view sat/plugins/plugin_xep_0106.py @ 3528:849374e59178

component file sharing: quotas implementation: quotas can now be specified using the `quotas_json` option of `component file_sharing` section in settings. This must be a dict where: - `users` key contains default quotas for all users - `admins` key contains quotas for administrators (not implemented yet) - `jids` contain bare JID to quota mapping, to have user-specific quota The value can be either a int for quota in bytes, or a case insensitive string with an optional multiplier symbol (e.g. "500 Mio"). `None` can be used for explicit unlimited quota (which is the default is `users` is not set). When a file size is too big for quota, upload is refused with an error message indicating allowed quota, used space, and the size of the file that user wants to upload.
author Goffi <goffi@goffi.org>
date Wed, 05 May 2021 15:37:33 +0200
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 []