<?php
/**
+-------------------------------------------------------------------------+
| GnuPG (PGP) driver for the Enigma Plugin |
| |
| Copyright (C) The Roundcube Dev Team |
| |
| Licensed under the GNU General Public License version 3 or |
| any later version with exceptions for skins & plugins. |
| See the README file for a full license statement. |
+-------------------------------------------------------------------------+
| Author: Aleksander Machniak <alec@alec.pl> |
+-------------------------------------------------------------------------+
*/
require_once 'Crypt/GPG.php';
class enigma_driver_gnupg extends enigma_driver
{
protected $rc;
protected $gpg;
protected $homedir;
protected $user;
protected $last_sig_algorithm;
protected $debug = false;
protected $db_files = array('pubring.gpg', 'secring.gpg', 'pubring.kbx');
function __construct($user)
{
$this->rc = rcmail::get_instance();
$this->user = $user;
}
/**
* Driver initialization and environment checking.
* Should only return critical errors.
*
* @return mixed NULL on success, enigma_error on failure
*/
function init()
{
$homedir = $this->rc->config->get('enigma_pgp_homedir');
$debug = $this->rc->config->get('enigma_debug');
$binary = $this->rc->config->get('enigma_pgp_binary');
$agent = $this->rc->config->get('enigma_pgp_agent');
$gpgconf = $this->rc->config->get('enigma_pgp_gpgconf');
if (!$homedir) {
return new enigma_error(enigma_error::INTERNAL,
"Option 'enigma_pgp_homedir' not specified");
}
// check if homedir exists (create it if not) and is readable
if (!file_exists($homedir)) {
return new enigma_error(enigma_error::INTERNAL,
"Keys directory doesn't exists: $homedir");
}
if (!is_writable($homedir)) {
return new enigma_error(enigma_error::INTERNAL,
"Keys directory isn't writeable: $homedir");
}
$homedir = $homedir . '/' . $this->user;
// check if user's homedir exists (create it if not) and is readable
if (!file_exists($homedir)) {
mkdir($homedir, 0700);
}
if (!file_exists($homedir)) {
return new enigma_error(enigma_error::INTERNAL,
"Unable to create keys directory: $homedir");
}
if (!is_writable($homedir)) {
return new enigma_error(enigma_error::INTERNAL,
"Unable to write to keys directory: $homedir");
}
$this->debug = $debug;
$this->homedir = $homedir;
$options = array('homedir' => $this->homedir);
if ($debug) {
$options['debug'] = array($this, 'debug');
}
if ($binary) {
$options['binary'] = $binary;
}
if ($agent) {
$options['agent'] = $agent;
}
if ($gpgconf) {
$options['gpgconf'] = $gpgconf;
}
$options['cipher-algo'] = $this->rc->config->get('enigma_pgp_cipher_algo');
$options['digest-algo'] = $this->rc->config->get('enigma_pgp_digest_algo');
// Create Crypt_GPG object
try {
$this->gpg = new Crypt_GPG($options);
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
$this->db_sync();
}
/**
* Encryption (and optional signing).
*
* @param string Message body
* @param array List of keys (enigma_key objects)
* @param enigma_key Optional signing Key ID
*
* @return mixed Encrypted message or enigma_error on failure
*/
function encrypt($text, $keys, $sign_key = null)
{
try {
foreach ($keys as $key) {
$this->gpg->addEncryptKey($key->reference);
}
if ($sign_key) {
$this->gpg->addSignKey($sign_key->reference, $sign_key->password);
$res = $this->gpg->encryptAndSign($text, true);
$sigInfo = $this->gpg->getLastSignatureInfo();
$this->last_sig_algorithm = $sigInfo->getHashAlgorithmName();
return $res;
}
return $this->gpg->encrypt($text, true);
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Decrypt a message (and verify if signature found)
*
* @param string Encrypted message
* @param array List of key-password mapping
* @param enigma_signature Signature information (if available)
*
* @return mixed Decrypted message or enigma_error on failure
*/
function decrypt($text, $keys = array(), &$signature = null)
{
try {
foreach ($keys as $key => $password) {
$this->gpg->addDecryptKey($key, $password);
}
$result = $this->gpg->decryptAndVerify($text, true);
if (!empty($result['signatures'])) {
$signature = $this->parse_signature($result['signatures'][0]);
}
// EFAIL vulnerability mitigation (#6289)
// Handle MDC warning as an exception, this is the default for gpg 2.3.
if (method_exists($this->gpg, 'getWarnings')) {
foreach ($this->gpg->getWarnings() as $warning_msg) {
if (strpos($warning_msg, 'not integrity protected') !== false) {
return new enigma_error(enigma_error::NOMDC, ucfirst($warning_msg));
}
}
}
return $result['data'];
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Signing.
*
* @param string Message body
* @param enigma_key The key
* @param int Signing mode (enigma_engine::SIGN_*)
*
* @return mixed True on success or enigma_error on failure
*/
function sign($text, $key, $mode = null)
{
try {
$this->gpg->addSignKey($key->reference, $key->password);
$res = $this->gpg->sign($text, $mode, CRYPT_GPG::ARMOR_ASCII, true);
$sigInfo = $this->gpg->getLastSignatureInfo();
$this->last_sig_algorithm = $sigInfo->getHashAlgorithmName();
return $res;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Signature verification.
*
* @param string Message body
* @param string Signature, if message is of type PGP/MIME and body doesn't contain it
*
* @return mixed Signature information (enigma_signature) or enigma_error
*/
function verify($text, $signature)
{
try {
$verified = $this->gpg->verify($text, $signature);
return $this->parse_signature($verified[0]);
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Key file import.
*
* @param string File name or file content
* @param bolean True if first argument is a filename
* @param array Optional key => password map
*
* @return mixed Import status array or enigma_error
*/
public function import($content, $isfile = false, $passwords = array())
{
try {
// GnuPG 2.1 requires secret key passphrases on import
foreach ($passwords as $keyid => $pass) {
$this->gpg->addPassphrase($keyid, $pass);
}
if ($isfile) {
$result = $this->gpg->importKeyFile($content);
}
else {
$result = $this->gpg->importKey($content);
}
$this->db_save();
return $result;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Key export.
*
* @param string Key ID
* @param bool Include private key
* @param array Optional key => password map
*
* @return mixed Key content or enigma_error
*/
public function export($keyid, $with_private = false, $passwords = array())
{
try {
$key = $this->gpg->exportPublicKey($keyid, true);
if ($with_private) {
// GnuPG 2.1 requires secret key passphrases on export
foreach ($passwords as $_keyid => $pass) {
$this->gpg->addPassphrase($_keyid, $pass);
}
$priv = $this->gpg->exportPrivateKey($keyid, true);
$key .= $priv;
}
return $key;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Keys listing.
*
* @param string Optional pattern for key ID, user ID or fingerprint
*
* @return mixed Array of enigma_key objects or enigma_error
*/
public function list_keys($pattern = '')
{
try {
$keys = $this->gpg->getKeys($pattern);
$result = array();
foreach ($keys as $idx => $key) {
$result[] = $this->parse_key($key);
unset($keys[$idx]);
}
return $result;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Single key information.
*
* @param string Key ID, user ID or fingerprint
*
* @return mixed Key (enigma_key) object or enigma_error
*/
public function get_key($keyid)
{
$list = $this->list_keys($keyid);
if (is_array($list)) {
return $list[key($list)];
}
// error
return $list;
}
/**
* Key pair generation.
*
* @param array Key/User data (user, email, password, size)
*
* @return mixed Key (enigma_key) object or enigma_error
*/
public function gen_key($data)
{
try {
$debug = $this->rc->config->get('enigma_debug');
$keygen = new Crypt_GPG_KeyGenerator(array(
'homedir' => $this->homedir,
// 'binary' => '/usr/bin/gpg2',
'debug' => $debug ? array($this, 'debug') : false,
));
$key = $keygen
->setExpirationDate(0)
->setPassphrase($data['password'])
->generateKey($data['user'], $data['email']);
return $this->parse_key($key);
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Key deletion.
*
* @param string Key ID
*
* @return mixed True on success or enigma_error
*/
public function delete_key($keyid)
{
// delete public key
$result = $this->delete_pubkey($keyid);
// error handling
if ($result !== true) {
$code = $result->getCode();
// if not found, delete private key
if ($code == enigma_error::KEYNOTFOUND) {
$result = $this->delete_privkey($keyid);
}
// need to delete private key first
else if ($code == enigma_error::DELKEY) {
$result = $this->delete_privkey($keyid);
if ($result === true) {
$result = $this->delete_pubkey($keyid);
}
}
}
$this->db_save();
return $result;
}
/**
* Returns a name of the hash algorithm used for the last
* signing operation.
*
* @return string Hash algorithm name e.g. sha1
*/
public function signature_algorithm()
{
return $this->last_sig_algorithm;
}
/**
* Private key deletion.
*/
protected function delete_privkey($keyid)
{
try {
$this->gpg->deletePrivateKey($keyid);
return true;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Public key deletion.
*/
protected function delete_pubkey($keyid)
{
try {
$this->gpg->deletePublicKey($keyid);
return true;
}
catch (Exception $e) {
return $this->get_error_from_exception($e);
}
}
/**
* Converts Crypt_GPG exception into Enigma's error object
*
* @param mixed Exception object
*
* @return enigma_error Error object
*/
protected function get_error_from_exception($e)
{
$data = array();
if ($e instanceof Crypt_GPG_KeyNotFoundException) {
$error = enigma_error::KEYNOTFOUND;
$data['id'] = $e->getKeyId();
}
else if ($e instanceof Crypt_GPG_BadPassphraseException) {
$error = enigma_error::BADPASS;
$data['bad'] = $e->getBadPassphrases();
$data['missing'] = $e->getMissingPassphrases();
}
else if ($e instanceof Crypt_GPG_NoDataException) {
$error = enigma_error::NODATA;
}
else if ($e instanceof Crypt_GPG_DeletePrivateKeyException) {
$error = enigma_error::DELKEY;
}
else {
$error = enigma_error::INTERNAL;
}
$msg = $e->getMessage();
return new enigma_error($error, $msg, $data);
}
/**
* Converts Crypt_GPG_Signature object into Enigma's signature object
*
* @param Crypt_GPG_Signature Signature object
*
* @return enigma_signature Signature object
*/
protected function parse_signature($sig)
{
$data = new enigma_signature();
$data->id = $sig->getId() ?: $sig->getKeyId();
$data->valid = $sig->isValid();
$data->fingerprint = $sig->getKeyFingerprint();
$data->created = $sig->getCreationDate();
$data->expires = $sig->getExpirationDate();
// In case of ERRSIG user may not be set
if ($user = $sig->getUserId()) {
$data->name = $user->getName();
$data->comment = $user->getComment();
$data->email = $user->getEmail();
}
return $data;
}
/**
* Converts Crypt_GPG_Key object into Enigma's key object
*
* @param Crypt_GPG_Key Key object
*
* @return enigma_key Key object
*/
protected function parse_key($key)
{
$ekey = new enigma_key();
foreach ($key->getUserIds() as $idx => $user) {
$id = new enigma_userid();
$id->name = $user->getName();
$id->comment = $user->getComment();
$id->email = $user->getEmail();
$id->valid = $user->isValid();
$id->revoked = $user->isRevoked();
$ekey->users[$idx] = $id;
}
$ekey->name = trim($ekey->users[0]->name . ' <' . $ekey->users[0]->email . '>');
// keep reference to Crypt_GPG's key for performance reasons
$ekey->reference = $key;
foreach ($key->getSubKeys() as $idx => $subkey) {
$skey = new enigma_subkey();
$skey->id = $subkey->getId();
$skey->revoked = $subkey->isRevoked();
$skey->created = $subkey->getCreationDate();
$skey->expires = $subkey->getExpirationDate();
$skey->fingerprint = $subkey->getFingerprint();
$skey->has_private = $subkey->hasPrivate();
$skey->algorithm = $subkey->getAlgorithm();
$skey->length = $subkey->getLength();
$skey->usage = $subkey->usage();
$ekey->subkeys[$idx] = $skey;
};
$ekey->id = $ekey->subkeys[0]->id;
return $ekey;
}
/**
* Syncronize keys database on multi-host setups
*/
protected function db_sync()
{
if (!$this->rc->config->get('enigma_multihost')) {
return;
}
$db = $this->rc->get_dbh();
$table = $db->table_name('filestore', true);
$files = array();
$result = $db->query(
"SELECT `file_id`, `filename`, `mtime` FROM $table WHERE `user_id` = ? AND `context` = ?",
$this->rc->user->ID, 'enigma');
while ($record = $db->fetch_assoc($result)) {
$file = $this->homedir . '/' . $record['filename'];
$mtime = @filemtime($file);
$files[] = $record['filename'];
if ($mtime < $record['mtime']) {
$data_result = $db->query("SELECT `data`, `mtime` FROM $table"
. " WHERE `file_id` = ?", $record['file_id']);
$record = $db->fetch_assoc($data_result);
$data = $record ? base64_decode($record['data']) : null;
if ($data === null || $data === false) {
rcube::raise_error(array(
'code' => 605, 'line' => __LINE__, 'file' => __FILE__,
'message' => "Enigma: Failed to sync $file ({$record['file_id']}). Decode error."
), true, false);
continue;
}
$tmpfile = $file . '.tmp';
if (file_put_contents($tmpfile, $data, LOCK_EX) === strlen($data)) {
rename($tmpfile, $file);
touch($file, $record['mtime']);
if ($this->debug) {
$this->debug("SYNC: Fetched file: $file");
}
}
else {
// error
@unlink($tmpfile);
rcube::raise_error(array(
'code' => 605, 'line' => __LINE__, 'file' => __FILE__,
'message' => "Enigma: Failed to sync $file."
), true, false);
}
}
}
// Remove files not in database
if (!$db->is_error($result)) {
foreach (array_diff($this->db_files_list(), $files) as $file) {
$file = $this->homedir . '/' . $file;
if (unlink($file)) {
if ($this->debug) {
$this->debug("SYNC: Removed file: $file");
}
}
}
}
// No records found, do initial sync if already have the keyring
if (!$db->is_error($result) && empty($file)) {
$this->db_save(true);
}
}
/**
* Save keys database for multi-host setups
*/
protected function db_save($is_empty = false)
{
if (!$this->rc->config->get('enigma_multihost')) {
return true;
}
$db = $this->rc->get_dbh();
$table = $db->table_name('filestore', true);
$records = array();
if (!$is_empty) {
$result = $db->query(
"SELECT `file_id`, `filename`, `mtime` FROM $table WHERE `user_id` = ? AND `context` = ?",
$this->rc->user->ID, 'enigma'
);
while ($record = $db->fetch_assoc($result)) {
$records[$record['filename']] = $record;
}
}
foreach ($this->db_files_list() as $filename) {
$file = $this->homedir . '/' . $filename;
$mtime = @filemtime($file);
$existing = $records[$filename];
unset($records[$filename]);
if ($mtime && (empty($existing) || $mtime > $existing['mtime'])) {
$data = file_get_contents($file);
$data = base64_encode($data);
$datasize = strlen($data);
if (empty($maxsize)) {
$maxsize = min($db->get_variable('max_allowed_packet', 1048500), 4*1024*1024) - 2000;
}
if ($datasize > $maxsize) {
rcube::raise_error(array(
'code' => 605, 'line' => __LINE__, 'file' => __FILE__,
'message' => "Enigma: Failed to save $file. Size exceeds max_allowed_packet."
), true, false);
continue;
}
if (empty($existing)) {
$result = $db->query(
"INSERT INTO $table (`user_id`, `context`, `filename`, `mtime`, `data`)"
. " VALUES(?, 'enigma', ?, ?, ?)",
$this->rc->user->ID, $filename, $mtime, $data);
}
else {
$result = $db->query(
"UPDATE $table SET `mtime` = ?, `data` = ? WHERE `file_id` = ?",
$mtime, $data, $existing['file_id']);
}
if ($db->is_error($result)) {
rcube::raise_error(array(
'code' => 605, 'line' => __LINE__, 'file' => __FILE__,
'message' => "Enigma: Failed to save $file into database."
), true, false);
break;
}
if ($this->debug) {
$this->debug("SYNC: Pushed file: $file");
}
}
}
// Delete removed files from database
foreach (array_keys($records) as $filename) {
$file = $this->homedir . '/' . $filename;
$result = $db->query("DELETE FROM $table WHERE `user_id` = ? AND `context` = ? AND `filename` = ?",
$this->rc->user->ID, 'enigma', $filename);
if ($db->is_error($result)) {
rcube::raise_error(array(
'code' => 605, 'line' => __LINE__, 'file' => __FILE__,
'message' => "Enigma: Failed to delete $file from database."
), true, false);
break;
}
if ($this->debug) {
$this->debug("SYNC: Removed file: $file");
}
}
}
/**
* Returns list of homedir files to backup
*/
protected function db_files_list()
{
$files = array();
foreach ($this->db_files as $file) {
if (file_exists($this->homedir . '/' . $file)) {
$files[] = $file;
}
}
foreach (glob($this->homedir . '/private-keys-v1.d/*.key') as $file) {
$files[] = ltrim(substr($file, strlen($this->homedir)), '/');
}
return $files;
}
/**
* Write debug info from Crypt_GPG to logs/enigma
*/
public function debug($line)
{
rcube::write_log('enigma', 'GPG: ' . $line);
}
}
|