view sat/plugins/plugin_xep_0106.py @ 4002:5245b675f7ad

plugin XEP-0313: don't wait for MAM to be retrieved in connection workflow: MAM retrieval can be long, and can be done after connection, message just need to be sorted when being inserted (i.e. frontends must do insort). To avoid blocking connection for too long and result in bad UX and timeout risk, one2one MAM message are not retrieved in background.
author Goffi <goffi@goffi.org>
date Fri, 10 Mar 2023 17:22:45 +0100
parents be6d91572633
children 524856bd7b19
line wrap: on
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#!/usr/bin/env python3


# SAT plugin for Explicit Message Encryption
# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core.log import getLogger
from twisted.words.protocols.jabber import xmlstream
from zope.interface import implementer
from wokkel import disco

log = getLogger(__name__)

PLUGIN_INFO = {
    C.PI_NAME: "JID Escaping",
    C.PI_IMPORT_NAME: "XEP-0106",
    C.PI_TYPE: "XEP",
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0106"],
    C.PI_DEPENDENCIES: [],
    C.PI_MAIN: "XEP_0106",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""(Un)escape JID to use disallowed chars in local parts"""),
}

NS_JID_ESCAPING = r"jid\20escaping"
ESCAPE_MAP = {
    ' ': r'\20',
    '"': r'\22',
    '&': r'\26',
    "'": r'\27',
    '/': r'\2f',
    ':': r'\3a',
    '<': r'\3c',
    '>': r'\3e',
    '@': r'\40',
    '\\': r'\5c',
}


class XEP_0106(object):

    def __init__(self, host):
        self.reverse_map = {v:k for k,v in ESCAPE_MAP.items()}

    def getHandler(self, client):
        return XEP_0106_handler()

    def escape(self, text):
        """Escape text

        @param text(unicode): text to escape
        @return (unicode): escaped text
        @raise ValueError: text can't be escaped
        """
        if not text or text[0] == ' ' or text[-1] == ' ':
            raise ValueError("text must not be empty, or start or end with a whitespace")
        escaped = []
        for c in text:
            if c in ESCAPE_MAP:
                escaped.append(ESCAPE_MAP[c])
            else:
                escaped.append(c)
        return ''.join(escaped)

    def unescape(self, escaped):
        """Unescape text

        @param escaped(unicode): text to unescape
        @return (unicode): unescaped text
        @raise ValueError: text can't be unescaped
        """
        if not escaped or escaped.startswith(r'\27') or escaped.endswith(r'\27'):
            raise ValueError("escaped value must not be empty, or start or end with a "
                             f"whitespace: rejected value is {escaped!r}")
        unescaped = []
        idx = 0
        while idx < len(escaped):
            char_seq = escaped[idx:idx+3]
            if char_seq in self.reverse_map:
                unescaped.append(self.reverse_map[char_seq])
                idx += 3
            else:
                unescaped.append(escaped[idx])
                idx += 1
        return ''.join(unescaped)


@implementer(disco.IDisco)
class XEP_0106_handler(xmlstream.XMPPHandler):

    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_JID_ESCAPING)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
        return []