<?php
namespace Zotlabs\Zot;
class Receiver {
protected $data;
protected $encrypted;
protected $error;
protected $messagetype;
protected $sender;
protected $validated;
protected $recipients;
protected $response;
protected $handler;
function __construct($data,$prvkey,$handler) {
$this->error = false;
$this->validated = false;
$this->messagetype = '';
$this->response = array('success' => false);
$this->handler = $handler;
if(! is_array($data))
$data = json_decode($data,true);
if($data && is_array($data)) {
$this->encrypted = ((array_key_exists('iv',$data)) ? true : false);
if($this->encrypted) {
$this->data = @json_decode(@crypto_unencapsulate($data,$prvkey),true);
}
if(! $this->data)
$this->data = $data;
if($this->data && is_array($this->data) && array_key_exists('type',$this->data))
$this->messagetype = $this->data['type'];
}
if(! $this->messagetype)
$this->error = true;
if($this->data) {
$this->sender = ((array_key_exists('sender',$this->data)) ? $this->data['sender'] : null);
$this->recipients = ((array_key_exists('recipients',$this->data)) ? $this->data['recipients'] : null);
}
if($this->sender)
$this->ValidateSender();
$this->Dispatch();
}
function ValidateSender() {
$hubs = zot_gethub($this->sender,true);
if (! $hubs) {
/* Have never seen this guid or this guid coming from this location. Check it and register it. */
/* (!!) this will validate the sender. */
$result = zot_register_hub($this->sender);
if ((! $result['success']) || (! ($hubs = zot_gethub($this->sender,true)))) {
$this->response['message'] = 'Hub not available.';
json_return_and_die($this->response);
}
}
foreach($hubs as $hub) {
update_hub_connected($hub,((array_key_exists('sitekey',$this->sender)) ? $this->sender['sitekey'] : ''));
}
$this->validated = true;
}
function Dispatch() {
/* Handle tasks which don't require sender validation */
switch($this->messagetype) {
case 'ping':
/* no validation needed */
$this->handler->Ping();
break;
case 'pickup':
/* perform site validation, as opposed to sender validation */
$this->handler->Pickup($this->data);
break;
default:
if(! $this->validated) {
$this->response['message'] = 'Sender not valid';
json_return_and_die($this->response);
}
break;
}
/* Now handle tasks which require sender validation */
switch($this->messagetype) {
case 'auth_check':
$this->handler->AuthCheck($this->data,$this->encrypted);
break;
case 'request':
$this->handler->Request($this->data);
break;
case 'purge':
$this->handler->Purge($this->sender,$this->recipients);
break;
case 'refresh':
case 'force_refresh':
$this->handler->Refresh($this->sender,$this->recipients);
break;
case 'notify':
$this->handler->Notify($this->data);
break;
default:
$this->response['message'] = 'Not implemented';
json_return_and_die($this->response);
break;
}
}
}
/**
* @brief zot communications and messaging.
*
* Sender HTTP posts to this endpoint ($site/post typically) with 'data' parameter set to json zot message packet.
* This packet is optionally encrypted, which we will discover if the json has an 'iv' element.
* $contents => array( 'alg' => 'aes256cbc', 'iv' => initialisation vector, 'key' => decryption key, 'data' => encrypted data);
* $contents->iv and $contents->key are random strings encrypted with this site's RSA public key and then base64url encoded.
* Currently only 'aes256cbc' is used, but this is extensible should that algorithm prove inadequate.
*
* Once decrypted, one will find the normal json_encoded zot message packet.
*
* Defined packet types are: notify, purge, refresh, force_refresh, auth_check, ping, and pickup
*
* Standard packet: (used by notify, purge, refresh, force_refresh, and auth_check)
* \code{.json}
* {
* "type": "notify",
* "sender":{
* "guid":"kgVFf_1...",
* "guid_sig":"PT9-TApzp...",
* "url":"http:\/\/podunk.edu",
* "url_sig":"T8Bp7j5...",
* },
* "recipients": { optional recipient array },
* "callback":"\/post",
* "version":1,
* "secret":"1eaa...",
* "secret_sig": "df89025470fac8..."
* }
* \endcode
*
* Signature fields are all signed with the sender channel private key and base64url encoded.
* Recipients are arrays of guid and guid_sig, which were previously signed with the recipients private
* key and base64url encoded and later obtained via channel discovery. Absence of recipients indicates
* a public message or visible to all potential listeners on this site.
*
* "pickup" packet:
* The pickup packet is sent in response to a notify packet from another site
* \code{.json}
* {
* "type":"pickup",
* "url":"http:\/\/example.com",
* "callback":"http:\/\/example.com\/post",
* "callback_sig":"teE1_fLI...",
* "secret":"1eaa...",
* "secret_sig":"O7nB4_..."
* }
* \endcode
*
* In the pickup packet, the sig fields correspond to the respective data
* element signed with this site's system private key and then base64url encoded.
* The "secret" is the same as the original secret from the notify packet.
*
* If verification is successful, a json structure is returned containing a
* success indicator and an array of type 'pickup'.
* Each pickup element contains the original notify request and a message field
* whose contents are dependent on the message type.
*
* This JSON array is AES encapsulated using the site public key of the site
* that sent the initial zot pickup packet.
* Using the above example, this would be example.com.
*
* \code{.json}
* {
* "success":1,
* "pickup":{
* "notify":{
* "type":"notify",
* "sender":{
* "guid":"kgVFf_...",
* "guid_sig":"PT9-TApz...",
* "url":"http:\/\/z.podunk.edu",
* "url_sig":"T8Bp7j5D..."
* },
* "callback":"\/post",
* "version":1,
* "secret":"1eaa661..."
* },
* "message":{
* "type":"activity",
* "message_id":"10b049ce384cbb2da9467319bc98169ab36290b8bbb403aa0c0accd9cb072e76@podunk.edu",
* "message_top":"10b049ce384cbb2da9467319bc98169ab36290b8bbb403aa0c0accd9cb072e76@podunk.edu",
* "message_parent":"10b049ce384cbb2da9467319bc98169ab36290b8bbb403aa0c0accd9cb072e76@podunk.edu",
* "created":"2012-11-20 04:04:16",
* "edited":"2012-11-20 04:04:16",
* "title":"",
* "body":"Hi Nickordo",
* "app":"",
* "verb":"post",
* "object_type":"",
* "target_type":"",
* "permalink":"",
* "location":"",
* "longlat":"",
* "owner":{
* "name":"Indigo",
* "address":"indigo@podunk.edu",
* "url":"http:\/\/podunk.edu",
* "photo":{
* "mimetype":"image\/jpeg",
* "src":"http:\/\/podunk.edu\/photo\/profile\/m\/5"
* },
* "guid":"kgVFf_...",
* "guid_sig":"PT9-TAp...",
* },
* "author":{
* "name":"Indigo",
* "address":"indigo@podunk.edu",
* "url":"http:\/\/podunk.edu",
* "photo":{
* "mimetype":"image\/jpeg",
* "src":"http:\/\/podunk.edu\/photo\/profile\/m\/5"
* },
* "guid":"kgVFf_...",
* "guid_sig":"PT9-TAp..."
* }
* }
* }
* }
* \endcode
*
* Currently defined message types are 'activity', 'mail', 'profile', 'location'
* and 'channel_sync', which each have different content schemas.
*
* Ping packet:
* A ping packet does not require any parameters except the type. It may or may
* not be encrypted.
*
* \code{.json}
* {
* "type": "ping"
* }
* \endcode
*
* On receipt of a ping packet a ping response will be returned:
*
* \code{.json}
* {
* "success" : 1,
* "site" {
* "url": "http:\/\/podunk.edu",
* "url_sig": "T8Bp7j5...",
* "sitekey": "-----BEGIN PUBLIC KEY-----
* MIICIjANBgkqhkiG9w0BAQE..."
* }
* }
* \endcode
*
* The ping packet can be used to verify that a site has not been re-installed, and to
* initiate corrective action if it has. The url_sig is signed with the site private key
* and base64url encoded - and this should verify with the enclosed sitekey. Failure to
* verify indicates the site is corrupt or otherwise unable to communicate using zot.
* This return packet is not otherwise verified, so should be compared with other
* results obtained from this site which were verified prior to taking action. For instance
* if you have one verified result with this signature and key, and other records for this
* url which have different signatures and keys, it indicates that the site was re-installed
* and corrective action may commence (remove or mark invalid any entries with different
* signatures).
* If you have no records which match this url_sig and key - no corrective action should
* be taken as this packet may have been returned by an imposter.
*
* @param[in,out] App &$a
*/
