/**
* decrypt given file with recovery key and encrypt it again to the owner and his new key
* @param string $file
* @param string $privateKey recovery key to decrypt the file
*/
private function recoverFile($file, $privateKey)
{
$sharingEnabled = \OCP\Share::isEnabled();
// Find out who, if anyone, is sharing the file
if ($sharingEnabled) {
$result = \OCP\Share::getUsersSharingFile($file, $this->userId, true);
$userIds = $result['users'];
$userIds[] = $this->recoveryKeyId;
if ($result['public']) {
$userIds[] = $this->publicShareKeyId;
}
} else {
$userIds = array($this->userId, $this->recoveryKeyId);
}
$filteredUids = $this->filterShareReadyUsers($userIds);
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
//decrypt file key
$encKeyfile = $this->view->file_get_contents($this->keyfilesPath . $file . ".key");
$shareKey = $this->view->file_get_contents($this->shareKeysPath . $file . "." . $this->recoveryKeyId . ".shareKey");
$plainKeyfile = Crypt::multiKeyDecrypt($encKeyfile, $shareKey, $privateKey);
// encrypt file key again to all users, this time with the new public key for the recovered use
$userPubKeys = Keymanager::getPublicKeys($this->view, $filteredUids['ready']);
$multiEncKey = Crypt::multiKeyEncrypt($plainKeyfile, $userPubKeys);
// write new keys to filesystem TDOO!
$this->view->file_put_contents($this->keyfilesPath . $file . '.key', $multiEncKey['data']);
foreach ($multiEncKey['keys'] as $userId => $shareKey) {
$shareKeyPath = $this->shareKeysPath . $file . '.' . $userId . '.shareKey';
$this->view->file_put_contents($shareKeyPath, $shareKey);
}
// Return proxy to original status
\OC_FileProxy::$enabled = $proxyStatus;
}
