self
+    {
+        if (\strlen($message) < SODIUM_CRYPTO_STREAM_NONCEBYTES) {
+            throw new \RuntimeException('Invalid ciphertext. Message is too short.');
+        }
+
+        $nonce = substr($message, 0, SODIUM_CRYPTO_STREAM_NONCEBYTES);
+        $ciphertext = substr($message, SODIUM_CRYPTO_STREAM_NONCEBYTES);
+
+        return new self($ciphertext, $nonce);
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Secret/FilesSecretStorage.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Secret;
+
+class FilesSecretStorage implements SecretStorageInterface
+{
+    /**
+     * @var string
+     */
+    private $secretsFolder;
+    /**
+     * @var string
+     */
+    private $encryptionKey;
+
+    public function __construct(string $secretsFolder, string $encryptionKey)
+    {
+        $this->secretsFolder = $secretsFolder;
+        $this->encryptionKey = $encryptionKey;
+    }
+
+    public function getSecret(string $key): string
+    {
+        return $this->decryptFile($this->getFilePath($key));
+    }
+
+    public function putSecret(string $key, string $secret): void
+    {
+        $nonce = random_bytes(SODIUM_CRYPTO_STREAM_NONCEBYTES);
+        $ciphertext = sodium_crypto_stream_xor($secret, $nonce, $this->encryptionKey);
+
+        sodium_memzero($secret);
+
+        $message = new EncryptedMessage($ciphertext, $nonce);
+
+        file_put_contents($this->getFilePath($key), (string) $message);
+    }
+
+    public function deleteSecret(string $key): void
+    {
+        unlink($this->getFilePath($key));
+    }
+
+    public function listSecrets(): iterable
+    {
+        foreach (scandir($this->secretsFolder) as $fileName) {
+            if ('.' === $fileName || '..' === $fileName) {
+                continue;
+            }
+
+            $key = basename($fileName, '.bin');
+            yield $key => $this->getSecret($key);
+        }
+    }
+
+    private function decryptFile(string $filePath): string
+    {
+        $encrypted = file_get_contents($filePath);
+
+        $message = EncryptedMessage::createFromString($encrypted);
+
+        return sodium_crypto_stream_xor($message->getCiphertext(), $message->getNonce(), $this->encryptionKey);
+    }
+
+    private function getFilePath(string $key): string
+    {
+        return $this->secretsFolder.$key.'.bin';
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Secret/SecretEnvVarProcessor.php

@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\FrameworkBundle\Secret;
+
+use Symfony\Component\DependencyInjection\EnvVarProcessorInterface;
+
+class SecretEnvVarProcessor implements EnvVarProcessorInterface
+{
+    private $secretStorage;
+
+    public function __construct(SecretStorageInterface $secretStorage)
+    {
+        $this->secretStorage = $secretStorage;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getProvidedTypes()
+    {
+        return [
+            'secret' => 'string',
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getEnv($prefix, $name, \Closure $getEnv)
+    {
+        return $this->secretStorage->getSecret($name);
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Secret/SecretStorageInterface.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Symfony\Bundle\FrameworkBundle\Secret;
+
+interface SecretStorageInterface
+{
+    public function getSecret(string $key): string;
+
+    public function putSecret(string $key, string $secret): void;
+
+    public function deleteSecret(string $key): void;
+
+    public function listSecrets(): iterable;
+}