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|
<?php
/**
* ownCloud
*
* @author Sam Tuke, Frank Karlitschek
* @copyright 2012 Sam Tuke samtuke@owncloud.com,
* Frank Karlitschek frank@owncloud.org
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU AFFERO GENERAL PUBLIC LICENSE for more details.
*
* You should have received a copy of the GNU Affero General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*/
// Todo:
// - Crypt/decrypt button in the userinterface
// - Setting if crypto should be on by default
// - Add a setting "Don´t encrypt files larger than xx because of performance reasons"
// - Transparent decrypt/encrypt in filesystem.php. Autodetect if a file is encrypted (.encrypted extension)
// - Don't use a password directly as encryption key. but a key which is stored on the server and encrypted with the user password. -> password change faster
// - IMPORTANT! Check if the block lenght of the encrypted data stays the same
namespace OCA_Encryption;
/**
* @brief Class for utilities relating to encrypted file storage system
* @param $view OC_FilesystemView object, expected to have OC '/' as root path
* @param $client flag indicating status of client side encryption. Currently
* unused, likely to become obsolete shortly
*/
class Util {
# DONE: add method to check if file is encrypted using new system
# DONE: add method to check if file is encrypted using old system
# DONE: add method to fetch legacy key
# DONE: add method to decrypt legacy encrypted data
# DONE: fix / test the crypt stream proxy class
# TODO: replace cryptstream wrapper with stream_socket_enable_crypto, or fix it to use new crypt class methods
# TODO: add support for optional recovery user in case of lost passphrase / keys
# TODO: add admin optional required long passphrase for users
# TODO: implement flag system to allow user to specify encryption by folder, subfolder, etc.
# TODO: add UI buttons for encrypt / decrypt everything?
# TODO: add method to encrypt all user files using new system
# TODO: add method to decrypt all user files using new system
# TODO: add method to encrypt all user files using old system
# TODO: add method to decrypt all user files using old system
# TODO: test new encryption with webdav
# TODO: test new encryption with versioning
# TODO: test new encryption with sharing
# TODO: test new encryption with proxies
private $view; // OC_FilesystemView object for filesystem operations
private $pwd; // User Password
private $client; // Client side encryption mode flag
public function __construct( \OC_FilesystemView $view, $userId, $client = false ) {
$this->view = $view;
$this->userId = $userId;
$this->client = $client;
$this->publicKeyDir = '/' . 'public-keys';
$this->encryptionDir = '/' . $this->userId . '/' . 'files_encryption';
$this->keyfilesPath = $this->encryptionDir . '/' . 'keyfiles';
$this->publicKeyPath = $this->publicKeyDir . '/' . $this->userId . '.public.key'; // e.g. data/public-keys/admin.public.key
$this->privateKeyPath = $this->encryptionDir . '/' . $this->userId . '.private.key'; // e.g. data/admin/admin.private.key
}
public function ready() {
if(
!$this->view->file_exists( $this->keyfilesPath )
or !$this->view->file_exists( $this->publicKeyPath )
or !$this->view->file_exists( $this->privateKeyPath )
) {
return false;
} else {
return true;
}
}
/**
* @brief Sets up user folders and keys for serverside encryption
* @param $passphrase passphrase to encrypt server-stored private key with
*/
public function setupServerSide( $passphrase = null ) {
// Log changes to user's filesystem
$this->appInfo = \OC_APP::getAppInfo( 'files_encryption' );
\OC_Log::write( $this->appInfo['name'], 'File encryption for user "' . $this->userId . '" will be set up' , \OC_Log::INFO );
// Create shared public key directory
if( !$this->view->file_exists( $this->publicKeyDir ) ) {
$this->view->mkdir( $this->publicKeyDir );
}
// Create encryption app directory
if( !$this->view->file_exists( $this->encryptionDir ) ) {
$this->view->mkdir( $this->encryptionDir );
}
// Create mirrored keyfile directory
if( !$this->view->file_exists( $this->keyfilesPath ) ) {
$this->view->mkdir( $this->keyfilesPath );
}
// Create user keypair
if (
!$this->view->file_exists( $this->publicKeyPath )
or !$this->view->file_exists( $this->privateKeyPath )
) {
// Generate keypair
$keypair = Crypt::createKeypair();
\OC_FileProxy::$enabled = false;
// Save public key
$this->view->file_put_contents( $this->publicKeyPath, $keypair['publicKey'] );
// Encrypt private key with user pwd as passphrase
$encryptedPrivateKey = Crypt::symmetricEncryptFileContent( $keypair['privateKey'], $passphrase );
// Save private key
$this->view->file_put_contents( $this->privateKeyPath, $encryptedPrivateKey );
\OC_FileProxy::$enabled = true;
}
}
public function findFiles( $directory, $type = 'plain' ) {
# TODO: test finding non plain content
if ( $handle = $this->view->opendir( $directory ) ) {
while ( false !== ( $file = readdir( $handle ) ) ) {
if (
$file != "."
&& $file != ".."
) {
$filePath = $directory . '/' . $this->view->getRelativePath( '/' . $file );
var_dump($filePath);
if ( $this->view->is_dir( $filePath ) ) {
$this->findFiles( $filePath );
} elseif ( $this->view->is_file( $filePath ) ) {
if ( $type == 'plain' ) {
$this->files[] = array( 'name' => $file, 'path' => $filePath );
} elseif ( $type == 'encrypted' ) {
if ( Crypt::isEncryptedContent( $this->view->file_get_contents( $filePath ) ) ) {
$this->files[] = array( 'name' => $file, 'path' => $filePath );
}
} elseif ( $type == 'legacy' ) {
if ( Crypt::isLegacyEncryptedContent( $this->view->file_get_contents( $filePath ) ) ) {
$this->files[] = array( 'name' => $file, 'path' => $filePath );
}
}
}
}
}
if ( !empty( $this->files ) ) {
return $this->files;
} else {
return false;
}
}
return false;
}
public function encryptAll( OC_FilesystemView $view ) {
$plainFiles = $this->findPlainFiles( $view );
if ( $this->encryptFiles( $plainFiles ) ) {
return true;
} else {
return false;
}
}
/**
* @brief Get the blowfish encryption handeler for a key
* @param $key string (optional)
* @return Crypt_Blowfish blowfish object
*
* if the key is left out, the default handeler will be used
*/
public function getBlowfish( $key = '' ) {
if ( $key ) {
return new \Crypt_Blowfish( $key );
} else {
return false;
}
}
/**
* @brief Fetch the legacy encryption key from user files
* @param string $login used to locate the legacy key
* @param string $passphrase used to decrypt the legacy key
* @return true / false
*
* if the key is left out, the default handeler will be used
*/
public function getLegacyKey( $passphrase ) {
// Disable proxies to prevent attempt to automatically decrypt key
OC_FileProxy::$enabled = false;
if (
$passphrase
and $key = $this->view->file_get_contents( '/encryption.key' )
) {
OC_FileProxy::$enabled = true;
if ( $this->legacyKey = $this->legacyDecrypt( $key, $passphrase ) ) {
return true;
} else {
return false;
}
} else {
OC_FileProxy::$enabled = true;
return false;
}
}
/**
* @brief encrypts content using legacy blowfish system
* @param $content the cleartext message you want to encrypt
* @param $key the encryption key (optional)
* @returns encrypted content
*
* This function encrypts an content
*/
public function legacyEncrypt( $content, $passphrase = '' ) {
$bf = $this->getBlowfish( $passphrase );
return $bf->encrypt( $content );
}
/**
* @brief decryption of an content
* @param $content the cleartext message you want to decrypt
* @param $key the encryption key (optional)
* @returns cleartext content
*
* This function decrypts an content
*/
public function legacyDecrypt( $content, $passphrase = '' ) {
$bf = $this->getBlowfish( $passphrase );
$data = $bf->decrypt( $content );
return $data;
}
/**
* @brief Re-encryptes a legacy blowfish encrypted file using AES with integrated IV
* @param $legacyContent the legacy encrypted content to re-encrypt
* @returns cleartext content
*
* This function decrypts an content
*/
public function legacyRecrypt( $legacyContent ) {
# TODO: write me
}
}
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