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<?php
/**
* ownCloud
*
* @author Bjoern Schiessle
* @copyright 2012 Bjoern Schiessle <schiessle@owncloud.com>
*
* 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/>.
*
*/
namespace OCA\Encryption;
/**
* @brief Class to manage storage and retrieval of encryption keys
* @note Where a method requires a view object, it's root must be '/'
*/
class Keymanager {
/**
* @brief retrieve the ENCRYPTED private key from a user
*
* @return string private key or false
* @note the key returned by this method must be decrypted before use
*/
public static function getPrivateKey( \OC_FilesystemView $view, $user ) {
$path = '/' . $user . '/' . 'files_encryption' . '/' . $user.'.private.key';
$key = $view->file_get_contents( $path );
return $key;
}
/**
* @brief retrieve public key for a specified user
* @param \OC_FilesystemView $view
* @param $userId
* @return string public key or false
*/
public static function getPublicKey( \OC_FilesystemView $view, $userId ) {
return $view->file_get_contents( '/public-keys/' . '/' . $userId . '.public.key' );
}
/**
* @brief retrieve both keys from a user (private and public)
* @param \OC_FilesystemView $view
* @param $userId
* @return array keys: privateKey, publicKey
*/
public static function getUserKeys( \OC_FilesystemView $view, $userId ) {
return array(
'publicKey' => self::getPublicKey( $view, $userId )
, 'privateKey' => self::getPrivateKey( $view, $userId )
);
}
/**
* @brief Retrieve public keys of all users with access to a file
* @param string $path Path to file
* @return array of public keys for the given file
* @note Checks that the sharing app is enabled should be performed
* by client code, that isn't checked here
*/
public static function getPublicKeys( \OC_FilesystemView $view, $userId, $filePath ) {
$path = ltrim( $path, '/' );
$filepath = '/' . $userId . '/files/' . $filePath;
// Check if sharing is enabled
if ( OC_App::isEnabled( 'files_sharing' ) ) {
} else {
// check if it is a file owned by the user and not shared at all
$userview = new \OC_FilesystemView( '/'.$userId.'/files/' );
if ( $userview->file_exists( $path ) ) {
$users[] = $userId;
}
}
$view = new \OC_FilesystemView( '/public-keys/' );
$keylist = array();
$count = 0;
foreach ( $users as $user ) {
$keylist['key'.++$count] = $view->file_get_contents( $user.'.public.key' );
}
return $keylist;
}
/**
* @brief store file encryption key
*
* @param string $path relative path of the file, including filename
* @param string $key
* @return bool true/false
* @note The keyfile is not encrypted here. Client code must
* asymmetrically encrypt the keyfile before passing it to this method
*/
public static function setFileKey( \OC_FilesystemView $view, $path, $userId, $catfile ) {
$basePath = '/' . $userId . '/files_encryption/keyfiles';
$targetPath = self::keySetPreparation( $view, $path, $basePath, $userId );
if ( $view->is_dir( $basePath . '/' . $targetPath ) ) {
} else {
// Save the keyfile in parallel directory
return $view->file_put_contents( $basePath . '/' . $targetPath . '.key', $catfile );
}
}
/**
* @brief retrieve keyfile for an encrypted file
* @param \OC_FilesystemView $view
* @param $userId
* @param $filePath
* @internal param \OCA\Encryption\file $string name
* @return string file key or false
* @note The keyfile returned is asymmetrically encrypted. Decryption
* of the keyfile must be performed by client code
*/
public static function getFileKey( \OC_FilesystemView $view, $userId, $filePath ) {
$filePath_f = ltrim( $filePath, '/' );
$catfilePath = '/' . $userId . '/files_encryption/keyfiles/' . $filePath_f . '.key';
if ( $view->file_exists( $catfilePath ) ) {
return $view->file_get_contents( $catfilePath );
} else {
return false;
}
}
/**
* @brief Delete a keyfile
*
* @param OC_FilesystemView $view
* @param string $userId username
* @param string $path path of the file the key belongs to
* @return bool Outcome of unlink operation
* @note $path must be relative to data/user/files. e.g. mydoc.txt NOT
* /data/admin/files/mydoc.txt
*/
public static function deleteFileKey( \OC_FilesystemView $view, $userId, $path ) {
$trimmed = ltrim( $path, '/' );
$keyPath = '/' . $userId . '/files_encryption/keyfiles/' . $trimmed . '.key';
// Unlink doesn't tell us if file was deleted (not found returns
// true), so we perform our own test
if ( $view->file_exists( $keyPath ) ) {
return $view->unlink( $keyPath );
} else {
\OC_Log::write( 'Encryption library', 'Could not delete keyfile; does not exist: "' . $keyPath, \OC_Log::ERROR );
return false;
}
}
/**
* @brief store private key from the user
* @param string key
* @return bool
* @note Encryption of the private key must be performed by client code
* as no encryption takes place here
*/
public static function setPrivateKey( $key ) {
$user = \OCP\User::getUser();
$view = new \OC_FilesystemView( '/' . $user . '/files_encryption' );
\OC_FileProxy::$enabled = false;
if ( !$view->file_exists( '' ) ) $view->mkdir( '' );
return $view->file_put_contents( $user . '.private.key', $key );
\OC_FileProxy::$enabled = true;
}
/**
* @brief store private keys from the user
*
* @param string privatekey
* @param string publickey
* @return bool true/false
*/
public static function setUserKeys($privatekey, $publickey) {
return ( self::setPrivateKey( $privatekey ) && self::setPublicKey( $publickey ) );
}
/**
* @brief store public key of the user
*
* @param string key
* @return bool true/false
*/
public static function setPublicKey( $key ) {
$view = new \OC_FilesystemView( '/public-keys' );
\OC_FileProxy::$enabled = false;
if ( !$view->file_exists( '' ) ) $view->mkdir( '' );
return $view->file_put_contents( \OCP\User::getUser() . '.public.key', $key );
\OC_FileProxy::$enabled = true;
}
/**
* @brief store file encryption key
*
* @param string $path relative path of the file, including filename
* @param string $key
* @param null $view
* @param string $dbClassName
* @return bool true/false
* @note The keyfile is not encrypted here. Client code must
* asymmetrically encrypt the keyfile before passing it to this method
*/
public static function setShareKey( \OC_FilesystemView $view, $path, $userId, $shareKey ) {
$basePath = '/' . $userId . '/files_encryption/share-keys';
$shareKeyPath = self::keySetPreparation( $view, $path, $basePath, $userId );
return $view->file_put_contents( $basePath . '/' . $shareKeyPath . '.shareKey', $shareKey );
}
/**
* @brief Make preparations to vars and filesystem for saving a keyfile
*/
public static function keySetPreparation( \OC_FilesystemView $view, $path, $basePath, $userId ) {
$targetPath = ltrim( $path, '/' );
$path_parts = pathinfo( $targetPath );
// If the file resides within a subdirectory, create it
if (
isset( $path_parts['dirname'] )
&& ! $view->file_exists( $basePath . '/' . $path_parts['dirname'] )
) {
$view->mkdir( $basePath . '/' . $path_parts['dirname'] );
}
return $targetPath;
}
/**
* @brief change password of private encryption key
*
* @param string $oldpasswd old password
* @param string $newpasswd new password
* @return bool true/false
*/
public static function changePasswd($oldpasswd, $newpasswd) {
if ( \OCP\User::checkPassword(\OCP\User::getUser(), $newpasswd) ) {
return Crypt::changekeypasscode($oldpasswd, $newpasswd);
}
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() {
$user = \OCP\User::getUser();
$view = new \OC_FilesystemView( '/' . $user );
return $view->file_get_contents( 'encryption.key' );
}
}
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