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########################################################################
# File name: caps390.py
# This file is part of: aioxmpp
#
# LICENSE
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program. If not, see
# <http://www.gnu.org/licenses/>.
#
########################################################################
import base64
import pathlib
import collections
import urllib.parse
import aioxmpp.hashes
from .common import AbstractKey
from . import xso as caps_xso
def _process_features(features):
"""
Generate the `Features String` from an iterable of features.
:param features: The features to generate the features string from.
:type features: :class:`~collections.abc.Iterable` of :class:`str`
:return: The `Features String`
:rtype: :class:`bytes`
Generate the `Features String` from the given `features` as specified in
:xep:`390`.
"""
parts = [
feature.encode("utf-8")+b"\x1f"
for feature in features
]
parts.sort()
return b"".join(parts)+b"\x1c"
def _process_identity(identity):
category = (identity.category or "").encode("utf-8")+b"\x1f"
type_ = (identity.type_ or "").encode("utf-8")+b"\x1f"
lang = str(identity.lang or "").encode("utf-8")+b"\x1f"
name = (identity.name or "").encode("utf-8")+b"\x1f"
return b"".join([category, type_, lang, name]) + b"\x1e"
def _process_identities(identities):
"""
Generate the `Identities String` from an iterable of identities.
:param identities: The identities to generate the features string from.
:type identities: :class:`~collections.abc.Iterable` of
:class:`~.disco.xso.Identity`
:return: The `Identities String`
:rtype: :class:`bytes`
Generate the `Identities String` from the given `identities` as specified
in :xep:`390`.
"""
parts = [
_process_identity(identity)
for identity in identities
]
parts.sort()
return b"".join(parts)+b"\x1c"
def _process_field(field):
parts = [
(value or "").encode("utf-8") + b"\x1f"
for value in field.values
]
parts.insert(0, field.var.encode("utf-8")+b"\x1f")
return b"".join(parts)+b"\x1e"
def _process_form(form):
parts = [
_process_field(form)
for form in form.fields
]
parts.sort()
return b"".join(parts)+b"\x1d"
def _process_extensions(exts):
"""
Generate the `Extensions String` from an iterable of data forms.
:param exts: The data forms to generate the extensions string from.
:type exts: :class:`~collections.abc.Iterable` of
:class:`~.forms.xso.Data`
:return: The `Extensions String`
:rtype: :class:`bytes`
Generate the `Extensions String` from the given `exts` as specified
in :xep:`390`.
"""
parts = [
_process_form(form)
for form in exts
]
parts.sort()
return b"".join(parts)+b"\x1c"
def _get_hash_input(info):
return b"".join([
_process_features(info.features),
_process_identities(info.identities),
_process_extensions(info.exts)
])
def _calculate_hash(algo, hash_input):
impl = aioxmpp.hashes.hash_from_algo(algo)
impl.update(hash_input)
return impl.digest()
Key = collections.namedtuple("Key", ["algo", "digest"])
class Key(Key, AbstractKey):
@property
def node(self):
return "urn:xmpp:caps#{}.{}".format(
self.algo,
base64.b64encode(self.digest).decode("ascii")
)
@property
def path(self):
encoded = base64.b32encode(
self.digest
).decode("ascii").rstrip("=").lower()
return (pathlib.Path("caps2") /
urllib.parse.quote(self.algo, safe="") /
encoded[:2] /
encoded[2:4] /
"{}.xml".format(encoded[4:]))
def verify(self, info):
if not isinstance(info, bytes):
info = _get_hash_input(info)
digest = _calculate_hash(self.algo, info)
return digest == self.digest
class Implementation:
def __init__(self, algorithms, **kwargs):
super().__init__(**kwargs)
self.__algorithms = algorithms
def extract_keys(self, presence):
if presence.xep0390_caps is None:
return ()
return (
Key(algo, digest)
for algo, digest in presence.xep0390_caps.digests.items()
if aioxmpp.hashes.is_algo_supported(algo)
)
def put_keys(self, keys, presence):
presence.xep0390_caps = caps_xso.Caps390()
presence.xep0390_caps.digests.update({
key.algo: key.digest
for key in keys
})
def calculate_keys(self, query_response):
input = _get_hash_input(query_response)
for algo in self.__algorithms:
yield Key(algo, _calculate_hash(algo, input))
|
