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−#!/usr/bin/env python3
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−
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−
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−# SAT plugin for Explicit Message Encryption
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−# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
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−
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−# This program is free software: you can redistribute it and/or modify
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−# it under the terms of the GNU Affero General Public License as published by
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−# the Free Software Foundation, either version 3 of the License, or
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−# (at your option) any later version.
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−
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−# This program is distributed in the hope that it will be useful,
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−# but WITHOUT ANY WARRANTY; without even the implied warranty of
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−# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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−# GNU Affero General Public License for more details.
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−
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−# You should have received a copy of the GNU Affero General Public License
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−# along with this program.  If not, see <http://www.gnu.org/licenses/>.
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−
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−from sat.core.i18n import _
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−from sat.core.constants import Const as C
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−from sat.core.log import getLogger
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−from twisted.words.protocols.jabber import xmlstream
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−from zope.interface import implementer
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−from wokkel import disco
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−
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−log = getLogger(__name__)
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−
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−PLUGIN_INFO = {
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−    C.PI_NAME: "JID Escaping",
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−    C.PI_IMPORT_NAME: "XEP-0106",
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−    C.PI_TYPE: "XEP",
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−    C.PI_MODES: C.PLUG_MODE_BOTH,
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−    C.PI_PROTOCOLS: ["XEP-0106"],
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−    C.PI_DEPENDENCIES: [],
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−    C.PI_MAIN: "XEP_0106",
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−    C.PI_HANDLER: "yes",
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−    C.PI_DESCRIPTION: _("""(Un)escape JID to use disallowed chars in local parts"""),
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−}
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−
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−NS_JID_ESCAPING = r"jid\20escaping"
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−ESCAPE_MAP = {
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−    ' ': r'\20',
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−    '"': r'\22',
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−    '&': r'\26',
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−    "'": r'\27',
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−    '/': r'\2f',
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−    ':': r'\3a',
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−    '<': r'\3c',
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−    '>': r'\3e',
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−    '@': r'\40',
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−    '\\': r'\5c',
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−}
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−
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−
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−class XEP_0106(object):
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−
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−    def __init__(self, host):
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−        self.reverse_map = {v:k for k,v in ESCAPE_MAP.items()}
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−
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−    def get_handler(self, client):
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−        return XEP_0106_handler()
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−
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−    def escape(self, text):
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−        """Escape text
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−
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−        @param text(unicode): text to escape
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−        @return (unicode): escaped text
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−        @raise ValueError: text can't be escaped
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−        """
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−        if not text or text[0] == ' ' or text[-1] == ' ':
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−            raise ValueError("text must not be empty, or start or end with a whitespace")
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−        escaped = []
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−        for c in text:
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−            if c in ESCAPE_MAP:
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−                escaped.append(ESCAPE_MAP[c])
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−            else:
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−                escaped.append(c)
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−        return ''.join(escaped)
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−
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−    def unescape(self, escaped):
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−        """Unescape text
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−
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−        @param escaped(unicode): text to unescape
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−        @return (unicode): unescaped text
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−        @raise ValueError: text can't be unescaped
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−        """
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−        if not escaped or escaped.startswith(r'\27') or escaped.endswith(r'\27'):
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−            raise ValueError("escaped value must not be empty, or start or end with a "
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−                             f"whitespace: rejected value is {escaped!r}")
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−        unescaped = []
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−        idx = 0
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−        while idx < len(escaped):
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−            char_seq = escaped[idx:idx+3]
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−            if char_seq in self.reverse_map:
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−                unescaped.append(self.reverse_map[char_seq])
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−                idx += 3
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−            else:
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−                unescaped.append(escaped[idx])
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−                idx += 1
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−        return ''.join(unescaped)
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−
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−
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−@implementer(disco.IDisco)
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−class XEP_0106_handler(xmlstream.XMPPHandler):
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−
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−    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
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−        return [disco.DiscoFeature(NS_JID_ESCAPING)]
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−
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−    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
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−        return []