egroupware/phpgwapi/inc/class.ischedule_client.inc.php

519 lines
15 KiB
PHP

<?php
/**
* EGroupware: iSchedule client
*
* @link http://www.egroupware.org
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @package api
* @subpackage groupdav
* @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @copyright (c) 2012-13 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @version $Id$
*/
/**
* iSchedule client: clientside of iSchedule
*
* @link https://tools.ietf.org/html/draft-desruisseaux-ischedule-03 iSchedule draft from 2013-01-22
*/
class ischedule_client
{
/**
* Own iSchedule version
*/
const VERSION = '1.0';
/**
* Allow to specify iSchedule urls without publishing them in DNS
*
* @var array domain => url pairs
*/
static public $domain2url = array(
'example.com' => 'https://caldav.egroupware.net/.well-known/ischedule',
);
/**
* Headers in DKIM signature (DKIM-Signature is always a required header!)
*/
const DKIM_HEADERS = 'iSchedule-Version:Content-Type:Originator:Recipient:User-Agent:iSchedule-Message-ID';
/**
* URL to use to contact iSchedule receiver
*
* @var string
*/
private $url;
/**
* Recipient email addresses
*
* @param array
*/
private $recipients;
/**
* Originator email address
*
* @var string
*/
private $originator;
/**
* Private key of originators domain
*
* @var string
*/
private $dkim_private_key;
/**
* Constructor
*
* @param string|array $recipients=null recipient email-address(es)
* @param string $url=null ischedule url, if it should NOT be discovered
* @throws Exception in case of an error or discovery failure
*/
public function __construct($recipients, $url=null)
{
$this->recipients = (array)$recipients;
$this->originator = 'mailto:'.$GLOBALS['egw_info']['user']['account_email'];
if (is_null($url))
{
list(,$domain) = explode('@', $this->recipients[0]);
$this->url = self::discover($domain);
}
else
{
$this->url = $url;
}
$this->dkim_private_key = $GLOBALS['egw_info']['server']['dkim_private_key'];
}
/**
* Check if we can iSchedule with a given email address or domain
*
* We assume when a private key was generated, it is also published!
*
* @param string $domain domain or email/scheduling address
* @return boolean true
*/
public static function available($domain)
{
if (empty($GLOBALS['egw_info']['server']['dkim_private_key']))
{
return false;
}
if (strpos($domain, '@') !== false) list(, $domain) = explode('@', $domain);
try {
$url = self::discover($domain);
}
catch (Exception $e) {
return false;
}
return true;
}
/**
* Send FREEBUSY request via iSchedule
*
* @param string|array $recipients (array of) mailto urls (from same domain!)
* @param int $start starttime
* @param int $end endtime
* @param string $uid=null
* @param string $originator=null default current user's email
* @return array with values for keys 'schedule-response' or 'error'
* @throws Exception if discovery of recipient(s) fails
*/
public static function freebusy_request($recipients, $start, $end, $uid=null, $originator=null)
{
$client = new ischedule_client($recipients);
if ($originator) $client->setOriginator($originator);
$vcal = new Horde_iCalendar;
$vcal->setAttribute('PRODID','-//EGroupware//NONSGML EGroupware Calendar '.$GLOBALS['egw_info']['apps']['calendar']['version'].'//'.
strtoupper($GLOBALS['egw_info']['user']['preferences']['common']['lang']));
$vcal->setAttribute('VERSION','2.0');
$vcal->setAttribute('METHOD',$method='REQUEST');
$vfreebusy = Horde_iCalendar::newComponent($component='VFREEBUSY', $vcal);
if ($uid) $vfreebusy->setAttribute('UID', $uid);
$vfreebusy->setAttribute('DTSTAMP', time());
$vfreebusy->setAttribute('DTSTART', $start);
$vfreebusy->setAttribute('DTEND', $end);
$vfreebusy->setAttribute('ORGANIZER', $client->originator);
foreach($client->recipients as $recipient)
{
$vfreebusy->setAttribute('ATTENDEE', $recipient);
}
$vcal->addComponent($vfreebusy);
$content = $vcal->exportvCalendar('utf-8');
$content_type = 'text/calendar; component='.$component.'; method='.$method;
$xml = $client->post_msg($content, $content_type);
$reader = new XMLReader();
$reader->XML($xml, 'utf-8');
return self::xml2assoc($reader);
}
/**
* Generate private/public key pair
*
* Private and public key are stored in api config as dkim_private_key / dkim_public_key and loaded automatic by constructor.
*
* @return string public key
*/
public static function generateKeyPair()
{
// Create the keypair
$res = openssl_pkey_new();
// Get private key
openssl_pkey_export($res, $dkim_private_key);
// Get public key
$details = openssl_pkey_get_details($res);
$dkim_public_key = $details['key'];
// store both in config
config::save_value('dkim_private_key', $dkim_private_key, 'phpgwapi');
config::save_value('dkim_public_key', $dkim_public_key, 'phpgwapi');
return $dkim_public_key;
}
const EMAIL_PREG = '/^([a-z0-9][a-z0-9._-]*)?[a-z0-9]@([a-z0-9](|[a-z0-9_-]*[a-z0-9])\.)+[a-z]{2,6}$/i';
/**
* Set originator and (optional) DKIM private key
*
* @param string $originator
* @param string $dkim_private_key=null
* @throws Exception for invalid / not an email originator
*/
public function setOriginator($originator, $dkim_private_key=null)
{
if (!preg_match(self::EMAIL_PREG, $originator))
{
throw new Exception("Invalid orginator '$originator'!");
}
$this->originator = 'mailto:'.$originator;
if (!is_null($dkim_private_key))
{
$this->dkim_private_key = $dkim_private_key;
}
}
/**
* Discover iSchedule url of a given domain
*
* @param string $domain
* @return string discovered ischedule url
* @throws Exception in case of an error or discovery failure
*/
public static function discover($domain)
{
static $scheme2port = array(
'https' => 443,
'http' => 80,
);
if (isset(self::$domain2url[$domain])) return self::$domain2url[$domain];
$d = $domain;
for($n = 0; $n < 3; ++$n)
{
if (!($records = dns_get_record($host='_ischedules._tcp.'.$d, DNS_SRV+DNS_TXT)) &&
!($records = dns_get_record($host='_ischedule._tcp.'.$d, DNS_SRV+DNS_TXT)))
{
// try without subdomain(s)
$parts = explode('.', $d);
if (count($parts) < 3) break;
array_shift($parts);
$d = implode('.', $parts);
}
}
if (!$records) throw new Exception("Could not discover iSchedule service for domain '$domain'!");
$path = '/.well-known/ischedule';
foreach($records as $record)
{
switch($record['type'])
{
case 'SRV':
// for multiple SRV records we use the one with smallest priority and heighest weight
if (!isset($srv) || $srv['pri'] > $record['pri'] ||
$srv['pri'] == $record['pri'] && $srv['weight'] < $record['weight'])
{
$srv = $record;
}
break;
case 'TXT':
if (strpos($record['txt'], 'path=') === 0) $path = substr($record['txt'], 5);
break;
}
}
if (!isset($srv)) throw new Exception("Could not discover iSchedule service for domain '$domain'!");
$url = strpos($host, '_ischedules') === 0 ? 'https' : 'http';
if ($scheme2port[$url] == $srv['port'])
{
$url .= '://'.$srv['target'];
}
else
{
$url .= '://'.$srv['target'].':'.$srv['port'];
}
$url .= $path;
return $url;
}
/**
* Post dkim signed message to recipients iSchedule server
*
* @param string $content
* @param string $content_type
* @param boolean $debug=false true echo request before posting
* @param int $max_redirect=3 maximum number of redirect before failing
* @return string
* @throws Exception with http status code and message, if server responds other then 2xx
*/
public function post_msg($content, $content_type, $debug=false, $max_redirect=3)
{
if (empty($this->dkim_private_key))
{
throw new Exception('You need to generate a key pair first!');
}
$url_parts = parse_url($this->url);
$user_agent = 'EGroupware-iSchedule-client/'.$GLOBALS['egw_info']['server']['versions']['phpgwapi'].' '.
preg_replace('|^\$Id$').
' PHP/'.PHP_VERSION;
$headers = array(
'Host' => $url_parts['host'].($url_parts['port'] ? ':'.$url_parts['port'] : ''),
'iSchedule-Version' => self::VERSION,
'iSchedule-Message-ID' => uniqid(),
'Content-Type' => $content_type,
'Originator' => $this->originator,
'Recipient' => $this->recipients,
'Cache-Control' => 'no-cache, no-transform', // required by iSchedule spec
'User-Agent' => $user_agent,
'Content-Length' => bytes($content),
);
$header_string = '';
foreach($headers as $name => $value)
{
foreach((array)$value as $val)
{
$header_string .= $name.': '.$val."\r\n";
}
}
$header_string .= $this->dkim_sign($headers, $content)."\r\n";
$opts = array('http' =>
array(
'method' => 'POST',
'header' => $header_string,
'user_agent' => $user_agent,
//'follow_location' => 1, // default 1=follow, but only for GET, not POST!
//'timeout' => $timeout, // max timeout in seconds (float)
'content' => $content,
'ignore_errors' => true, // return response, even for http-status != 2xx
)
);
if ($debug) echo "POST $this->url HTTP/1.1\n$header_string\n$content\n";
// need to suppress warning, if http-status not 2xx
$response = @file_get_contents($this->url, false, stream_context_create($opts));
list(, $code, $message) = explode(' ', $http_response_header[0], 3);
if ($code[0] !== '2')
{
if ($max_redirect && $code[0] === '3')
{
foreach($http_response_header as $header)
{
if (stripos($header, 'location:') === 0)
{
list(,$location) = preg_split('/: ?/', $header, 2);
if ($location[0] == '/')
{
$parts = parse_url($this->url);
$location = $parts['scheme'].'://'.$parts['host'].($parts['port'] ? ':'.$parts['port'] : '').$location;
}
$this->url = $location;
// follow redirect
return $this->post_msg($content, $content_type, $debug, $max_redirect-1);
}
}
}
if ($debug && $http_response_header) echo implode("\r\n", $http_response_header)."\r\n\r\n".$response;
if (preg_match('|<response-description>(.*)</response-description>|', $response, $matches)) $message .= ': '.$matches[1];
throw new Exception($message, $code);
}
return $response;
}
/**
* Calculate DKIM signature for headers and body using originators domains private key
*
* @param array $headers name => value pairs, names as in $sign_headers
* @param string $body
* @param string $selector='calendar'
* @param string $sign_headers='iSchedule-Version:Content-Type:Originator:Recipient'
* @param int $expires seconds the signature is valid, default 300
* @return string DKIM-Signature: ...
*/
public function dkim_sign(array $headers, $body, $selector='calendar',$sign_headers=self::DKIM_HEADERS,$expires=300)
{
$header_values = $header_names = array();
foreach(explode(':', $sign_headers) as $header)
{
foreach((array)$headers[$header] as $value)
{
$header_values[] = $header.': '.$value;
$header_names[] = $header;
}
}
list(,$domain) = explode('@', $this->originator);
$mds = new mailDomainSigner($this->dkim_private_key, $domain, $selector);
// generate DKIM signature according to iSchedule spec
$dkim = $mds->getDKIM(implode(':', $header_names), $header_values, $body, 'ischedule-relaxed/simple', 'rsa-sha256',
"DKIM-Signature: ".
"v=1; ". // DKIM Version
"a=\$a; ". // The algorithm used to generate the signature "rsa-sha1"
"q=dns/txt:http/well-known; ". // how to fetch public key: dns/txt, http/well-known or private-exchange
"x=".(time()+$expires)."; ". // how long request will be valid as timestamp
// end iSchedule specific
"s=\$s; ". // The selector subdividing the namespace for the "d=" (domain) tag
"d=\$d; ". // The domain of the signing entity
"l=\$l; ". // Canonicalizated Body length count
"t=\$t; ". // Signature Timestamp
"c=\$c; ". // Message (Headers/Body) Canonicalization "relaxed/relaxed"
"h=\$h; ". // Signed header fields
"bh=\$bh;\r\n\t". // The hash of the canonicalized body part of the message
"b="); // The signature data (Empty because we will calculate it later));
// as we do http, no need to fold dkim, in fact recommendation is not to
$dkim = str_replace(array(";\r\n\t", "\r\n\t"), array('; ', ''), $dkim);
return $dkim;
}
/**
* Capabilities
*
* @var array
*/
private $capabilities;
/**
* Query capabilities of iSchedule server
*
* @param string $name=null name of capability to return, default null to return internal array with all capabilities
* @return mixed
* @throws Exception in case of an error or discovery failure
*/
public function capabilities($name=null)
{
if (!isset($this->capabilities))
{
$reader = new XMLReader();
if (!$reader->open($this->url.'?action=capabilities'))
{
throw new Exception("Could not read iSchedule server capabilities $this->url!");
}
$this->capabilities = self::xml2assoc($reader);
$reader->close();
if (!isset($this->capabilities['query-result']) || !isset($this->capabilities['query-result']['capability-set']))
{
throw new Exception("Server returned invalid capabilities!");
}
$this->capabilities = $this->capabilities['query-result']['capability-set'];
print_r($this->capabilities);
}
return $name ? $this->capabilities[$name] : $this->capabilities;
}
/**
* Parse capabilities xml into an associativ array
*
* @param XMLReader $xml
* @param &$target=array()
* @return mixed
*/
private static function xml2assoc(XMLReader $xml, &$target = array())
{
while ($xml->read())
{
switch ($xml->nodeType) {
case XMLReader::END_ELEMENT:
return $target;
case XMLReader::ELEMENT:
$name = $xml->name;
$empty = $xml->isEmptyElement;
$attr_name = $xml->getAttribute('name');
if (($name_attr = $xml->getAttribute('name')))
{
$name = $attr_name;
}
if (isset($target[$name]))
{
if (!is_array($target[$name]))
{
$target[$name] = array($target[$name]);
}
$t = &$target[$name][count($target[$name])];
}
else
{
$t = &$target[$name];
}
if ($xml->isEmptyElement)
{
$t = '';
}
else
{
self::xml2assoc($xml, $t);
}
if ($xml->hasAttributes)
{
while($xml->moveToNextAttribute())
{
if ($xml->name != 'name')
{
$t['@'.$xml->name] = $xml->value;
}
}
}
break;
case XMLReader::TEXT:
case XMLReader::CDATA:
$target = $xml->value;
}
}
return $target;
}
/**
* Make private vars readable
*
* @param string $name
* @return mixed
*/
public function __get($name)
{
return $this->$name;
}
}