Merge pull request #323 from fermionic/add-relayable-retraction-support-for-diaspora

Add relayable retraction support for diaspora

boot.php

@@ -11,7 +11,7 @@ require_once('include/cache.php');
 define ( 'FRIENDICA_PLATFORM',     'Friendica');
 define ( 'FRIENDICA_VERSION',      '3.0.1362' );
 define ( 'DFRN_PROTOCOL_VERSION',  '2.23'    );
-define ( 'DB_UPDATE_VERSION',      1147      );
+define ( 'DB_UPDATE_VERSION',      1148      );
 
 define ( 'EOL',                    "<br />\r\n"     );
 define ( 'ATOM_TIME',              'Y-m-d\TH:i:s\Z' );

database.sql

@@ -944,12 +944,14 @@ CREATE TABLE IF NOT EXISTS `session` (
 
 CREATE TABLE IF NOT EXISTS `sign` (
   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
-  `iid` int(10) unsigned NOT NULL,
+  `iid` int(10) unsigned NOT NULL DEFAULT '0',
+  `retract_iid` int(10) unsigned NOT NULL DEFAULT '0',
   `signed_text` mediumtext NOT NULL,
   `signature` text NOT NULL,
   `signer` char(255) NOT NULL,
   PRIMARY KEY (`id`),
-  KEY `iid` (`iid`)
+  KEY `iid` (`iid`),
+  KEY `retract_iid` (`retract_iid`)
 ) ENGINE=MyISAM  DEFAULT CHARSET=utf8;
 
 -- --------------------------------------------------------

include/delivery.php

@@ -113,6 +113,7 @@ function delivery_run($argv, $argc){
 			$uid = $r[0]['uid'];
 			$updated = $r[0]['edited'];
 
+			// The following seems superfluous. We've already checked for "if (! intval($r[0]['parent']))" a few lines up
 			if(! $parent_id)
 				continue;
 
@@ -508,17 +509,17 @@ function delivery_run($argv, $argc){
 					// unsupported
 					break;
 				}
-				elseif(($target_item['deleted']) && ($target_item['verb'] !== ACTIVITY_LIKE)) {
+				elseif(($target_item['deleted']) && ($target_item['uri'] === $target_item['parent-uri'])) {
+					// top-level retraction
 					logger('delivery: diaspora retract: ' . $loc);
-					// diaspora delete, 
+
 					diaspora_send_retraction($target_item,$owner,$contact,$public_message);
 					break;
 				}
-				elseif($target_item['parent'] != $target_item['id']) {
+				elseif($target_item['uri'] !== $target_item['parent-uri']) {
-
+					// we are the relay - send comments, likes and relayable_retractions to our conversants
 					logger('delivery: diaspora relay: ' . $loc);
 
-					// we are the relay - send comments, likes and unlikes to our conversants
 					diaspora_send_relay($target_item,$owner,$contact,$public_message);
 					break;
 				}		

include/diaspora.php

@@ -83,6 +83,9 @@ function diaspora_dispatch($importer,$msg) {
 	elseif($xmlbase->signed_retraction) {
 		$ret = diaspora_signed_retraction($importer,$xmlbase->signed_retraction,$msg);
 	}
+	elseif($xmlbase->relayable_retraction) {
+		$ret = diaspora_signed_retraction($importer,$xmlbase->relayable_retraction,$msg);
+	}
 	elseif($xmlbase->photo) {
 		$ret = diaspora_photo($importer,$xmlbase->photo,$msg);
 	}
@@ -1602,22 +1605,28 @@ function diaspora_like($importer,$xml,$msg) {
 			logger('diaspora_like: duplicate like: ' . $guid);
 			return;
 		} 
+		// Note: I don't think "Like" objects with positive = "false" are ever actually used
+		// It looks like "RelayableRetractions" are used for "unlike" instead
 		if($positive === 'false') {
-			q("UPDATE `item` SET `deleted` = 1 WHERE `id` = %d AND `uid` = %d LIMIT 1",
+			logger('diaspora_like: received a like with positive set to "false"...ignoring');
+/*			q("UPDATE `item` SET `deleted` = 1 WHERE `id` = %d AND `uid` = %d LIMIT 1",
 				intval($r[0]['id']),
 				intval($importer['uid'])
-			);
+			);*/
 			// FIXME
 			//  send notification via proc_run()
 			return;
 		}
 	}
+	// Note: I don't think "Like" objects with positive = "false" are ever actually used
+	// It looks like "RelayableRetractions" are used for "unlike" instead
 	if($positive === 'false') {
-		logger('diaspora_like: unlike received with no corresponding like');
+		logger('diaspora_like: received a like with positive set to "false"');
+		logger('diaspora_like: unlike received with no corresponding like...ignoring');
 		return;	
 	}
 
-	$author_signed_data = $guid . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $diaspora_handle;
+	$signed_data = $guid . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $diaspora_handle;
 
 	$author_signature = base64_decode($author_signature);
 
@@ -1635,20 +1644,20 @@ function diaspora_like($importer,$xml,$msg) {
 		}
 	}
 
-	if(! rsa_verify($author_signed_data,$author_signature,$key,'sha256')) {
+	if(! rsa_verify($signed_data,$author_signature,$key,'sha256')) {
 		logger('diaspora_like: verification failed.');
 		return;
 	}
 
 	if($parent_author_signature) {
 
-		$owner_signed_data = $guid . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $diaspora_handle;
+		//$owner_signed_data = $guid . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $diaspora_handle;
 
 		$parent_author_signature = base64_decode($parent_author_signature);
 
 		$key = $msg['key'];
 
-		if(! rsa_verify($owner_signed_data,$parent_author_signature,$key,'sha256')) {
+		if(! rsa_verify($signed_data,$parent_author_signature,$key,'sha256')) {
 			logger('diaspora_like: owner verification failed.');
 			return;
 		}
@@ -1783,38 +1792,89 @@ function diaspora_signed_retraction($importer,$xml,$msg) {
 	$type = notags(unxmlify($xml->target_type));
 	$sig = notags(unxmlify($xml->target_author_signature));
 
+	$parent_author_signature = (($xml->parent_author_signature) ? notags(unxmlify($xml->parent_author_signature)) : '');
+
 	$contact = diaspora_get_contact_by_handle($importer['uid'],$diaspora_handle);
 	if(! $contact) {
 		logger('diaspora_signed_retraction: no contact');
 		return;
 	}
 
-	// this may not yet work for comments. Need to see how the relaying works
-	// and figure out who signs it.
-
 
 	$signed_data = $guid . ';' . $type ;
 
-	$sig = base64_decode($sig);
+	$sig_decode = base64_decode($sig);
 
+	if(strcasecmp($diaspora_handle,$msg['author']) == 0) {
+		$person = $contact;
 		$key = $msg['key'];
+	}
+	else {
+		$person = find_diaspora_person_by_handle($diaspora_handle);	
 
-	if(! rsa_verify($signed_data,$sig,$key,'sha256')) {
+		if(is_array($person) && x($person,'pubkey'))
-		logger('diaspora_signed_retraction: owner verification failed.' . print_r($msg,true));
+			$key = $person['pubkey'];
+		else {
+			logger('diaspora_signed_retraction: unable to find author details');
+			return;
+		}
+	}
+
+	if(! rsa_verify($signed_data,$sig_decode,$key,'sha256')) {
+		logger('diaspora_signed_retraction: retraction-owner verification failed.' . print_r($msg,true));
 		return;
 	}
 
-	if($type === 'StatusMessage') {
+	if($parent_author_signature) {
+		$parent_author_signature = base64_decode($parent_author_signature);
+
+		$key = $msg['key'];
+
+		if(! rsa_verify($signed_data,$parent_author_signature,$key,'sha256')) {
+			logger('diaspora_signed_retraction: failed to verify person relaying the retraction (e.g. owner of a post relaying a retracted comment');
+			return;
+		}
+
+	}
+
+	if($type === 'StatusMessage' || $type === 'Comment' || $type === 'Like') {
 		$r = q("select * from item where guid = '%s' and uid = %d and not file like '%%[%%' limit 1",
 			dbesc($guid),
 			intval($importer['uid'])
 		);
 		if(count($r)) {
 			if(link_compare($r[0]['author-link'],$contact['url'])) {
-				q("update item set `deleted` = 1, `changed` = '%s' where `id` = %d limit 1",
+				q("update item set `deleted` = 1, `edited` = '%s', `changed` = '%s', `body` = '' , `title` = '' where `id` = %d limit 1",
+					dbesc(datetime_convert()),			
 					dbesc(datetime_convert()),			
 					intval($r[0]['id'])
 				);
+	
+				// Now check if the retraction needs to be relayed by us
+				//
+				// The first item in the `item` table with the parent id is the parent. However, MySQL doesn't always
+				// return the items ordered by `item`.`id`, in which case the wrong item is chosen as the parent.
+				// The only item with `parent` and `id` as the parent id is the parent item.
+				$p = q("select origin from item where parent = %d and id = %d limit 1",
+					$r[0]['parent'],
+					$r[0]['parent']
+				);
+				if(count($p)) {
+					if(($p[0]['origin']) && (! $parent_author_signature)) {
+						q("insert into sign (`retract_iid`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
+							$r[0]['id'],
+							dbesc($signed_data),
+							dbesc($sig),
+							dbesc($diaspora_handle)
+						);
+
+						// the existence of parent_author_signature would have meant the parent_author or owner
+						// is already relaying.
+						logger('diaspora_signed_retraction: relaying relayable_retraction');
+
+						proc_run('php','include/notifier.php','relayable_retraction',$r[0]['id']);
+					}
+				}
 			}
 		}
 	}
@@ -2071,7 +2131,11 @@ function diaspora_send_followup($item,$owner,$contact,$public_batch = false) {
 		$tpl = get_markup_template('diaspora_like.tpl');
 		$like = true;
 		$target_type = 'Post';
-		$positive = (($item['deleted']) ? 'false' : 'true');
+//		$positive = (($item['deleted']) ? 'false' : 'true');
+		$positive = 'true';
+
+		if(($item['deleted']))
+			logger('diaspora_send_followup: received deleted "like". Those should go to diaspora_send_retraction');
 	}
 	else {
 		$tpl = get_markup_template('diaspora_comment.tpl');
@@ -2127,29 +2191,35 @@ function diaspora_send_relay($item,$owner,$contact,$public_batch = false) {
 	else
 		return;
 
-	if($item['verb'] === ACTIVITY_LIKE) {
+	$like = false;
+	$relay_retract = false;
+	$sql_sign_id = 'iid';
+	if( $item['deleted']) {
+		$tpl = get_markup_template('diaspora_relayable_retraction.tpl');
+		$relay_retract = true;
+		$sql_sign_id = 'retract_iid';
+		$target_type = ( ($item['verb'] === ACTIVITY_LIKE) ? 'Like' : 'Comment');
+	}
+	elseif($item['verb'] === ACTIVITY_LIKE) {
 		$tpl = get_markup_template('diaspora_like_relay.tpl');
 		$like = true;
 		$target_type = 'Post';
-		$positive = (($item['deleted']) ? 'false' : 'true');
+//		$positive = (($item['deleted']) ? 'false' : 'true');
+		$positive = 'true';
 	}
 	else {
 		$tpl = get_markup_template('diaspora_comment_relay.tpl');
-		$like = false;
 	}
 
 	$body = $item['body'];
 
 	$text = html_entity_decode(bb2diaspora($body));
 
-	// fetch the original signature	if somebody sent the post to us to relay
-	// If we are relaying for a reply originating on our own account, there wasn't a 'send to relay'
-	// action. It wasn't needed. In that case create the original signature and the 
-	// owner (parent author) signature
-	// comments from other networks will be relayed under our name, with a brief 
-	// preamble to describe what's happening and noting the real author
 
-	$r = q("select * from sign where iid = %d limit 1",
+	// fetch the original signature	if the relayable was created by a Diaspora
+	// or DFRN user. Relayables for other networks are not supported.
+
+	$r = q("select * from sign where " . $sql_sign_id . " = %d limit 1",
 		intval($item['id'])
 	);
 	if(count($r)) { 
@@ -2160,6 +2230,12 @@ function diaspora_send_relay($item,$owner,$contact,$public_batch = false) {
 	}
 	else {
 
+		// Author signature information (for likes, comments, and retractions of likes or comments,
+		// whether from Diaspora or Friendica) must be placed in the `sign` table before this 
+		// function is called
+		logger('diaspora_send_relay: original author signature not found, cannot send relayable');
+		return;
+/*
 		$itemcontact = q("select * from contact where `id` = %d limit 1",
 			intval($item['contact-id'])
 		);
@@ -2168,29 +2244,40 @@ function diaspora_send_relay($item,$owner,$contact,$public_batch = false) {
 				$prefix = sprintf( t('[Relayed] Comment authored by %s from network %s'),
 					'['. $item['author-name'] . ']' . '(' . $item['author-link'] . ')',  
 					network_to_name($itemcontact['network'])) . "\n";
+				// "$body" was assigned to "$text" above. It isn't used after that, so I don't think
+				// the following change will do anything
 				$body = $prefix . $body;
+
+				// I think this comment will fail upon reaching Diaspora, because "$signed_text" is not defined
 			}
 		}
 		else {
+		// I'm confused about this "else." Since it sets "$handle = $myaddr," it seems like it should be for the case
+		// where the top-level post owner commented on his own post, i.e. "$itemcontact[0]['self']" is true. But it's
+		// positioned to be for the case where "count($itemcontact)" is 0.
+
+			$handle = $myaddr;
 
 			if($like)
-				$signed_text = $item['guid'] . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $myaddr;
+				$signed_text = $item['guid'] . ';' . $target_type . ';' . $parent_guid . ';' . $positive . ';' . $handle;
+			elseif($relay_retract)
+				$signed_text = $item['guid'] . ';' . $target_type;
 			else
-				$signed_text = $item['guid'] . ';' . $parent_guid . ';' . $text . ';' . $myaddr;
+				$signed_text = $item['guid'] . ';' . $parent_guid . ';' . $text . ';' . $handle;
 
 			$authorsig = base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256'));
 
-			q("insert into sign (`iid`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
+			q("insert into sign (`" . $sql_sign_id . "`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
 				intval($item['id']),
 				dbesc($signed_text),
-				dbesc(base64_encode($authorsig)),
+				dbesc($authorsig),
-				dbesc($myaddr)
+				dbesc($handle)
 			);
-			$handle = $myaddr;
 		}
+*/
 	}
 
-	// sign it
+	// sign it with the top-level owner's signature
 
 	$parentauthorsig = base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256'));
 
@@ -2198,14 +2285,15 @@ function diaspora_send_relay($item,$owner,$contact,$public_batch = false) {
 		'$guid' => xmlify($item['guid']),
 		'$parent_guid' => xmlify($parent_guid),
 		'$target_type' =>xmlify($target_type),
-		'$authorsig' => xmlify($orig_sign['signature']),
+		'$authorsig' => xmlify($authorsig),
 		'$parentsig' => xmlify($parentauthorsig),
 		'$body' => xmlify($text),
 		'$positive' => xmlify($positive),
 		'$handle' => xmlify($handle)
 	));
 
-	logger('diaspora_relay_comment: base message: ' . $msg, LOGGER_DATA);
+	logger('diaspora_send_relay: base message: ' . $msg, LOGGER_DATA);
+
 
 	$slap = 'xml=' . urlencode(urlencode(diaspora_msg_build($msg,$owner,$contact,$owner['uprvkey'],$contact['pubkey'],$public_batch)));
 
@@ -2220,14 +2308,25 @@ function diaspora_send_retraction($item,$owner,$contact,$public_batch = false) {
 	$a = get_app();
 	$myaddr = $owner['nickname'] . '@' .  substr($a->get_baseurl(), strpos($a->get_baseurl(),'://') + 3);
 
-	$signed_text = $item['guid'] . ';' . 'StatusMessage';
+	// Check whether the retraction is for a top-level post or whether it's a relayable
+	if( $item['uri'] !== $item['parent-uri'] ) {
+
+		$tpl = get_markup_template('diaspora_relay_retraction.tpl');
+		$target_type = (($item['verb'] === ACTIVITY_LIKE) ? 'Like' : 'Comment');
+	}
+	else {
 		
 		$tpl = get_markup_template('diaspora_signed_retract.tpl');
+		$target_type = 'StatusMessage';
+	}
+
+	$signed_text = $item['guid'] . ';' . $target_type;
+
 	$msg = replace_macros($tpl, array(
-		'$guid'   => $item['guid'],
+		'$guid'   => xmlify($item['guid']),
-		'$type'   => 'StatusMessage',
+		'$type'   => xmlify($target_type),
-		'$handle' => $myaddr,
+		'$handle' => xmlify($myaddr),
-		'$signature' => base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256'))
+		'$signature' => xmlify(base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256')))
 	));
 
 	$slap = 'xml=' . urlencode(urlencode(diaspora_msg_build($msg,$owner,$contact,$owner['uprvkey'],$contact['pubkey'],$public_batch)));
@@ -2351,3 +2450,5 @@ function diaspora_transmit($owner,$contact,$slap,$public_batch) {
 
 	return(($return_code) ? $return_code : (-1));
 }
+
+

include/items.php

@@ -3279,6 +3279,41 @@ function drop_item($id,$interactive = true) {
 					intval($r[0]['id'])
 				);
 			}
+
+			// Add a relayable_retraction signature for Diaspora. Note that we can't add a target_author_signature
+			// if the comment was deleted by a remote user. That should be ok, because if a remote user is deleting
+			// the comment, that means we're the home of the post, and Diaspora will only
+			// check the parent_author_signature of retractions that it doesn't have to relay further
+			//
+			// I don't think this function gets called for an "unlike," but I'll check anyway
+			$signed_text = $item['guid'] . ';' . ( ($item['verb'] === ACTIVITY_LIKE) ? 'Like' : 'Comment');
+
+			if(local_user() == $item['uid']) {
+
+				$handle = $a->user['nickname'] . '@' . substr($a->get_baseurl(), strpos($a->get_baseurl(),'://') + 3);
+				$authorsig = base64_encode(rsa_sign($signed_text,$a->user['prvkey'],'sha256'));
+			}
+			else {
+				$r = q("SELECT `nick`, `url` FROM `contact` WHERE `id` = '%d' LIMIT 1",
+					$item['contact-id']
+				);
+				if(count($r)) {
+					// The below handle only works for NETWORK_DFRN. I think that's ok, because this function
+					// only handles DFRN deletes
+					$handle_baseurl_start = strpos($r['url'],'://') + 3;
+					$handle_baseurl_length = strpos($r['url'],'/profile') - $handle_baseurl_start;
+					$handle = $r['nick'] . '@' . substr($r['url'], $handle_baseurl_start, $handle_baseurl_length);
+					$authorsig = '';
+				}
+			}
+
+			if(isset($handle))
+				q("insert into sign (`retract_iid`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
+					intval($item['id']),
+					dbesc($signed_text),
+					dbesc($authorsig),
+					dbesc($handle)
+				);
 		}
 		$drop_id = intval($item['id']);
 

include/notifier.php

@@ -125,6 +125,7 @@ function notifier_run($argv, $argc){
 		$uid = $r[0]['uid'];
 		$updated = $r[0]['edited'];
 
+		// The following seems superfluous. We've already checked for "if (! intval($r[0]['parent']))" a few lines up
 		if(! $parent_id)
 			return;
 
@@ -596,7 +597,7 @@ function notifier_run($argv, $argc){
 					break;
 				case NETWORK_OSTATUS:
 
-					// Do not send to otatus if we are not configured to send to public networks
+					// Do not send to ostatus if we are not configured to send to public networks
 					if($owner['prvnets'])
 						break;
 					if(get_config('system','ostatus_disabled') || get_config('system','dfrn_only'))
@@ -737,18 +738,19 @@ function notifier_run($argv, $argc){
 						// unsupported
 						break;
 					}
-					elseif(($target_item['deleted']) && ($target_item['verb'] !== ACTIVITY_LIKE)) {
+					elseif(($target_item['deleted']) && (($target_item['uri'] === $target_item['parent-uri']) || $followup)) {
-						// diaspora delete, 
+						// send both top-level retractions and relayable retractions for owner to relay
 						diaspora_send_retraction($target_item,$owner,$contact);
 						break;
 					}
 					elseif($followup) {
-						// send comments, likes and retractions of likes to owner to relay
+						// send comments and likes to owner to relay
 						diaspora_send_followup($target_item,$owner,$contact);
 						break;
 					}
-					elseif($target_item['parent'] != $target_item['id']) {
+					elseif($target_item['uri'] !== $target_item['parent-uri']) {
-						// we are the relay - send comments, likes and unlikes to our conversants
+						// we are the relay - send comments, likes and relayable_retractions
+						// (of comments and likes) to our conversants
 						diaspora_send_relay($target_item,$owner,$contact);
 						break;
 					}
@@ -858,6 +860,13 @@ function notifier_run($argv, $argc){
 
 	}
 
+	// If the item was deleted, clean up the `sign` table
+	if($target_item['deleted']) {
+		$r = q("DELETE FROM sign where `retract_iid` = %d",
+			intval($target_item['id'])
+		);
+	}
+
 	logger('notifier: calling hooks', LOGGER_DEBUG);
 
 	if($normal_mode)

mod/like.php

@@ -104,7 +104,8 @@ function like_content(&$a) {
 		return;
 	}
 
-	$r = q("SELECT `id` FROM `item` WHERE `verb` = '%s' AND `deleted` = 0 
+
+	$r = q("SELECT * FROM `item` WHERE `verb` = '%s' AND `deleted` = 0 
 		AND `contact-id` = %d AND ( `parent` = '%s' OR `parent-uri` = '%s') LIMIT 1",
 		dbesc($activity),
 		intval($contact['id']),
@@ -112,13 +113,70 @@ function like_content(&$a) {
 		dbesc($item_id)
 	);
 	if(count($r)) {
+		$like_item = $r[0];
+
 		// Already voted, undo it
 		$r = q("UPDATE `item` SET `deleted` = 1, `changed` = '%s' WHERE `id` = %d LIMIT 1",
 			dbesc(datetime_convert()),
-			intval($r[0]['id'])
+			intval($like_item['id'])
 		);
 
-		proc_run('php',"include/notifier.php","like","$post_id");
+		// Clean up the `sign` table
+		$r = q("DELETE FROM `sign` WHERE `iid` = %d",
+			intval($like_item['id'])
+		);
+
+		// Save the author information for the unlike in case we need to relay to Diaspora
+		// Note that we can only create a signature for a user of the local server. We don't have
+		// a key for remote users. That is ok, because if a remote user is "unlike"ing a post, it 
+		// means we are the relay, and for relayable_retractions, Diaspora
+		// only checks the parent_author_signature if it doesn't have to relay further
+		//
+		// If $item['resource-id'] exists, it means the item is a photo. Diaspora doesn't support
+		// likes on photos, so don't bother.
+
+		if(($activity === ACTIVITY_LIKE) && (! $item['resource-id'])) {
+			$signed_text = $like_item['guid'] . ';' . 'Like';
+
+			if( $contact['network'] === NETWORK_DIASPORA)
+				$diaspora_handle = $contact['addr'];
+			else { // Only works for NETWORK_DFRN
+				$contact_baseurl_start = strpos($contact['url'],'://') + 3;
+				$contact_baseurl_length = strpos($contact['url'],'/profile') - $contact_baseurl_start;
+				$contact_baseurl = substr($contact['url'], $contact_baseurl_start, $contact_baseurl_length);
+				$diaspora_handle = $contact['nick'] . '@' . $contact_baseurl;
+
+				// Get contact's private key if he's a user of the local Friendica server
+				$r = q("SELECT `contact`.`uid` FROM `contact` WHERE `url` = '%s' AND `self` = 1 LIMIT 1",
+					dbesc($contact['url'])
+				);
+
+				if( $r) {
+					$contact_uid = $r['uid'];
+					$r = q("SELECT prvkey FROM user WHERE uid = %d LIMIT 1",
+						intval($contact_uid)
+					);
+
+					if( $r)
+						$authorsig = base64_encode(rsa_sign($signed_text,$r['prvkey'],'sha256'));
+				}
+			}
+
+			if(! isset($authorsig))
+				$authorsig = '';
+
+			q("insert into sign (`retract_iid`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
+				intval($like_item['id']),
+				dbesc($signed_text),
+				dbesc($authorsig),
+				dbesc($diaspora_handle)
+			);
+		}
+
+
+//		proc_run('php',"include/notifier.php","like","$post_id"); // $post_id isn't defined here!
+		$like_item_id = $like_item['id'];
+		proc_run('php',"include/notifier.php","like","$like_item_id");
 		return;
 	}
 
@@ -191,6 +249,65 @@ EOT;
 		);
 	}			
 
+
+	// Save the author information for the like in case we need to relay to Diaspora
+	// Note that we can only create a signature for a user of the local server. We don't have
+	// a key for remote users. That is ok, because if a remote user is "unlike"ing a post, it 
+	// means we are the relay, and for relayable_retractions, Diaspora
+	// only checks the parent_author_signature if it doesn't have to relay further
+
+	if(($activity === ACTIVITY_LIKE) && ($post_type === t('status'))) {
+		if( $contact['network'] === NETWORK_DIASPORA)
+			$diaspora_handle = $contact['addr'];
+		else { // Only works for NETWORK_DFRN
+			$contact_baseurl_start = strpos($contact['url'],'://') + 3;
+			$contact_baseurl_length = strpos($contact['url'],'/profile') - $contact_baseurl_start;
+			$contact_baseurl = substr($contact['url'], $contact_baseurl_start, $contact_baseurl_length);
+			$diaspora_handle = $contact['nick'] . '@' . $contact_baseurl;
+
+			// Get contact's private key if he's a user of the local Friendica server
+			$r = q("SELECT `contact`.`uid` FROM `contact` WHERE `url` = '%s' AND `self` = 1 LIMIT 1",
+				dbesc($contact['url'])
+			);
+
+			if( $r) {
+				$contact_uid = $r['uid'];
+				$r = q("SELECT prvkey FROM user WHERE uid = %d LIMIT 1",
+					intval($contact_uid)
+				);
+
+				if( $r)
+					$contact_uprvkey = $r['prvkey'];
+			}
+		}
+
+		$r = q("SELECT guid, parent FROM `item` WHERE id = %d LIMIT 1",
+			intval($post_id)
+		);
+		if( $r) {
+			$p = q("SELECT guid FROM `item` WHERE id = %d AND parent = %d LIMIT 1",
+				intval($r[0]['parent']),
+				intval($r[0]['parent'])
+			);
+			if( $p) {
+				$signed_text = $r[0]['guid'] . ';Post;' . $p[0]['guid'] . ';true;' . $diaspora_handle;
+
+				if(isset($contact_uprvkey))
+					$authorsig = base64_encode(rsa_sign($signed_text,$contact_uprvkey,'sha256'));
+				else
+					$authorsig = '';
+
+				q("insert into sign (`iid`,`signed_text`,`signature`,`signer`) values (%d,'%s','%s','%s') ",
+					intval($post_id),
+					dbesc($signed_text),
+					dbesc($authorsig),
+					dbesc($diaspora_handle)
+				);
+			}
+		}
+	}
+
+
 	$arr['id'] = $post_id;
 
 	call_hooks('post_local_end', $arr);

update.php

@@ -1,6 +1,6 @@
 <?php
 
-define( 'UPDATE_VERSION' , 1147 );
+define( 'UPDATE_VERSION' , 1148 );
 
 /**
  *
@@ -1274,4 +1274,12 @@ function update_1146() {
 	return UPDATE_SUCCESS ;
 }
 
+function update_1147() {
+	$r1 = q("ALTER TABLE `sign` ALTER `iid` SET DEFAULT '0'");
+	$r2 = q("ALTER TABLE `sign` ADD `retract_iid` INT(10) UNSIGNED NOT NULL DEFAULT '0' AFTER `iid`");
+	$r3 = q("ALTER TABLE `sign` ADD INDEX ( `retract_iid` )");  
+	if((! $r1) || (! $r2) || (! $r3))
+		return UPDATE_FAILED ;
+	return UPDATE_SUCCESS ;
+}
 

view/diaspora_like_relay.tpl

@@ -5,7 +5,7 @@
       <target_type>$target_type</target_type>
       <parent_guid>$parent_guid</parent_guid>
       <parent_author_signature>$parentsig</parent_author_signature>
-      <author_signature>$authrosig</author_signature>
+      <author_signature>$authorsig</author_signature>
       <positive>$positive</positive>
       <diaspora_handle>$handle</diaspora_handle>
     </like>

view/diaspora_relay_retraction.tpl

@@ -0,0 +1,10 @@
+<XML>
+  <post>
+    <relayable_retraction>
+      <target_type>$type</target_type>
+      <target_guid>$guid</target_guid>
+      <target_author_signature>$signature</target_author_signature>
+      <sender_handle>$handle</sender_handle>
+    </relayable_retraction>
+  </post>
+</XML>

view/diaspora_relayable_retraction.tpl

@@ -0,0 +1,11 @@
+<XML>
+  <post>
+    <relayable_retraction>
+      <target_type>$target_type</target_type>
+      <target_guid>$guid</target_guid>
+      <parent_author_signature>$parentsig</parent_author_signature>
+      <target_author_signature>$authorsig</target_author_signature>
+      <sender_handle>$handle</sender_handle>
+    </relayable_retraction>
+  </post>
+</XML>