Merge remote-tracking branch 'mike/master' into dev

12 files changed, 512 insertions, 220 deletions

diff --git a/Zotlabs/Daemon/Notifier.php b/Zotlabs/Daemon/Notifier.php
index 20dd96ddd..f64e6748c 100644
--- a/Zotlabs/Daemon/Notifier.php
+++ b/Zotlabs/Daemon/Notifier.php
@@ -67,6 +67,7 @@ require_once('include/bbcode.php');
  *       location               channel_id
  *       request                channel_id            xchan_hash             message_id
  *       rating                 xlink_id
+ *       keychange              channel_id
  *
  */
 
@@ -144,6 +145,20 @@ class Notifier {
 			$packet_type = 'request';
 			$normal_mode = false;
 		}
+		elseif($cmd === 'keychange') {
+			$channel = channelx_by_n($item_id);
+			$r = q("select abook_xchan from abook where abook_channel = %d",
+				intval($item_id)
+			);
+			if($r) {
+				foreach($r as $rr) {
+					$recipients[] = $rr['abook_xchan'];
+				}
+			}
+			$private = false;
+			$packet_type = 'keychange';
+			$normal_mode = false;
+		}
 		elseif($cmd == 'permission_update' || $cmd == 'permission_create') {
 			// Get the (single) recipient	
 			$r = q("select * from abook left join xchan on abook_xchan = xchan_hash where abook_id = %d and abook_self = 0",
@@ -570,12 +585,17 @@ class Notifier {
 
 			}
 
-			$hash = random_string();
+			$hash   = random_string();
 			$packet = null;
+			$pmsg   = '';
 
 			if($packet_type === 'refresh' || $packet_type === 'purge') {
 				$packet = zot_build_packet($channel,$packet_type,(($packet_recips) ? $packet_recips : null));
 			}
+			if($packet_type === 'keychange') {
+				$packet = zot_build_packet($channel,$packet_type,(($packet_recips) ? $packet_recips : null));
+				$pmsg = get_pconfig($channel['channel_id'],'system','keychange');
+			}
 			elseif($packet_type === 'request') {
 				$env = (($hub_env && $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']]) ? $hub_env[$hub['hubloc_host'] . $hub['hubloc_sitekey']] : '');
 				$packet = zot_build_packet($channel,$packet_type,$env,$hub['hubloc_sitekey'],$hub['site_crypto'],
@@ -589,7 +609,8 @@ class Notifier {
 					'account_id' => $channel['channel_account_id'],
 					'channel_id' => $channel['channel_id'],
 					'posturl'    => $hub['hubloc_callback'],
-					'notify'     => $packet
+					'notify'     => $packet,
+					'msg'        => (($pmsg) ? json_encode($pmsg) : '')
 				));
 			}
 			else {
diff --git a/Zotlabs/Storage/File.php b/Zotlabs/Storage/File.php
index 1475241ab..7a102134f 100644
--- a/Zotlabs/Storage/File.php
+++ b/Zotlabs/Storage/File.php
@@ -265,7 +265,7 @@ class File extends DAV\Node implements DAV\IFile {
 					$f = 'store/' . $this->auth->owner_nick . '/' . (($this->os_path) ? $this->os_path . '/' : '') . $x;
 				else
 					$f = $x;
-				return fopen($f, 'rb');
+				return @fopen($f, 'rb');
 			}
 			return dbunescbin($r[0]['content']);
 		}
diff --git a/Zotlabs/Zot/IHandler.php b/Zotlabs/Zot/IHandler.php
index eeca1555c..dd82f5be6 100644
--- a/Zotlabs/Zot/IHandler.php
+++ b/Zotlabs/Zot/IHandler.php
@@ -12,6 +12,8 @@ interface IHandler {
 
 	function Request($data);
 
+	function Rekey($sender,$data);
+
 	function AuthCheck($data,$encrypted);
 
 	function Purge($sender,$recipients);
diff --git a/Zotlabs/Zot/Receiver.php b/Zotlabs/Zot/Receiver.php
index 0050a2559..c521c9d64 100644
--- a/Zotlabs/Zot/Receiver.php
+++ b/Zotlabs/Zot/Receiver.php
@@ -120,6 +120,10 @@ class Receiver {
 				$this->handler->Notify($this->data);
 				break;
 
+			case 'rekey':
+				$this->handler->Rekey($this->sender, $this->data);
+				break;
+
 			default:
 				$this->response['message'] = 'Not implemented';
 				json_return_and_die($this->response);
diff --git a/Zotlabs/Zot/ZotHandler.php b/Zotlabs/Zot/ZotHandler.php
index aab336545..ab8815b3d 100644
--- a/Zotlabs/Zot/ZotHandler.php
+++ b/Zotlabs/Zot/ZotHandler.php
@@ -20,6 +20,10 @@ class ZotHandler implements IHandler {
 		zot_reply_message_request($data);
 	}
 
+	function Rekey($sender,$data) {
+		zot_rekey_request($sender,$data);
+	}
+
 	function AuthCheck($data,$encrypted) {
 		zot_reply_auth_check($data,$encrypted);
 	}
diff --git a/boot.php b/boot.php
index d5d2d9c6e..838570697 100755
--- a/boot.php
+++ b/boot.php
@@ -50,7 +50,7 @@ require_once('include/attach.php');
 
 define ( 'PLATFORM_NAME',           'hubzilla' );
 define ( 'STD_VERSION',             '2.5.10' );
-define ( 'ZOT_REVISION',            '1.2' );
+define ( 'ZOT_REVISION',            '1.3' );
 
 define ( 'DB_UPDATE_VERSION',       1192  );
 
diff --git a/include/channel.php b/include/channel.php
index 49da57fd6..f6252f094 100644
--- a/include/channel.php
+++ b/include/channel.php
@@ -454,6 +454,108 @@ function create_identity($arr) {
 	return $ret;
 }
 
+
+function change_channel_keys($channel) {
+
+	$ret = array('success' => false);
+
+	$stored = [];
+
+	$key = new_keypair(4096);
+
+	$sig = base64url_encode(rsa_sign($channel['channel_guid'],$key['prvkey']));
+	$hash = make_xchan_hash($channel['channel_guid'],$sig);
+
+	$stored['old_guid']     = $channel['channel_guid'];
+	$stored['old_guid_sig'] = $channel['channel_guid_sig'];
+	$stored['old_key']      = $channel['channel_pubkey'];
+	$stored['old_hash']     = $channel['channel_hash'];
+
+	$stored['new_key']      = $key['pubkey'];
+	$stored['new_sig']      = base64url_encode(rsa_sign($key['pubkey'],$channel['channel_prvkey']));
+
+	// Save this info for the notifier to collect
+
+	set_pconfig($channel['channel_id'],'system','keychange',$stored);
+
+	$r = q("update channel set channel_prvkey = '%s', channel_pubkey = '%s', channel_guid_sig = '%s', channel_hash = '%s' where channel_id = %d",
+		dbesc($key['prvkey']),
+		dbesc($key['pubkey']),
+		dbesc($sig),
+		dbesc($hash),
+		intval($channel['channel_id'])
+	);
+	if(! $r) {
+		return $ret;
+ 	}
+
+	$r = q("select * from channel where channel_id = %d",
+		intval($channel['channel_id'])
+	);
+
+	if(! $r) {
+		$ret['message'] = t('Unable to retrieve modified identity');
+		return $ret;
+	}
+
+	$modified = $r[0];
+
+	$h = q("select * from hubloc where hubloc_hash = '%s' and hubloc_url = '%s' ",
+		dbesc($stored['old_hash']),
+		dbesc(z_root())
+	);
+
+	if($h) {
+		foreach($h as $hv) {
+			$hv['hubloc_guid_sig'] = $sig;
+			$hv['hubloc_hash']     = $hash;
+			$hv['hubloc_url_sig']  = base64url_encode(rsa_sign(z_root(),$modifed['channel_prvkey']));
+			hubloc_store_lowlevel($hv);
+		}
+	}
+
+	$x = q("select * from xchan where xchan_hash = '%s' ",
+		dbesc($stored['old_hash'])
+	);
+
+	$check = q("select * from xchan where xchan_hash = '%s'",
+		dbesc($hash)
+	);
+
+	if(($x) && (! $check)) {
+		$oldxchan = $x[0];
+		foreach($x as $xv) {
+			$xv['xchan_guid_sig']  = $sig;
+			$xv['xchan_hash']      = $hash;
+			$xv['xchan_pubkey']    = $key['pubkey'];
+			xchan_store_lowlevel($xv);
+			$newxchan = $xv;
+		}
+	}
+
+	build_sync_packet($channel['channel_id'], [ 'keychange' => $stored ]);
+
+	$a = q("select * from abook where abook_xchan = '%s' and abook_self = 1",
+		dbesc($stored['old_hash'])
+	);
+
+	if($a) {
+		q("update abook set abook_xchan = '%s' where abook_id = %d",
+			dbesc($hash),
+			intval($a[0]['abook_id'])
+		);
+	}
+
+	xchan_change_key($oldxchan,$newxchan,$stored);
+
+	Zotlabs\Daemon\Master::Summon(array('Notifier', 'keychange', $channel['channel_id']));
+
+	$ret['success'] = true;
+	return $ret;
+}
+
+
+
 /**
  * @brief Set default channel to be used on login.
  *
diff --git a/include/crypto.php b/include/crypto.php
index 2c5545e9b..6ac3fd732 100644
--- a/include/crypto.php
+++ b/include/crypto.php
@@ -185,6 +185,16 @@ function crypto_methods() {
 }
 
 
+function signing_methods() {
+
+
+	$r = [ 'sha256' ];
+	call_hooks('signing_methods',$r);
+	return $r;
+
+}
+
+
 function aes_encapsulate($data,$pubkey) {
 	if(! $pubkey)
 		logger('aes_encapsulate: no key. data: ' . $data);
diff --git a/include/feedutils.php b/include/feedutils.php
index 4f68fdeef..eb24f9032 100644
--- a/include/feedutils.php
+++ b/include/feedutils.php
@@ -999,6 +999,7 @@ function consume_feed($xml, $importer, &$contact, $pass = 0) {
 		foreach($items as $item) {
 
 			$is_reply = false;
+			$send_downstream = false;
 			$parent_link = '';
 
 			logger('processing ' . $item->get_id(), LOGGER_DEBUG);
@@ -1200,6 +1201,15 @@ function consume_feed($xml, $importer, &$contact, $pass = 0) {
 							$status = 202;
 							continue;
 						}
+
+						// The salmon endpoint sets this to indicate that we should send comments from
+						// interactive feeds (such as OStatus) downstream to our followers
+						// We do not want to set it for non-interactive feeds or conversations we do not own
+
+						if(array_key_exists('send_downstream',$importer) && intval($importer['send_downstream']) 
+							&& ($parent_item['owner_xchan'] == $importer['channel_hash'])) {
+							$send_downstream = true;
+						}
 					}
 					else {
 						if((! perm_is_allowed($importer['channel_id'],$contact['xchan_hash'],'send_stream')) && (! $importer['system'])) {
@@ -1229,6 +1239,11 @@ function consume_feed($xml, $importer, &$contact, $pass = 0) {
 
 				$xx = item_store($datarray);
 				$r = $xx['item_id'];
+
+				if($send_downstream) {
+					\Zotlabs\Daemon\Master::Summon(array('Notifier', 'comment', $r));
+				}
+
 				continue;
 			}
 			else {
@@ -1868,185 +1883,3 @@ function atom_entry($item, $type, $author, $owner, $comment = false, $cid = 0, $
 	return $x['entry'];
 }
 
-/**
- * @brief
- *
- * @param array $items
- * @return array
- */
-function gen_asld($items) {
-	$ret = array();
-	if(! $items)
-		return $ret;
-
-	foreach($items as $item) {
-		$ret[] = i2asld($item);
-	}
-
-	return $ret;
-}
-
-/**
- * @brief
- *
- * @param array $i
- * @return array
- */
-function i2asld($i) {
-
-	if(! $i)
-		return array();
-
-	$ret = array();
-
-	$ret['@context'] = array( 'https://www.w3.org/ns/activitystreams', 'zot' => 'http://purl.org/zot/protocol');
-
-	if($i['verb']) {
-		if(strpos(dirname($i['verb'],'activitystrea.ms/schema/1.0'))) {
-			$ret['type'] = ucfirst(basename($i['verb']));
-		}
-		elseif(strpos(dirname($i['verb'],'purl.org/zot'))) {
-			$ret['type'] = 'zot:' . ucfirst(basename($i['verb']));
-		}
-	}
-	$ret['id'] = $i['plink'];
-
-	$ret['published'] = datetime_convert('UTC','UTC',$i['created'],ATOM_TIME);
-
-	// we need to pass the parent into this
-//	if($i['id'] != $i['parent'] && $i['obj_type'] === ACTIVITY_OBJ_NOTE) {
-//		$ret['inReplyTo'] = asencode_note
-//	}
-
-	if($i['obj_type'] === ACTIVITY_OBJ_NOTE)
-		$ret['object'] = asencode_note($i);
-
-	$ret['actor'] = asencode_person($i['author']);
-
-	return $ret;
-}
-
-function asencode_note($i) {
-
-	$ret = array();
-
-	$ret['@type'] = 'Note';
-	$ret['id'] = $i['plink'];
-	if($i['title'])
-		$ret['title'] = bbcode($i['title']);
-
-	$ret['content'] = bbcode($i['body']);
-	$ret['zot:owner'] = asencode_person($i['owner']);
-	$ret['published'] = datetime_convert('UTC','UTC',$i['created'],ATOM_TIME);
-	if($i['created'] !== $i['edited'])
-		$ret['updated'] = datetime_convert('UTC','UTC',$i['edited'],ATOM_TIME);
-
-	return $ret;
-}
-
-
-function asencode_person($p) {
-	$ret = [];
-	$ret['type']  = 'Person';
-	$ret['id']    = $p['xchan_url'];
-	$ret['name']  = $p['xchan_name'];
-	$ret['icon']  = [ 
-		[
-			'type'      => 'Image',
-			'mediaType' => $p['xchan_photo_mimetype'],
-			'url'       => $p['xchan_photo_l'],
-			'height'    => 300,
-			'width'     => 300,
-		],
-		[
-			'type'      => 'Image',
-			'mediaType' => $p['xchan_photo_mimetype'],
-			'url'       => $p['xchan_photo_m'],
-			'height'    => 80,
-			'width'     => 80,
-		],
-		[
-			'type'      => 'Image',
-			'mediaType' => $p['xchan_photo_mimetype'],
-			'url'       => $p['xchan_photo_l'],
-			'height'    => 48,
-			'width'     => 48,
-		]
-	];
-	$ret['url'] = [
-		'type'      => 'Link',
-		'mediaType' => 'text/html',
-		'href'      => $p['xchan_url']
-	];
-
-	if(array_key_exists('channel_id',$p)) {
-		$ret['inbox'] = z_root() . '/inbox/' . $p['channel_address'];
-		$ret['outbox'] = z_root() . '/outbox/' . $p['channel_address'];
-		$ret['me:magic_keys'] = [
-			[ 
-				'value' => salmon_key($p['channel_pubkey']), 
-				'key_id' => base64url_encode(hash('sha256',salmon_key($p['channel_pubkey'])),true)
-			]
-		];
-
-
-	}
-	else {
-		$collections = get_xconfig($p['xchan_hash'],'activitystreams','collections',[]);
-		if($collections) {
-			$ret = array_merge($ret,$collections);
-		}
-	}
-
-	return $ret;
-}
-
-
-function activity_mapper($verb) {
-
-	$acts = [
-		'http://activitystrea.ms/schema/1.0/post'      => 'Create',
-		'http://activitystrea.ms/schema/1.0/update'    => 'Update',
-		'http://activitystrea.ms/schema/1.0/like'      => 'Like',
-		'http://activitystrea.ms/schema/1.0/favorite'  => 'Like',
-		'http://purl.org/zot/activity/dislike'         => 'Dislike',
-		'http://activitystrea.ms/schema/1.0/tag'       => 'Add',
-		'http://activitystrea.ms/schema/1.0/follow'    => 'Follow',
-		'http://activitystrea.ms/schema/1.0/unfollow'  => 'Unfollow',
-	];
-
-
-	if(array_key_exists($acts[$verb])) {
-		return $acts[$verb];
-	}
-	return false;
-}
-
-
-function activity_obj_mapper($obj,$reverse = false) {
-
-	$objs = [
-		'http://activitystrea.ms/schema/1.0/note'           => 'Note',
-		'http://activitystrea.ms/schema/1.0/comment'        => 'Note',
-		'http://activitystrea.ms/schema/1.0/person'         => 'Person',
-		'http://purl.org/zot/activity/profile'              => 'Profile',
-		'http://activitystrea.ms/schema/1.0/photo'          => 'Image',
-		'http://activitystrea.ms/schema/1.0/profile-photo'  => 'Icon',
-		'http://activitystrea.ms/schema/1.0/event'          => 'Event',
-		'http://activitystrea.ms/schema/1.0/wiki'           => 'Document',
-		'http://purl.org/zot/activity/location'             => 'Place',
-		'http://purl.org/zot/activity/chessgame'            => 'Game',
-		'http://purl.org/zot/activity/tagterm'              => 'zot:Tag',
-		'http://purl.org/zot/activity/thing'                => 'zot:Thing',
-		'http://purl.org/zot/activity/file'                 => 'zot:File',
-		'http://purl.org/zot/activity/poke'                 => 'zot:Action',
-		'http://purl.org/zot/activity/react'                => 'zot:Reaction',
-		'http://purl.org/zot/activity/mood'                 => 'zot:Mood',
-		
-	];
-
-	if(array_key_exists($objs[$verb])) {
-		return $objs[$verb];
-	}
-	return false;
-}
diff --git a/include/markdown.php b/include/markdown.php
index 5d3c4c7df..ccd108c1b 100644
--- a/include/markdown.php
+++ b/include/markdown.php
@@ -84,6 +84,72 @@ function markdown_to_bb($s, $use_zrl = false, $options = []) {
 
 
 
+function bb_to_markdown_share($match) {
+
+	$matches = array();
+	$attributes = $match[1];
+
+	$author = "";
+	preg_match("/author='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$author = urldecode($matches[1]);
+
+	$link = "";
+	preg_match("/link='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$link = $matches[1];
+
+	$avatar = "";
+	preg_match("/avatar='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$avatar = $matches[1];
+
+	$profile = "";
+	preg_match("/profile='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$profile = $matches[1];
+
+	$posted = "";
+	preg_match("/posted='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$posted = $matches[1];
+
+	// message_id is never used, do we still need it?
+	$message_id = "";
+	preg_match("/message_id='(.*?)'/ism", $attributes, $matches);
+	if ($matches[1] != "")
+		$message_id = $matches[1];
+
+	if(! $message_id) {
+		preg_match("/guid='(.*?)'/ism", $attributes, $matches);
+		if ($matches[1] != "")
+			$message_id = $matches[1];
+	}
+
+
+	$reldate = datetime_convert('UTC', date_default_timezone_get(), $posted, 'r');
+
+	$headline = '';
+
+	if ($avatar != "")
+		$headline .= '[url=' . zid($profile) . '][img]' . $avatar . '[/img][/url]';
+
+	// Bob Smith wrote the following post 2 hours ago
+
+	$fmt = sprintf( t('%1$s wrote the following %2$s %3$s'),
+		'[url=' . zid($profile) . ']' . $author . '[/url]',
+		'[url=' . zid($link) . ']' . t('post') . '[/url]',
+		$reldate
+	);
+
+	$headline .= $fmt . "\n\n";
+
+	$text = $headline . trim($match[2]);
+
+	return $text;
+}
+
+
 
 function bb_to_markdown($Text) {
 
@@ -100,9 +166,12 @@ function bb_to_markdown($Text) {
 	// Converting images with size parameters to simple images. Markdown doesn't know it.
 	$Text = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $Text);
 
+	$Text = preg_replace_callback("/\[share(.*?)\](.*?)\[\/share\]/ism", 'bb_to_markdown_share', $Text);
+
 
 	call_hooks('bb_to_markdown_bb',$Text);
 
+
 	// Convert it to HTML - don't try oembed
 	$Text = bbcode($Text, $preserve_nl, false);
 
diff --git a/include/xchan.php b/include/xchan.php
index 12eb674fa..8c9c09c72 100644
--- a/include/xchan.php
+++ b/include/xchan.php
@@ -137,3 +137,83 @@ function xchan_fetch($arr) {
 }
 
 
+function xchan_keychange_table($table,$column,$oldxchan,$newxchan) {
+	$r = q("update $table set $column = '%s' where $column = '%s'",
+		dbesc($newxchan['xchan_hash']),
+		dbesc($oldxchan['xchan_hash'])
+	);
+	return $r;
+}
+
+function xchan_keychange_acl($table,$column,$oldxchan,$newxchan) {
+
+	$allow = (($table === 'channel') ? 'channel_allow_cid' : 'allow_cid');
+	$deny  = (($table === 'channel') ? 'channel_deny_cid'  : 'deny_cid');
+
+
+	$r = q("select $column, $allow, $deny from $table where ($allow like '%s' or $deny like '%s') ",
+		dbesc('<' . $oldxchan['xchan_hash'] . '>'),
+		dbesc('<' . $oldxchan['xchan_hash'] . '>')
+	);
+
+	if($r) {
+		foreach($r as $rv) {
+			$z = q("update $table set $allow = '%s', $deny = '%s' where $column = %d",
+				dbesc(str_replace('<' . $oldxchan['xchan_hash'] . '>', '<' . $newxchan['xchan_hash'] . '>', 
+					$rv[$allow])),
+				dbesc(str_replace('<' . $oldxchan['xchan_hash'] . '>', '<' . $newxchan['xchan_hash'] . '>', 
+					$rv[$deny])),
+				intval($rv[$column])
+			);
+		}
+	}
+	return $z;
+}
+
+
+function xchan_change_key($oldx,$newx,$data) {
+
+	$tables = [
+		'abook'        => 'abook_xchan',
+		'abconfig'     => 'xchan',
+		'group_member' => 'xchan',
+		'chat'         => 'chat_xchan',
+		'chatpresence' => 'cp_xchan',
+		'event'        => 'event_xchan',
+		'item'         => 'owner_xchan',
+		'item'         => 'author_xchan',
+		'item'         => 'source_xchan',
+		'mail'         => 'from_xchan',
+		'mail'         => 'to_xchan',
+		'shares'       => 'share_xchan',
+		'source'       => 'src_channel_xchan',
+		'source'       => 'src_xchan',
+		'xchat'        => 'xchat_xchan',
+		'xconfig'      => 'xchan',
+		'xign'         => 'xchan',
+		'xlink'        => 'xlink_xchan',
+		'xprof'        => 'xprof_hash',
+		'xtag'         => 'xtag_hash'
+	];
+	
+
+	$acls = [
+		'channel'   => 'channel_id',
+		'attach'    => 'id',
+		'chatroom'  => 'cr_id',
+		'event'     => 'id',
+		'item'      => 'id',
+		'menu_item' => 'mitem_id',
+		'obj'       => 'obj_id',
+		'photo'     => 'id'
+	];
+
+
+	foreach($tables as $k => $v) {
+		xchan_keychange_table($k,$v,$oldx,$newx);
+	}
+
+	foreach($acls as $k => $v) {
+		xchan_keychange_acl($k,$v,$oldx,$newx);
+	}
+}
\ No newline at end of file
diff --git a/include/zot.php b/include/zot.php
index 8bbc4a969..75c37836d 100644
--- a/include/zot.php
+++ b/include/zot.php
@@ -31,9 +31,9 @@ require_once('include/perm_upgrade.php');
  * @param string $channel_nick a unique nickname of controlling entity
  * @returns string
  */
+
 function zot_new_uid($channel_nick) {
 	$rawstr = z_root() . '/' . $channel_nick . '.' . mt_rand();
-
 	return(base64url_encode(hash('whirlpool', $rawstr, true), true));
 }
 
@@ -49,6 +49,7 @@ function zot_new_uid($channel_nick) {
  * @param string $guid
  * @param string $guid_sig
  */
+
 function make_xchan_hash($guid, $guid_sig) {
 	return base64url_encode(hash('whirlpool', $guid . $guid_sig, true));
 }
@@ -62,17 +63,17 @@ function make_xchan_hash($guid, $guid_sig) {
  * @param string $hash - xchan_hash
  * @returns array of hubloc (hub location structures)
  *  * \b hubloc_id          int
- *  * \b hubloc_guid        char(255)
+ *  * \b hubloc_guid        char(191)
  *  * \b hubloc_guid_sig    text
- *  * \b hubloc_hash        char(255)
- *  * \b hubloc_addr        char(255)
+ *  * \b hubloc_hash        char(191)
+ *  * \b hubloc_addr        char(191)
  *  * \b hubloc_flags       int
  *  * \b hubloc_status      int
- *  * \b hubloc_url         char(255)
+ *  * \b hubloc_url         char(191)
  *  * \b hubloc_url_sig     text
- *  * \b hubloc_host        char(255)
- *  * \b hubloc_callback    char(255)
- *  * \b hubloc_connect     char(255)
+ *  * \b hubloc_host        char(191)
+ *  * \b hubloc_callback    char(191)
+ *  * \b hubloc_connect     char(191)
  *  * \b hubloc_sitekey     text
  *  * \b hubloc_updated     datetime
  *  * \b hubloc_connected   datetime
@@ -97,7 +98,7 @@ function zot_get_hublocs($hash) {
  * @param array $channel
  *   sender channel structure
  * @param string $type
- *   packet type: one of 'ping', 'pickup', 'purge', 'refresh', 'force_refresh', 'notify', 'auth_check'
+ *   packet type: one of 'ping', 'pickup', 'purge', 'refresh', 'keychange', 'force_refresh', 'notify', 'auth_check'
  * @param array $recipients
  *   envelope information, array ( 'guid' => string, 'guid_sig' => string ); empty for public posts
  * @param string $remote_key
@@ -111,18 +112,21 @@ function zot_get_hublocs($hash) {
  */
 function zot_build_packet($channel, $type = 'notify', $recipients = null, $remote_key = null, $methods = '', $secret = null, $extra = null) {
 
+	$sig_method = get_config('system','signature_algorithm','sha256');
+
 	$data = [
 		'type' => $type,
 		'sender' => [
 			'guid' => $channel['channel_guid'],
-			'guid_sig' => base64url_encode(rsa_sign($channel['channel_guid'],$channel['channel_prvkey'])),
+			'guid_sig' => base64url_encode(rsa_sign($channel['channel_guid'],$channel['channel_prvkey'],$sig_method)),
 			'url' => z_root(),
-			'url_sig' => base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey'])),
+			'url_sig' => base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey'],$sig_method)),
 			'sitekey' => get_config('system','pubkey')
 		],
 		'callback' => '/post',
 		'version' => ZOT_REVISION,
-		'encryption' => crypto_methods()
+		'encryption' => crypto_methods(),
+		'signing' => signing_methods()
 	];
 
 	if ($recipients) {
@@ -134,7 +138,7 @@ function zot_build_packet($channel, $type = 'notify', $recipients = null, $remot
 
 	if ($secret) {
 		$data['secret'] = $secret;
-		$data['secret_sig'] = base64url_encode(rsa_sign($secret,$channel['channel_prvkey']));
+		$data['secret_sig'] = base64url_encode(rsa_sign($secret,$channel['channel_prvkey'],$sig_method));
 	}
 
 	if ($extra) {
@@ -529,7 +533,7 @@ function zot_gethub($arr, $multiple = false) {
 		}
 
 		$limit = (($multiple) ? '' : ' limit 1 ');
-		$sitekey = ((array_key_exists('sitekey',$arr) && $arr['sitekey']) ? " and hubloc_sitekey = '" . protect_sprintf($arr['sitekey']) . "' " : '');
+		$sitekey = ((array_key_exists('sitekey',$arr) && $arr['sitekey']) ? " and hubloc_sitekey = '" . dbesc(protect_sprintf($arr['sitekey'])) . "' " : '');
 
 		$r = q("select hubloc.*, site.site_crypto from hubloc left join site on hubloc_url = site_url
 				where hubloc_guid = '%s' and hubloc_guid_sig = '%s'
@@ -575,6 +579,8 @@ function zot_register_hub($arr) {
 
 	if($arr['url'] && $arr['url_sig'] && $arr['guid'] && $arr['guid_sig']) {
 
+		$sig_methods = ((array_key_exists('signing',$arr) && is_array($arr['signing'])) ? $arr['signing'] : [ 'sha256' ]);
+
 		$guid_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);
 
 		$url = $arr['url'] . '/.well-known/zot-info/?f=&guid_hash=' . $guid_hash;
@@ -594,17 +600,18 @@ function zot_register_hub($arr) {
 			 * our current communication.
 			 */
 
-			if((rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$record['key']))
-				&& (rsa_verify($arr['url'],base64url_decode($arr['url_sig']),$record['key']))
+			foreach($sig_methods as $method) {
+				if((rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$record['key'],$method))
+				&& (rsa_verify($arr['url'],base64url_decode($arr['url_sig']),$record['key'],$method))
 				&& ($arr['guid'] === $record['guid'])
 				&& ($arr['guid_sig'] === $record['guid_sig'])) {
-
-				$c = import_xchan($record);
-				if($c['success'])
-					$result['success'] = true;
-			}
-			else {
-				logger('zot_register_hub: failure to verify returned packet.');
+					$c = import_xchan($record);
+					if($c['success'])
+						$result['success'] = true;
+				}
+				else {
+					logger('zot_register_hub: failure to verify returned packet using ' . $method);
+				}
 			}
 		}
 	}
@@ -657,8 +664,19 @@ function import_xchan($arr,$ud_flags = UPDATE_FLAGS_UPDATED, $ud_arr = null) {
 
 	$import_photos = false;
 
-	if(! rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$arr['key'])) {
-		logger('import_xchan: Unable to verify channel signature for ' . $arr['address']);
+	$sig_methods = ((array_key_exists('signing',$arr) && is_array($arr['signing'])) ? $arr['signing'] : [ 'sha256' ]);
+	$verified = false;
+
+	foreach($sig_methods as $method) {
+		if(! rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$arr['key'],$method)) {
+			logger('import_xchan: Unable to verify channel signature for ' . $arr['address'] . ' using ' . $method);
+			continue;
+		}
+		else {
+			$verified = true;
+		}
+	}
+	if(! $verified) {
 		$ret['message'] = t('Unable to verify channel signature');
 		return $ret;
 	}
@@ -917,7 +935,7 @@ function import_xchan($arr,$ud_flags = UPDATE_FLAGS_UPDATED, $ud_arr = null) {
 	}
 	elseif(! $ud_flags) {
 		// nothing changed but we still need to update the updates record
-		q("update updates set ud_flags = ( ud_flags | %d ) where ud_addr = '%s' and not (ud_flags & %d)>0 ",
+		q("update updates set ud_flags = ( ud_flags | %d ) where ud_addr = '%s' and not (ud_flags & %d) > 0 ",
 			intval(UPDATE_FLAGS_UPDATED),
 			dbesc($address),
 			intval(UPDATE_FLAGS_UPDATED)
@@ -2948,6 +2966,11 @@ function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {
 	if($packet)
 		logger('packet: ' . print_r($packet, true),LOGGER_DATA, LOG_DEBUG);
 
+	$keychange = (($packet && array_key_exists('keychange',$packet)) ? true : false);
+	if($keychange) {
+		logger('keychange sync');
+	}
+
 	if(! $uid)
 		$uid = local_channel();
 
@@ -2961,6 +2984,7 @@ function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {
 		return;
 
 	$channel = $r[0];
+
 	unset($channel['channel_password']);
 	unset($channel['channel_salt']);
 
@@ -2971,12 +2995,11 @@ function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {
 		}
 	}
 
-
 	if(intval($channel['channel_removed']))
 		return;
 
 	$h = q("select hubloc.*, site.site_crypto from hubloc left join site on site_url = hubloc_url where hubloc_hash = '%s' and hubloc_deleted = 0",
-		dbesc($channel['channel_hash'])
+		dbesc(($keychange) ? $packet['keychange']['old_hash'] : $channel['channel_hash'])
 	);
 
 	if(! $h)
@@ -3031,7 +3054,15 @@ function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {
 
 			// don't pass these elements, they should not be synchronised
 
-			$disallowed = array('channel_id','channel_account_id','channel_primary','channel_prvkey','channel_address','channel_deleted','channel_removed','channel_system');
+
+			$disallowed = [
+				'channel_id','channel_account_id','channel_primary','channel_address',
+				'channel_deleted','channel_removed','channel_system'
+			];
+
+			if(! $keychange) {
+				$disallowed[] = 'channel_prvkey';
+			}
 
 			if(in_array($k,$disallowed))
 				continue;
@@ -3091,17 +3122,18 @@ function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {
 
 function process_channel_sync_delivery($sender, $arr, $deliveries) {
 
-
 	require_once('include/import.php');
 
 	/** @FIXME this will sync red structures (channel, pconfig and abook).
 		Eventually we need to make this application agnostic. */
 
-	$result = array();
+	$result = [];
+
+	$keychange = ((array_key_exists('keychange',$arr)) ? true : false);
 
 	foreach ($deliveries as $d) {
 		$r = q("select * from channel where channel_hash = '%s' limit 1",
-			dbesc($d['hash'])
+			dbesc(($keychange) ? $arr['keychange']['old_hash'] : $d['hash'])
 		);
 
 		if (! $r) {
@@ -3120,6 +3152,94 @@ function process_channel_sync_delivery($sender, $arr, $deliveries) {
 			continue;
 		}
 
+		if($keychange) {
+			// verify the keychange operation
+			if(! rsa_verify($arr['channel']['channel_pubkey'],base64url_decode($arr['keychange']['new_sig']),$channel['channel_prvkey'])) {
+				logger('sync keychange: verification failed');
+				continue;
+			}
+
+			$sig = base64url_encode(rsa_sign($channel['channel_guid'],$arr['channel']['channel_prvkey']));
+			$hash = make_xchan_hash($channel['channel_guid'],$sig);
+
+
+			$r = q("update channel set channel_prvkey = '%s', channel_pubkey = '%s', channel_guid_sig = '%s', 
+				channel_hash = '%s' where channel_id = %d",
+				dbesc($arr['channel']['channel_prvkey']),
+				dbesc($arr['channel']['channel_pubkey']),
+				dbesc($sig),
+				dbesc($hash),
+				intval($channel['channel_id'])
+			);
+			if(! $r) {
+				logger('keychange sync: channel update failed');
+				continue;
+ 			}
+
+			$r = q("select * from channel where channel_id = %d",
+				intval($channel['channel_id'])
+			);
+
+			if(! $r) {
+				logger('keychange sync: channel retrieve failed');
+				continue;
+			}
+
+			$channel = $r[0];
+
+			$h = q("select * from hubloc where hubloc_hash = '%s' and hubloc_url = '%s' ",
+				dbesc($arr['keychange']['old_hash']),
+				dbesc(z_root())
+			);
+
+			if($h) {
+				foreach($h as $hv) {
+					$hv['hubloc_guid_sig'] = $sig;
+					$hv['hubloc_hash']     = $hash;
+					$hv['hubloc_url_sig']  = base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey']));
+					hubloc_store_lowlevel($hv);
+				}
+			}
+
+			$x = q("select * from xchan where xchan_hash = '%s' ",
+				dbesc($arr['keychange']['old_hash'])
+			);
+
+			$check = q("select * from xchan where xchan_hash = '%s'",
+				dbesc($hash)
+			);
+
+			if(($x) && (! $check)) {
+				$oldxchan = $x[0];
+				foreach($x as $xv) {
+					$xv['xchan_guid_sig']  = $sig;
+					$xv['xchan_hash']      = $hash;
+					$xv['xchan_pubkey']    = $channel['channel_pubkey'];
+					xchan_store_lowlevel($xv);
+					$newxchan = $xv;
+				}
+			}
+
+			$a = q("select * from abook where abook_xchan = '%s' and abook_self = 1",
+				dbesc($arr['keychange']['old_hash'])
+			);
+
+			if($a) {
+				q("update abook set abook_xchan = '%s' where abook_id = %d",
+					dbesc($hash),
+					intval($a[0]['abook_id'])
+				);
+			}
+
+			xchan_change_key($oldxchan,$newxchan,$arr['keychange']);
+
+			// keychange operations can end up in a confused state if you try and sync anything else
+			// besides the channel keys, so ignore any other packets.
+
+			continue;
+		}
+
+
 		if(array_key_exists('config',$arr) && is_array($arr['config']) && count($arr['config'])) {
 			foreach($arr['config'] as $cat => $k) {
 				foreach($arr['config'][$cat] as $k => $v)
@@ -3757,11 +3877,57 @@ function zot_reply_message_request($data) {
 	json_return_and_die($ret);
 }
 
+function zot_rekey_request($sender,$data) {
+
+	$ret = array('success' => false);
+
+	//	newsig is newkey signed with oldkey
+
+	// The original xchan will remain. In Zot/Receiver we will have imported the new xchan and hubloc to verify
+	// the packet authenticity. What we will do now is verify that the keychange operation was signed by the 
+	// oldkey, and if so change all the abook, abconfig, group, and permission elements which reference the 
+	// old xchan_hash. 
+
+	if((! $data['old_key']) && (! $data['new_key']) && (! $data['new_sig']))
+		json_return_and_die($ret);
+
+	$oldhash = make_xchan_hash($data['old_guid'],$data['old_guid_sig']);
+
+	$r = q("select * from xchan where xchan_hash = '%s' limit 1",
+		dbesc($oldhash)
+	);
+
+	if(! $r) {
+		json_return_and_die($ret);
+	}
+
+	$xchan = $r[0];
+
+	if(! rsa_verify($data['new_key'],base64url_decode($data['new_sig']),$xchan['xchan_pubkey'])) {
+		json_return_and_die($ret);
+	}
+
+	$newhash = make_xchan_hash($sender['guid'],$sender['guid_sig']);
+
+	$r = q("select * from xchan where xchan_hash = '%s' limit 1",
+		dbesc($newhash)
+	);
+
+	$newxchan = $r[0];
+
+	xchan_change_key($xchan,$newxchan,$data);
+
+	$ret['success'] = true;
+	json_return_and_die($ret);
+}
+
 
 function zotinfo($arr) {
 
 	$ret = array('success' => false);
 
+	$sig_method = get_config('system','signature_algorithm','sha256');
+
 	$zhash     = ((x($arr,'guid_hash'))  ? $arr['guid_hash']   : '');
 	$zguid     = ((x($arr,'guid'))       ? $arr['guid']        : '');
 	$zguid_sig = ((x($arr,'guid_sig'))   ? $arr['guid_sig']    : '');
@@ -3925,7 +4091,7 @@ function zotinfo($arr) {
 	// Communication details
 
 	if($token)
-		$ret['signed_token'] = base64url_encode(rsa_sign('token.' . $token,$e['channel_prvkey']));
+		$ret['signed_token'] = base64url_encode(rsa_sign('token.' . $token,$e['channel_prvkey'],$sig_method));
 
 
 	$ret['guid']           = $e['xchan_guid'];
@@ -3994,7 +4160,7 @@ function zotinfo($arr) {
 
 	$ret['site'] = array();
 	$ret['site']['url'] = z_root();
-	$ret['site']['url_sig'] = base64url_encode(rsa_sign(z_root(),$e['channel_prvkey']));
+	$ret['site']['url_sig'] = base64url_encode(rsa_sign(z_root(),$e['channel_prvkey'],$sig_method));
 	$ret['site']['zot_auth'] = z_root() . '/magic';
 
 	$dirmode = get_config('system','directory_mode');
@@ -4012,6 +4178,7 @@ function zotinfo($arr) {
 
 
 	$ret['site']['encryption'] = crypto_methods();
+	$ret['site']['signing'] = signing_methods();
 
 	// hide detailed site information if you're off the grid