235 lines
7.6 KiB
Python
235 lines
7.6 KiB
Python
"""
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.. warning:: THE OTR LIB IS IN AN EXPERIMENTAL STATE AND SHOULD NOT BE
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CONSIDERED AS ENTIRELY RELIABLE
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This plugin implements `Off The Record messaging`_.
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This is a plugin used to encrypt one-to-one conversation using the OTR
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encryption method. You can use it if you want good privacy, deniability,
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authentication, and strong secrecy. Without this
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encryption, your messages are encrypted **at least** from your client (poezio) to
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your server. The message is decrypted by your server and you cannot control the
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encryption method of your messages from your server to your contact’s server
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(unless you are your own server’s administrator), nor from your contact’s
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server to your contact’s client.
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This plugin does end-to-end encryption. This means that **only** your contact can
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decrypt your messages, and it is fully encrypted during **all** its travel
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through the internet.
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Note that if you are having an encrypted conversation with a contact, you can
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**not** send XHTML-IM messages to him. They will be removed and be replaced by
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plain text messages.
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Installation and configuration
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------------------------------
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To use the OTR plugin, you must first install libopenotr.
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If you use Archlinux, there is a `libopenotr-git`_ package on the AUR.
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If not, then you will have to install it by hand.
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First, clone the repo and go inside the created directory:
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.. code-block:: bash
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git clone https://github.com/teisenbe/libopenotr.git
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cd libopenotr
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Then run autogen.sh and configure
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.. code-block:: bash
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sh autogen.sh
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./configure --enable-gaping-security-hole
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(as of now, you *should* have been warned enough that the library is not finished)
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Then compile & install the lib:
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.. code-block:: bash
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make
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sudo make install
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Finally, install the python module:
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.. code-block:: bash
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python3 setup.py build
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sudo python3 setup.py install
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Usage
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-----
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To use OTR, make sure the plugin is loaded (if not, then do ``/load otr``).
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Once you are in a private conversation, you have to do a:
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.. code-block:: none
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/otr start
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The status of the OTR encryption should appear in the bar between the chat and
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the input as ``OTR: encrypted``.
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Once you’re done, end the OTR session with
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.. code-block:: none
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/otr end
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Known problems
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--------------
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Empty messages send when changing status.
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.. _Off The Record messaging: http://wiki.xmpp.org/web/OTR
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.. _libopenotr-git: https://aur.archlinux.org/packages.php?ID=57957
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"""
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import pyotr
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from sleekxmpp.xmlstream.stanzabase import JID
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import logging
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log = logging.getLogger(__name__)
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from plugin import BasePlugin
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import tabs
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from tabs import ConversationTab
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class Plugin(BasePlugin):
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def init(self):
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self.contacts = {}
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# a dict of {full-JID: OTR object}
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self.api.add_event_handler('conversation_say_after', self.on_conversation_say)
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self.api.add_event_handler('conversation_msg', self.on_conversation_msg)
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self.api.add_tab_command(ConversationTab, 'otr', self.command_otr,
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usage='<start|end|fpr>',
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help='Start or stop OTR for the current conversation.',
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short='Manage OTR status',
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completion=self.otr_completion)
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ConversationTab.add_information_element('otr', self.display_encryption_status)
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def cleanup(self):
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ConversationTab.remove_information_element('otr')
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self.del_tab_command(ConversationTab, 'otr')
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def otr_special(self, tab, typ):
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def helper(msg):
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tab.add_message('%s: %s' % (typ, msg.decode()))
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return helper
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def otr_on_state_change(self, tab):
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def helper(old, new):
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old = self.otr_state(old)
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new = self.otr_state(new)
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tab.add_message('OTR state has changed from %s to %s' % (old, new))
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return helper
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def get_otr(self, tab):
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if tab not in self.contacts:
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self.contacts[tab] = pyotr.OTR(on_error=self.otr_special(tab, 'Error'), on_warn=self.otr_special(tab, 'Warn'), on_state_change=self.otr_on_state_change(tab))
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return self.contacts[tab]
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def on_conversation_say(self, message, tab):
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"""
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Feed the message through the OTR filter
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"""
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to = message['to']
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if not message['body']:
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# there’s nothing to encrypt if this is a chatstate, for example
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return
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otr_state = self.get_otr(tab)
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# Not sure what to do with xhtml bodies, and I don't like them anyway ;)
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del message['xhtml_im']
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say = otr_state.transform_msg(message['body'].encode())
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if say is not None:
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message['body'] = say.decode()
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else:
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del message['body']
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def on_conversation_msg(self, message, tab):
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"""
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Feed the message through the OTR filter
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"""
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fro = message['from']
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if not message['body']:
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# there’s nothing to decrypt if this is a chatstate, for example
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return
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otr_state = self.get_otr(tab)
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# Not sure what to do with xhtml bodies, and I don't like them anyway ;)
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del message['xhtml_im']
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display, reply = otr_state.handle_msg(message['body'].encode())
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#self.core.information('D: {!r}, R: {!r}'.format(display, reply))
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if display is not None:
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message['body'] = display.decode()
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else:
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del message['body']
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if reply is not None:
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self.otr_say(tab, reply.decode())
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@staticmethod
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def otr_state(state):
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if state == pyotr.MSG_STATE_PLAINTEXT:
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return 'plaintext'
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elif state == pyotr.MSG_STATE_ENCRYPTED:
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return 'encrypted'
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elif state == pyotr.MSG_STATE_FINISHED:
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return 'finished'
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def display_encryption_status(self, jid):
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"""
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Returns the status of encryption for the associated jid. This is to be used
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in the ConversationTab’s InfoWin.
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"""
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tab = self.core.get_tab_by_name(jid, tabs.ConversationTab)
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if tab not in self.contacts:
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return ''
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state = self.otr_state(self.contacts[tab].state)
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return ' OTR: %s' % (state,)
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def otr_say(self, tab, line):
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msg = self.core.xmpp.make_message(tab.get_name())
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msg['type'] = 'chat'
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msg['body'] = line
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msg.send()
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def command_otr(self, args):
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"""
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A command to start or end OTR encryption
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"""
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args = args.split()
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if not args:
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return self.api.run_command("/help otr")
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if isinstance(self.api.current_tab(), ConversationTab):
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jid = JID(self.api.current_tab().get_name())
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command = args[0]
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if command == 'start':
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otr_state = self.get_otr(self.api.current_tab())
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self.otr_say(self.api.current_tab(), otr_state.start().decode())
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elif command == 'end':
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otr_state = self.get_otr(self.api.current_tab())
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msg = otr_state.end()
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if msg is not None:
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self.otr_say(self.api.current_tab(), msg.decode())
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elif command == 'fpr':
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otr_state = self.get_otr(self.api.current_tab())
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our = otr_state.our_fpr
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if our:
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our = hex(int.from_bytes(our, 'big'))[2:].ljust(40).upper()
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their = otr_state.their_fpr
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if their:
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their = hex(int.from_bytes(their, 'big'))[2:].ljust(40).upper()
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self.api.current_tab().add_message('Your: %s Their: %s' % (our, their))
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self.core.refresh_window()
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def otr_completion(self, the_input):
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return the_input.auto_completion(['start', 'fpr', 'end'], '', quotify=False)
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