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'] : '');
}
$this->validated = true;
}
/**
* @function post_post(&$a)
* 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)
*
* {
* "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..."
* }
*
* 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
*
* {
* "type":"pickup",
* "url":"http:\/\/example.com",
* "callback":"http:\/\/example.com\/post",
* "callback_sig":"teE1_fLI...",
* "secret":"1eaa...",
* "secret_sig":"O7nB4_..."
* }
*
* 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.
*
*
* {
* "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":"*****@*****.**",
* "message_top":"*****@*****.**",
* "message_parent":"*****@*****.**",
* "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":"*****@*****.**",
* "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":"*****@*****.**",
* "url":"http:\/\/podunk.edu",
* "photo":{
* "mimetype":"image\/jpeg",
* "src":"http:\/\/podunk.edu\/photo\/profile\/m\/5"
* },
* "guid":"kgVFf_...",
* "guid_sig":"PT9-TAp..."
* }
* }
* }
*}
*
* Currently defined message types are 'activity', 'mail', 'profile' 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.
*
* {
* "type": "ping"
* }
*
* On receipt of a ping packet a ping response will be returned:
*
* {
* "success" : 1,
* "site" {
* "url":"http:\/\/podunk.edu",
* "url_sig":"T8Bp7j5...",
* "sitekey": "-----BEGIN PUBLIC KEY-----
* MIICIjANBgkqhkiG9w0BAQE..."
* }
* }
*
* 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.
*
*/
function post_post(&$a)
{
$encrypted_packet = false;
$ret = array('success' => false);
$data = json_decode($_REQUEST['data'], true);
/**
* Many message packets will arrive encrypted. The existence of an 'iv' element
* tells us we need to unencapsulate the AES-256-CBC content using the site private key
*/
if (array_key_exists('iv', $data)) {
$encrypted_packet = true;
$data = crypto_unencapsulate($data, get_config('system', 'prvkey'));
logger('mod_zot: decrypt1: ' . $data, LOGGER_DATA);
$data = json_decode($data, true);
}
if (!$data) {
// possible Bleichenbacher's attack, just treat it as a
// message we have no handler for. It should fail a bit
// further along with "no hub". Our public key is public
// knowledge. There's no reason why anybody should get the
// encryption wrong unless they're fishing or hacking. If
// they're developing and made a goof, this can be discovered
// in the logs of the destination site. If they're fishing or
// hacking, the bottom line is we can't verify their hub.
// That's all we're going to tell them.
$data = array('type' => 'bogus');
}
$msgtype = array_key_exists('type', $data) ? $data['type'] : '';
if ($msgtype === 'ping') {
// Useful to get a health check on a remote site.
// This will let us know if any important communication details
// that we may have stored are no longer valid, regardless of xchan details.
logger('POST: got ping send pong now back: ' . z_root(), LOGGER_DEBUG);
$ret['success'] = true;
$ret['site'] = array();
$ret['site']['url'] = z_root();
$ret['site']['url_sig'] = base64url_encode(rsa_sign(z_root(), get_config('system', 'prvkey')));
$ret['site']['sitekey'] = get_config('system', 'pubkey');
json_return_and_die($ret);
}
if ($msgtype === 'pickup') {
/**
* The 'pickup' message arrives with a tracking ID which is associated with a particular outq_hash
* First verify that that the returned signatures verify, then check that we have an outbound queue item
* with the correct hash.
* If everything verifies, find any/all outbound messages in the queue for this hubloc and send them back
*
*/
if (!$data['secret'] || !$data['secret_sig']) {
$ret['message'] = 'no verification signature';
logger('mod_zot: pickup: ' . $ret['message'], LOGGER_DEBUG);
json_return_and_die($ret);
}
$r = q("select distinct hubloc_sitekey from hubloc where hubloc_url = '%s' and hubloc_callback = '%s' and hubloc_sitekey != '' group by hubloc_sitekey ", dbesc($data['url']), dbesc($data['callback']));
if (!$r) {
$ret['message'] = 'site not found';
logger('mod_zot: pickup: ' . $ret['message']);
json_return_and_die($ret);
}
foreach ($r as $hubsite) {
// verify the url_sig
// If the server was re-installed at some point, there could be multiple hubs with the same url and callback.
// Only one will have a valid key.
$forgery = true;
$secret_fail = true;
$sitekey = $hubsite['hubloc_sitekey'];
logger('mod_zot: Checking sitekey: ' . $sitekey, LOGGER_DATA);
if (rsa_verify($data['callback'], base64url_decode($data['callback_sig']), $sitekey)) {
$forgery = false;
}
if (rsa_verify($data['secret'], base64url_decode($data['secret_sig']), $sitekey)) {
$secret_fail = false;
}
if (!$forgery && !$secret_fail) {
break;
}
}
if ($forgery) {
$ret['message'] = 'possible site forgery';
logger('mod_zot: pickup: ' . $ret['message']);
json_return_and_die($ret);
}
if ($secret_fail) {
$ret['message'] = 'secret validation failed';
logger('mod_zot: pickup: ' . $ret['message']);
json_return_and_die($ret);
}
/**
* If we made it to here, the signatures verify, but we still don't know if the tracking ID is valid.
* It wouldn't be an error if the tracking ID isn't found, because we may have sent this particular
* queue item with another pickup (after the tracking ID for the other pickup was verified).
*/
$r = q("select outq_posturl from outq where outq_hash = '%s' and outq_posturl = '%s' limit 1", dbesc($data['secret']), dbesc($data['callback']));
if (!$r) {
$ret['message'] = 'nothing to pick up';
logger('mod_zot: pickup: ' . $ret['message']);
json_return_and_die($ret);
}
/**
* Everything is good if we made it here, so find all messages that are going to this location
* and send them all.
*/
$r = q("select * from outq where outq_posturl = '%s'", dbesc($data['callback']));
if ($r) {
logger('mod_zot: succesful pickup message received from ' . $data['callback'] . ' ' . count($r) . ' message(s) picked up', LOGGER_DEBUG);
$ret['success'] = true;
$ret['pickup'] = array();
foreach ($r as $rr) {
$ret['pickup'][] = array('notify' => json_decode($rr['outq_notify'], true), 'message' => json_decode($rr['outq_msg'], true));
$x = q("delete from outq where outq_hash = '%s' limit 1", dbesc($rr['outq_hash']));
}
}
$encrypted = crypto_encapsulate(json_encode($ret), $sitekey);
json_return_and_die($encrypted);
/** pickup: end */
}
/**
* All other message types require us to verify the sender. This is a generic check, so we
* will do it once here and bail if anything goes wrong.
*/
if (array_key_exists('sender', $data)) {
$sender = $data['sender'];
}
/** Check if the sender is already verified here */
$hub = zot_gethub($sender);
if (!$hub) {
/** Have never seen this guid or this guid coming from this location. Check it and register it. */
// (!!) this will validate the sender
$result = zot_register_hub($sender);
if (!$result['success'] || !($hub = zot_gethub($sender))) {
$ret['message'] = 'Hub not available.';
logger('mod_zot: no hub');
json_return_and_die($ret);
}
}
// Update our DB to show when we last communicated successfully with this hub
// This will allow us to prune dead hubs from using up resources
$r = q("update hubloc set hubloc_connected = '%s' where hubloc_id = %d limit 1", dbesc(datetime_convert()), intval($hub['hubloc_id']));
// a dead hub came back to life - reset any tombstones we might have
if ($hub['hubloc_status'] & HUBLOC_OFFLINE) {
q("update hubloc set hubloc_status = (hubloc_status ^ %d) where hubloc_id = %d limit 1", intval(HUBLOC_OFFLINE), intval($hub['hubloc_id']));
if ($r[0]['hubloc_flags'] & HUBLOC_FLAGS_ORPHANCHECK) {
q("update hubloc set hubloc_flags = (hubloc_flags ^ %d) where hubloc_id = %d limit 1", intval(HUBLOC_FLAGS_ORPHANCHECK), intval($hub['hubloc_id']));
}
q("update xchan set xchan_flags = (xchan_flags ^ %d) where (xchan_flags & %d) and xchan_hash = '%s' limit 1", intval(XCHAN_FLAGS_ORPHAN), intval(XCHAN_FLAGS_ORPHAN), dbesc($hub['hubloc_hash']));
}
/**
* This hub has now been proven to be valid.
* Any hub with the same URL and a different sitekey cannot be valid.
* Get rid of them (mark them deleted). There's a good chance they were re-installs.
*
*/
q("update hubloc set hubloc_flags = ( hubloc_flags | %d ) where hubloc_url = '%s' and hubloc_sitekey != '%s' ", intval(HUBLOC_FLAGS_DELETED), dbesc($hub['hubloc_url']), dbesc($hub['hubloc_sitekey']));
// TODO: check which hub is primary and take action if mismatched
if (array_key_exists('recipients', $data)) {
$recipients = $data['recipients'];
}
if ($msgtype === 'auth_check') {
/**
* Requestor visits /magic/?dest=somewhere on their own site with a browser
* magic redirects them to $destsite/post [with auth args....]
* $destsite sends an auth_check packet to originator site
* The auth_check packet is handled here by the originator's site
* - the browser session is still waiting
* inside $destsite/post for everything to verify
* If everything checks out we'll return a token to $destsite
* and then $destsite will verify the token, authenticate the browser
* session and then redirect to the original destination.
* If authentication fails, the redirection to the original destination
* will still take place but without authentication.
*/
logger('mod_zot: auth_check', LOGGER_DEBUG);
if (!$encrypted_packet) {
logger('mod_zot: auth_check packet was not encrypted.');
$ret['message'] .= 'no packet encryption' . EOL;
json_return_and_die($ret);
}
$arr = $data['sender'];
$sender_hash = make_xchan_hash($arr['guid'], $arr['guid_sig']);
// garbage collect any old unused notifications
q("delete from verify where type = 'auth' and created < UTC_TIMESTAMP() - INTERVAL 10 MINUTE");
$y = q("select xchan_pubkey from xchan where xchan_hash = '%s' limit 1", dbesc($sender_hash));
// We created a unique hash in mod/magic.php when we invoked remote auth, and stored it in
// the verify table. It is now coming back to us as 'secret' and is signed by a channel at the other end.
// First verify their signature. We will have obtained a zot-info packet from them as part of the sender
// verification.
if (!$y || !rsa_verify($data['secret'], base64url_decode($data['secret_sig']), $y[0]['xchan_pubkey'])) {
logger('mod_zot: auth_check: sender not found or secret_sig invalid.');
$ret['message'] .= 'sender not found or sig invalid ' . print_r($y, true) . EOL;
json_return_and_die($ret);
}
// There should be exactly one recipient, the original auth requestor
$ret['message'] .= 'recipients ' . print_r($recipients, true) . EOL;
if ($data['recipients']) {
$arr = $data['recipients'][0];
$recip_hash = make_xchan_hash($arr['guid'], $arr['guid_sig']);
$c = q("select channel_id, channel_account_id, channel_prvkey from channel where channel_hash = '%s' limit 1", dbesc($recip_hash));
if (!$c) {
logger('mod_zot: auth_check: recipient channel not found.');
$ret['message'] .= 'recipient not found.' . EOL;
json_return_and_die($ret);
}
$confirm = base64url_encode(rsa_sign($data['secret'] . $recip_hash, $c[0]['channel_prvkey']));
// This additionally checks for forged sites since we already stored the expected result in meta
// and we've already verified that this is them via zot_gethub() and that their key signed our token
$z = q("select id from verify where channel = %d and type = 'auth' and token = '%s' and meta = '%s' limit 1", intval($c[0]['channel_id']), dbesc($data['secret']), dbesc($data['sender']['url']));
if (!$z) {
logger('mod_zot: auth_check: verification key not found.');
$ret['message'] .= 'verification key not found' . EOL;
json_return_and_die($ret);
}
$r = q("delete from verify where id = %d limit 1", intval($z[0]['id']));
$u = q("select account_service_class from account where account_id = %d limit 1", intval($c[0]['channel_account_id']));
logger('mod_zot: auth_check: success', LOGGER_DEBUG);
$ret['success'] = true;
$ret['confirm'] = $confirm;
if ($u && $u[0]['account_service_class']) {
$ret['service_class'] = $u[0]['account_service_class'];
}
// Set "do not track" flag if this site or this channel's profile is restricted
if (intval(get_config('system', 'block_public'))) {
$ret['DNT'] = true;
}
if (!perm_is_allowed($c[0]['channel_id'], '', 'view_profile')) {
$ret['DNT'] = true;
}
if (get_pconfig($c[0]['channel_id'], 'system', 'do_not_track')) {
$ret['DNT'] = true;
}
json_return_and_die($ret);
}
json_return_and_die($ret);
}
if ($msgtype === 'purge') {
if ($recipients) {
// basically this means "unfriend"
foreach ($recipients as $recip) {
$r = q("select channel.*,xchan.* from channel \n\t\t\t\t\tleft join xchan on channel_hash = xchan_hash\n\t\t\t\t\twhere channel_guid = '%s' and channel_guid_sig = '%s' limit 1", dbesc($recip['guid']), dbesc($recip['guid_sig']));
if ($r) {
$r = q("select abook_id from abook where uid = %d and abook_xchan = '%s' limit 1", intval($r[0]['channel_id']), dbesc(make_xchan_hash($sender['guid'], $sender['guid_sig'])));
if ($r) {
contact_remove($r[0]['channel_id'], $r[0]['abook_id']);
}
}
}
} else {
// Unfriend everybody - basically this means the channel has committed suicide
$arr = $data['sender'];
$sender_hash = make_xchan_hash($arr['guid'], $arr['guid_sig']);
require_once 'include/Contact.php';
remove_all_xchan_resources($sender_hash);
$ret['success'] = true;
json_return_and_die($ret);
}
}
if ($msgtype === 'refresh' || $msgtype === 'force_refresh') {
// remote channel info (such as permissions or photo or something)
// has been updated. Grab a fresh copy and sync it.
// The difference between refresh and force_refresh is that
// force_refresh unconditionally creates a directory update record,
// even if no changes were detected upon processing.
if ($recipients) {
// This would be a permissions update, typically for one connection
foreach ($recipients as $recip) {
$r = q("select channel.*,xchan.* from channel \n\t\t\t\t\tleft join xchan on channel_hash = xchan_hash\n\t\t\t\t\twhere channel_guid = '%s' and channel_guid_sig = '%s' limit 1", dbesc($recip['guid']), dbesc($recip['guid_sig']));
$x = zot_refresh(array('xchan_guid' => $sender['guid'], 'xchan_guid_sig' => $sender['guid_sig'], 'hubloc_url' => $sender['url']), $r[0], $msgtype === 'force_refresh' ? true : false);
}
} else {
// system wide refresh
$x = zot_refresh(array('xchan_guid' => $sender['guid'], 'xchan_guid_sig' => $sender['guid_sig'], 'hubloc_url' => $sender['url']), null, $msgtype === 'force_refresh' ? true : false);
}
$ret['success'] = true;
json_return_and_die($ret);
}
if ($msgtype === 'notify') {
$async = get_config('system', 'queued_fetch');
if ($async) {
// add to receive queue
// qreceive_add($data);
} else {
$x = zot_fetch($data);
$ret['delivery_report'] = $x;
}
$ret['success'] = true;
json_return_and_die($ret);
}
// catchall
json_return_and_die($ret);
}
