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roundcubemail/program/lib/Crypt/GPG/PinEntry.php

876 lines
23 KiB
PHP

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Contains a class implementing automatic pinentry for gpg-agent
*
* PHP version 5
*
* LICENSE:
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* @category Encryption
* @package Crypt_GPG
* @author Michael Gauthier <mike@silverorange.com>
* @copyright 2013 silverorange
* @license http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
* @version CVS: $Id$
* @link http://pear.php.net/package/Crypt_GPG
*/
/**
* CLI user-interface and parser.
*/
require_once 'Console/CommandLine.php';
// {{{ class Crypt_GPG_PinEntry
/**
* A command-line dummy pinentry program for use with gpg-agent and Crypt_GPG
*
* This pinentry receives passphrases through en environment variable and
* automatically enters the PIN in response to gpg-agent requests. No user-
* interaction required.
*
* Thie pinentry can be run independently for testing and debugging with the
* following syntax:
*
* <pre>
* Usage:
* crypt-gpg-pinentry [options]
*
* Options:
* -l log, --log=log Optional location to log pinentry activity.
* -v, --verbose Sets verbosity level. Use multiples for more detail
* (e.g. "-vv").
* -h, --help show this help message and exit
* --version show the program version and exit
* </pre>
*
* @category Encryption
* @package Crypt_GPG
* @author Michael Gauthier <mike@silverorange.com>
* @copyright 2013 silverorange
* @license http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
* @link http://pear.php.net/package/Crypt_GPG
* @see Crypt_GPG::getKeys()
*/
class Crypt_GPG_PinEntry
{
// {{{ class constants
/**
* Verbosity level for showing no output.
*/
const VERBOSITY_NONE = 0;
/**
* Verbosity level for showing error output.
*/
const VERBOSITY_ERRORS = 1;
/**
* Verbosity level for showing all output, including Assuan protocol
* messages.
*/
const VERBOSITY_ALL = 2;
/**
* Length of buffer for reading lines from the Assuan server.
*
* PHP reads 8192 bytes. If this is set to less than 8192, PHP reads 8192
* and buffers the rest so we might as well just read 8192.
*
* Using values other than 8192 also triggers PHP bugs.
*
* @see http://bugs.php.net/bug.php?id=35224
*/
const CHUNK_SIZE = 8192;
// }}}
// {{{ protected properties
/**
* File handle for the input stream
*
* @var resource
*/
protected $stdin = null;
/**
* File handle for the output stream
*
* @var resource
*/
protected $stdout = null;
/**
* File handle for the log file if a log file is used
*
* @var resource
*/
protected $logFile = null;
/**
* Whether or not this pinentry is finished and is exiting
*
* @var boolean
*/
protected $moribund = false;
/**
* Verbosity level
*
* One of:
* - {@link Crypt_GPG_PinEntry::VERBOSITY_NONE},
* - {@link Crypt_GPG_PinEntry::VERBOSITY_ERRORS}, or
* - {@link Crypt_GPG_PinEntry::VERBOSITY_ALL}
*
* @var integer
*/
protected $verbosity = self::VERBOSITY_NONE;
/**
* The command-line interface parser for this pinentry
*
* @var Console_CommandLine
*
* @see Crypt_GPG_PinEntry::getParser()
*/
protected $parser = null;
/**
* PINs to be entered by this pinentry
*
* An indexed array of associative arrays in the form:
* <code>
* <?php
* array(
* array(
* 'keyId' => $keyId,
* 'passphrase' => $passphrase
* ),
* ...
* );
* ?>
* </code>
*
* This array is parsed from the environment variable
* <kbd>PINENTRY_USER_DATA</kbd>.
*
* @var array
*
* @see Crypt_GPG_PinEntry::initPinsFromENV()
*/
protected $pins = array();
/**
* PINs that have been tried for the current PIN
*
* This is an associative array indexed by the key identifier with
* values being the same as elements in the {@link Crypt_GPG_PinEntry::$pins}
* array.
*
* @var array
*/
protected $triedPins = array();
/**
* The PIN currently being requested by the Assuan server
*
* If set, this is an associative array in the form:
* <code>
* <?php
* array(
* 'keyId' => $shortKeyId,
* 'userId' => $userIdString
* );
* ?>
* </code>
*
* @var array|null
*/
protected $currentPin = null;
// }}}
// {{{ __invoke()
/**
* Runs this pinentry
*
* @return void
*/
public function __invoke()
{
$this->parser = $this->getCommandLineParser();
try {
$result = $this->parser->parse();
$this->setVerbosity($result->options['verbose']);
$this->setLogFilename($result->options['log']);
$this->connect();
$this->initPinsFromENV();
while (($line = fgets($this->stdin, self::CHUNK_SIZE)) !== false) {
$this->parseCommand(mb_substr($line, 0, -1, '8bit'));
if ($this->moribund) {
break;
}
}
$this->disconnect();
} catch (Console_CommandLineException $e) {
$this->log($e->getMessage() . PHP_EOL, slf::VERBOSITY_ERRORS);
exit(1);
} catch (Exception $e) {
$this->log($e->getMessage() . PHP_EOL, self::VERBOSITY_ERRORS);
$this->log($e->getTraceAsString() . PHP_EOL, self::VERBOSITY_ERRORS);
exit(1);
}
}
// }}}
// {{{ setVerbosity()
/**
* Sets the verbosity of logging for this pinentry
*
* Verbosity levels are:
*
* - {@link Crypt_GPG_PinEntry::VERBOSITY_NONE} - no logging.
* - {@link Crypt_GPG_PinEntry::VERBOSITY_ERRORS} - log errors only.
* - {@link Crypt_GPG_PinEntry::VERBOSITY_ALL} - log everything, including
* the assuan protocol.
*
* @param integer $verbosity the level of verbosity of this pinentry.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
public function setVerbosity($verbosity)
{
$this->verbosity = (integer)$verbosity;
return $this;
}
// }}}
// {{{ setLogFilename()
/**
* Sets the log file location
*
* @param string $filename the new log filename to use. If an empty string
* is used, file-based logging is disabled.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
public function setLogFilename($filename)
{
if (is_resource($this->logFile)) {
fflush($this->logFile);
fclose($this->logFile);
$this->logFile = null;
}
if ($filename != '') {
if (($this->logFile = fopen($filename, 'w')) === false) {
$this->log(
'Unable to open log file "' . $filename . '" '
. 'for writing.' . PHP_EOL,
self::VERBOSITY_ERRORS
);
exit(1);
} else {
stream_set_write_buffer($this->logFile, 0);
}
}
return $this;
}
// }}}
// {{{ getUIXML()
/**
* Gets the CLI user-interface definition for this pinentry
*
* Detects whether or not this package is PEAR-installed and appropriately
* locates the XML UI definition.
*
* @return string the location of the CLI user-interface definition XML.
*/
protected function getUIXML()
{
$dir = '@data-dir@' . DIRECTORY_SEPARATOR
. '@package-name@' . DIRECTORY_SEPARATOR . 'data';
// Check if we're running directly from a git checkout or if we're
// running from a PEAR-packaged version.
if ($dir[0] == '@') {
$dir = dirname(__FILE__) . DIRECTORY_SEPARATOR . '..'
. DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR . 'data';
}
return $dir . DIRECTORY_SEPARATOR . 'pinentry-cli.xml';
}
// }}}
// {{{ getCommandLineParser()
/**
* Gets the CLI parser for this pinentry
*
* @return Console_CommandLine the CLI parser for this pinentry.
*/
protected function getCommandLineParser()
{
return Console_CommandLine::fromXmlFile($this->getUIXML());
}
// }}}
// {{{ log()
/**
* Logs a message at the specified verbosity level
*
* If a log file is used, the message is written to the log. Otherwise,
* the message is sent to STDERR.
*
* @param string $data the message to log.
* @param integer $level the verbosity level above which the message should
* be logged.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function log($data, $level)
{
if ($this->verbosity >= $level) {
if (is_resource($this->logFile)) {
fwrite($this->logFile, $data);
fflush($this->logFile);
} else {
$this->parser->outputter->stderr($data);
}
}
return $this;
}
// }}}
// {{{ connect()
/**
* Connects this pinentry to the assuan server
*
* Opens I/O streams and sends initial handshake.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function connect()
{
// Binary operations will not work on Windows with PHP < 5.2.6.
$rb = (version_compare(PHP_VERSION, '5.2.6') < 0) ? 'r' : 'rb';
$wb = (version_compare(PHP_VERSION, '5.2.6') < 0) ? 'w' : 'wb';
$this->stdin = fopen('php://stdin', $rb);
$this->stdout = fopen('php://stdout', $wb);
if (function_exists('stream_set_read_buffer')) {
stream_set_read_buffer($this->stdin, 0);
}
stream_set_write_buffer($this->stdout, 0);
// initial handshake
$this->send($this->getOK('Crypt_GPG pinentry ready and waiting'));
return $this;
}
// }}}
// {{{ parseCommand()
/**
* Parses an assuan command and performs the appropriate action
*
* Documentation of the assuan commands for pinentry is limited to
* non-existent. Most of these commands were taken from the C source code
* to gpg-agent and pinentry.
*
* Additional context was provided by using strace -f when calling the
* gpg-agent.
*
* @param string $line the assuan command line to parse
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function parseCommand($line)
{
$this->log('<- ' . $line . PHP_EOL, self::VERBOSITY_ALL);
$parts = explode(' ', $line, 2);
$command = $parts[0];
if (count($parts) === 2) {
$data = $parts[1];
} else {
$data = null;
}
switch ($command) {
case 'SETDESC':
return $this->sendSetDescription($data);
case 'SETPROMPT':
case 'SETERROR':
case 'SETOK':
case 'SETNOTOK':
case 'SETCANCEL':
case 'SETQUALITYBAR':
case 'SETQUALITYBAR_TT':
case 'OPTION':
return $this->sendNotImplementedOK();
case 'MESSAGE':
return $this->sendMessage();
case 'CONFIRM':
return $this->sendConfirm();
case 'GETINFO':
return $this->sendGetInfo($data);
case 'GETPIN':
return $this->sendGetPin($data);
case 'RESET':
return $this->sendReset();
case 'BYE':
return $this->sendBye();
}
}
// }}}
// {{{ initPinsFromENV()
/**
* Initializes the PINs to be entered by this pinentry from the environment
* variable PINENTRY_USER_DATA
*
* The PINs are parsed from a JSON-encoded string.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function initPinsFromENV()
{
if (($userData = getenv('PINENTRY_USER_DATA')) !== false) {
$pins = json_decode($userData, true);
if ($pins === null) {
$this->log(
'-- failed to parse user data' . PHP_EOL,
self::VERBOSITY_ERRORS
);
} else {
$this->pins = $pins;
$this->log(
'-- got user data [not showing passphrases]' . PHP_EOL,
self::VERBOSITY_ALL
);
}
}
return $this;
}
// }}}
// {{{ disconnect()
/**
* Disconnects this pinentry from the Assuan server
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function disconnect()
{
$this->log('-- disconnecting' . PHP_EOL, self::VERBOSITY_ALL);
fflush($this->stdout);
fclose($this->stdout);
fclose($this->stdin);
$this->stdin = null;
$this->stdout = null;
$this->log('-- disconnected' . PHP_EOL, self::VERBOSITY_ALL);
if (is_resource($this->logFile)) {
fflush($this->logFile);
fclose($this->logFile);
$this->logFile = null;
}
return $this;
}
// }}}
// {{{ sendNotImplementedOK()
/**
* Sends an OK response for a not implemented feature
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendNotImplementedOK()
{
return $this->send($this->getOK());
}
// }}}
// {{{ sendSetDescription()
/**
* Parses the currently requested key identifier and user identifier from
* the description passed to this pinentry
*
* @param string $text the raw description sent from gpg-agent.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendSetDescription($text)
{
$text = rawurldecode($text);
$matches = array();
// TODO: handle user id with quotation marks
$exp = '/\n"(.+)"\n.*\sID ([A-Z0-9]+),\n/mu';
if (preg_match($exp, $text, $matches) === 1) {
$userId = $matches[1];
$keyId = $matches[2];
// only reset tried pins for new requested pin
if ( $this->currentPin === null
|| $this->currentPin['keyId'] !== $keyId
) {
$this->currentPin = array(
'userId' => $userId,
'keyId' => $keyId
);
$this->triedPins = array();
$this->log(
'-- looking for PIN for ' . $keyId . PHP_EOL,
self::VERBOSITY_ALL
);
}
}
return $this->send($this->getOK());
}
// }}}
// {{{ sendConfirm()
/**
* Tells the assuan server the PIN entry was confirmed (not cancelled)
* by pressing the fake 'close' button
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendConfirm()
{
return $this->sendButtonInfo('close');
}
// }}}
// {{{ sendMessage()
/**
* Tells the assuan server that any requested pop-up messages were confirmed
* by pressing the fake 'close' button
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendMessage()
{
return $this->sendButtonInfo('close');
}
// }}}
// {{{ sendButtonInfo()
/**
* Sends information about pressed buttons to the assuan server
*
* This is used to fake a user-interface for this pinentry.
*
* @param string $text the button status to send.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendButtonInfo($text)
{
return $this->send('BUTTON_INFO ' . $text . "\n");
}
// }}}
// {{{ sendGetPin()
/**
* Sends the PIN value for the currently requested key
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendGetPin()
{
$foundPin = '';
if (is_array($this->currentPin)) {
$keyIdLength = mb_strlen($this->currentPin['keyId'], '8bit');
// search for the pin
foreach ($this->pins as $pin) {
// only check pins we haven't tried
if (!isset($this->triedPins[$pin['keyId']])) {
// get last X characters of key identifier to compare
$keyId = mb_substr(
$pin['keyId'],
-$keyIdLength,
mb_strlen($pin['keyId'], '8bit'),
'8bit'
);
if ($keyId === $this->currentPin['keyId']) {
$foundPin = $pin['passphrase'];
$this->triedPins[$pin['keyId']] = $pin;
break;
}
}
}
}
return $this
->send($this->getData($foundPin))
->send($this->getOK());
}
// }}}
// {{{ sendGetInfo()
/**
* Sends information about this pinentry
*
* @param string $data the information requested by the assuan server.
* Currently only 'pid' is supported. Other requests
* return no information.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendGetInfo($data)
{
$parts = explode(' ', $data, 2);
$command = reset($parts);
switch ($command) {
case 'pid':
return $this->sendGetInfoPID();
default:
return $this->send($this->getOK());
}
return $this;
}
// }}}
// {{{ sendGetInfoPID()
/**
* Sends the PID of this pinentry to the assuan server
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendGetInfoPID()
{
return $this
->send($this->getData(getmypid()))
->send($this->getOK());
}
// }}}
// {{{ sendBye()
/**
* Flags this pinentry for disconnection and sends an OK response
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendBye()
{
$return = $this->send($this->getOK('closing connection'));
$this->moribund = true;
return $return;
}
// }}}
// {{{ sendReset()
/**
* Resets this pinentry and sends an OK response
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function sendReset()
{
$this->currentPin = null;
$this->triedPins = array();
return $this->send($this->getOK());
}
// }}}
// {{{ getOK()
/**
* Gets an OK response to send to the assuan server
*
* @param string $data an optional message to include with the OK response.
*
* @return string the OK response.
*/
protected function getOK($data = null)
{
$return = 'OK';
if ($data) {
$return .= ' ' . $data;
}
return $return . "\n";
}
// }}}
// {{{ getData()
/**
* Gets data ready to send to the assuan server
*
* Data is appropriately escaped and long lines are wrapped.
*
* @param string $data the data to send to the assuan server.
*
* @return string the properly escaped, formatted data.
*
* @see http://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
*/
protected function getData($data)
{
// Escape data. Only %, \n and \r need to be escaped but other
// values are allowed to be escaped. See
// http://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
$data = rawurlencode($data);
$data = $this->getWordWrappedData($data, 'D');
return $data;
}
// }}}
// {{{ getComment()
/**
* Gets a comment ready to send to the assuan server
*
* @param string $data the comment to send to the assuan server.
*
* @return string the properly formatted comment.
*
* @see http://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
*/
protected function getComment($data)
{
return $this->getWordWrappedData($data, '#');
}
// }}}
// {{{ getWordWrappedData()
/**
* Wraps strings at 1,000 bytes without splitting UTF-8 multibyte
* characters
*
* Each line is prepended with the specified line prefix. Wrapped lines
* are automatically appended with \ characters.
*
* Protocol strings are UTF-8 but maximum line length is 1,000 bytes.
* <kbd>mb_strcut()</kbd> is used so we can limit line length by bytes
* and not split characters across multiple lines.
*
* @param string $data the data to wrap.
* @param string $prefix a single character to use as the line prefix. For
* example, 'D' or '#'.
*
* @return string the word-wrapped, prefixed string.
*
* @see http://www.gnupg.org/documentation/manuals/assuan/Server-responses.html
*/
protected function getWordWrappedData($data, $prefix)
{
$lines = array();
do {
if (mb_strlen($data, '8bit') > 997) {
$line = $prefix . ' ' . mb_strcut($data, 0, 996, 'utf-8') . "\\\n";
$lines[] = $line;
$lineLength = mb_strlen($line, '8bit') - 1;
$dataLength = mb_substr($data, '8bit');
$data = mb_substr(
$data,
$lineLength,
$dataLength - $lineLength,
'8bit'
);
} else {
$lines[] = $prefix . ' ' . $data . "\n";
$data = '';
}
} while ($data != '');
return implode('', $lines);
}
// }}}
// {{{ send()
/**
* Sends raw data to the assuan server
*
* @param string $data the data to send.
*
* @return Crypt_GPG_PinEntry the current object, for fluent interface.
*/
protected function send($data)
{
$this->log('-> ' . $data, self::VERBOSITY_ALL);
fwrite($this->stdout, $data);
fflush($this->stdout);
return $this;
}
// }}}
}
// }}}
?>