libervia-backend: sat/plugins/plugin_sec

comparison sat/plugins/plugin_sec_aesgcm.py @ 3174:c90f27ce52b0

plugin aesgcm: look for "aesgcm" links in body to use them as attachments

author	Goffi <goffi@goffi.org>
date	Tue, 18 Feb 2020 18:17:18 +0100
parents	9d0df638c8b4
children	98b321234068

comparison

equal deleted inserted replaced

-:343b8076e967
+:c90f27ce52b0
 #!/usr/bin/env python3
-# SAT plugin for handling AES-GCM file encryption
+# SàT plugin for handling AES-GCM file encryption
 # Copyright (C) 2009-2020 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
 # 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/>.
+import re
 from textwrap import dedent
 from functools import partial
+from urllib.parse import urlparse
+import mimetypes
 import secrets
 from cryptography.hazmat.primitives import ciphers
 from cryptography.hazmat.primitives.ciphers import modes
 from cryptography.hazmat import backends
 from cryptography.exceptions import AlreadyFinalized
 Implementation of AES-GCM scheme, a way to encrypt files (not official XMPP standard).
 See https://xmpp.org/extensions/inbox/omemo-media-sharing.html for details
 """)),
 }
+AESGCM_RE = re.compile(
+r'aesgcm:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9'
+r'()@:%_\+.~#?&\/\/=]*)')
 class AESGCM(object):
 def __init__(self, host):
 self.host = host
 host.plugins["DOWNLOAD"].registerScheme(
 "aesgcm", self.download
 )
 host.trigger.add("XEP-0363_upload_size", self._uploadSizeTrigger)
 host.trigger.add("XEP-0363_upload", self._uploadTrigger)
+host.trigger.add("messageReceived", self._messageReceivedTrigger)
 async def download(self, client, uri_parsed, dest_path, options):
 fragment = bytes.fromhex(uri_parsed.fragment)
 # legacy method use 16 bits IV, but OMEMO media sharing published spec indicates
 f"data_cb was expected to be None, it is set to {sat_file.data_cb}")
 # with data_cb we encrypt the file on the fly
 sat_file.data_cb = partial(self._encrypt, encryptor=encryptor)
 return True
+def _popAESGCMLinks(self, match, links):
+link = match.group()
+if link not in links:
+links.append(link)
+return ""
+def _checkAESGCMAttachments(self, client, data):
+if not data.get('message'):
+return data
+links = []
+for lang, message in list(data['message'].items()):
+message = AESGCM_RE.sub(
+partial(self._popAESGCMLinks, links=links),
+message)
+if links:
+message = message.strip()
+if not message:
+del data['message'][lang]
+else:
+data['message'][lang] = message
+mess_encrypted = client.encryption.isEncrypted(data)
+attachments = data['extra'].setdefault(C.MESS_KEY_ATTACHMENTS, [])
+for link in links:
+path = urlparse(link).path
+attachment = {
+"url": link,
+}
+media_type = mimetypes.guess_type(path, strict=False)[0]
+if media_type is not None:
+attachment[C.MESS_KEY_MEDIA_TYPE] = media_type
+if mess_encrypted:
+# we don't add the encrypted flag if the message itself is not
+# encrypted, because the decryption key is part of the link,
+# so sending it over unencrypted channel is like having no
+# encryption at all.
+attachment['encrypted'] = True
+attachments.append(attachment)
+return data
+def _messageReceivedTrigger(self, client, message_elt, post_treat):
+# we use a post_treat callback instead of "message_parse" trigger because we need
+# to check if the "encrypted" flag is set to decide if we add the same flag to the
+# attachment
+post_treat.addCallback(partial(self._checkAESGCMAttachments, client))
+return True

Mercurial > libervia-backend

comparison sat/plugins/plugin_sec_aesgcm.py @ 3174:c90f27ce52b0