]> git.mxchange.org Git - friendica.git/blobdiff - include/diaspora.php
Small bugfix
[friendica.git] / include / diaspora.php
index da69cdc7992fe62f590c00de9640f93a9bcbecb5..18206be8ed88bae758a1cf83a694bdc125851ff8 100644 (file)
@@ -21,6 +21,13 @@ require_once("include/queue_fn.php");
  */
 class diaspora {
 
+       /**
+        * @brief Return a list of relay servers
+        *
+        * This is an experimental Diaspora feature.
+        *
+        * @return array of relay servers
+        */
        public static function relay_list() {
 
                $serverdata = get_config("system", "relay_server");
@@ -65,7 +72,18 @@ class diaspora {
                return $relay;
        }
 
-       function repair_signature($signature, $handle = "", $level = 1) {
+       /**
+        * @brief repairs a signature that was double encoded
+        *
+        * The function is unused at the moment. It was copied from the old implementation.
+        *
+        * @param string $signature The signature
+        * @param string $handle The handle of the signature owner
+        * @param integer $level This value is only set inside this function to avoid endless loops
+        *
+        * @return string the repaired signature
+        */
+       private function repair_signature($signature, $handle = "", $level = 1) {
 
                if ($signature == "")
                        return ($signature);
@@ -85,7 +103,7 @@ class diaspora {
        /**
         * @brief: Decodes incoming Diaspora message
         *
-        * @param array $importer from user table
+        * @param array $importer Array of the importer user
         * @param string $xml urldecoded Diaspora salmon
         *
         * @return array
@@ -93,7 +111,7 @@ class diaspora {
         * 'author' -> author diaspora handle
         * 'key' -> author public key (converted to pkcs#8)
         */
-       function decode($importer, $xml) {
+       public static function decode($importer, $xml) {
 
                $public = false;
                $basedom = parse_xml_string($xml);
@@ -126,16 +144,6 @@ class diaspora {
 
                        $decrypted = pkcs5_unpad($decrypted);
 
-                       /**
-                        * $decrypted now contains something like
-                        *
-                        *  <decrypted_header>
-                        *     <iv>8e+G2+ET8l5BPuW0sVTnQw==</iv>
-                        *     <aes_key>UvSMb4puPeB14STkcDWq+4QE302Edu15oaprAQSkLKU=</aes_key>
-                        *     <author_id>galaxor@diaspora.priateship.org</author_id>
-                        *  </decrypted_header>
-                        */
-
                        logger('decrypted: '.$decrypted, LOGGER_DEBUG);
                        $idom = parse_xml_string($decrypted,false);
 
@@ -234,7 +242,7 @@ class diaspora {
         *
         * @param array $msg The post that will be dispatched
         *
-        * @return bool Was the message accepted?
+        * @return int The message id of the generated message, "true" or "false" if there was an error
         */
        public static function dispatch_public($msg) {
 
@@ -246,7 +254,7 @@ class diaspora {
 
                // Use a dummy importer to import the data for the public copy
                $importer = array("uid" => 0, "page-flags" => PAGE_FREELOVE);
-               $item_id = self::dispatch($importer,$msg);
+               $message_id = self::dispatch($importer,$msg);
 
                // Now distribute it to the followers
                $r = q("SELECT `user`.* FROM `user` WHERE `user`.`uid` IN
@@ -263,7 +271,7 @@ class diaspora {
                } else
                        logger("No subscribers for ".$msg["author"]." ".print_r($msg, true));
 
-               return $item_id;
+               return $message_id;
        }
 
        /**
@@ -272,7 +280,7 @@ class diaspora {
         * @param array $importer Array of the importer user
         * @param array $msg The post that will be dispatched
         *
-        * @return bool Was the message accepted?
+        * @return int The message id of the generated message, "true" or "false" if there was an error
         */
        public static function dispatch($importer, $msg) {
 
@@ -296,6 +304,9 @@ class diaspora {
                        case "comment":
                                return self::receive_comment($importer, $sender, $fields, $msg["message"]);
 
+                       case "contact":
+                               return self::receive_contact_request($importer, $fields);
+
                        case "conversation":
                                return self::receive_conversation($importer, $msg, $fields);
 
@@ -317,9 +328,6 @@ class diaspora {
                        case "profile":
                                return self::receive_profile($importer, $fields);
 
-                       case "request":
-                               return self::receive_request($importer, $fields);
-
                        case "reshare":
                                return self::receive_reshare($importer, $fields, $msg["message"]);
 
@@ -352,8 +360,10 @@ class diaspora {
 
                $data = parse_xml_string($msg["message"], false);
 
-               if (!is_object($data))
+               if (!is_object($data)) {
+                       logger("No valid XML ".$msg["message"], LOGGER_DEBUG);
                        return false;
+               }
 
                $first_child = $data->getName();
 
@@ -375,6 +385,9 @@ class diaspora {
                if (in_array($type, array("signed_retraction", "relayable_retraction")))
                        $type = "retraction";
 
+               if ($type == "request")
+                       $type = "contact";
+
                $fields = new SimpleXMLElement("<".$type."/>");
 
                $signed_data = "";
@@ -411,11 +424,11 @@ class diaspora {
                                }
                        }
 
-                       if ($fieldname == "author_signature")
+                       if (($fieldname == "author_signature") AND ($entry != ""))
                                $author_signature = base64_decode($entry);
-                       elseif ($fieldname == "parent_author_signature")
+                       elseif (($fieldname == "parent_author_signature") AND ($entry != ""))
                                $parent_author_signature = base64_decode($entry);
-                       elseif ($fieldname != "target_author_signature") {
+                       elseif (!in_array($fieldname, array("author_signature", "parent_author_signature", "target_author_signature"))) {
                                if ($signed_data != "") {
                                        $signed_data .= ";";
                                        $signed_data_parent .= ";";
@@ -440,19 +453,27 @@ class diaspora {
                        return true;
 
                // No author_signature? This is a must, so we quit.
-               if (!isset($author_signature))
+               if (!isset($author_signature)) {
+                       logger("No author signature for type ".$type." - Message: ".$msg["message"], LOGGER_DEBUG);
                        return false;
+               }
 
                if (isset($parent_author_signature)) {
                        $key = self::key($msg["author"]);
 
-                       if (!rsa_verify($signed_data, $parent_author_signature, $key, "sha256"))
+                       if (!rsa_verify($signed_data, $parent_author_signature, $key, "sha256")) {
+                               logger("No valid parent author signature for author ".$msg["author"]. " in type ".$type." - signed data: ".$signed_data." - Message: ".$msg["message"]." - Signature ".$parent_author_signature, LOGGER_DEBUG);
                                return false;
+                       }
                }
 
                $key = self::key($fields->author);
 
-               return rsa_verify($signed_data, $author_signature, $key, "sha256");
+               if (!rsa_verify($signed_data, $author_signature, $key, "sha256")) {
+                       logger("No valid author signature for author ".$msg["author"]. " in type ".$type." - signed data: ".$signed_data." - Message: ".$msg["message"]." - Signature ".$author_signature, LOGGER_DEBUG);
+                       return false;
+               } else
+                       return true;
        }
 
        /**
@@ -575,22 +596,36 @@ class diaspora {
                return $r;
        }
 
-       public static function handle_from_contact($contact_id) {
+       /**
+        * @brief get a handle (user@domain.tld) from a given contact id or gcontact id
+        *
+        * @param int $contact_id The id in the contact table
+        * @param int $gcontact_id The id in the gcontact table
+        *
+        * @return string the handle
+        */
+       public static function handle_from_contact($contact_id, $gcontact_id = 0) {
                $handle = False;
 
-               logger("contact id is ".$contact_id, LOGGER_DEBUG);
+               logger("contact id is ".$contact_id." - gcontact id is ".$gcontact_id, LOGGER_DEBUG);
+
+               if ($gcontact_id != 0) {
+                       $r = q("SELECT `addr` FROM `gcontact` WHERE `id` = %d AND `addr` != ''",
+                               intval($gcontact_id));
+                       if ($r)
+                               return $r[0]["addr"];
+               }
 
                $r = q("SELECT `network`, `addr`, `self`, `url`, `nick` FROM `contact` WHERE `id` = %d",
-                      intval($contact_id)
-               );
-               if($r) {
+                       intval($contact_id));
+               if ($r) {
                        $contact = $r[0];
 
                        logger("contact 'self' = ".$contact['self']." 'url' = ".$contact['url'], LOGGER_DEBUG);
 
                        if($contact['addr'] != "")
                                $handle = $contact['addr'];
-                       elseif(($contact['network'] === NETWORK_DFRN) || ($contact['self'] == 1)) {
+                       else {
                                $baseurl_start = strpos($contact['url'],'://') + 3;
                                $baseurl_length = strpos($contact['url'],'/profile') - $baseurl_start; // allows installations in a subdirectory--not sure how Diaspora will handle
                                $baseurl = substr($contact['url'], $baseurl_start, $baseurl_length);
@@ -601,6 +636,14 @@ class diaspora {
                return $handle;
        }
 
+       /**
+        * @brief Get a contact id for a given handle
+        *
+        * @param int $uid The user id
+        * @param string $handle The handle in the format user@domain.tld
+        *
+        * @return The contact id
+        */
        private function contact_by_handle($uid, $handle) {
                $r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `addr` = '%s' LIMIT 1",
                        intval($uid),
@@ -623,6 +666,15 @@ class diaspora {
                return false;
        }
 
+       /**
+        * @brief Check if posting is allowed for this contact
+        *
+        * @param array $importer Array of the importer user
+        * @param array $contact The contact that is checked
+        * @param bool $is_comment Is the check for a comment?
+        *
+        * @return bool is the contact allowed to post?
+        */
        private function post_allow($importer, $contact, $is_comment = false) {
 
                // perhaps we were already sharing with this person. Now they're sharing with us.
@@ -653,6 +705,15 @@ class diaspora {
                return false;
        }
 
+       /**
+        * @brief Fetches the contact id for a handle and checks if posting is allowed
+        *
+        * @param array $importer Array of the importer user
+        * @param string $handle The checked handle in the format user@domain.tld
+        * @param bool $is_comment Is the check for a comment?
+        *
+        * @return array The contact data
+        */
        private function allowed_contact_by_handle($importer, $handle, $is_comment = false) {
                $contact = self::contact_by_handle($importer["uid"], $handle);
                if (!$contact) {
@@ -667,6 +728,14 @@ class diaspora {
                return $contact;
        }
 
+       /**
+        * @brief Does the message already exists on the system?
+        *
+        * @param int $uid The user id
+        * @param string $guid The guid of the message
+        *
+        * @return int|bool message id if the message already was stored into the system - or false.
+        */
        private function message_exists($uid, $guid) {
                $r = q("SELECT `id` FROM `item` WHERE `uid` = %d AND `guid` = '%s' LIMIT 1",
                        intval($uid),
@@ -675,12 +744,17 @@ class diaspora {
 
                if($r) {
                        logger("message ".$guid." already exists for user ".$uid);
-                       return true;
+                       return $r[0]["id"];
                }
 
                return false;
        }
 
+       /**
+        * @brief Checks for links to posts in a message
+        *
+        * @param array $item The item array
+        */
        private function fetch_guid($item) {
                preg_replace_callback("&\[url=/posts/([^\[\]]*)\](.*)\[\/url\]&Usi",
                        function ($match) use ($item){
@@ -688,11 +762,26 @@ class diaspora {
                        },$item["body"]);
        }
 
+       /**
+        * @brief sub function of "fetch_guid" which checks for links in messages
+        *
+        * @param array $match array containing a link that has to be checked for a message link
+        * @param array $item The item array
+        */
        private function fetch_guid_sub($match, $item) {
                if (!self::store_by_guid($match[1], $item["author-link"]))
                        self::store_by_guid($match[1], $item["owner-link"]);
        }
 
+       /**
+        * @brief Fetches an item with a given guid from a given server
+        *
+        * @param string $guid the message guid
+        * @param string $server The server address
+        * @param int $uid The user id of the user
+        *
+        * @return int the message id of the stored message or false
+        */
        private function store_by_guid($guid, $server, $uid = 0) {
                $serverparts = parse_url($server);
                $server = $serverparts["scheme"]."://".$serverparts["host"];
@@ -710,6 +799,18 @@ class diaspora {
                return self::dispatch_public($msg);
        }
 
+       /**
+        * @brief Fetches a message from a server
+        *
+        * @param string $guid message guid
+        * @param string $server The url of the server
+        * @param int $level Endless loop prevention
+        *
+        * @return array
+        *      'message' => The message XML
+        *      'author' => The author handle
+        *      'key' => The public key of the author
+        */
        private function message($guid, $server, $level = 0) {
 
                if ($level > 5)
@@ -753,6 +854,16 @@ class diaspora {
                return $msg;
        }
 
+       /**
+        * @brief Fetches the item record of a given guid
+        *
+        * @param int $uid The user id
+        * @param string $guid message guid
+        * @param string $author The handle of the item
+        * @param array $contact The contact of the item owner
+        *
+        * @return array the item record
+        */
        private function parent_item($uid, $guid, $author, $contact) {
                $r = q("SELECT `id`, `body`, `wall`, `uri`, `private`, `origin`,
                                `author-name`, `author-link`, `author-avatar`,
@@ -788,6 +899,17 @@ class diaspora {
                }
        }
 
+       /**
+        * @brief returns contact details
+        *
+        * @param array $contact The default contact if the person isn't found
+        * @param array $person The record of the person
+        * @param int $uid The user id
+        *
+        * @return array
+        *      'cid' => contact id
+        *      'network' => network type
+        */
        private function author_contact_by_url($contact, $person, $uid) {
 
                $r = q("SELECT `id`, `network` FROM `contact` WHERE `nurl` = '%s' AND `uid` = %d LIMIT 1",
@@ -803,10 +925,25 @@ class diaspora {
                return (array("cid" => $cid, "network" => $network));
        }
 
+       /**
+        * @brief Is the profile a hubzilla profile?
+        *
+        * @param string $url The profile link
+        *
+        * @return bool is it a hubzilla server?
+        */
        public static function is_redmatrix($url) {
                return(strstr($url, "/channel/"));
        }
 
+       /**
+        * @brief Generate a post link with a given handle and message guid
+        *
+        * @param string $addr The user handle
+        * @param string $guid message guid
+        *
+        * @return string the post link
+        */
        private function plink($addr, $guid) {
                $r = q("SELECT `url`, `nick`, `network` FROM `fcontact` WHERE `addr`='%s' LIMIT 1", dbesc($addr));
 
@@ -829,7 +966,18 @@ class diaspora {
                return "https://".substr($addr,strpos($addr,"@")+1)."/posts/".$guid;
        }
 
+       /**
+        * @brief Processes an account deletion
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool Success
+        */
        private function receive_account_deletion($importer, $data) {
+
+               /// @todo Account deletion should remove the contact from the global contacts as well
+
                $author = notags(unxmlify($data->author));
 
                $contact = self::contact_by_handle($importer["uid"], $author);
@@ -843,6 +991,33 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Fetch the uri from our database if we already have this item (maybe from ourselves)
+        *
+        * @param string $author Author handle
+        * @param string $guid Message guid
+        *
+        * @return string The constructed uri or the one from our database
+        */
+       private function get_uri_from_guid($author, $guid) {
+
+               $r = q("SELECT `uri` FROM `item` WHERE `guid` = '%s' LIMIT 1", dbesc($guid));
+               if ($r)
+                       return $r[0]["uri"];
+               else
+                       return $author.":".$guid;
+       }
+
+       /**
+        * @brief Processes an incoming comment
+        *
+        * @param array $importer Array of the importer user
+        * @param string $sender The sender of the message
+        * @param object $data The message object
+        * @param string $xml The original XML of the message
+        *
+        * @return int The message id of the generated comment or "false" if there was an error
+        */
        private function receive_comment($importer, $sender, $data, $xml) {
                $guid = notags(unxmlify($data->guid));
                $parent_guid = notags(unxmlify($data->parent_guid));
@@ -853,8 +1028,9 @@ class diaspora {
                if (!$contact)
                        return false;
 
-               if (self::message_exists($importer["uid"], $guid))
-                       return false;
+               $message_id = self::message_exists($importer["uid"], $guid);
+               if ($message_id)
+                       return $message_id;
 
                $parent_item = self::parent_item($importer["uid"], $parent_guid, $author, $contact);
                if (!$parent_item)
@@ -884,7 +1060,7 @@ class diaspora {
                $datarray["owner-avatar"] = ((x($contact,"thumb")) ? $contact["thumb"] : $contact["photo"]);
 
                $datarray["guid"] = $guid;
-               $datarray["uri"] = $author.":".$guid;
+               $datarray["uri"] = self::get_uri_from_guid($author, $guid);
 
                $datarray["type"] = "remote-comment";
                $datarray["verb"] = ACTIVITY_POST;
@@ -920,6 +1096,18 @@ class diaspora {
                return $message_id;
        }
 
+       /**
+        * @brief processes and stores private messages
+        *
+        * @param array $importer Array of the importer user
+        * @param array $contact The contact of the message
+        * @param object $data The message object
+        * @param array $msg Array of the processed message, author handle and key
+        * @param object $mesg The private message
+        * @param array $conversation The conversation record to which this message belongs
+        *
+        * @return bool "true" if it was successful
+        */
        private function receive_conversation_message($importer, $contact, $data, $msg, $mesg, $conversation) {
                $guid = notags(unxmlify($data->guid));
                $subject = notags(unxmlify($data->subject));
@@ -1034,8 +1222,18 @@ class diaspora {
                        "verb" => ACTIVITY_POST,
                        "otype" => "mail"
                ));
+               return true;
        }
 
+       /**
+        * @brief Processes new private messages (answers to private messages are processed elsewhere)
+        *
+        * @param array $importer Array of the importer user
+        * @param array $msg Array of the processed message, author handle and key
+        * @param object $data The message object
+        *
+        * @return bool Success
+        */
        private function receive_conversation($importer, $msg, $data) {
                $guid = notags(unxmlify($data->guid));
                $subject = notags(unxmlify($data->subject));
@@ -1093,6 +1291,15 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Creates the body for a "like" message
+        *
+        * @param array $contact The contact that send us the "like"
+        * @param array $parent_item The item array of the parent item
+        * @param string $guid message guid
+        *
+        * @return string the body
+        */
        private function construct_like_body($contact, $parent_item, $guid) {
                $bodyverb = t('%1$s likes %2$s\'s %3$s');
 
@@ -1103,6 +1310,14 @@ class diaspora {
                return sprintf($bodyverb, $ulink, $alink, $plink);
        }
 
+       /**
+        * @brief Creates a XML object for a "like"
+        *
+        * @param array $importer Array of the importer user
+        * @param array $parent_item The item array of the parent item
+        *
+        * @return string The XML
+        */
        private function construct_like_object($importer, $parent_item) {
                $objtype = ACTIVITY_OBJ_NOTE;
                $link = '<link rel="alternate" type="text/html" href="'.App::get_baseurl()."/display/".$importer["nickname"]."/".$parent_item["id"].'" />';
@@ -1118,6 +1333,15 @@ class diaspora {
                return xml::from_array($xmldata, $xml, true);
        }
 
+       /**
+        * @brief Processes "like" messages
+        *
+        * @param array $importer Array of the importer user
+        * @param string $sender The sender of the message
+        * @param object $data The message object
+        *
+        * @return int The message id of the generated like or "false" if there was an error
+        */
        private function receive_like($importer, $sender, $data) {
                $positive = notags(unxmlify($data->positive));
                $guid = notags(unxmlify($data->guid));
@@ -1134,8 +1358,9 @@ class diaspora {
                if (!$contact)
                        return false;
 
-               if (self::message_exists($importer["uid"], $guid))
-                       return false;
+               $message_id = self::message_exists($importer["uid"], $guid);
+               if ($message_id)
+                       return $message_id;
 
                $parent_item = self::parent_item($importer["uid"], $parent_guid, $author, $contact);
                if (!$parent_item)
@@ -1152,7 +1377,7 @@ class diaspora {
 
                // "positive" = "false" would be a Dislike - wich isn't currently supported by Diaspora
                // We would accept this anyhow.
-               if ($positive === "true")
+               if ($positive == "true")
                        $verb = ACTIVITY_LIKE;
                else
                        $verb = ACTIVITY_DISLIKE;
@@ -1172,7 +1397,7 @@ class diaspora {
                $datarray["owner-avatar"] = ((x($contact,"thumb")) ? $contact["thumb"] : $contact["photo"]);
 
                $datarray["guid"] = $guid;
-               $datarray["uri"] = $author.":".$guid;
+               $datarray["uri"] = self::get_uri_from_guid($author, $guid);
 
                $datarray["type"] = "activity";
                $datarray["verb"] = $verb;
@@ -1206,6 +1431,14 @@ class diaspora {
                return $message_id;
        }
 
+       /**
+        * @brief Processes private messages
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool Success?
+        */
        private function receive_message($importer, $data) {
                $guid = notags(unxmlify($data->guid));
                $parent_guid = notags(unxmlify($data->parent_guid));
@@ -1277,27 +1510,59 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Processes participations - unsupported by now
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool always true
+        */
        private function receive_participation($importer, $data) {
                // I'm not sure if we can fully support this message type
                return true;
        }
 
+       /**
+        * @brief Processes photos - unneeded
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool always true
+        */
        private function receive_photo($importer, $data) {
                // There doesn't seem to be a reason for this function, since the photo data is transmitted in the status message as well
                return true;
        }
 
+       /**
+        * @brief Processes poll participations - unssupported
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool always true
+        */
        private function receive_poll_participation($importer, $data) {
                // We don't support polls by now
                return true;
        }
 
+       /**
+        * @brief Processes incoming profile updates
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool Success
+        */
        private function receive_profile($importer, $data) {
                $author = notags(unxmlify($data->author));
 
                $contact = self::contact_by_handle($importer["uid"], $author);
                if (!$contact)
-                       return;
+                       return false;
 
                $name = unxmlify($data->first_name).((strlen($data->last_name)) ? " ".unxmlify($data->last_name) : "");
                $image_url = unxmlify($data->image_url);
@@ -1377,6 +1642,12 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Processes incoming friend requests
+        *
+        * @param array $importer Array of the importer user
+        * @param array $contact The contact that send the request
+        */
        private function receive_request_make_friend($importer, $contact) {
 
                $a = get_app();
@@ -1423,11 +1694,8 @@ class diaspora {
                                $BPhoto = "[url=".$contact["url"]."][img]".$contact["thumb"]."[/img][/url]";
                                $arr["body"] = sprintf(t("%1$s is now friends with %2$s"), $A, $B)."\n\n\n".$Bphoto;
 
-                               $arr["object"] = "<object><type>".ACTIVITY_OBJ_PERSON."</type><title>".$contact["name"]."</title>"
-                                       ."<id>".$contact["url"]."/".$contact["name"]."</id>";
-                               $arr["object"] .= "<link>".xmlify('<link rel="alternate" type="text/html" href="'.$contact["url"].'" />'."\n");
-                               $arr["object"] .= xmlify('<link rel="photo" type="image/jpeg" href="'.$contact["thumb"].'" />'."\n");
-                               $arr["object"] .= "</link></object>\n";
+                               $arr["object"] = self::construct_new_friend_object($contact);
+
                                $arr["last-child"] = 1;
 
                                $arr["allow_cid"] = $user[0]["allow_cid"];
@@ -1438,28 +1706,75 @@ class diaspora {
                                $i = item_store($arr);
                                if($i)
                                        proc_run("php", "include/notifier.php", "activity", $i);
-
                        }
-
                }
        }
 
-       private function receive_request($importer, $data) {
+       /**
+        * @brief Creates a XML object for a "new friend" message
+        *
+        * @param array $contact Array of the contact
+        *
+        * @return string The XML
+        */
+        private function construct_new_friend_object($contact) {
+                $objtype = ACTIVITY_OBJ_PERSON;
+                $link = '<link rel="alternate" type="text/html" href="'.$contact["url"].'" />'."\n".
+                        '<link rel="photo" type="image/jpeg" href="'.$contact["thumb"].'" />'."\n";
+
+                $xmldata = array("object" => array("type" => $objtype,
+                                                "title" => $contact["name"],
+                                                "id" => $contact["url"]."/".$contact["name"],
+                                                "link" => $link));
+
+                return xml::from_array($xmldata, $xml, true);
+        }
+
+       /**
+        * @brief Processes incoming sharing notification
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        *
+        * @return bool Success
+        */
+       private function receive_contact_request($importer, $data) {
                $author = unxmlify($data->author);
                $recipient = unxmlify($data->recipient);
 
                if (!$author || !$recipient)
-                       return;
+                       return false;
 
-               $contact = self::contact_by_handle($importer["uid"],$author);
+               // the current protocol version doesn't know these fields
+               // That means that we will assume their existance
+               if (isset($data->following))
+                       $following = (unxmlify($data->following) == "true");
+               else
+                       $following = true;
 
-               if($contact) {
+               if (isset($data->sharing))
+                       $sharing = (unxmlify($data->sharing) == "true");
+               else
+                       $sharing = true;
 
-                       // perhaps we were already sharing with this person. Now they're sharing with us.
-                       // That makes us friends.
+               $contact = self::contact_by_handle($importer["uid"],$author);
 
-                       self::receive_request_make_friend($importer, $contact);
-                       return true;
+               // perhaps we were already sharing with this person. Now they're sharing with us.
+               // That makes us friends.
+               if ($contact) {
+                       if ($following AND $sharing) {
+                               self::receive_request_make_friend($importer, $contact);
+                               return true;
+                       } else /// @todo Handle all possible variations of adding and retracting of permissions
+                               return false;
+               }
+
+               if (!$following AND $sharing AND in_array($importer["page-flags"], array(PAGE_SOAPBOX, PAGE_NORMAL))) {
+                       logger("Author ".$author." wants to share with us - but doesn't want to listen. Request is ignored.", LOGGER_DEBUG);
+                       return false;
+               } elseif (!$following AND !$sharing) {
+                       logger("Author ".$author." doesn't want anything - and we don't know the author. Request is ignored.", LOGGER_DEBUG);
+                       return false;
                }
 
                $ret = self::person_by_handle($author);
@@ -1499,12 +1814,12 @@ class diaspora {
                        return;
                }
 
-               $g = q("SELECT `def_gid` FROM `user` WHERE `uid` = %d LIMIT 1",
-                       intval($importer["uid"])
-               );
+               $def_gid = get_default_group($importer['uid'], $ret["network"]);
 
-               if($g && intval($g[0]["def_gid"]))
-                       group_add_member($importer["uid"], "", $contact_record["id"], $g[0]["def_gid"]);
+               if(intval($def_gid))
+                       group_add_member($importer["uid"], "", $contact_record["id"], $def_gid);
+
+               update_contact_avatar($ret["photo"], $importer['uid'], $contact_record["id"], true);
 
                if($importer["page-flags"] == PAGE_NORMAL) {
 
@@ -1530,8 +1845,10 @@ class diaspora {
                        // but if our page-type is PAGE_COMMUNITY or PAGE_SOAPBOX
                        // we are going to change the relationship and make them a follower.
 
-                       if($importer["page-flags"] == PAGE_FREELOVE)
+                       if (($importer["page-flags"] == PAGE_FREELOVE) AND $sharing AND $following)
                                $new_relation = CONTACT_IS_FRIEND;
+                       elseif (($importer["page-flags"] == PAGE_FREELOVE) AND $sharing)
+                               $new_relation = CONTACT_IS_SHARING;
                        else
                                $new_relation = CONTACT_IS_FOLLOWER;
 
@@ -1557,6 +1874,15 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Fetches a message with a given guid
+        *
+        * @param string $guid message guid
+        * @param string $orig_author handle of the original post
+        * @param string $author handle of the sharer
+        *
+        * @return array The fetched item
+        */
        private function original_item($guid, $orig_author, $author) {
 
                // Do we already have this item?
@@ -1569,10 +1895,18 @@ class diaspora {
                        logger("reshared message ".$guid." already exists on system.");
 
                        // Maybe it is already a reshared item?
-                       // Then refetch the content, since there can be many side effects with reshared posts from other networks or reshares from reshares
-                       if (self::is_reshare($r[0]["body"]))
+                       // Then refetch the content, if it is a reshare from a reshare.
+                       // If it is a reshared post from another network then reformat to avoid display problems with two share elements
+                       if (self::is_reshare($r[0]["body"], true))
                                $r = array();
-                       else
+                       elseif (self::is_reshare($r[0]["body"], false)) {
+                               $r[0]["body"] = diaspora2bb(bb2diaspora($r[0]["body"]));
+
+                               // Add OEmbed and other information to the body
+                               $r[0]["body"] = add_page_info_to_body($r[0]["body"], false, true);
+
+                               return $r[0];
+                       } else
                                return $r[0];
                }
 
@@ -1605,14 +1939,28 @@ class diaspora {
                                        FROM `item` WHERE `id` = %d AND `visible` AND NOT `deleted` AND `body` != '' LIMIT 1",
                                        intval($item_id));
 
-                               if ($r)
+                               if ($r) {
+                                       // If it is a reshared post from another network then reformat to avoid display problems with two share elements
+                                       if (self::is_reshare($r[0]["body"], false))
+                                               $r[0]["body"] = diaspora2bb(bb2diaspora($r[0]["body"]));
+
                                        return $r[0];
+                               }
 
                        }
                }
                return false;
        }
 
+       /**
+        * @brief Processes a reshare message
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        * @param string $xml The original XML of the message
+        *
+        * @return int the message id
+        */
        private function receive_reshare($importer, $data, $xml) {
                $root_author = notags(unxmlify($data->root_author));
                $root_guid = notags(unxmlify($data->root_guid));
@@ -1625,8 +1973,9 @@ class diaspora {
                if (!$contact)
                        return false;
 
-               if (self::message_exists($importer["uid"], $guid))
-                       return false;
+               $message_id = self::message_exists($importer["uid"], $guid);
+               if ($message_id)
+                       return $message_id;
 
                $original_item = self::original_item($root_guid, $root_author, $author);
                if (!$original_item)
@@ -1649,7 +1998,7 @@ class diaspora {
                $datarray["owner-avatar"] = $datarray["author-avatar"];
 
                $datarray["guid"] = $guid;
-               $datarray["uri"] = $datarray["parent-uri"] = $author.":".$guid;
+               $datarray["uri"] = $datarray["parent-uri"] = self::get_uri_from_guid($author, $guid);
 
                $datarray["verb"] = ACTIVITY_POST;
                $datarray["gravity"] = GRAVITY_PARENT;
@@ -1678,6 +2027,15 @@ class diaspora {
                return $message_id;
        }
 
+       /**
+        * @brief Processes retractions
+        *
+        * @param array $importer Array of the importer user
+        * @param array $contact The contact of the item owner
+        * @param object $data The message object
+        *
+        * @return bool success
+        */
        private function item_retraction($importer, $contact, $data) {
                $target_type = notags(unxmlify($data->target_type));
                $target_guid = notags(unxmlify($data->target_guid));
@@ -1724,21 +2082,22 @@ class diaspora {
 
                // Now check if the retraction needs to be relayed by us
                if($p[0]["origin"]) {
-
-                       // Formerly we stored the signed text, the signature and the author in different fields.
-                       // We now store the raw data so that we are more flexible.
-                       q("INSERT INTO `sign` (`retract_iid`,`signed_text`) VALUES (%d,'%s')",
-                               intval($r[0]["id"]),
-                               dbesc(json_encode($data))
-                       );
-                       $s = q("select * from sign where retract_iid = %d", intval($r[0]["id"]));
-                       logger("Stored signatur for item ".$r[0]["id"]." - ".print_r($s, true), LOGGER_DEBUG);
-
                        // notify others
                        proc_run("php", "include/notifier.php", "drop", $r[0]["id"]);
                }
+
+               return true;
        }
 
+       /**
+        * @brief Receives retraction messages
+        *
+        * @param array $importer Array of the importer user
+        * @param string $sender The sender of the message
+        * @param object $data The message object
+        *
+        * @return bool Success
+        */
        private function receive_retraction($importer, $sender, $data) {
                $target_type = notags(unxmlify($data->target_type));
 
@@ -1758,10 +2117,11 @@ class diaspora {
                        case "StatusMessage":
                                return self::item_retraction($importer, $contact, $data);;
 
+                       case "Contact":
                        case "Person":
                                /// @todo What should we do with an "unshare"?
                                // Removing the contact isn't correct since we still can read the public items
-                               //contact_remove($contact["id"]);
+                               contact_remove($contact["id"]);
                                return true;
 
                        default:
@@ -1771,6 +2131,15 @@ class diaspora {
                return true;
        }
 
+       /**
+        * @brief Receives status messages
+        *
+        * @param array $importer Array of the importer user
+        * @param object $data The message object
+        * @param string $xml The original XML of the message
+        *
+        * @return int The message id of the newly created item
+        */
        private function receive_status_message($importer, $data, $xml) {
 
                $raw_message = unxmlify($data->raw_message);
@@ -1790,8 +2159,9 @@ class diaspora {
                if (!$contact)
                        return false;
 
-               if (self::message_exists($importer["uid"], $guid))
-                       return false;
+               $message_id = self::message_exists($importer["uid"], $guid);
+               if ($message_id)
+                       return $message_id;
 
                $address = array();
                if ($data->location)
@@ -1802,6 +2172,7 @@ class diaspora {
 
                $datarray = array();
 
+               // Attach embedded pictures to the body
                if ($data->photo) {
                        foreach ($data->photo AS $photo)
                                $body = "[img]".unxmlify($photo->remote_photo_path).
@@ -1829,7 +2200,7 @@ class diaspora {
                $datarray["owner-avatar"] = $datarray["author-avatar"];
 
                $datarray["guid"] = $guid;
-               $datarray["uri"] = $datarray["parent-uri"] = $author.":".$guid;
+               $datarray["uri"] = $datarray["parent-uri"] = self::get_uri_from_guid($author, $guid);
 
                $datarray["verb"] = ACTIVITY_POST;
                $datarray["gravity"] = GRAVITY_PARENT;
@@ -1860,19 +2231,76 @@ class diaspora {
                return $message_id;
        }
 
-       /******************************************************************************************
+       /* ************************************************************************************** *
         * Here are all the functions that are needed to transmit data with the Diaspora protocol *
-        ******************************************************************************************/
+        * ************************************************************************************** */
 
-       private function my_handle($me) {
+       /**
+        * @brief returnes the handle of a contact
+        *
+        * @param array $me contact array
+        *
+        * @return string the handle in the format user@domain.tld
+        */
+       private function my_handle($contact) {
                if ($contact["addr"] != "")
                        return $contact["addr"];
 
                // Normally we should have a filled "addr" field - but in the past this wasn't the case
                // So - just in case - we build the the address here.
-               return $me["nickname"]."@".substr(App::get_baseurl(), strpos(App::get_baseurl(),"://") + 3);
+               if ($contact["nickname"] != "")
+                       $nick = $contact["nickname"];
+               else
+                       $nick = $contact["nick"];
+
+               return $nick."@".substr(App::get_baseurl(), strpos(App::get_baseurl(),"://") + 3);
+       }
+
+       /**
+        * @brief Creates the envelope for the "fetch" endpoint
+        *
+        * @param string $msg The message that is to be transmitted
+        * @param array $user The record of the sender
+        *
+        * @return string The envelope
+        */
+
+       function build_magic_envelope($msg, $user) {
+
+               $b64url_data = base64url_encode($msg);
+               $data = str_replace(array("\n", "\r", " ", "\t"), array("", "", "", ""), $b64url_data);
+
+               $key_id = base64url_encode(diaspora::my_handle($user));
+               $type = "application/xml";
+               $encoding = "base64url";
+               $alg = "RSA-SHA256";
+               $signable_data = $data.".".base64url_encode($type).".".base64url_encode($encoding).".".base64url_encode($alg);
+               $signature = rsa_sign($signable_data, $user["prvkey"]);
+               $sig = base64url_encode($signature);
+
+               $xmldata = array("me:env" => array("me:data" => $data,
+                                                       "@attributes" => array("type" => $type),
+                                                       "me:encoding" => $encoding,
+                                                       "me:alg" => $alg,
+                                                       "me:sig" => $sig,
+                                                       "@attributes2" => array("key_id" => $key_id)));
+
+               $namespaces = array("me" => "http://salmon-protocol.org/ns/magic-env");
+
+               return xml::from_array($xmldata, $xml, false, $namespaces);
        }
 
+       /**
+        * @brief Creates the envelope for a public message
+        *
+        * @param string $msg The message that is to be transmitted
+        * @param array $user The record of the sender
+        * @param array $contact Target of the communication
+        * @param string $prvkey The private key of the sender
+        * @param string $pubkey The public key of the receiver
+        *
+        * @return string The envelope
+        */
        private function build_public_message($msg, $user, $contact, $prvkey, $pubkey) {
 
                logger("Message: ".$msg, LOGGER_DATA);
@@ -1893,11 +2321,11 @@ class diaspora {
                $sig = base64url_encode($signature);
 
                $xmldata = array("diaspora" => array("header" => array("author_id" => $handle),
-                                               "me:env" => array("me:encoding" => "base64url",
-                                                               "me:alg" => "RSA-SHA256",
-                                                               "me:data" => $data,
-                                                               "@attributes" => array("type" => "application/xml"),
-                                                               "me:sig" => $sig)));
+                                                       "me:env" => array("me:encoding" => $encoding,
+                                                       "me:alg" => $alg,
+                                                       "me:data" => $data,
+                                                       "@attributes" => array("type" => $type),
+                                                       "me:sig" => $sig)));
 
                $namespaces = array("" => "https://joindiaspora.com/protocol",
                                "me" => "http://salmon-protocol.org/ns/magic-env");
@@ -1908,6 +2336,17 @@ class diaspora {
                return $magic_env;
        }
 
+       /**
+        * @brief Creates the envelope for a private message
+        *
+        * @param string $msg The message that is to be transmitted
+        * @param array $user The record of the sender
+        * @param array $contact Target of the communication
+        * @param string $prvkey The private key of the sender
+        * @param string $pubkey The public key of the receiver
+        *
+        * @return string The envelope
+        */
        private function build_private_message($msg, $user, $contact, $prvkey, $pubkey) {
 
                logger("Message: ".$msg, LOGGER_DATA);
@@ -1972,10 +2411,10 @@ class diaspora {
                $cipher_json = base64_encode($encrypted_header_json_object);
 
                $xmldata = array("diaspora" => array("encrypted_header" => $cipher_json,
-                                               "me:env" => array("me:encoding" => "base64url",
-                                                               "me:alg" => "RSA-SHA256",
+                                               "me:env" => array("me:encoding" => $encoding,
+                                                               "me:alg" => $alg,
                                                                "me:data" => $data,
-                                                               "@attributes" => array("type" => "application/xml"),
+                                                               "@attributes" => array("type" => $type),
                                                                "me:sig" => $sig)));
 
                $namespaces = array("" => "https://joindiaspora.com/protocol",
@@ -1987,6 +2426,18 @@ class diaspora {
                return $magic_env;
        }
 
+       /**
+        * @brief Create the envelope for a message
+        *
+        * @param string $msg The message that is to be transmitted
+        * @param array $user The record of the sender
+        * @param array $contact Target of the communication
+        * @param string $prvkey The private key of the sender
+        * @param string $pubkey The public key of the receiver
+        * @param bool $public Is the message public?
+        *
+        * @return string The message that will be transmitted to other servers
+        */
        private function build_message($msg, $user, $contact, $prvkey, $pubkey, $public = false) {
 
                if ($public)
@@ -1999,6 +2450,14 @@ class diaspora {
                return $slap;
        }
 
+       /**
+        * @brief Creates a signature for a message
+        *
+        * @param array $owner the array of the owner of the message
+        * @param array $message The message that is to be signed
+        *
+        * @return string The signature
+        */
        private function signature($owner, $message) {
                $sigmsg = $message;
                unset($sigmsg["author_signature"]);
@@ -2009,6 +2468,18 @@ class diaspora {
                return base64_encode(rsa_sign($signed_text, $owner["uprvkey"], "sha256"));
        }
 
+       /**
+        * @brief Transmit a message to a target server
+        *
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param string $slap The message that is to be transmitted
+        * @param bool $public_batch Is it a public post?
+        * @param bool $queue_run Is the transmission called from the queue?
+        * @param string $guid message guid
+        *
+        * @return int Result of the transmission
+        */
        public static function transmit($owner, $contact, $slap, $public_batch, $queue_run=false, $guid = "") {
 
                $a = get_app();
@@ -2061,11 +2532,36 @@ class diaspora {
        }
 
 
-       private function build_and_transmit($owner, $contact, $type, $message, $public_batch = false, $guid = "", $spool = false) {
+       /**
+        * @brief Build the post xml
+        *
+        * @param string $type The message type
+        * @param array $message The message data
+        *
+        * @return string The post XML
+        */
+       public static function build_post_xml($type, $message) {
 
                $data = array("XML" => array("post" => array($type => $message)));
+               return xml::from_array($data, $xml);
+       }
 
-               $msg = xml::from_array($data, $xml);
+       /**
+        * @brief Builds and transmit messages
+        *
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param string $type The message type
+        * @param array $message The message data
+        * @param bool $public_batch Is it a public post?
+        * @param string $guid message guid
+        * @param bool $spool Should the transmission be spooled or transmitted?
+        *
+        * @return int Result of the transmission
+        */
+       private function build_and_transmit($owner, $contact, $type, $message, $public_batch = false, $guid = "", $spool = false) {
+
+               $msg = self::build_post_xml($type, $message);
 
                logger('message: '.$msg, LOGGER_DATA);
                logger('send guid '.$guid, LOGGER_DEBUG);
@@ -2083,6 +2579,14 @@ class diaspora {
                return $return_code;
        }
 
+       /**
+        * @brief Sends a "share" message
+        *
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        *
+        * @return int The result of the transmission
+        */
        public static function send_share($owner,$contact) {
 
                $message = array("sender_handle" => self::my_handle($owner),
@@ -2091,6 +2595,14 @@ class diaspora {
                return self::build_and_transmit($owner, $contact, "request", $message);
        }
 
+       /**
+        * @brief sends an "unshare"
+        *
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        *
+        * @return int The result of the transmission
+        */
        public static function send_unshare($owner,$contact) {
 
                $message = array("post_guid" => $owner["guid"],
@@ -2100,12 +2612,20 @@ class diaspora {
                return self::build_and_transmit($owner, $contact, "retraction", $message);
        }
 
-       public static function is_reshare($body) {
+       /**
+        * @brief Checks a message body if it is a reshare
+        *
+        * @param string $body The message body that is to be check
+        * @param bool $complete Should it be a complete check or a simple check?
+        *
+        * @return array|bool Reshare details or "false" if no reshare
+        */
+       public static function is_reshare($body, $complete = true) {
                $body = trim($body);
 
                // Skip if it isn't a pure repeated messages
                // Does it start with a share?
-               if (strpos($body, "[share") > 0)
+               if ((strpos($body, "[share") > 0) AND $complete)
                        return(false);
 
                // Does it end with a share?
@@ -2117,6 +2637,10 @@ class diaspora {
                if ($body == $attributes)
                        return(false);
 
+               // If we don't do the complete check we quit here
+               if (!$complete)
+                       return true;
+
                $guid = "";
                preg_match("/guid='(.*?)'/ism", $attributes, $matches);
                if ($matches[1] != "")
@@ -2162,12 +2686,23 @@ class diaspora {
                        $link = $matches[1];
 
                $ret["root_guid"] = preg_replace("=https?://(.*)/posts/(.*)=ism", "$2", $link);
-               if (($ret["root_guid"] == $link) OR ($ret["root_guid"] == ""))
+               if (($ret["root_guid"] == $link) OR (trim($ret["root_guid"]) == ""))
                        return(false);
+
                return($ret);
        }
 
-       public static function send_status($item, $owner, $contact, $public_batch = false) {
+       /**
+        * @brief Create a post (status message or reshare)
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        *
+        * @return array
+        * 'type' -> Message type ("status_message" or "reshare")
+        * 'message' -> Array of XML elements of the status
+        */
+       public static function build_status($item, $owner) {
 
                $myaddr = self::my_handle($owner);
 
@@ -2230,14 +2765,36 @@ class diaspora {
 
                        $type = "status_message";
                }
+               return array("type" => $type, "message" => $message);
+       }
 
-               return self::build_and_transmit($owner, $contact, $type, $message, $public_batch, $item["guid"]);
+       /**
+        * @brief Sends a post
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param bool $public_batch Is it a public post?
+        *
+        * @return int The result of the transmission
+        */
+       public static function send_status($item, $owner, $contact, $public_batch = false) {
+
+               $status = diaspora::build_status($item, $owner);
+
+               return self::build_and_transmit($owner, $contact, $status["type"], $status["message"], $public_batch, $item["guid"]);
        }
 
+       /**
+        * @brief Creates a "like" object
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        *
+        * @return array The data for a "like"
+        */
        private function construct_like($item, $owner) {
 
-               $myaddr = self::my_handle($owner);
-
                $p = q("SELECT `guid`, `uri`, `parent-uri` FROM `item` WHERE `uri` = '%s' LIMIT 1",
                        dbesc($item["thr-parent"]));
                if(!$p)
@@ -2252,14 +2809,20 @@ class diaspora {
                                "guid" => $item["guid"],
                                "target_type" => $target_type,
                                "parent_guid" => $parent["guid"],
-                               "author_signature" => $authorsig,
-                               "diaspora_handle" => $myaddr));
+                               "author_signature" => "",
+                               "diaspora_handle" => self::my_handle($owner)));
        }
 
+       /**
+        * @brief Creates the object for a comment
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        *
+        * @return array The data for a comment
+        */
        private function construct_comment($item, $owner) {
 
-               $myaddr = self::my_handle($owner);
-
                $p = q("SELECT `guid` FROM `item` WHERE `parent` = %d AND `id` = %d LIMIT 1",
                        intval($item["parent"]),
                        intval($item["parent"])
@@ -2276,9 +2839,19 @@ class diaspora {
                                "parent_guid" => $parent["guid"],
                                "author_signature" => "",
                                "text" => $text,
-                               "diaspora_handle" => $myaddr));
+                               "diaspora_handle" => self::my_handle($owner)));
        }
 
+       /**
+        * @brief Send a like or a comment
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param bool $public_batch Is it a public post?
+        *
+        * @return int The result of the transmission
+        */
        public static function send_followup($item,$owner,$contact,$public_batch = false) {
 
                if($item['verb'] === ACTIVITY_LIKE) {
@@ -2297,7 +2870,15 @@ class diaspora {
                return self::build_and_transmit($owner, $contact, $type, $message, $public_batch, $item["guid"]);
        }
 
-       private function message_from_signatur($item, $signature) {
+       /**
+        * @brief Creates a message from a signature record entry
+        *
+        * @param array $item The item that will be exported
+        * @param array $signature The entry of the "sign" record
+        *
+        * @return string The message
+        */
+       private function message_from_signature($item, $signature) {
 
                // Split the signed text
                $signed_parts = explode(";", $signature['signed_text']);
@@ -2339,28 +2920,34 @@ class diaspora {
                return $message;
        }
 
+       /**
+        * @brief Relays messages (like, comment, retraction) to other servers if we are the thread owner
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param bool $public_batch Is it a public post?
+        *
+        * @return int The result of the transmission
+        */
        public static function send_relay($item, $owner, $contact, $public_batch = false) {
 
-               if ($item["deleted"]) {
-                       $sql_sign_id = "retract_iid";
-                       $type = "relayable_retraction";
-               } elseif ($item['verb'] === ACTIVITY_LIKE) {
-                       $sql_sign_id = "iid";
+               if ($item["deleted"])
+                       return self::send_retraction($item, $owner, $contact, $public_batch, true);
+               elseif ($item['verb'] === ACTIVITY_LIKE)
                        $type = "like";
-               } else {
-                       $sql_sign_id = "iid";
+               else
                        $type = "comment";
-               }
 
                logger("Got relayable data ".$type." for item ".$item["guid"]." (".$item["id"].")", LOGGER_DEBUG);
 
                // fetch the original signature
 
-               $r = q("SELECT `signed_text`, `signature`, `signer` FROM `sign` WHERE `".$sql_sign_id."` = %d LIMIT 1",
+               $r = q("SELECT `signed_text`, `signature`, `signer` FROM `sign` WHERE `iid` = %d LIMIT 1",
                        intval($item["id"]));
 
                if (!$r) {
-                       logger("Couldn't fetch signatur for contact ".$contact["addr"]." at item ".$item["guid"]." (".$item["id"].")", LOGGER_DEBUG);
+                       logger("Couldn't fetch signatur for item ".$item["guid"]." (".$item["id"].")", LOGGER_DEBUG);
                        return false;
                }
 
@@ -2369,37 +2956,47 @@ class diaspora {
                // Old way - is used by the internal Friendica functions
                /// @todo Change all signatur storing functions to the new format
                if ($signature['signed_text'] AND $signature['signature'] AND $signature['signer'])
-                       $message = self::message_from_signatur($item, $signature);
+                       $message = self::message_from_signature($item, $signature);
                else {// New way
                        $msg = json_decode($signature['signed_text'], true);
 
                        $message = array();
-                       foreach ($msg AS $field => $data) {
-                               if (!$item["deleted"]) {
-                                       if ($field == "author")
-                                               $field = "diaspora_handle";
-                                       if ($field == "parent_type")
-                                               $field = "target_type";
-                               }
+                       if (is_array($msg)) {
+                               foreach ($msg AS $field => $data) {
+                                       if (!$item["deleted"]) {
+                                               if ($field == "author")
+                                                       $field = "diaspora_handle";
+                                               if ($field == "parent_type")
+                                                       $field = "target_type";
+                                       }
 
-                               $message[$field] = $data;
-                       }
+                                       $message[$field] = $data;
+                               }
+                       } else
+                               logger("Signature text for item ".$item["guid"]." (".$item["id"].") couldn't be extracted: ".$signature['signed_text'], LOGGER_DEBUG);
                }
 
-               if ($item["deleted"]) {
-                       $signed_text = $message["target_guid"].';'.$message["target_type"];
-                       $message["parent_author_signature"] = base64_encode(rsa_sign($signed_text, $owner["uprvkey"], "sha256"));
-               } else
-                       $message["parent_author_signature"] = self::signature($owner, $message);
+               $message["parent_author_signature"] = self::signature($owner, $message);
 
                logger("Relayed data ".print_r($message, true), LOGGER_DEBUG);
 
                return self::build_and_transmit($owner, $contact, $type, $message, $public_batch, $item["guid"]);
        }
 
-       public static function send_retraction($item, $owner, $contact, $public_batch = false) {
+       /**
+        * @brief Sends a retraction (deletion) of a message, like or comment
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner the array of the item owner
+        * @param array $contact Target of the communication
+        * @param bool $public_batch Is it a public post?
+        * @param bool $relay Is the retraction transmitted from a relay?
+        *
+        * @return int The result of the transmission
+        */
+       public static function send_retraction($item, $owner, $contact, $public_batch = false, $relay = false) {
 
-               $myaddr = self::my_handle($owner);
+               $itemaddr = self::handle_from_contact($item["contact-id"], $item["gcontact-id"]);
 
                // Check whether the retraction is for a top-level post or whether it's a relayable
                if ($item["uri"] !== $item["parent-uri"]) {
@@ -2410,16 +3007,32 @@ class diaspora {
                        $target_type = "StatusMessage";
                }
 
+               if ($relay AND ($item["uri"] !== $item["parent-uri"]))
+                       $signature = "parent_author_signature";
+               else
+                       $signature = "target_author_signature";
+
                $signed_text = $item["guid"].";".$target_type;
 
                $message = array("target_guid" => $item['guid'],
                                "target_type" => $target_type,
-                               "sender_handle" => $myaddr,
-                               "target_author_signature" => base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256')));
+                               "sender_handle" => $itemaddr,
+                               $signature => base64_encode(rsa_sign($signed_text,$owner['uprvkey'],'sha256')));
+
+               logger("Got message ".print_r($message, true), LOGGER_DEBUG);
 
                return self::build_and_transmit($owner, $contact, $msg_type, $message, $public_batch, $item["guid"]);
        }
 
+       /**
+        * @brief Sends a mail
+        *
+        * @param array $item The item that will be exported
+        * @param array $owner The owner
+        * @param array $contact Target of the communication
+        *
+        * @return int The result of the transmission
+        */
        public static function send_mail($item, $owner, $contact) {
 
                $myaddr = self::my_handle($owner);
@@ -2477,6 +3090,11 @@ class diaspora {
                return self::build_and_transmit($owner, $contact, $type, $message, false, $item["guid"]);
        }
 
+       /**
+        * @brief Sends profile data
+        *
+        * @param int $uid The user id
+        */
        public static function send_profile($uid) {
 
                if (!$uid)
@@ -2554,5 +3172,106 @@ class diaspora {
                foreach($recips as $recip)
                        self::build_and_transmit($profile, $recip, "profile", $message, false, "", true);
        }
+
+       /**
+        * @brief Stores the signature for likes that are created on our system
+        *
+        * @param array $contact The contact array of the "like"
+        * @param int $post_id The post id of the "like"
+        *
+        * @return bool Success
+        */
+       public static function store_like_signature($contact, $post_id) {
+
+               // Is the contact the owner? Then fetch the private key
+               if (!$contact['self'] OR ($contact['uid'] == 0)) {
+                       logger("No owner post, so not storing signature", LOGGER_DEBUG);
+                       return false;
+               }
+
+               $r = q("SELECT `prvkey` FROM `user` WHERE `uid` = %d LIMIT 1", intval($contact['uid']));
+               if(!$r)
+                       return false;
+
+               $contact["uprvkey"] = $r[0]['prvkey'];
+
+               $r = q("SELECT * FROM `item` WHERE `id` = %d LIMIT 1", intval($post_id));
+               if (!$r)
+                       return false;
+
+               if (!in_array($r[0]["verb"], array(ACTIVITY_LIKE, ACTIVITY_DISLIKE)))
+                       return false;
+
+               $message = self::construct_like($r[0], $contact);
+               $message["author_signature"] = self::signature($contact, $message);
+
+               // In the future we will store the signature more flexible to support new fields.
+               // Right now we cannot change this since old Friendica versions (prior to 3.5) can only handle this format.
+               // (We are transmitting this data here via DFRN)
+
+               $signed_text = $message["positive"].";".$message["guid"].";".$message["target_type"].";".
+                               $message["parent_guid"].";".$message["diaspora_handle"];
+
+               q("INSERT INTO `sign` (`iid`,`signed_text`,`signature`,`signer`) VALUES (%d,'%s','%s','%s')",
+                       intval($post_id),
+                       dbesc($signed_text),
+                       dbesc($message["author_signature"]),
+                       dbesc($message["diaspora_handle"])
+               );
+
+               // This here will replace the lines above, once Diaspora changed its protocol
+               //q("INSERT INTO `sign` (`iid`,`signed_text`) VALUES (%d,'%s')",
+               //      intval($message_id),
+               //      dbesc(json_encode($message))
+               //);
+
+               logger('Stored diaspora like signature');
+               return true;
+       }
+
+       /**
+        * @brief Stores the signature for comments that are created on our system
+        *
+        * @param array $item The item array of the comment
+        * @param array $contact The contact array of the item owner
+        * @param string $uprvkey The private key of the sender
+        * @param int $message_id The message id of the comment
+        *
+        * @return bool Success
+        */
+       public static function store_comment_signature($item, $contact, $uprvkey, $message_id) {
+
+               if ($uprvkey == "") {
+                       logger('No private key, so not storing comment signature', LOGGER_DEBUG);
+                       return false;
+               }
+
+               $contact["uprvkey"] = $uprvkey;
+
+               $message = self::construct_comment($item, $contact);
+               $message["author_signature"] = self::signature($contact, $message);
+
+               // In the future we will store the signature more flexible to support new fields.
+               // Right now we cannot change this since old Friendica versions (prior to 3.5) can only handle this format.
+               // (We are transmitting this data here via DFRN)
+               $signed_text = $message["guid"].";".$message["parent_guid"].";".
+                               $message["text"].";".$message["diaspora_handle"];
+
+               q("INSERT INTO `sign` (`iid`,`signed_text`,`signature`,`signer`) VALUES (%d,'%s','%s','%s')",
+                       intval($message_id),
+                       dbesc($signed_text),
+                       dbesc($message["author_signature"]),
+                       dbesc($message["diaspora_handle"])
+               );
+
+               // This here will replace the lines above, once Diaspora changed its protocol
+               //q("INSERT INTO `sign` (`iid`,`signed_text`) VALUES (%d,'%s')",
+               //      intval($message_id),
+               //      dbesc(json_encode($message))
+               //);
+
+               logger('Stored diaspora comment signature');
+               return true;
+       }
 }
 ?>