nextcloud/apps/files_encryption/tests/crypt.php

<?php
/**
 * Copyright (c) 2012 Sam Tuke <samtuke@owncloud.com>, and
 * Robin Appelman <icewind@owncloud.com>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */

require_once realpath(dirname(__FILE__) . '/../3rdparty/Crypt_Blowfish/Blowfish.php');
require_once realpath(dirname(__FILE__) . '/../../../lib/base.php');
require_once realpath(dirname(__FILE__) . '/../lib/crypt.php');
require_once realpath(dirname(__FILE__) . '/../lib/keymanager.php');
require_once realpath(dirname(__FILE__) . '/../lib/proxy.php');
require_once realpath(dirname(__FILE__) . '/../lib/stream.php');
require_once realpath(dirname(__FILE__) . '/../lib/util.php');
require_once realpath(dirname(__FILE__) . '/../lib/helper.php');
require_once realpath(dirname(__FILE__) . '/../appinfo/app.php');
require_once realpath(dirname(__FILE__) . '/util.php');

use OCA\Encryption;

/**
 * Class Test_Encryption_Crypt
 */
class Test_Encryption_Crypt extends \PHPUnit_Framework_TestCase {

	const TEST_ENCRYPTION_CRYPT_USER1 = "test-crypt-user1";

	public $userId;
	public $pass;
	public $stateFilesTrashbin;
	public $dataLong;
	public $dataUrl;
	public $dataShort;
	/**
	 * @var OC_FilesystemView
	 */
	public $view;
	public $legacyEncryptedData;
	public $genPrivateKey;
	public $genPublicKey;

	public static function setUpBeforeClass() {
		// reset backend
		\OC_User::clearBackends();
		\OC_User::useBackend('database');

		// Filesystem related hooks
		\OCA\Encryption\Helper::registerFilesystemHooks();

		// Filesystem related hooks
		\OCA\Encryption\Helper::registerUserHooks();

		// clear and register hooks
		\OC_FileProxy::clearProxies();
		\OC_FileProxy::register(new OCA\Encryption\Proxy());

		// create test user
		\Test_Encryption_Util::loginHelper(\Test_Encryption_Crypt::TEST_ENCRYPTION_CRYPT_USER1, true);
	}

	function setUp() {
		// set user id
		\OC_User::setUserId(\Test_Encryption_Crypt::TEST_ENCRYPTION_CRYPT_USER1);
		$this->userId = \Test_Encryption_Crypt::TEST_ENCRYPTION_CRYPT_USER1;
		$this->pass = \Test_Encryption_Crypt::TEST_ENCRYPTION_CRYPT_USER1;

		// set content for encrypting / decrypting in tests
		$this->dataLong = file_get_contents(realpath(dirname(__FILE__) . '/../lib/crypt.php'));
		$this->dataShort = 'hats';
		$this->dataUrl = realpath(dirname(__FILE__) . '/../lib/crypt.php');
		$this->legacyData = realpath(dirname(__FILE__) . '/legacy-text.txt');
		$this->legacyEncryptedData = realpath(dirname(__FILE__) . '/legacy-encrypted-text.txt');
		$this->legacyEncryptedDataKey = realpath(dirname(__FILE__) . '/encryption.key');
		$this->randomKey = Encryption\Crypt::generateKey();

		$keypair = Encryption\Crypt::createKeypair();
		$this->genPublicKey = $keypair['publicKey'];
		$this->genPrivateKey = $keypair['privateKey'];

		$this->view = new \OC_FilesystemView('/');

		// remember files_trashbin state
		$this->stateFilesTrashbin = OC_App::isEnabled('files_trashbin');

		// we don't want to tests with app files_trashbin enabled
		\OC_App::disable('files_trashbin');
	}

	function tearDown() {
		// reset app files_trashbin
		if ($this->stateFilesTrashbin) {
			OC_App::enable('files_trashbin');
		}
		else {
			OC_App::disable('files_trashbin');
		}
	}

	public static function tearDownAfterClass() {
		// cleanup test user
		\OC_User::deleteUser(\Test_Encryption_Crypt::TEST_ENCRYPTION_CRYPT_USER1);
	}

	function testGenerateKey() {

		# TODO: use more accurate (larger) string length for test confirmation

		$key = Encryption\Crypt::generateKey();

		$this->assertTrue(strlen($key) > 16);

	}

	/**
	 * @return String
	 */
	function testGenerateIv() {

		$iv = Encryption\Crypt::generateIv();

		$this->assertEquals(16, strlen($iv));

		return $iv;

	}

	/**
	 * @depends testGenerateIv
	 */
	function testConcatIv($iv) {

		$catFile = Encryption\Crypt::concatIv($this->dataLong, $iv);

		// Fetch encryption metadata from end of file
		$meta = substr($catFile, -22);

		$identifier = substr($meta, 0, 6);

		// Fetch IV from end of file
		$foundIv = substr($meta, 6);

		$this->assertEquals('00iv00', $identifier);

		$this->assertEquals($iv, $foundIv);

		// Remove IV and IV identifier text to expose encrypted content
		$data = substr($catFile, 0, -22);

		$this->assertEquals($this->dataLong, $data);

		return array(
			'iv' => $iv
		,
			'catfile' => $catFile
		);

	}

	/**
	 * @depends testConcatIv
	 */
	function testSplitIv($testConcatIv) {

		// Split catfile into components
		$splitCatfile = Encryption\Crypt::splitIv($testConcatIv['catfile']);

		// Check that original IV and split IV match
		$this->assertEquals($testConcatIv['iv'], $splitCatfile['iv']);

		// Check that original data and split data match
		$this->assertEquals($this->dataLong, $splitCatfile['encrypted']);

	}

	/**
	 * @return string padded
	 */
	function testAddPadding() {

		$padded = Encryption\Crypt::addPadding($this->dataLong);

		$padding = substr($padded, -2);

		$this->assertEquals('xx', $padding);

		return $padded;

	}

	/**
	 * @depends testAddPadding
	 */
	function testRemovePadding($padded) {

		$noPadding = Encryption\Crypt::RemovePadding($padded);

		$this->assertEquals($this->dataLong, $noPadding);

	}

	function testEncrypt() {

		$random = openssl_random_pseudo_bytes(13);

		$iv = substr(base64_encode($random), 0, -4); // i.e. E5IG033j+mRNKrht

		$crypted = Encryption\Crypt::encrypt($this->dataUrl, $iv, 'hat');

		$this->assertNotEquals($this->dataUrl, $crypted);

	}

	function testDecrypt() {

		$random = openssl_random_pseudo_bytes(13);

		$iv = substr(base64_encode($random), 0, -4); // i.e. E5IG033j+mRNKrht

		$crypted = Encryption\Crypt::encrypt($this->dataUrl, $iv, 'hat');

		$decrypt = Encryption\Crypt::decrypt($crypted, $iv, 'hat');

		$this->assertEquals($this->dataUrl, $decrypt);

	}

	function testSymmetricEncryptFileContent() {

		# TODO: search in keyfile for actual content as IV will ensure this test always passes

		$crypted = Encryption\Crypt::symmetricEncryptFileContent($this->dataShort, 'hat');

		$this->assertNotEquals($this->dataShort, $crypted);


		$decrypt = Encryption\Crypt::symmetricDecryptFileContent($crypted, 'hat');

		$this->assertEquals($this->dataShort, $decrypt);

	}

	function testSymmetricStreamEncryptShortFileContent() {

		$filename = 'tmp-' . time() . '.test';

		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Disable encryption proxy to prevent recursive calls
		$proxyStatus = \OC_FileProxy::$enabled;
		\OC_FileProxy::$enabled = false;

		// Get file contents without using any wrapper to get it's actual contents on disk
		$retreivedCryptedFile = $this->view->file_get_contents($this->userId . '/files/' . $filename);

		// Re-enable proxy - our work is done
		\OC_FileProxy::$enabled = $proxyStatus;

		// Check that the file was encrypted before being written to disk
		$this->assertNotEquals($this->dataShort, $retreivedCryptedFile);

		// Get the encrypted keyfile
		$encKeyfile = Encryption\Keymanager::getFileKey($this->view, $this->userId, $filename);

		// Attempt to fetch the user's shareKey
		$shareKey = Encryption\Keymanager::getShareKey($this->view, $this->userId, $filename);

		// get session
		$session = new Encryption\Session($this->view);

		// get private key
		$privateKey = $session->getPrivateKey($this->userId);

		// Decrypt keyfile with shareKey
		$plainKeyfile = Encryption\Crypt::multiKeyDecrypt($encKeyfile, $shareKey, $privateKey);

		// Manually decrypt
		$manualDecrypt = Encryption\Crypt::symmetricDecryptFileContent($retreivedCryptedFile, $plainKeyfile);

		// Check that decrypted data matches
		$this->assertEquals($this->dataShort, $manualDecrypt);

		// Teardown
		$this->view->unlink($this->userId . '/files/' . $filename);

		Encryption\Keymanager::deleteFileKey($this->view, $this->userId, $filename);
	}

	/**
	 * @brief Test that data that is written by the crypto stream wrapper
	 * @note Encrypted data is manually prepared and decrypted here to avoid dependency on success of stream_read
	 * @note If this test fails with truncate content, check that enough array slices are being rejoined to form $e, as the crypt.php file may have gotten longer and broken the manual
	 * reassembly of its data
	 */
	function testSymmetricStreamEncryptLongFileContent() {

		// Generate a a random filename
		$filename = 'tmp-' . time() . '.test';

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataLong . $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Disable encryption proxy to prevent recursive calls
		$proxyStatus = \OC_FileProxy::$enabled;
		\OC_FileProxy::$enabled = false;

		// Get file contents without using any wrapper to get it's actual contents on disk
		$retreivedCryptedFile = $this->view->file_get_contents($this->userId . '/files/' . $filename);

		// Re-enable proxy - our work is done
		\OC_FileProxy::$enabled = $proxyStatus;


		// Check that the file was encrypted before being written to disk
		$this->assertNotEquals($this->dataLong . $this->dataLong, $retreivedCryptedFile);

		// Manuallly split saved file into separate IVs and encrypted chunks
		$r = preg_split('/(00iv00.{16,18})/', $retreivedCryptedFile, NULL, PREG_SPLIT_DELIM_CAPTURE);

		//print_r($r);

		// Join IVs and their respective data chunks
		$e = array(
			$r[0] . $r[1],
			$r[2] . $r[3],
			$r[4] . $r[5],
			$r[6] . $r[7],
			$r[8] . $r[9],
			$r[10] . $r[11]
		); //.$r[11], $r[12].$r[13], $r[14] );

		//print_r($e);

		// Get the encrypted keyfile
		$encKeyfile = Encryption\Keymanager::getFileKey($this->view, $this->userId, $filename);

		// Attempt to fetch the user's shareKey
		$shareKey = Encryption\Keymanager::getShareKey($this->view, $this->userId, $filename);

		// get session
		$session = new Encryption\Session($this->view);

		// get private key
		$privateKey = $session->getPrivateKey($this->userId);

		// Decrypt keyfile with shareKey
		$plainKeyfile = Encryption\Crypt::multiKeyDecrypt($encKeyfile, $shareKey, $privateKey);

		// Set var for reassembling decrypted content
		$decrypt = '';

		// Manually decrypt chunk
		foreach ($e as $chunk) {

			$chunkDecrypt = Encryption\Crypt::symmetricDecryptFileContent($chunk, $plainKeyfile);

			// Assemble decrypted chunks
			$decrypt .= $chunkDecrypt;

		}

		$this->assertEquals($this->dataLong . $this->dataLong, $decrypt);

		// Teardown

		$this->view->unlink($this->userId . '/files/' . $filename);

		Encryption\Keymanager::deleteFileKey($this->view, $this->userId, $filename);

	}

	/**
	 * @brief Test that data that is read by the crypto stream wrapper
	 */
	function testSymmetricStreamDecryptShortFileContent() {

		$filename = 'tmp-' . time();

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Disable encryption proxy to prevent recursive calls
		$proxyStatus = \OC_FileProxy::$enabled;
		\OC_FileProxy::$enabled = false;

		$this->assertTrue(Encryption\Crypt::isEncryptedMeta($filename));

		\OC_FileProxy::$enabled = $proxyStatus;

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataShort, $decrypt);

		// tear down
		$this->view->unlink($this->userId . '/files/' . $filename);
	}

	function testSymmetricStreamDecryptLongFileContent() {

		$filename = 'tmp-' . time();

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataLong, $decrypt);

		// tear down
		$this->view->unlink($this->userId . '/files/' . $filename);
	}

	function testSymmetricEncryptFileContentKeyfile() {

		# TODO: search in keyfile for actual content as IV will ensure this test always passes

		$crypted = Encryption\Crypt::symmetricEncryptFileContentKeyfile($this->dataUrl);

		$this->assertNotEquals($this->dataUrl, $crypted['encrypted']);


		$decrypt = Encryption\Crypt::symmetricDecryptFileContent($crypted['encrypted'], $crypted['key']);

		$this->assertEquals($this->dataUrl, $decrypt);

	}

	function testIsEncryptedContent() {

		$this->assertFalse(Encryption\Crypt::isCatfileContent($this->dataUrl));

		$this->assertFalse(Encryption\Crypt::isCatfileContent($this->legacyEncryptedData));

		$keyfileContent = Encryption\Crypt::symmetricEncryptFileContent($this->dataUrl, 'hat');

		$this->assertTrue(Encryption\Crypt::isCatfileContent($keyfileContent));

	}

	function testMultiKeyEncrypt() {

		# TODO: search in keyfile for actual content as IV will ensure this test always passes

		$pair1 = Encryption\Crypt::createKeypair();

		$this->assertEquals(2, count($pair1));

		$this->assertTrue(strlen($pair1['publicKey']) > 1);

		$this->assertTrue(strlen($pair1['privateKey']) > 1);


		$crypted = Encryption\Crypt::multiKeyEncrypt($this->dataShort, array($pair1['publicKey']));

		$this->assertNotEquals($this->dataShort, $crypted['data']);


		$decrypt = Encryption\Crypt::multiKeyDecrypt($crypted['data'], $crypted['keys'][0], $pair1['privateKey']);

		$this->assertEquals($this->dataShort, $decrypt);

	}

	function testKeyEncrypt() {

		// Generate keypair
		$pair1 = Encryption\Crypt::createKeypair();

		// Encrypt data
		$crypted = Encryption\Crypt::keyEncrypt($this->dataUrl, $pair1['publicKey']);

		$this->assertNotEquals($this->dataUrl, $crypted);

		// Decrypt data
		$decrypt = Encryption\Crypt::keyDecrypt($crypted, $pair1['privateKey']);

		$this->assertEquals($this->dataUrl, $decrypt);

	}

	/**
	 * @brief test encryption using legacy blowfish method
	 */
	function testLegacyEncryptShort() {

		$crypted = Encryption\Crypt::legacyEncrypt($this->dataShort, $this->pass);

		$this->assertNotEquals($this->dataShort, $crypted);

		# TODO: search inencrypted text for actual content to ensure it
		# genuine transformation

		return $crypted;

	}

	/**
	 * @brief test decryption using legacy blowfish method
	 * @depends testLegacyEncryptShort
	 */
	function testLegacyDecryptShort($crypted) {

		$decrypted = Encryption\Crypt::legacyBlockDecrypt($crypted, $this->pass);

		$this->assertEquals($this->dataShort, $decrypted);

	}

	/**
	 * @brief test encryption using legacy blowfish method
	 */
	function testLegacyEncryptLong() {

		$crypted = Encryption\Crypt::legacyEncrypt($this->dataLong, $this->pass);

		$this->assertNotEquals($this->dataLong, $crypted);

		# TODO: search inencrypted text for actual content to ensure it
		# genuine transformation

		return $crypted;

	}

	/**
	 * @brief test decryption using legacy blowfish method
	 * @depends testLegacyEncryptLong
	 */
	function testLegacyDecryptLong($crypted) {

		$decrypted = Encryption\Crypt::legacyBlockDecrypt($crypted, $this->pass);

		$this->assertEquals($this->dataLong, $decrypted);

		$this->assertFalse(Encryption\Crypt::getBlowfish(''));
	}

	/**
	 * @brief test generation of legacy encryption key
	 * @depends testLegacyDecryptShort
	 */
	function testLegacyCreateKey() {

		// Create encrypted key
		$encKey = Encryption\Crypt::legacyCreateKey($this->pass);

		// Decrypt key
		$key = Encryption\Crypt::legacyBlockDecrypt($encKey, $this->pass);

		$this->assertTrue(is_numeric($key));

		// Check that key is correct length
		$this->assertEquals(20, strlen($key));

	}

	/**
	 * @brief test decryption using legacy blowfish method
	 * @depends testLegacyEncryptLong
	 */
	function testLegacyKeyRecryptKeyfileEncrypt($crypted) {

		$recrypted = Encryption\Crypt::LegacyKeyRecryptKeyfile($crypted, $this->pass, array($this->genPublicKey), $this->pass, '');

		$this->assertNotEquals($this->dataLong, $recrypted['data']);

		return $recrypted;

		# TODO: search inencrypted text for actual content to ensure it
		# genuine transformation

	}

	function testRenameFile() {

		$filename = 'tmp-' . time();

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataLong, $decrypt);

		$newFilename = 'tmp-new-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');
		$view->rename($filename, $newFilename);

		// Get file decrypted contents
		$newDecrypt = file_get_contents('crypt://' . $newFilename);

		$this->assertEquals($this->dataLong, $newDecrypt);

		// tear down
		$view->unlink($newFilename);
	}

	function testMoveFileIntoFolder() {

		$filename = 'tmp-' . time();

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataLong, $decrypt);

		$newFolder = '/newfolder' . time();
		$newFilename = 'tmp-new-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');
		$view->mkdir($newFolder);
		$view->rename($filename, $newFolder . '/' . $newFilename);

		// Get file decrypted contents
		$newDecrypt = file_get_contents('crypt://' . $newFolder . '/' . $newFilename);

		$this->assertEquals($this->dataLong, $newDecrypt);

		// tear down
		$view->unlink($newFolder);
	}

	function testMoveFolder() {

		$view = new \OC\Files\View('/' . $this->userId . '/files');

		$filename = '/tmp-' . time();
		$folder = '/folder' . time();

		$view->mkdir($folder);

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $folder . $filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $folder . $filename);

		$this->assertEquals($this->dataLong, $decrypt);

		$newFolder = '/newfolder/subfolder' . time();
		$view->mkdir('/newfolder');

		$view->rename($folder, $newFolder);

		// Get file decrypted contents
		$newDecrypt = file_get_contents('crypt://' . $newFolder . $filename);

		$this->assertEquals($this->dataLong, $newDecrypt);

		// tear down
		$view->unlink($newFolder);
		$view->unlink('/newfolder');
	}

	function testChangePassphrase() {
		$filename = 'tmp-' . time();

		// Save long data as encrypted file using stream wrapper
		$cryptedFile = file_put_contents('crypt://' . $filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataLong, $decrypt);

		// change password
		\OC_User::setPassword($this->userId, 'test', null);

		// relogin
		$params['uid'] = $this->userId;
		$params['password'] = 'test';
		OCA\Encryption\Hooks::login($params);

		// Get file decrypted contents
		$newDecrypt = file_get_contents('crypt://' . $filename);

		$this->assertEquals($this->dataLong, $newDecrypt);

		// tear down
		// change password back
		\OC_User::setPassword($this->userId, $this->pass);
		$view = new \OC\Files\View('/' . $this->userId . '/files');
		$view->unlink($filename);
	}

	function testViewFilePutAndGetContents() {

		$filename = '/tmp-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');

		// Save short data as encrypted file using stream wrapper
		$cryptedFile = $view->file_put_contents($filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = $view->file_get_contents($filename);

		$this->assertEquals($this->dataShort, $decrypt);

		// Save long data as encrypted file using stream wrapper
		$cryptedFileLong = $view->file_put_contents($filename, $this->dataLong);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFileLong));

		// Get file decrypted contents
		$decryptLong = $view->file_get_contents($filename);

		$this->assertEquals($this->dataLong, $decryptLong);

		// tear down
		$view->unlink($filename);
	}

	function testTouchExistingFile() {
		$filename = '/tmp-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');

		// Save short data as encrypted file using stream wrapper
		$cryptedFile = $view->file_put_contents($filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		$view->touch($filename);

		// Get file decrypted contents
		$decrypt = $view->file_get_contents($filename);

		$this->assertEquals($this->dataShort, $decrypt);

		// tear down
		$view->unlink($filename);
	}

	function testTouchFile() {
		$filename = '/tmp-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');

		$view->touch($filename);

		// Save short data as encrypted file using stream wrapper
		$cryptedFile = $view->file_put_contents($filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		// Get file decrypted contents
		$decrypt = $view->file_get_contents($filename);

		$this->assertEquals($this->dataShort, $decrypt);

		// tear down
		$view->unlink($filename);
	}

	function testFopenFile() {
		$filename = '/tmp-' . time();
		$view = new \OC\Files\View('/' . $this->userId . '/files');

		// Save short data as encrypted file using stream wrapper
		$cryptedFile = $view->file_put_contents($filename, $this->dataShort);

		// Test that data was successfully written
		$this->assertTrue(is_int($cryptedFile));

		$handle = $view->fopen($filename, 'r');

		// Get file decrypted contents
		$decrypt = fgets($handle);

		$this->assertEquals($this->dataShort, $decrypt);

		// tear down
		$view->unlink($filename);
	}
}