/**
* Encrypt keyfile to multiple users
* @param Session $session
* @param array $users list of users which should be able to access the file
* @param string $filePath path of the file to be shared
* @return bool
*/
public function setSharedFileKeyfiles(Session $session, array $users, $filePath)
{
// Make sure users are capable of sharing
$filteredUids = $this->filterShareReadyUsers($users);
// If we're attempting to share to unready users
if (!empty($filteredUids['unready'])) {
\OCP\Util::writeLog('Encryption library', 'Sharing to these user(s) failed as they are unready for encryption:"' . print_r($filteredUids['unready'], 1), \OCP\Util::WARN);
return false;
}
// Get public keys for each user, ready for generating sharekeys
$userPubKeys = Keymanager::getPublicKeys($this->view, $filteredUids['ready']);
// Note proxy status then disable it
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
// Get the current users's private key for decrypting existing keyfile
$privateKey = $session->getPrivateKey();
try {
// Decrypt keyfile
$plainKeyfile = $this->decryptKeyfile($filePath, $privateKey);
// Re-enc keyfile to (additional) sharekeys
$multiEncKey = Crypt::multiKeyEncrypt($plainKeyfile, $userPubKeys);
} catch (Exceptions\EncryptionException $e) {
$msg = 'set shareFileKeyFailed (code: ' . $e->getCode() . '): ' . $e->getMessage();
\OCP\Util::writeLog('files_encryption', $msg, \OCP\Util::FATAL);
return false;
} catch (\Exception $e) {
$msg = 'set shareFileKeyFailed (unknown error): ' . $e->getMessage();
\OCP\Util::writeLog('files_encryption', $msg, \OCP\Util::FATAL);
return false;
}
// Save the recrypted key to it's owner's keyfiles directory
// Save new sharekeys to all necessary user directory
if (!Keymanager::setFileKey($this->view, $this, $filePath, $multiEncKey['data']) || !Keymanager::setShareKeys($this->view, $this, $filePath, $multiEncKey['keys'])) {
\OCP\Util::writeLog('Encryption library', 'Keyfiles could not be saved for users sharing ' . $filePath, \OCP\Util::ERROR);
return false;
}
// Return proxy to original status
\OC_FileProxy::$enabled = $proxyStatus;
return true;
}
