friendica-addons/jappixmini/jappixmini.php

<?php


/**
* Name: jappixmini
* Description: Inserts a jabber chat
* Version: 1.0
* Author: leberwurscht
*
*/

/*

Problem:
* jabber password should not be stored on server
* jabber password should not be sent between server and browser as soon as the user is logged in
* jabber password should not be reconstructible from communication between server and browser as soon as the user is logged in

Solution:
Only store an encrypted version of the jabber password on the server. The encryption key is only available to the browser
and not to the server (at least as soon as the user is logged in). It can be stored using the jappix setDB function.

This encryption key could be the friendica password, but then this password would be stored in the browser in cleartext.
It is better to use a hash of the password.
The server should not be able to reconstruct the password, so we can't take the same hash the server stores. But we can
 use hash("some_prefix"+password). This will however not work with OpenID logins, for this type of login the password must
be queried manually.

Problem:
How to discover the jabber addresses of the friendica contacts?

Solution:
Each Friendica site with this addon provides a /jappixmini/ module page. We go through our contacts and retrieve
this information every week using a cron hook.

Problem:
We do not want to make the jabber address public.

Solution:
When two friendica users connect using DFRN, the relation gets a DFRN ID and a keypair is generated.
Using this keypair, we can provide the jabber address only to contacts:

Alice:
  signed_address = openssl_*_encrypt(alice_jabber_address)
send signed_address to Bob, who does
  trusted_address = openssl_*_decrypt(signed_address)
  save trusted_address
  encrypted_address = openssl_*_encrypt(bob_jabber_address)
reply with encrypted_address to Alice, who does
  decrypted_address = openssl_*_decrypt(encrypted_address)
  save decrypted_address

Interface for this:
GET /jappixmini/?role=%s&signed_address=%s&dfrn_id=%s

Response:
json({"status":"ok", "encrypted_address":"%s"})

*/

function jappixmini_install() {
register_hook('plugin_settings', 'addon/jappixmini/jappixmini.php', 'jappixmini_settings');
register_hook('plugin_settings_post', 'addon/jappixmini/jappixmini.php', 'jappixmini_settings_post');

register_hook('page_end', 'addon/jappixmini/jappixmini.php', 'jappixmini_script');
register_hook('authenticate', 'addon/jappixmini/jappixmini.php', 'jappixmini_login');

register_hook('cron', 'addon/jappixmini/jappixmini.php', 'jappixmini_cron');

// Jappix source download as required by AGPL
register_hook('about_hook', 'addon/jappixmini/jappixmini.php', 'jappixmini_download_source');
}


function jappixmini_uninstall() {
unregister_hook('plugin_settings', 'addon/jappixmini/jappixmini.php', 'jappixmini_settings');
unregister_hook('plugin_settings_post', 'addon/jappixmini/jappixmini.php', 'jappixmini_settings_post');

unregister_hook('page_end', 'addon/jappixmini/jappixmini.php', 'jappixmini_script');
unregister_hook('authenticate', 'addon/jappixmini/jappixmini.php', 'jappixmini_login');

unregister_hook('cron', 'addon/jappixmini/jappixmini.php', 'jappixmini_cron');

unregister_hook('about_hook', 'addon/jappixmini/jappixmini.php', 'jappixmini_download_source');
}

function jappixmini_plugin_admin(&$a, &$o) {
	// display instructions and warnings on addon settings page for admin

	if (!file_exists("addon/jappixmini/jappix")) {
		$o .= '<p><strong>You need to install the Jappix application, adapted for Friendica (see README).</strong></p>';
	}
	else if (!file_exists("addon/jappixmini/jappix.zip")) {
		$o .= '<p><strong style="color:#fff;background-color:#f00">The source archive jappix.zip does not exist. This is probably a violation of the Jappix License (see README).</strong></p>';
	}
}

function jappixmini_plugin_admin_post(&$a) {
}

function jappixmini_module() {}
function jappixmini_init(&$a) {
	// module page where other Friendica sites can submit Jabber addresses to and also can query Jabber addresses
        // of local users

	$dfrn_id = $_REQUEST["dfrn_id"];
	if (!$dfrn_id) killme();

	$role = $_REQUEST["role"];
	if ($role=="pub") {
		$r = q("SELECT * FROM `contact` WHERE LENGTH(`pubkey`) AND `dfrn-id`='%s' LIMIT 1",
			dbesc($dfrn_id)
		);
		if (!count($r)) killme();

		$encrypt_func = openssl_public_encrypt;
		$decrypt_func = openssl_public_decrypt;
		$key = $r[0]["pubkey"];
	} else if ($role=="prv") {
		$r = q("SELECT * FROM `contact` WHERE LENGTH(`prvkey`) AND `issued-id`='%s' LIMIT 1",
			dbesc($dfrn_id)
		);
		if (!count($r)) killme();

		$encrypt_func = openssl_private_encrypt;
		$decrypt_func = openssl_private_decrypt;
		$key = $r[0]["prvkey"];
	} else {
		killme();
	}

	$uid = $r[0]["uid"];

	// save the Jabber address we received
	try {
		$signed_address_hex = $_REQUEST["signed_address"];
		$signed_address = hex2bin($signed_address_hex);

		$trusted_address = "";
		$decrypt_func($signed_address, $trusted_address, $key);

		$now = intval(time());
		set_pconfig($uid, "jappixmini", "id:$dfrn_id", "$now:$trusted_address");
	} catch (Exception $e) {
	}

	// return the requested Jabber address
	try {
		$username = get_pconfig($uid, 'jappixmini', 'username');
		$server = get_pconfig($uid, 'jappixmini', 'server');
		$address = "$username@$server";

		$encrypted_address = "";
		$encrypt_func($address, $encrypted_address, $key);

		$encrypted_address_hex = bin2hex($encrypted_address);

		$answer = Array(
			"status"=>"ok",
			"encrypted_address"=>$encrypted_address_hex
		);

		$answer_json = json_encode($answer);
		echo $answer_json;
		killme();
	} catch (Exception $e) {
		killme();
	}
}

function jappixmini_settings(&$a, &$s) {
    // addon settings for a user

    $activate = get_pconfig(local_user(),'jappixmini','activate');
    $activate = intval($activate) ? ' checked="checked"' : '';

    $username = get_pconfig(local_user(),'jappixmini','username');
    $username = htmlentities($username);
    $server = get_pconfig(local_user(),'jappixmini','server');
    $server = htmlentities($server);
    $bosh = get_pconfig(local_user(),'jappixmini','bosh');
    $bosh = htmlentities($bosh);
    $encrypted_password = get_pconfig(local_user(),'jappixmini','encrypted-password');
    $autosubscribe = get_pconfig(local_user(),'jappixmini','autosubscribe');
    $autosubscribe = intval($autosubscribe) ? ' checked="checked"' : '';
    $autoapprove = get_pconfig(local_user(),'jappixmini','autoapprove');
    $autoapprove = intval($autoapprove) ? ' checked="checked"' : '';

    $s .= '<div class="settings-block">';
    $s .= '<h3>Jappix Mini addon settings</h3>';
    $s .= '<div>';
    $s .= '<label for="jappixmini-activate">Activate addon</label>';
    $s .= ' <input id="jappixmini-activate" type="checkbox" name="jappixmini-activate" value="1"'.$activate.' />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-username">Jabber username</label>';
    $s .= ' <input id="jappixmini-username" type="text" name="jappixmini-username" value="'.$username.'" />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-server">Jabber server</label>';
    $s .= ' <input id="jappixmini-server" type="text" name="jappixmini-server" value="'.$server.'" />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-bosh">Jabber BOSH host</label>';
    $s .= ' <input id="jappixmini-bosh" type="text" name="jappixmini-bosh" value="'.$bosh.'" />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-password">Jabber password</label>';
    $s .= ' <input type="hidden" id="jappixmini-encrypted-password" name="jappixmini-encrypted-password" value="'.$encrypted_password.'" />';
    $onchange = "document.getElementById('jappixmini-encrypted-password').value = jappixmini_addon_encrypt_password(document.getElementById('jappixmini-password').value);";
    $s .= ' <input id="jappixmini-password" type="password" value="" onchange="'.$onchange.'" />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-autoapprove">Approve subscription requests from Friendica contacts automatically</label>';
    $s .= ' <input id="jappixmini-autoapprove" type="checkbox" name="jappixmini-autoapprove" value="1"'.$autoapprove.' />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-autosubscribe">Subscribe to Friendica contacts automatically</label>';
    $s .= ' <input id="jappixmini-autosubscribe" type="checkbox" name="jappixmini-autosubscribe" value="1"'.$autosubscribe.' />';
    $s .= '<br />';
    $s .= '<label for="jappixmini-purge">Purge internal list of jabber addresses of contacts</label>';
    $s .= ' <input id="jappixmini-purge" type="checkbox" name="jappixmini-purge" value="1" />';
    $s .= '<br />';
    $s .= '<input type="submit" name="jappixmini-submit" value="' . t('Submit') . '" />';
    $s .= '</div>';

    $a->page['htmlhead'] .= "<script type=\"text/javascript\">
        jQuery(document).ready(function() {
            document.getElementById('jappixmini-password').value = jappixmini_addon_decrypt_password('$encrypted_password');
        });
    </script>";
}

function jappixmini_settings_post(&$a,&$b) {
	// save addon settings for a user

	if(! local_user()) return;
	$uid = local_user();

	if($_POST['jappixmini-submit']) {
		$purge = intval($b['jappixmini-purge']);

		$username = trim($b['jappixmini-username']);
		$old_username = get_pconfig($uid,'jappixmini','username');
		if ($username!=$old_username) $purge = 1;

		$server = trim($b['jappixmini-server']);
		$old_server = get_pconfig($uid,'jappixmini','server');
		if ($server!=$old_server) $purge = 1;

		set_pconfig($uid,'jappixmini','username',$username);
		set_pconfig($uid,'jappixmini','server',$server);
		set_pconfig($uid,'jappixmini','bosh',trim($b['jappixmini-bosh']));
		set_pconfig($uid,'jappixmini','encrypted-password',trim($b['jappixmini-encrypted-password']));
		set_pconfig($uid,'jappixmini','autosubscribe',intval($b['jappixmini-autosubscribe']));
		set_pconfig($uid,'jappixmini','autoapprove',intval($b['jappixmini-autoapprove']));
		set_pconfig($uid,'jappixmini','activate',intval($b['jappixmini-activate']));
		info( 'Jappix Mini settings saved.' );

		if ($purge) {
			q("DELETE FROM `pconfig` WHERE `uid`=$uid AND `cat`='jappixmini' and `k` LIKE 'id%%'");
			info( 'List of addresses purged.' );
		}
	}
}

function jappixmini_script(&$a,&$s) {
    // adds the script to the page header which starts Jappix Mini

    if(! local_user()) return;

    $activate = get_pconfig(local_user(),'jappixmini','activate');
    if (!$activate) return;

    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;g=mini.xml"></script>'."\r\n";
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=presence.js"></script>'."\r\n";

    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=caps.js"></script>'."\r\n";
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=name.js"></script>'."\r\n";
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=roster.js"></script>'."\r\n";

    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/lib.js"></script>'."\r\n";

    $username = get_pconfig(local_user(),'jappixmini','username');
    $username = str_replace("'", "\\'", $username);
    $server = get_pconfig(local_user(),'jappixmini','server');
    $server = str_replace("'", "\\'", $server);
    $bosh = get_pconfig(local_user(),'jappixmini','bosh');
    $bosh = str_replace("'", "\\'", $bosh);
    $encrypted_password = get_pconfig(local_user(),'jappixmini','encrypted-password');
    $encrypted_password = str_replace("'", "\\'", $encrypted_password);

    $autoapprove = get_pconfig(local_user(),'jappixmini','autoapprove');
    $autoapprove = intval($autoapprove);
    $autosubscribe = get_pconfig(local_user(),'jappixmini','autosubscribe');
    $autosubscribe = intval($autosubscribe);

    // get a list of jabber accounts of the contacts
    $contacts = Array();
    $uid = local_user();
    $rows = q("SELECT * FROM `pconfig` WHERE `uid`=$uid AND `cat`='jappixmini' and `k` LIKE 'id%%'");
    foreach ($rows as $row) {
        $key = $row['k'];
	$pos = strpos($key, ":");
	$dfrn_id = substr($key, $pos+1);
        $r = q("SELECT `name` FROM `contact` WHERE `uid`=$uid AND `dfrn-id`='%s' OR `issued-id`='%s'",
		dbesc($dfrn_id),
		dbesc($dfrn_id)
	);
	$name = $r[0]["name"];

        $value = $row['v'];
        $pos = strpos($value, ":");
        $address = substr($value, $pos+1);
	if (!$address) continue;
	if (!$name) $name = $address;

	$contacts[$address] = $name;
    }
    $contacts_json = json_encode($contacts);

    // get nickname
    $r = q("SELECT `username` FROM `user` WHERE `uid`=$uid");
    $nickname = json_encode($r[0]["username"]);

    // add javascript to start Jappix Mini
    $a->page['htmlhead'] .= "<script type=\"text/javascript\">
        jQuery(document).ready(function() {
           jappixmini_addon_start('$server', '$username', '$bosh', '$encrypted_password', $nickname);
           jappixmini_manage_roster($contacts_json, $autoapprove, $autosubscribe);
        });
    </script>";

    return;
}

function jappixmini_login(&$a, &$o) {
    // for setDB, needed by jappixmini_addon_set_client_secret
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=datastore.js"></script>'."\r\n";

    // for str_sha1, needed by jappixmini_addon_set_client_secret
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/jappix/php/get.php?t=js&amp;f=jsjac.js"></script>'."\r\n";

    // for jappixmini_addon_set_client_secret
    $a->page['htmlhead'] .= '<script type="text/javascript" src="' . $a->get_baseurl() . '/addon/jappixmini/lib.js"></script>'."\r\n";

    // save hash of password
    $o = str_replace("<form ", "<form onsubmit=\"jappixmini_addon_set_client_secret(this.elements['id_password'].value);return true;\" ", $o);
}

function jappixmini_cron(&$a, $d) {
	// For autosubscribe/autoapprove, we need to maintain a list of jabber addresses of our contacts.

	// go through list of users with jabber enabled
	$users = q("SELECT `uid` FROM `pconfig` WHERE `cat`='jappixmini' AND (`k`='autosubscribe' OR `k`='autoapprove') AND `v`='1'");

	foreach ($users as $row) {
		$uid = $row["uid"];

		// for each user, go through list of contacts
		$contacts = q("SELECT * FROM `contact` WHERE `uid`=%d AND ((LENGTH(`dfrn-id`) AND LENGTH(`pubkey`)) OR (LENGTH(`issued-id`) AND LENGTH(`prvkey`)))", intval($uid));
		foreach ($contacts as $contact_row) {
			$request = $contact_row["request"];
			if (!$request) continue;

			$dfrn_id = $contact_row["dfrn-id"];
			if ($dfrn_id) {
				$key = $contact_row["pubkey"];
				$encrypt_func = openssl_public_encrypt;
				$decrypt_func = openssl_public_decrypt;
				$role = "prv";
			} else {
				$dfrn_id = $contact_row["issued-id"];
				$key = $contact_row["prvkey"];
				$encrypt_func = openssl_private_encrypt;
				$decrypt_func = openssl_private_decrypt;
				$role = "pub";
			}

			// check if jabber address already present
			$present = get_pconfig($uid, "jappixmini", "id:".$dfrn_id);
			$now = intval(time());
			if ($present) {
				// $present has format "timestamp:jabber_address"
				$p = strpos($present, ":");
				$timestamp = intval(substr($present, 0, $p));

				// do not re-retrieve jabber address if last retrieval
				// is not older than a week
				if ($now-$timestamp<3600*24*7) continue;
			}

			// construct base retrieval address
			$pos = strpos($request, "/dfrn_request/");
			if ($pos===false) continue;

			$base = substr($request, 0, $pos)."/jappixmini?role=$role";

			// construct own address
			$username = get_pconfig($uid, 'jappixmini', 'username');
			if (!$username) continue;
			$server = get_pconfig($uid, 'jappixmini', 'server');
			if (!$server) continue;

			$address = $username."@".$server;

			// sign address
			$signed_address = "";
			$encrypt_func($address, $signed_address, $key);

			// construct request url
			$signed_address_hex = bin2hex($signed_address);
			$url = $base."&signed_address=$signed_address_hex&dfrn_id=".urlencode($dfrn_id);

			try {
				// send request
				$answer_json = fetch_url($url);

				// parse answer
				$answer = json_decode($answer_json);
				if ($answer->status != "ok") throw new Exception();

				$encrypted_address_hex = $answer->encrypted_address;
				if (!$encrypted_address_hex) throw new Exception();

				$encrypted_address = hex2bin($encrypted_address_hex);
				if (!$encrypted_address) throw new Exception();

				// decrypt address
				$decrypted_address = "";
				$decrypt_func($encrypted_address, $decrypted_address, $key);
				if (!$decrypted_address) throw new Exception();
			} catch (Exception $e) {
				$decrypted_address = "";
			}

			// save address
			set_pconfig($uid, "jappixmini", "id:$dfrn_id", "$now:$decrypted_address");
		}
	}
}

function jappixmini_download_source(&$a,&$b) {
	// Jappix Mini source download link on About page

	$b .= '<h1>Jappix Mini</h1>';
	$b .= '<p>This site uses Jappix Mini by the <a href="'.$a->get_baseurl().'/addon/jappixmini/jappix/AUTHORS">Jappix authors</a>, which is distributed under the terms of the <a href="'.$a->get_baseurl().'/addon/jappixmini/jappix/COPYING">GNU Affero General Public License</a>.</p>';
	$b .= '<p>You can download the <a href="'.$a->get_baseurl().'/addon/jappixmini/jappix.zip">source code</a>.</p>';
}