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plugin XEP-0234: hash checksum proper handling

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This commit is contained in:
Goffi 2015-11-17 20:13:27 +01:00
commit 51aecd012a
1 changed files with 116 additions and 9 deletions
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129
src/plugins/plugin_xep_0234.py
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@ -31,6 +31,8 @@ from twisted.words.protocols.jabber import jid
from twisted.python import failure
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from twisted.internet import defer
from twisted.internet import reactor
from twisted.internet import error as internet_error
NS_JINGLE_FT = 'urn:xmpp:jingle:apps:file-transfer:4'
@ -49,7 +51,7 @@ PLUGIN_INFO = {
class XEP_0234(object):
# TODO: assure everything is closed when file is sent or session terminate is received
# TODO: call self._f.unregister when unloading order will be managing (i.e. when depenencies will be unloaded at the end)
# TODO: call self._f.unregister when unloading order will be managing (i.e. when dependencies will be unloaded at the end)
def __init__(self, host):
log.info(_("plugin Jingle File Transfer initialization"))
@ -138,6 +140,16 @@ class XEP_0234(object):
except StopIteration:
file_data[name] = ''
try:
hash_algo, file_data['hash_given'] = self._hash.parseHashElt(file_elt)
except exceptions.NotFound:
raise failure.Failure(exceptions.DataError)
if hash_algo is not None:
file_data['hash_algo'] = hash_algo
file_data['hash_hasher'] = hasher = self._hash.getHasher(hash_algo)
file_data['data_cb'] = lambda data: hasher.update(data)
try:
file_data['size'] = int(file_data['size'])
except ValueError:
@ -148,8 +160,6 @@ class XEP_0234(object):
log.warning(u"File name contain path characters, we replace them: {}".format(name))
file_data['name'] = name.replace('/', '_').replace('\\', '_')
# TODO: parse hash using plugin XEP-0300
content_data['application_data']['file_data'] = file_data
# now we actualy request permission to user
@ -164,7 +174,6 @@ class XEP_0234(object):
d.addCallback(gotConfirmation)
return d
def jingleHandler(self, action, session, content_name, desc_elt, profile):
content_data = session['contents'][content_name]
application_data = content_data['application_data']
@ -180,12 +189,16 @@ class XEP_0234(object):
file_elt.addElement('range')
elif action == self._j.A_SESSION_ACCEPT:
assert not 'file_obj' in content_data
file_data = application_data['file_data']
file_path = application_data['file_path']
size = application_data['file_data']['size']
size = file_data['size']
# XXX: hash security is not critical here, so we just take the higher mandatory one
hasher = file_data['hash_hasher'] = self._hash.getHasher('sha-256')
content_data['file_obj'] = self._f.File(self.host,
file_path,
uid=self._getProgressId(session, content_name),
size=size,
data_cb=lambda data: hasher.update(data),
profile=profile
)
finished_d = content_data['finished_d'] = defer.Deferred()
@ -195,13 +208,107 @@ class XEP_0234(object):
log.warning(u"FIXME: unmanaged action {}".format(action))
return desc_elt
def _finishedCb(self, dummy, session, content_name, content_data, profile):
log.info(u"File transfer completed successfuly")
if content_data['senders'] != session['role']:
# we terminate the session only if we are the received,
# as recommanded in XEP-0234 §2 (after example 6)
self._j.contentTerminate(session, content_name, profile=profile)
def jingleSessionInfo(self, action, session, content_name, jingle_elt, profile):
"""Called on session-info action
manage checksum, and ignore <received/> element
"""
# TODO: manage <received/> element
content_data = session['contents'][content_name]
elts = [elt for elt in jingle_elt.elements() if elt.uri == NS_JINGLE_FT]
if not elts:
return
for elt in elts:
if elt.name == 'received':
pass
elif elt.name == 'checksum':
# we have received the file hash, we need to parse it
if content_data['senders'] == session['role']:
log.warning(u"unexpected checksum received while we are the file sender")
raise exceptions.DataError
info_content_name = elt['name']
if info_content_name != content_name:
# it was for an other content...
return
file_data = content_data['application_data']['file_data']
try:
file_elt = elt.elements((NS_JINGLE_FT, 'file')).next()
except StopIteration:
raise exceptions.DataError
algo, file_data['hash_given'] = self._hash.parseHashElt(file_elt)
if algo != file_data.get('hash_algo'):
log.warning(u"Hash algorithm used in given hash ({peer_algo}) doesn't correspond to the one we have used ({our_algo})"
.format(peer_algo=algo, our_algo=file_data.get('hash_algo')))
else:
self._receiverTryTerminate(session, content_name, content_data, profile=profile)
else:
raise NotImplementedError
def _sendCheckSum(self, session, content_name, content_data, profile):
"""Send the session-info with the hash checksum"""
file_data = content_data['application_data']['file_data']
hasher = file_data['hash_hasher']
hash_ = hasher.hexdigest()
log.debug(u"Calculated hash: {}".format(hash_))
iq_elt, jingle_elt = self._j.buildSessionInfo(session, profile)
checksum_elt = jingle_elt.addElement((NS_JINGLE_FT, 'checksum'))
checksum_elt['creator'] = content_data['creator']
checksum_elt['name'] = content_name
file_elt = checksum_elt.addElement('file')
file_elt.addChild(self._hash.buildHashElt(hash_))
iq_elt.send()
def _receiverTryTerminate(self, session, content_name, content_data, last_try=False, profile=C.PROF_KEY_NONE):
"""Try to terminate the session
This method must only be used by the receiver.
It check if transfer is finished, and hash available,
if everything is OK, it check hash and terminate the session
@param last_try(bool): if True this mean than session must be terminated even given hash is not available
@return (bool): True if session was terminated
"""
if not content_data.get('transfer_finished', False):
return False
file_data = content_data['application_data']['file_data']
hash_given = file_data.get('hash_given')
if hash_given is None:
if last_try:
log.warning(u"sender didn't sent hash checksum, we can't check the file")
self._j.delayedContentTerminate(session, content_name, profile=profile)
content_data['file_obj'].close()
return True
return False
hasher = file_data['hash_hasher']
hash_ = hasher.hexdigest()
if hash_ == hash_given:
log.info(u"Hash checked, file was successfully transfered: {}".format(hash_))
else:
log.warning(u"Hash mismatch, the file was not transfered correctly")
self._j.delayedContentTerminate(session, content_name, profile=profile)
content_data['file_obj'].close()
# we may have the last_try timer still active, so we try to cancel it
try:
content_data['last_try_timer'].cancel()
except (KeyError, internet_error.AlreadyCalled):
pass
return True
def _finishedCb(self, dummy, session, content_name, content_data, profile):
log.info(u"File transfer completed")
if content_data['senders'] != session['role']:
# we terminate the session only if we are the receiver,
# as recommanded in XEP-0234 §2 (after example 6)
content_data['transfer_finished'] = True
if not self._receiverTryTerminate(session, content_name, content_data, profile=profile):
# we have not received the hash yet, we wait 5 more seconds
content_data['last_try_timer'] = reactor.callLater(
5, self._receiverTryTerminate, session, content_name, content_data, last_try=True, profile=profile)
else:
# we are the sender, we send the checksum
self._sendCheckSum(session, content_name, content_data, profile)
content_data['file_obj'].close()
def _finishedEb(self, failure, session, content_name, content_data, profile):
log.warning(u"Error while streaming through s5b: {}".format(failure))