184 lines
11 KiB
ReStructuredText
184 lines
11 KiB
ReStructuredText
.. raw:: html
|
|
|
|
<div id="banner"><a href="https://github.com/jcbrand/converse.js/blob/master/docs/source/features.rst">Edit me on GitHub</a></div>
|
|
|
|
.. _`features`:
|
|
|
|
========
|
|
Features
|
|
========
|
|
|
|
File sharing (`XEP-0363 HTTP File Upload <https://xmpp.org/extensions/xep-0363.html>`_)
|
|
=======================================================================================
|
|
|
|
Converse supports file sharing by first uploading the file to a file server and
|
|
then sending the file's URL to the recipient.
|
|
|
|
The file server that is used is configured by the XMPP server admin, and is not
|
|
something that Converse has any control over.
|
|
|
|
Often when people report file sharing not working, it's because the file server
|
|
is not configured to allow file uploads from other domains.
|
|
|
|
The file server needs to be configured for `Cross-Origin resource sharing <https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS>`_
|
|
(known by the acronym CORS). Specifically, it needs to add a
|
|
``Access-Control-Allow-Origin`` header which includes the domain hosting
|
|
Converse.
|
|
|
|
.. _`feature-omemo`:
|
|
|
|
End to end message encryption (`XEP-0384 OMEMO <https://xmpp.org/extensions/xep-0363.html>`_)
|
|
=============================================================================================
|
|
|
|
.. note::
|
|
Converse.js (as of version 4.1.2) does NOT support encryption or decryption
|
|
of uploaded files. Files will be uploaded WITHOUT ENCRYPTION, even when
|
|
OMEMO is enabled.
|
|
|
|
Converse supports OMEMO encryption based on the
|
|
`Signal Protocol <https://github.com/signalapp/libsignal-protocol-javascript>`_.
|
|
|
|
The Signal Protocol is session-oriented. Clients establish a session, which is
|
|
then used for all subsequent encrypt/decrypt operations. There is no need to
|
|
ever tear down a session once one has been established.
|
|
|
|
This means that a session needs to be stored permanently after logging out.
|
|
|
|
Converse stores this session information in the browser's `localStorage <https://developer.mozilla.org/en-US/docs/Web/API/Storage/LocalStorage>`_.
|
|
|
|
If you've checked the "This is not a trusted device" checkbox when logging in,
|
|
then `sessionStorage <https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage>`_
|
|
is used instead of localStorage and all data is cleared when you log out.
|
|
|
|
For this reason, OMEMO is disabled when you've indicated that you're using
|
|
an untrusted device. You would in any case not be able to decrypt previously
|
|
received OMEMO messages, due to the Signal Protocol's forward secrecy and the
|
|
fact that you don't have a pre-existing session.
|
|
|
|
Security considerations for browser-based crypto
|
|
------------------------------------------------
|
|
|
|
Crypto apps deployed via regular web hosting can be described as relying on
|
|
"host-based" security.
|
|
|
|
Host-based security services require you to trust the host every time you access
|
|
it, whereas with installable desktop software you trust the host when you
|
|
download/install the software (and whenever it gets updated).
|
|
|
|
The dynamic nature of "host-based" systems makes it impractical for security
|
|
researchers to do security audits because the hosted code can change at any
|
|
time.
|
|
|
|
In such a setup you need to fully trust the host that serves you the JavaScript code.
|
|
|
|
The host that serves the JavaScript code is not necessarily the same host that
|
|
stores and procesess your chat messages. So using OMEMO can still protect your
|
|
messages from snooping on the XMPP server where they're stored encrypted.
|
|
|
|
In other words, you do have to trust the webserver that hosts Converse for you,
|
|
but you don't necessarily have to trust the XMPP server (if it's on a different host),
|
|
because it never gets hold of your private key.
|
|
|
|
One way to improve this situation is to host Converse yourself, especially if
|
|
you host it locally on your own machine. If you're not able to do that, then
|
|
at least make sure you use a reputable host that serves files over HTTPS and
|
|
that set `CSP <https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy>`_
|
|
headers.
|
|
|
|
Due to these reasons, it's NOT a good idea to use encrypted messaging with a
|
|
browser-based solution in life-threatening situations.
|
|
|
|
Security can be increased by using an installable app (like one based on `Electron <https://electronjs.org/>`_)
|
|
with a strict Content Security Policy.
|
|
|
|
Look out for an Electron based version of Converse coming in the following months.
|
|
|
|
For further reading on the challenges of web-based crypto, take a look at these
|
|
articles:
|
|
|
|
* `What's wrong with webcrypto? <https://tonyarcieri.com/whats-wrong-with-webcrypto>`_
|
|
* `Heartbleed and JavaScript crypto <https://tankredhase.com/2014/04/13/heartbleed-and-javascript-crypto/>`_
|
|
|
|
OMEMO in Multi-user chats (MUC)
|
|
-------------------------------
|
|
|
|
Converse supports OMEMO encryption in groupchats, but only if the groupchat is
|
|
set to `members only` and `non-anonymous`. This is the same criteria used by
|
|
the popular Android XMPP client `Conversations <https://conversations.im/>`_.
|
|
|
|
If the groupchat is configured properly, you'll see the lock icon in the
|
|
toolbar.
|
|
|
|
|
|
Open chats via URL
|
|
==================
|
|
|
|
From version 3.3.0, converse.js now has the ability to open chats (private or
|
|
groupchat) based on the URL fragment.
|
|
|
|
A room (aka groupchat) can be opened with a URL fragment such as `#converse/room?jid=room@domain`
|
|
and a private chat with a URL fragment such as
|
|
`#converse/chat?jid=user@domain`.
|
|
|
|
|
|
Notifications
|
|
=============
|
|
|
|
From version 0.8.1 Converse can play a sound notification when you receive a
|
|
message.
|
|
|
|
For more info, refer to the :ref:`play-sounds` configuration setting.
|
|
|
|
It can also show `desktop notification messages <https://developer.mozilla.org/en-US/docs/Web/API/notification>`_
|
|
when the browser is not currently visible.
|
|
|
|
For more info, refer to the :ref:`show-desktop-notifications` configuration setting.
|
|
|
|
Multilingual Support
|
|
====================
|
|
|
|
Converse is translated into multiple languages. Translations are supplied in
|
|
JSON format and are loaded on demand. Converse will expect to find the
|
|
translations in the ``/locales`` path of your site. This can be changed via the
|
|
:ref:`locales-url` configuration setting.
|
|
|
|
Moderating chatrooms
|
|
====================
|
|
|
|
Here are the different commands that may be used to moderate a chatroom:
|
|
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| Event Type | When is it triggered? | Example (substitue $nickname with an actual user's nickname) |
|
|
+============+==============================================================================================+===============================================================+
|
|
| **ban** | Ban a user from the chatroom. They will not be able to join again. | /ban $nickname |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **clear** | Clear the messages shown in the chatroom. | /clear |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **deop** | Make a moderator a normal occupant. | /deop $nickname [$reason] |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **help** | Show the list of available commands. | /help |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **kick** | Kick a user out of a room. They will be able to join again. | /kick $nickname [$reason] |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **me** | Speak in the 3rd person. | /me $message |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **mute** | Remove a user's ability to post messages to the room. They will still be able to observe. | /mute $nickname [$reason] |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **nick** | Change your nickname. | /nick $nickname |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **op** | Make a normal occupant a moderator. | /op $nickname [$reason] |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **topic** | Set the topic of the chatroom. | /topic ${topic text} |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
| **voice** | Allow a muted user to post messages to the room. | /voice $nickname [$reason] |
|
|
+------------+----------------------------------------------------------------------------------------------+---------------------------------------------------------------+
|
|
|
|
Passwordless login with client certificates
|
|
===========================================
|
|
|
|
Converse supports the SASL-EXTERNAL authentication mechanism, which can be
|
|
used together with x509 client certificates to enable passwordless login or
|
|
even 2-factor authentication.
|
|
|
|
For more info, `read this blog post <https://opkode.com/blog/strophe_converse_sasl_external/>`_.
|